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·
ec ron1cs®

Operating scr's in parallel: page 60 Microwaves working on the production line: page 65 Special report on.overlay transistors: page 70

August 23, 1965 75 cents A McGraw-Hill Publication
Below: New jobs for automatic test equipment: page 88

HI-Fl

Transistor output;
matches any PP transistor to 4, 8, 16 !1 speaker. Primary 48, 36 , 12 !1 C.T.; 20 to 20 KC ; 40 watts.

Metal case hermetically sealed to MIL-T-278.
Gold Dumet leads spaced on 0.1 radius, for printed circuit ap-
plication.

Magnetic shielded plus electrostatic shield for voltage isolation of 2xl0·. Primary 200K
C.T. to within 0.1% . Secondary SOK.

HIGH POWERED AUDIO
Low distort ion 2.5 KW output transformer, PP 450 TH 's 18,500 ohms C.T. to 24/ 6 ohms, 20 KV hipot. 520 lbs.
HI-FREQUENCY CARRIER TO MIL·T-278
Electrostat i cally shielded , humbucking, +30 dbm level. With · in .5 db 250 cycles to 110 KC . 600/ 135 : 600 centertapped to .1 % tolerance.
SUBMINIATURE MOLDED
TRANSFORMER

CATHODE FOLLOWER
OUTPUT
Provides equal volt· ages to 5 loads. Primary inductance maintained to 5% with 20% change in DC unbalance and 30% change in AC voltages.
Two transformers each 600 !1 primary. 40 K !1 C.T. secondary 250
'I·cycles to 5 KC within db. 40 db isolation over band .
BOLOMETER TRANSFORMER

SPECIAL (CUSTOM BUILT)
Allllll TllAN~flllMlll~

TO YOUR SPECIFICATIONS

1:_ . I
MICROMODULE
Life tested per mi· cromodule specs.: no failures. lOK fl C.T. to
lOK f!, 100 mw from
400 "'"" to 20KC,
ULTRA· MINIATURE

Exceptional quality and reliability is provided in all UTC designs. Over 30 years of engineering knowledge and experience substantiated by extensive field performance assure the highest quality and most re· liable components in the industry. Complete en· vironmental testing facilities are incorporated to prove out new designs. Full analysis and evaluation of materials are conducted in UTC's Material and Chemical Laboratories. Rigid quality control measures coordinated with exhaustive statistical findings and latest production procedures results in the industry's highest degree of reliability. Range covered in Audio Transformers is from 0.1 cycles to 400 MC ... microwatts to 50 KW.

MILITARY AND COMMERCIAL TYPES FOR EVERY PHASE OF THE ELECTRONICS ART

Grade 3 with printed circuit leads for tran-
n n sistor application. 150 to 150 at 10 dbm
level. Size 1/2 x 1/2 x 1/2"; weight 5 grams.

Primary 10 ohms, secondary 530K ohms, 230: 1 ratio, response from 1/2 cycle to 25 cycles . 120 db magnetic shielding, plus full
electrostatic shielding.

Electrostatlcally & magnetically shielded output transformer ¥.6 D. x 1/4" H. Pri. 15K CT, Sec. SK CT; max. level 50 mw; audio range response . To MIL-T-278, grade 4.

POWER TRANSFORMERS · AUDIO TRANSFORMERS · INDUCTORS · PULSE TRANSFORMERS · ELECTRIC WAVE FILTERS · LUMPED CONSTANT DELAY LINES · HIGH Q COILS · MAGNETIC AMPLIFIERS · SAT· URABLE REACTORS · REFERENCE UNITS

Write for catalog of over
1,300 UTC HIGH RELIABILITY STOCK ITEMS
IMMEDIATELY AVAILABLE
from your local distributor.

UNIT

ORP.

150 VARICK STREET, NEW YORK 13, N. Y.

PACIFIC MFG. DIVISION: 3630 EASTHAM DRIVE, CULVER CITY, CALIF.

EXPORT DIVISION: 13 EAST 40th STREET, NEW YORK 16, N. Y.

CABLE : "ARLAll"

Circle 900 on reader service card

CONTINUOUS . PULSES
OR .
PULSE BURSTS

AT REP RATES
TO
100
MC

New hp 216A Pulse Generator

_ .... ... ~

., t.11 "

.... ·

><$ ....

·
·

·

2.5 nsec rise time at 10 v output
Continuously variable pulse amplitudes
DC coupled output to eliminate baseline shift
50-ohm source impedance to eliminate error-producing reflections
Two trigger outputs
A unique combination of clean pulse shape for accurate measurements and rep rates from 1to100 me for fastcircuit testing is yours with the new 216A. In addition to continuous trains of pulses, the216Aprovides pulse bursts, 20 to 750 nsec in width, generated internally in sync with individual pulses within the burst.
The 216A also may be triggered externally from 0 to 100 me for synchronization with other equipment. Trigger signals are available from the front panel at the output pulse rep rate, 130 nsec in advance of the pulse, or counted down, synchronized with the pulse rep rate and also with the burst envelope to allow viewing of burst responses on a sampling oscilloscope.
The 216A provides 10 v pulses into 50n which is ample to switch almost all semiconductor devices. Pulse amplitude is continuously variable to enable you to accurately set the amplitude to match a particular test requirement. Furthermore, the 216A has a 50n source impedance to eliminate error-causing re-reflections when driving non50n loads. The quality of the pulse is shown in the photo and in the specs. It is carefully controlled and specified to insure accurate, dependable measurements.
Ask your hp field engineer for a demonstration of the 216A. Or write for information to Hewlett-Packard, Palo Alto, Calif. 94304, Tel. (415) 326-7000; Europe: 54 Route des Acacias, Geneva; Canada: 8270 Mayrand St., Montreal.
Electronics 1 August 23, 1965

Source impedance: Pulse shape: Rise time: Overshoot and ringing:
Corner rounding: Time to achieve
flat top: Preshoot: Perturbations on
flat top: Pulse voltage:
Pulse width:
Max. duty cycle:
Price:

BRIEF SPECIFICATIONS
50 ohms ±3%, approx. 10 pf shunt (measured at 10 v output into 50-ohm-load) <2.5 nsec
overshoot <4% peak, ringing <4% of pulse amplitude occurs no sooner than 96% of pulse amplitude
approx. 20 nsec <2% on leading edge; < 5% on trailing edge
3% of pulse amplitude positive or negative, 1, 2, 5-step attenuator, with vernier, provides continuous adjustment from 0.4 to 10 v (into 50 ohms) continuously adjustable, 2 ranges, 5-25 nsec and 25-100 nsec; width jitter <100 psec +0.05% of pulse width >45% to 50 me, decreasing to approx. 20% at 100 me $1775

Carefully controlled pulse shape
insures accurate measurements; 10 v pulse; sweep speed: 10 nsec/cm.
Data subject to change without notice. Prices f. o. b. factory.

Circle 1 on reader service card

1

* * SOLID-STATE * * GAIN OF 1000

DC - 75 KC NO CHOPPER

Precisely measure thermocouple, strain gage and similar low level de outputs with this high performance new Model 8875A Data Amplifier. Use it with modern data acquisition systems employing analog-to-digital converters, digital printers, magnetic data recorders, oscillographs, digital voltmeters, and other readout instrumentation. The new 8875A is a solid-state wideband de amplifier with an output of ±10 v, 100 ma and features de
- 75 kc bandwidth, lOOOx amplification, ± 0.1 %
gain accuracy, ± 0.01 % gain stability, and 120 db common mode rejection - at $495 including
power supply.
This new Sanborn amplifier measures just 4-3 / 4" high by 1-9/1 6" wide by 15" deep, weighs 3.5 lbs., including integral power supply. For multi-channel use, ten units can be mounted in a 5" x 19" modular cabinet which contains input and output connections, power cable, on-off switch, cooling, fuse, and mating connectors for ten amplifiers. These modules can be stacked, or equipped with tilt stands for bench-top use. When used individually, the completely enclosed amplifier requires no cooling.

·SPECIFICATIONS

' aandw-ld~

de to 75 kc within 3 db.

Gain:

from 1 to 1000 i n seven fixed steps

Gain Accuracy:

± 0.1%.

Gain Stability:

± 0.01% .

Vernier Gain:

continuously adjustable between

fixed steps.

Gain Trim:

±3% with sufficient resolution

for setting any one gain to

±0.01%.

Common Mode Rejection : 120 db from de to 60 cps, 40v p-p

tolerance.

Output Circuit:

± 10 volts across 100 ohms and

0.2 ohms max. output impedance

at de.

Drift:

±3 µv referred to input. ± 0.2 mv

referred to output.

Non-Linearity:

Less than 0.01 % full scale value.

10 volts_

Overload Recovery Time : recovers to within 10 µv R.T.I.

+ 10 mv R.T .O. in 10 msec_ for

10 v overload.

Power:

115/ 230 volts ±10%, 50-400 cps,

6 watts.

Available options: Switch-selected filtering , dual output (± 10v,

± 10ma; ± 10v, ± 100ma ; a short on

one output has negligible effect on the

other output) .

For complete specifications and application assistance, call your local HP/ Sanborn field engineering office, or write: Sanborn Division , Hew lett-Packard Compan y,
175 Wyman Street, Waltham, Mass. 02154.

HEWLETT
PACKARD

SANBORN DIVISION

- Circle 2 on reader service card

Electronics
August 23, 1965 Volume 38, Number 17

Page 4 8
14 16 23 25 51 129 154 156 163

Readers Comment People Meetings Meeting Preview Editorial Electronics Newsletter Washington Newsletter New Products New Books Technical Abstracts New Literature

Electronics Review

Page 39 40 40 41 42

Time of trial Monolithic computer Bookbinding Bit of a squeeze FET switch

42 The silent world 44 Testing the mos 46 Migratory gold 47 Under pressure

Probing the News
111 Underwater city: Sealab II 118 A plug for microcircuits 120 Live tv from the moon

Electronics Abroad

165 Bridgehead for Secam 166 Mail sorter

165 Opto -electron ics

167 Great expectations

symposium

168 Changing alleg iance?

166 GE stakes its claim 168 Automobi le pilot

Technical Articles

Title R registered
U.S. Patent Office;
© copyright ig55
by McGraw-Hill, Inc. All rights reserved, including the right to reproduce the contents of this publication, in whole or in part.

I. Design

Solid state 60

Good teamwork from scr's Increased power handling comes from operating small silicon controlled rectifiers in parallel Reuben Wechsler, Motorola, Inc.

Instrumentation 65 Measure it, but don't touch Microwaves measure objects on production lines C.F. Augustine and J.E. Ebert, Weinschel Engineering Co.

Special report 70

The overlay transistor Part I: New geometries boost power Multiple emitters improve performance D.R. Carley, P.L. McGeough and J.F. O' Brien, RCA

78 Part II: Putting the overlay to work In communications the overlay handles 10 watts at 400 Mc D.J. Donahue and B.A. Jacoby, RCA

82 Part Ill: Matching the overlay's performance lnterdigitated geometry offers an alternative Jerome Eimbinder, solid state editor

Circuit design 85

Designer's casebook D One transistor multi delays digital pulses D Simple multivibrator operates at 5 Mc D Multivibrator provides bidirectional output

11. Application

Military electronics 88 Million dollar 'screwdriver' (cover) Growth of complex systems has spurred computerized testing W.J . Evanzia, military electronics ed itor

111. Manufacturi :~J

Production 98 Aluminum bonding ma:;::s high-power microcircuits Aluminum instead of gol .:.l bonding produces circuits that can handle up to 40 watts Edward M. Ruggiero, United Aircraft Corp.

Electronics

Editor: Lewis H. Young
Senior editors
Technical: Samuel Weber News: Kemp Anderson, Jr.
Senior associate editors: John F. Mason, George Sideris
Department editors Advanced technology: Joan Blum Avionics: W.J. Evanzia Circuit design: Michael Elia Components: Michael F. Tomaino Computers: Wallace B. Riley Consumer electronics: Richard Lipkin Industrial electronics: Robert Cushman Instrumentation: Carl Moskowitz Manufacturing: George Sideris Military electronics: John F. Mason New products: William P. O'Brien Solid state: Jerome Eimbinder Space electronics: Peter R. Sigmund Special projects: Richard M. Machol Staff writer: Stanley Zarowin
Regiona I editors Boston: Thomas Maguire, editor; Robin Carlson Los Angeles: William B. Wallace, editor; June Ranill San Francisco: Laurence D. Shergalis, Edmond G. Addeo, editors; Mary Jo Jadin
Copy editors Howard Rausch, Sally Powell, Walter Barney
Graphic design Art director: Saul Sussman As~lstant art director: Donna M. Ma rchyn Editorial production: Ann Mella Prioductlon editor: Arthur C. Miller
Editorial secretaries: Claire Benell, Mary D'Angelo, Lynn Emery, Kay Fontana, Carolyn Michnowicz, Lorraine Longo, Lorraine Werner
McGraw-Hill news service Director: John Wilhelm; Atlanta: Fran Ridgeway; Chicago: Bruce Cross, Louis S. Gomolak; Cleveland: Arthur Zimmerman; Dallas: Marvin Reid; Detroit: Donald MacDonald ; Los Angeles: Michael Murphy, Ron Lovell; San Francisco: Margaret Ralston; Seattle: Ray Bloomberg; Washington: Arthur L. Moore , Charles Gardner, Herbert W. Cheshire, Seth Payne, Warren Burkett, Warren Kornberg
McGraw-Hill world news service Bonn: Robert Dorang; Brussels: Arthur Erikson; London: John Shinn; Mexico City: Wesley Perry; Miian: Bruce Bendow; Moscow: Donald Winston; Paris: Dan Smith; Rio de Janeiro: Leslie Warren; Tokyo: Marvin Petal, Charles Cohen
Circulation manager: Hugh J. Quinn Reprints: T.M. Egan
Publisher: C.C. Randolph

Electronics: August 23, 1965, Vol. 38, No. 17

Printed at 99 North Broadway, Albany, N.Y. Second class postage paid at Albany, N.Y.

Sub.s~riptions are solicited onl~ from those .act_ively engaged in the f ield of the publication.

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Pos1t1on and _company connection must be indicated on orders. Subscrip ti on prices: United States·

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$?~~~1:~p~e25oa?100~h:/ceoa~n~i~:1$ f.'§PQ~s, United States and Possessions and Canada 75t.

Published every other Monday by McGraw-Hill Inc. 330 West 42nd Street. New York, N.Y. 10036. Founder: James H. McGraw, 1860-1948.

Subscribers: The Publisher, upon written request to our New York office from any subscriber, agrees to refund that part of the subscription price applying to copies not yet mailed. Please send change of address notices, subscription orders or complaints to Fulfillment Manager, Electronics, at the address below. Change of address notices should provide old as well as new address, including postal zone number if any. If possible, attach address label from recent issue. Allow one month for change to become effective.
Postmaster: Please send Form 3579 to Fulfillment Manager, Electronics, P.O. Box 430, Hightstown New Jersey 08520

4

Readers Comment
Traffic snarl
To the Editor: I have read with interest the brief
resume of the proposed traffic signal system now being developed for the City of New York [May 17, p. 30], and I also read the letter from Neal A. Irwin [July 12, p. 6].
Certainly I don't want to enter into a controversial discussion with Irwin concerning the merits or demerits of the Toronto system versus that planned for the City of New York. I can only say that while the Toronto system was supposed to have been fully operative some three years ago, it is not as yet in operation. Therefore, while he indicates it is far superior to the New York system, this is ques tionable inasmuch as neither his system nor ours are operative.
Frankly, if Toronto is happy with their signal system I am most pleased for them. On th e other hand, my responsibility is to design a signal system to handle the many extremely complex problems within the City of New York. While Toronto has only a total of about 500 traffic signals in their entire city, New York has more than 9,000; and while Toronto is a city of contiguous areas unbroken by rivers , bridges, tunnels, etc., New York is a city completely made up (except for the Bronx) of islands where one must use bridges and tunnels to get from one part of the city to anoth er. Until the Verrazano Bridge was opened about a year ago, one had to even use a boat to get to that part of New York City.
Our system was designed by engineers who have spent a total of nearly 100 years in th e electrical fi eld. Personally I have been in this fi eld for more than 45 years and have been in the traffic control fi eld nearly 30 of them. The Wilbur Smith Associates, who are the consultants on our job, certainly have a vast knowledge of worldwide traffic problems. Our engineering staff, who have worked consistently for nearly three years on the New York system, constitute more people than the entire personnel of the Traffic Research Corp. I would sug-
Electronics I August 23, 1965

(ADVERTISEMENT)
Extreme Size Reduction, Unusual Capacitance Stability Achieved with Filmite® 'K' Polycarbonate Film Capacitors

New Filmite 'K' Polycarbonate Film Capacitors are more than 13 times smaller than paper capacitors of equivalent capacitance value and voltage rating.

Designed and developed by the Sprague Electric Company, their polycarbonate film dielectric provides exceptionally high capacitance stability over the entire temperature range, due to the inherently low coefficient of expansion of polycarbonate film and a dielectric constant

which is nearly independent of temperature.

Filmite 'K' Capacitors exhibit almost no capacitance change with temperature - dramatically better than polyester-film types, they even surpass polystyrene capacitors. The low dissipation factor (high Q) makes these capacitors extremely desirable where high current capabilities are required, as in SCR commutating capacitor applications.

Low dielectric absorption, considerably lower than that of many other commonly-used film dielectrics, over a broad frequency / temperature spectrum makes Filmite 'K' Capacitors ideal for timing and in-

tegrating.

Type 260P Filmite 'K' Capacitors are metallized, utilizing non-induc-

tive construction. They feature spec-

ial self-healing characteristics in the

rare event of dielectric breakdown.

Designed for operation at tempera-

tures from -55 C to + 105 C, these

metal-clad capacitors are hermeti-

cally sealed and are available in a

variety of mounting styles. Types

237P and 238P are of high-purity

foil construction, and are hermeti-

cally sealed in metal cases. Their

operating temperature range is

-55 C to +125 C.

·

For complete technical data on Type 260P and on Type 237P and 238P Capacitors, write for Engineering Bulletins 2705 and 2700, respectively, to Technical Literature Service, Sprague Electric Co. , 35 Marshall St., North Adams, Mass.

Circle 5 on reader service card

6 Reasons Why SPRAGUE is a Maior Resistor Supplier

FILMISTOR"' PRECISION FILM RESISTORS
metal-film, molded case Distinct limited temperature coefficients and low tolerances to meet exacting appli cation requirements. Rugged end cap construction for long-term stability and reliability. Superior resistance to humidity and mechanical damage. Surpass MIL-R-10509E requirements. Send for Bulletin 7025B.
deposited-carbon, molded case Approach precision wirewounds in reliability and stability, yet are smaller in size and have lower self-inductance. Low, controlled temperature coefficient. Dense molded case provides outstanding humidity protection. Send for Bulletin 7000A.

ACRASIL®PRECISION/POWER WIREWOUND RESISTORS
silicone-encapsulated
Combine the best features of both precision and power wirewound types. Resistance tolerances to ± 0.05%. Unusually tough encapsulation protects against shock, vibration, mois· ture, fungus. Meet MIL-R·26C requirements. Smaller than conventiona I wirewounds, yet greater in stability. Send for Bulletin 7450.

deposited-carbon, conformal coated
Full rated load operation at 70 C with no wattage derating. Assured uprated loads at lower operating temperatures. Ideal for circuitry where small size, humidity resistance, and close tolerance ( ± 1%) are required. Send for Bulletin 7005A.

STACK OHM"' POWER WIREWOUND
RESISTORS

GLASS-JACKETED POWER WIREWOUND RESISTORS .
Ferrule terminals soldered to metallized ends of glass casing for true hermetic seal. Virtually failure-proof, even in ex· tremely corrosive industrial and salt atmosphere. Standard and non-inductive windings. External meter-multiplier types also availabfe. Send for Bulletins 7350, 7420, 7421.
Circle 274 on reader service card

Flat silhouette permits

stacking of resistor banks

in close quarters. Alumi-

mum thru·bar simplifies

mounting and conducts

heat from resistance ele·

ment. Vitreous enamel

protective coating. Meet

MI L-R·26C perform anee

requirements . Send for

... Bulletin 7430. ·

·

· I

For complete technical data, write for engineering bulletins on the resistors in which you are interested to: Technical Literature Service, Sprague Electric Company, 35 Marshall Street, North Adams, Massachusetts.
4 SR · 16 6 ·63 R2

SPRAGUE®
THE MARK OF RELIABILITY
'Sp111ue' 1nd ·@ · ire reaistered tr1d1m1rks ol the Spr11ue Electric Co.

5

An Extraordinary 2-c to 2-Mc Oscillator

Million-to-one frequency range.

Distortion is less than 0.25% from 50 c/s to 50 kc/s, even at full output and under short-circuit conditions.

Frequency characteristic is flat within ±2% from 20 c/s to 200 kc/s.

Output is over 20 V into open circuit, 160 mW into 600 a.

Transistorized, capacitance-tuned RC Wien-bridge oscillator and power supply are completely contained in a 8" x 6" x 8" package.

These features make the new GR Type 1310-A Oscillator an outstanding instrument for day-to-day applications. But, what definitely puts this oscillator in a class by itself is an entirely new feature by which its frequency can be synchronized with an external signal. Also, the oscillator can itself be used to furnish a sync signal to other equipment. Thanks to this sync provision, unique in an inexpensive oscillator, the new Type 1310 has a much wider range of application than the ordinary oscillator.
In a nutshell, the 1310-A now brings the small size, mechanical ruggedness and reliability of transistorized circuitry to a wide-range, generalpurpose instrument. It offers all the benefits you expect in a modern, two-feedback-path RC oscillator including high accuracy and infinite resolution of variable capacitance tuning - plus the new frequencysynchronization provision - all at a surprisingly low price.
Here Are Some Uses For Oscillator Synchronization:
as a tracking narrow-band filter to reduce hum, noise, and distortion in a signal; a source of amplitude-modulated signals; an automatic phase-controlled oscillator to reduce frequency modulation or Jitter; a single-frequency leveling amplifier; a phase-Jocked, sinusoidal frequency multiplier; a phase shifter; a narrow-band isolation amplifier; an amplitude-modulation filter.
Write for Complete Information

Accuracy: ±2% of reading
Stability: Typical drift after warm up, 0.001% short term (1 min) at 1 kc/s.
Synchronization : Jack provided for external phase-locking signal. Lock· ing range is about ±3% for 1-V, rms, input reference signal over entire 2-c to 2 -Mc range. Locking ranges up to 40% can be used.
Output
Voltage: Over 20 V, open circuit; con· tinuously adjustable attenuator (approximately 50 dB).
Amplitude Stability: Typical drift after warmup, 0.02% short term (1 min).
Impedance: 600·!1

~1

02

~~7,c.:.~

01

O·ST~T1!)0.' ~ ,.R(QU(h'T Sl'CC1r1C·T10'I

k:'.
J v2
~

)5
002 IQCJ.i

50
""'

i-
50

ll·Cls

"

100

IMCl'S 2

Distortion: As indicated. Hum less

than 0.02% independent of attenua-

tor setting.

Synchronization: High-impedance, constant-amplitude, 0.8 V, rms, output for use with oscilloscope, counter, or other oscillators.

General

Power Required: 105 to 125, 195 to 235, or 210 to 250 V, 50 to 400 c/s, Price: $295 in U.S.A.

IN CANADA: Toronto 247-2171, Montreal (Mt. Royal) 737-3673 IN EUROPE: Zurich, Switzerland - London, England

GENERAL RADIO COMPANY
WEST C 0 NC 0 RD, MASS AC HUSE TT S

BOSTON

NEW YORK, N. Y.. 964-2722

CHICAGO

PHILADELPHIA

WASHINGTON, D.C. SYRACUSE DALLAS SAN FRANCISCO LOS ANGELES . ORLANDO, FLA. CLEVELAND'

(W. Concord) 646·0550 (Ridgefield. N. J.) 943-3140 (Oak Park) 848·9400 (Fl. Washington) 646·8030 (Rockville. Md.) 946-1600 454-9323 FL 7·4031 (Los Allos) 948-8233 469·6201

425·4&7 l

886-0150

Circle 6 on reader service card

gest that Irwin confine his activities to that of trying to get his Toronto system to function as planned and to leave the problems of ew York City traffic to we who are capable of solving them.
H enry A. Barnes Commissioner Department of Traffic City of New York
Meteor burst
· To the Editor: In the July 26th issue, you report
that Boeing engineers have recently tested successfully a new technique called meteor burst communications [p. 27]. Amateurs have been experimenting with this phenomenon for several years.
In October, 1956, QST (the magazine of amateur radio operators) mentioned pioneering work in 1953 by W2UK (now KH6UK) and vV4HHK, in connection with the Perseid meteor shower.
Eric K. Albrecht, K8BFH Cleveland Heights, Ohio

feel will be necessary for good practical coverage. There are also other problems of a serious nature which have yet to be solved.
In short, contrary to the implication of your article, loran is here to stay for a long time. This writer is not denying that Omega has some attractive possibilities and his firm is acutely interested in the development of the system; however, it will be many years before Omega becomes practically operational, and the end of loran is not in sight.
R. E. Maine Executive vice president Electronic Concepts, Inc. Charlottesville, Va.
· Still, the Navy is planning to install the new Omega system. It says finding locations for eight stations, all that is necessary, is easier than locating sites needed for loran. Nobody could argue that loran has not performed superbly; but now something newer and better is coming on the scene.
For the record

Obviously from Sprague I
... the predsion/power wirewound resistor with more PLUS features!
Silicone Encapsulated-Seals resistance ele· ment. Provides exceptional protection against severe environmental conditions as well as physical damage.

Loran defended
To the Editor: The end of loran is not in sight. Your article [Aug. 9, page 27] en-
titled "End of loran" does a gross disservice to the manufacturers, distributors, dealers and users of loran equipment.
Unfortunately, it is an extremely biased article which ignores entirely the most serious problem of the Omega system-the location of the transmitters must be on friendly or, at least, neutral soil. So far, satisfactory locations for the eight transmitters have not been found, let alone the 16 to 24 which experts

To the Editor: In the ew Instrument section
[Aug. 9, 1965, p. 161], it was pointed out that the new Tektronix letter series storage oscilloscope, type 549, and their spectrum analyzer units makes it the first storagetype spectrum analyzer.
To set the record straight, Telson-Ross Electronics has been marketing plug-in spectrum analyzers for use with Tektronix 560 series oscilloscopes for over a year. Included in this series of scopes is the type 564 storage scope.
L. C. Weiner Nelson-Ross Electronics Inc. Hicksville, N. Y.

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ci~----~---~~~

Wide Application-Standard and non-inductive windings. Equally suited for printed wiring boards, custom packaging, and point-to-point wiring.
Close Resistance Tolerances-Standard toler· ances to +0.05%.
Wide Range of Ratings-% watt to 10 watts. Resistance values from .05n to 66Kn.
Minified Sizes-Smaller than other conven· tional wirewound resistors.
Excellent Stability-Under extended load life and environmental operating parameters, Acrasil Resistors show exceptionally small change in resistance values.
Outstanding Reliability-Fully meet electrical performance requirements of MIL·R·26C, as well as individual customer high reliability specifications.
For complete technical clata, write for Engineering Bulletin 7450 to Technical Literature Service, Sprague Electric Company, 35 Marshall St., North Ac/ams, Mass.
SPRAGUE®
THE MARK OF RELIABILITY
' Spraeue' ind ·@ · ire realstered trademarks of the Spra1u1 Electric Co.
OIMH·U

Electronics \ August 23, 1965

Circle 7 on reader service card

7

Magnetically Beamed Triode 250 kW CW with 1kW Drive 8 Mw High Duty Pulse
Machlett's new ML-8618 magnetically beamed water-cooled triode features high power gain, plate efficiency and maximum cathode utilization. As a Class Camplifier or oscillator, the ML-8618 is capable of a continuous out· put in excess of 250 kW with only 1000 W driving power. As a switch tube in pulse modulators, it can deliver more than 8Mw pulse power at long pulse widths and high duty. For details on this or the soon-to-be-available ML-8619 vapor· cooled or ML-8620 forced air-cooled versions, write: The Machlett Laboratories, Inc., Springdale, Conn. 06879. An affiliate of Raytheon Company.~
ELECTRON TUBE SPECIALIST
8 Circle 8 on reader service card

People
"What some people call molecular electronics, I call chemistry," says
Elliot Berman, recen tly named di-
r e c t o r of the Itek Corp.' s Lexington R e search Laboratories in Lexington, Mass.
Berman, a 35year-old chemist who joined Itek in 1959, s a y s there is little difference today between physics and chemistry, and that development of electronic devices depends heavily on both disciplines .
Much of Berman's work focuses on optical techniques for information storage. He says that optical computer systems are perhaps 5 or 10 years away, but that components of such systems are now beginning to appear.
"It is becoming clear," he says, "that there are better ways of doing things than by hooking wires together."
Itek has developed an optical memory disk on which a laser can write 100,000 bits per second in the form of dark spots and clear spaces. The memory device will be used in an information processing service center that Itek hopes to begin operating in New York before the year's end.
"Other optical devices will be coming along," says Berman, "until eventually whole computer systems will emerge. We will end up with optical and photographic ways of doing many things which today are being performed by electrical connections."
At the ational Cash Register Co., where Berman worked from 1955 to 1959, he explored the information storage possibilities of photochromic materials-which can be switched by light beams back and forth from a colorless to a colored state. Itek is also doing research work on photochromic materials.
The Lexington laboratory is exploring electron beam recording, which, says Berman, "is far from being a useful technique, but has interesting possibilities-for print-
Electronics I August 23, 1965

1
Hy Newman has been studying our silicon mesa power transistor competition.

They can't teach him a thing.

Because Hy Newman as chief engineer knows that Bendix consideration any type of load; inductive, resistive or

is alert to all there is to know about silicon mesa power capacitive. SOAR takes into consideration the maximum

transistors. And that includes a wide range of 2N types, current and the maximum voltage switched. SOAR elim-

all available in a wide selection of package options. All inates complicated calculations and complex derating for

competitively priced. All with high voltage capabilities. operation at various repetition rates, pulse widths, and

All with diffused construction for faster switching and case temperatures.

higher frequency capabilities. Some of the more popular

Hy's even been expanding the Bendix line to include

t ypes? 2N389,A, 2N424,A, 2N1015,A-D, 2N1016,A-D, commercial grades, lower cost types and newer-concept

2N1483-2N1490, 2Nl 722-2Nl 725, 2N3055, 2N3232 and silicon audio power types. In addition, popular types

2 3235.

2N1487-2N1490 are available meeting military specifica-

At Bendix you can get SOAR (§afe Qperating ARea ) tion MIL-S-19500/ 208 (EL).

specified silicon mesas. There are 12 types presently SOAR

With l e to 15 A, VCB to 200 V and P c to 150 W, Hy

specified with more on

will continue to provide

the way . Switching is

you with the latest state-

accomplished in microseconds or less at temperatures up to 200°C

? MAii C

SAFE OPERAT ING AREA

.Q

a

C O [ a.tA \ "' · " loLLOVlllll(

~lS[ ...10T"5

A OCOPE·llTIO;j

I l io S[C
c o ~ .. sec

0 D 25 ,.5[~
c ops ...stc

of-the-art t echnology. More information? Phone or writ e our nearest

wit hout failure due to

sales office. Just say,

secondary breakdown.

MT-1

T0-61 T0-8 T0-53

"Hy ... Newman." We'll

How? SOAR takes into

understand.

Bendix Semiconductor Division
HOLMDEL, NEW JERSEY

'~no'~
C 0 R P 0 R A I t U ti

Baltimore (Towson), Md.-(301) 828-6877; Chicago-(312) 637-6929; Dallas-(214) 357-1972; Detroit-(313) JO 6-1420; Holmdel, N. J.-(201) 747 -5400; Los Angeles-(213) 776-4100; Miami Springs, Fla.-(305 ) 887-55 2 1; Minneapolis-(612) 926-4633 ; Redwood City, Calif.-James S . Heaton Co., (415) 369-4671; Seattle-Ray Johnston Co., Inc ., (2 06) LA 4 -5 170; Syracuse, N. Y.-(315) 474-7531; Waltham, Mass.-(617) 899-0770;
Export-(212) 973-2121, Cable: "Bendixint," 605 Third Ave. N. Y.; Ottawa, Ont.-Computing Devices of Canada, P.O. Box 508-(613) TA 8-2711.

Electronics \ August 23, 1965

Circle 9 on reader service card

9

CONGRATULATIONS VDU JUST SAVED $2.95
We've just published the first truly authoritative text on shaft angle encoders. It's not a brochure. It's not a sales treatise. It's an 84-page text on how to put encoders to work - our encoders or anybody else's encoders. And, even though it's designed to sell for $2.95, we're willing to give a limited number of copies away gratis. There's one string attached. It cost a lot to publish the book. And it's not designed for bedside reading. So please don't ask for a copy unless you really have a need to know all there is to know about shaft angle encoders. Otherwise, your free copy awaits your inquiry. Just write for it on your company letterhead.
10 Circle 10 on reader service card

ing on-line with a computer, for example."
For the past year, Berman has been director of Itek's Research division. Before that, he was manager of the division's chemistry department. He holds chemistry degrees from Brown University and Boston University.
North American Aviation, Inc., which has been concerned with atmospheric and space flight, is invading a different mediumthe ocean. The company named 41 - vear - old Don ·H. Pickrell
as manager of its Deep Submergence S y s t ems Program . office.
The switch was as dramatic for Pickrell as it was for the company -he has a Ph.D in physics from the California Institute of Technology and served as first program manager for the Polaris missile while at North American's Autonetics division.
To prepare himself for the job ahead, Pickrell has been reading books on oceanography-and may get some firsthand information by taking lessons in skin diving.
He will be working with the Navy again on the deep submergence program. The first project for the new office will be the development of equipment for submersible vehicles.
Although many federal agencies are already working in oceanography, Pickrell hopes the government will resist the temptation to form a sort of "wet NASA" to do the job under the sea that the National Aeronautics and Space Administration does in space. "Having a lot of companies competing is the best way to get the job done in the long run ," he maintains.
In the fuhue, North American will study the problem of underwater oil drilling and mining minerals from the sea. Pickrell sees oceanography as a fascinating , almost unlimited field. "It's hard to ignore three-fourths of the earth's surface" he says, "when in some areas the land-based farms cannot produce enough food, and when natural resources are running out.''
Electronics I August 23, 1965

A

NEW KIND

New Integrated Circuit Reliability Over two-th irds of the transi stors in the Model 7100 are in hig h relia bi lity integrated circ uits. Lowest life expectancy of any component is greater tha n t wo years (t he numeric readout tube). A high ly dependable photocell chopper replaces a mechanical device.

OF DVM:

New stability Accuracy of the Model 7100 is c ompletely
independent of long-ter m drift. That"s because of (1 ) the i nheren t stabil ity of i ntegra ted c ircu its and (2) un ique
Dual-Sl ope In tegration (see dia gram). With d ual integ rati ng slopes, any changes are se lf-cance ling so t he integ rator is no longer a critical ci rcuit.

New high noise immunity No input noise filter is required . Noise merely causes instantaneous c hanges in the dua l i ntegrator sl opes. These cancel out lea vi ng total i ntegra t ion area-and the measurement itself- virt ually
unaffected . Rea dout acc uracy : 0 .01 %,
lOµ V resolution .

· · ~::~::1:;;~~··t~········11·····~New versatility

Measures lOµV to lOOOV; 1 ohm to

15.000 megohms; ratios fr om 0.0001 :

1 to1.5000: 1. Provides dig ital d isplay

New cost vs. performance ratio

a nd BCD readout-four dig its plus 50%

Beca use of the si m plified circuitry of

over-ra nge . WESCON Winner 1965

patented Dual-Slope Integration and

Industrial Design Award .

extensive use of integrated circuits, the

See Booth 2914-2917 .

Model 71 00 at less than $2000 offer s

t he precision and sta bility of a $6000

DV M. See com p lete price l ist be low.

DUAL-SLOPE INTEGRATING:

DUAL SLOPE vs. CONVENTIONAL
FAIRCHILD DUAl·SLDPf INTEGRATION
RD
CONVENTIONAL INTEGRATION

PRICES:

Tnt Functions

Manual Ranging Auto-ranging Model Price Model Price

Voltsohms-rat io Volts-ohms Volts-rat i o Volts Ohms Rat io

7100 $2500 7110 2250 7120 2250 7140 1900 71 50 1900 7160 1900

7101 $2750 7111 2500 7121 2500 714 1 2250 71 51 2250

Plug -ins (one of these is requ ired for proper operation )

Standard Plug-i n, Type DM-0 1 High Input Impeda nce,
Type DM-02 AC-DC Converter, Type DM ·Q3

$ 75 .00 400 .00 5 0 0 .0 0

For more information, contact the nearest representative listed below or write for the comprehensive data sheet. ·Patent pend ing.
FAIRCHILCJ
INSTRUMENTATION

FAIRCHILD INSTRUMENTATION REPRESENTATIVES
ALABAMA Huntsville, Gen try Associates, Inc., 534-9771. ARIZONA Scoltsdale , G. S. Marshall, 946-4276. CALIFORNIA Los Angeles, Fairchild ln strumenlation, 464 ·7464 / Palo A/lo ' Fa irc hild Sales Office and Factory, 962·2451 / San Diego , G. S. Marshall, 278-6350 / San Marino ' G. s. M arshall, 681-3292. COLORADO Denver ' Hyer Electronics, 771 ·5285 . CONNECTICUT Greenwich ' Circuit Sales, 869-2244 . FLORIDA Orlando : Gentry Associates, Inc., 424-0730/St . Petersburg : Fa irch ild Instrumentat ion, 867-1824. GEORGIA Atlanta : Gentry Associates, Inc., 233-3816. ILLINOIS Oak Park : Fairchild Ins trumentation , 848-5985. IOWA Cedar Rapids : Engineering Services Co., 366-1591 . MARYLAND Bethesda : Bartlett Associates, Inc ., 656-3061 . MASSACHU· SETTS Watertown , Circuit Sales, 926-1031 . MICHIGAN Detroit ' WKM Associates, Inc., 892-2500. MINNESOTA St. Paul, Northport Engineering, Inc.· 698-3941. MISSOURI Kan sas City, Engineering Services Co., 353-6000/St. Louis: Engineering Services Co., 726-2233. NEW MEXICO Albuquerque: Hyer Electronics, 268-6744 . NEW YORK Elmsford : SBM Associates, Inc., 592-8850 / Long Island: CDB Enterprises. 592-5200/Huntington, L.I .: Fairchild Instrumentation, 692-5735/Roches ter : SBM Associates, Inc ., 271 -7430/Syracuse : SBM Associates, Inc. , 454 · 9377. NORTH CAROLINA Burlington , Gentry Associates, Inc., 227-7916. OHIO Cleveland , WKM Associates, Inc., 855·5616/Dayton ' WKM Associates, Inc ., 298-7203. PENNSYLVANIA Pittsburgh : WKM As sociates, Inc., 892-29531 Wayne: Bartlett Associates, Inc ., 688-7325 . TEXAS Dallas : Norvell Associates, Inc., FL 7-6451 /Hou ston : Norvell Associates, Inc ., MO 5-0558. WASHINGTON Bellevue' Cane-Jessup Co. Inc., GL 4-0691 . CANADA-ONTARIO Ottawa , Wh ittaker Electronics Ltd., 722-7658/Weston, Wh ittaker Electronics Ltd., 247-7454. QUEBEC Roxboro : Whittaker Electronics Ltd., 684-3000. ASIA·JAPAN Tokyo : Tokyo Electron Labs, Inc. , TBS Building. EUROPE-BELGIUM Brussels : Fairch ild Instrumentation, 80 Chausee de Charleroi.

Electronics I August 23, 1965

Circle 11 on reader service card

11

301 at40V and100°C

no secondary breakdown

12

Electronics I August 23, 1965

/1700·B

Fl7207
NPN planar epitaxial power amplifier

AL METALIZATION

N

COLLECTOR

Cross Section of FT7207 Chip

What Makes It Best: The FT7207 delivers a full 30 watts of power at 40 volts and 100°C case temperature . Not intermittently. Not at peak. At full rated power. Most power transistors are subject to current hogging problems which cause secondary breakdown. Not the FT7207 . To solve this problem we had to invent a new method of building power transistors.

So we did. We combined thin film techniques with planar epitaxial processing and came up with nichrome thin film resistors in series with the emitters. Result? No more current hogging. No secondary breakdown. We put the FT7207 in an insulated 7/16 11 hex stud package, so that a number of individual devices can be attached to a common heat sink without requir-

FEATURES
POWER: 30 watts at 40V and 1oo·c case temperature
= LVcEO: aov min . (l e 50 mA) = = hH: 40-1 20 (l e 2A, VeE 5V) = = VcE (SAT): 1.5V max . (l e 5A, la 0.5A)
lcEs: lOµ A max . (VeE = 60V)
= = h1.: 3.5 min . (VeE 5V , le 0 .5A,
f = 20mc)
PLANAR : A PAT ENTED FAIRCHILD PROCESS
ing isolation of each individual device. You can get the FT7207 in the 7 / 16" hex stud package with either 60V or 80V limits . The 80V model costs $42.00 in quantities up to 99, and $28.00 in quantities up to 999. If you want the complete story on the FT7207, write for our data sheet. Or, better yet, get in touch with your nearest Fairchild Distributor.

FAIRC::l-llLCJ

SEMICONDUCTOR

f .FAIRCHILD SEMICONDUCTO R A DIVISION OF F.AIRCHILO CAMERA AND I NSTRUMENT CORPORATION · 3 1 3 FAIRCHILD DR I VE, MOUNTAI N VI EW, CALIFORN IA , ( 415) 962·501 1 · TW X: 910 · 379·6435-!

Electronics I August 23, 1965

Circle 13 on reader service card

13

Another Industry first!
NOW···· THE NEWEST
DUET* TRANSISTOR
IS A TWIN
IN A FLAT PACKI

Sprague leads again with two dual-emitter chopper transistors in one flat-pack case, with tight VoFF matching of both devices

CHECK THEil Kl1 'IRIMETERI

Type No.
3Nl 12 3Nl 13

Yeeo
JOY SOY

Yeco
JOY SOY

IYol A-8
20µY 20µY

Standard T0-1 8 case Duet* Transistors ··· the broadest line of dual-emitter choppers

Meetings
Radio-Products Fair, Stuttgarter Ausstellungs-GMBH; Stuttgart Kellesburg, Germany, Aug. 27-Sept. 5.

National Standards and National Test· ing Laboratories Meeting, Standards Engineers Society; Royal York Hotel, Toronto, Canada, Sept. 15·17.
Petroleum Mechanical Engineering Conference, ASME; Rice Hotel, Houston, Sept. 19.

International Antennas and Propagation Symposium, IEEE; Sheraton Park Hotel, Washington, D.C. Aug. 30-Sept. 1.
Boulder Millimeter Wave and Far Infrared Conference, IEEE et al; Stanley Hotel, Estes Park, Colorado, Aug. 30Sept. 1.
International Congress of Physiological Sciences Meeting, AFOSR, National Academy of Sciences-National Research Council et al ; National Education Center, Tokyo, Japan, Sept. 1-9.
American Physical Society Symposium, AFOSR and American Physical Society; Univ. of Honolulu, Honolulu, Hawaii, Sept. 2-4.
Opto·Electronic Components and Devices Symposium, Advisory Group for Aerospace Research and Development; Paris, Sept. 6-9.
Technical Conference on Materials Science and Technology in Integrated Electronics, Electronic Materials Committe, Institute of Metals Div. of the Metallurgical Society of San Francisco Section of the AIMMPE; St. Francis Hotel, San Francisco, Sept. 7-9.
International Electronics Exhibit INEL, Swiss Fair Authorities; Basel, Switzerland, Sept. 7-11.

Electronic Data Processing Conference, National Retail Merchants Association; Fairmont Hotel and Tower, San Francisco, Sept. 20-24.
Plasma Sheath-Plasma Electromagnetics of Hypersonic Flight Symposium, OAR; New England Life Hall and Classified section at Base Theater, Laurence G. Hanscom Field, Bedford, Mass., Sept. 21-23.
Systems Engineering Annual Conference, Clapp and Poliak, Inc.; McCormick Place, Chicago, Sept. 20-23.
Microelectronics Symposium, IEE; Univ. of Southampton, England, Sept. 21-23.
AE·4 Electromagnetic Compatibility Conference, SAE; Grumman Aircraft Corp., Bethpage, L.I., N.Y., Sept. 22-23.
Military Electronics Conference (MIL·E-CON 9), IEEE; Washington Hilton Hotel, Washington, D.C., Sept. 22-24.
Automation Conference, Cedar Rapids Section , IEEE; Town House Motel, Cedar Rapids, Iowa, Sept. 24-25
Optics in Space Conference, Institute of Physics and Physical Society Optical Group; Univ. of Southampton, England, Sept. 27-29.

__Gl Type No.
1~211,. JN90 i"' JN91
JN92
JN9J JN94
JN95 JN108 JN109 JN110 JN111 JN114
JN115 JN116 JN117 JNl 18
JN119

BVEEO
JOY JOY JOY 50V 50V 50V 50V 50V JOY JOY 12V 12V 12V 20V 20V 20V

Vo ...Ql
50µV .1[5:2 !), lOOµV ll!
200µV 50µV lOOµV 200µV JOµV 150µV JOµV 150µV SOµV lOOµV 200µV SOµV lOOµV 200µV

For complete technical data, write to Technical Literature Service, Sprague Electric Co., 35 Marshall st:,
North Adams, Mass. 01248
OS SUJ

International Congress on Acoustics, International Commission on Acoustics; Palais de Congres, Liege, Belgium, Sept. 7-14.
Industrial Electronics and Control Instrumentation International Congress, IEEE; Sheraton Hotel, Philadelphia, Sept. 8-10.
Recent Developments in the Mathematical Theory of Elementary Particles Conference, AFOSR, Massachusetts Institute of Technology; Endicott House MIT, Dedham, Mass., Sept. 12-15.
Integrated Circuit Seminar, Integrated Circuit Engineering Corp.; Cambridge Charter House, Cambridge, Mass. Sept. 13-17.

SPRAGUE ® Microwave Behavior of Ferrimagnetics and Plasmas Conference, IEE; London, Sept. 13-17.

THE MARK OF RELIABILITY
·O

Theory of Self-Adaptive Control Systems Symposium, IFAC/Teddington; Teddington, England, Sept. 14-17.

Call for papers
Region Six Annual Conference, IEEE; Pioneer International Hotel, Tucson, Arizona, Apr. 26-28. Dec. 1 is deadline to submit 4 copies of 50-word abstract and 3 copies of 500-word summary to Dr. L. 0. Huelsman, Technical Papers Chairman, 1966/IEEE Region Six An-
nual Conference, cl o Dept. of Elec.
Eng., Univ. of Ariz., Tucson, Ariz.
Anti-Missile Research Advisory Council Meeting, Advanced Research Projects Agency; U. S. Naval Postgraduate School, Monterey, Calif., Nov. 15-17. Aug. 30 is deadline for submission of papers to Earl Crisler, Chairman AMRAC, Institute for Defense Analyses , 400 Army-Navy Drive, Arlington, Va. 22202.
Meeting preview on page 16

14 Circle 14 on reader service card

Electronics I August 23, 1965

Astrodata's New Astrolock*-loop FM Subcarrier Discriniinator

Within ±0.01% of center frequency for
24-hours after a 5-minute warm-up.

Better than ± 0.02% of full
bandwith, best straight line.

The Astrodata Model 402-201, all solid-state FM subcarrier discriminator utilizes the new Astrolock phase-frequency detector, crystalreferenced, FET chopper-stabilized VCO, and current mode loop filter, which are proprietary developments of Astrodata, Inc.

level within the 66 db dynamic range. True locked-loop performance is provided for deviations up to ±40 %, with specified linearity. A quadrature detector mode of operation, selected by a switch on the front panel, provides correlation detection for extremely low SIN signals.

This completely new and different type of locked-loop discriminator gives performance exceeding that of both conventional phase-locked-loop and pulse-averaging types of discriminators.
The new crystal-referenced, FET chopper-stabilized VCO provides state-of-the-art performance in stability and linearity, without a temperature controlled oven.

The Model 402-201 introduces a new method of tape-speed compensation in which the reference frequency is processed in the frequency domain. As a result, tape speed compensation is perfect at any fixed frequency from lower bandedge to upper bandedge, and is better than 30 db for intelligence frequencies up to a modulation index of 4. Deviations of more than ± 3% anywhere in the band can be accommodated. No adjustments are

The Astrolock detector, with its com- necessary. posite phase-frequency characteristic, With this new Astrodata Tape Speed assures positive lock-in at any signal . Compensation system, the over-all

stability for a given data channel is that of the data discriminator alone, whereas in a conventional system the over-all stability is the sum of the stabilities of both the data discriminator and the reference discriminator.
A complete line of accessories is available for use with the Model 402-201. Channel Selectors and Low Pass Filters are provided for all standard IRIG and Constant Bandwidth center frequencies up to 300 kc. Six discriminators and one common power supply mount in a rack adapter which occupies a panel space of 7-in. x 19-in.
For complete technical information on Astrodata's unique Astrolock loop FM Subcarrier discriminator and full line of telemetry components, call your local Astrodata engineering sales representative 01· write to us directly. _,

Q

.A.&"1'":JR.O:x>.A."1'".A. X:l!lil"O.

P. 0. Box 3003 · 240 E. Palais Road· Anaheim, California 92803

*Trademark

TEL. (714) 772·1000. TWX 714-776-3760. FAX. TELEX 06-78828. CABLE ADDRESS. ASTRODATA, Anaheim

Electronics \ August 23, 1965

Circle 15 on reader service card

15

Meeting preview

how to measure in-phase, quadrature and angle while sweeping frequency to 100 kc

North Atlantic's latest addition to the PAV line of Phase Angle Voltmeters* enables

you to make measurements while frequency is varying over half-decades without

recalibration. The VM-301 Broadband Phase Angle Voltmeter* provides complete

coverage from 10 cps to 100 kc, and incorporates plug-in filters to reduce the

effects of harmonics in the range of 50 cps to 10 kc with only 16 sets of filters.

Vibration analysis and servo analysis are only two of the many applications for this

unit. Abridged specifications are listed below:

liiijiOiii==========:;:;;::;;==============;==-=-===:::-:~:::::""'~~-:::::::::::;;~

Voltage Range .. ..... ....... ..... .......... ......... ..... ... 1 mv to 300 volts full scale

Voltage Accuracy............. ......... ......... ..... .. ...... ........... .... ... 2% full scale

Phase Dial Range............... ... ....... ....... ......0° to 90° with 0.1 ° resolution (plus 4 quadrants)

Phase Accuracy ..... ............... ................. ..... ... ....... ... ....

. 0.25°

Input Impedance.... ........ ............ ... .. ... 10 megohms, 30l'l'f for all ranges (signal and reference inputs)

Reference Level Range .......... .. .... ........................... .... .0.15 to 130 volts

Harmonic Rejection............ ........... ... ............ ..... .. ..... ..... ............. 50 db

Nulling Sensitivity... ... ..... .......... ...... ...... ............. less than 2 microvolts

Size................... ...... ................. .... .. .... ........ .......... 1911 x 7" x 10" deep

Price......... ... .. ..... . ..... ...... ... .. ... $2290.00 plus $160.00 per set of filters

North Atlantic's sales representative in your area can tell you all about this unit as wel I as other Phase Angle Voltmeters* for both production test and ground support c;pplications. Send for our data sheet today.
·Trademark
NORTH ATLANTIC industries,inc.
TERMINAL DRIVE, PLAINVIEW, L. I., NEW YORK · OVerbrook 1-8600

16 Circle 16 on reader service card

Systems control in Tokyo
From both sides of the Iron Curtain, engineers are heading for Tokyo this week to participate in an international symposium on systems engineering for control-system design. The four-day meeting, Aug. 25 to 28, is sponsored by the International F ederation of Automatic Control.
Transportation, an international problem, will be the subject of five papers. Major interest probably will center on a description of the use of parametron circuits for traffic control on Japanese highways (see p. 168). This paper will be presented by Eiichi Kikuchi, Makoto Kumura and Shuntetsu Matsumoto of the Japanese Government Mechanical Laboratories, and Yasujiro Oshima of the Institute of Industrial Science at the University of Tokyo.
There will also be a report on computer control of train operation and automatic traffic control on Japanese railroads by Shigezu Yamazaki of the Japanese National Railways.
Learning machines. A session on learning systems will include a paper by A. Y. Lerner, N. V. Vapnik and A. Y. Chervonenkis, of the Soviet Academy of Sciences, on problems of learning machines and large-scale systems control. One topic of the paper will be pattern recognition in simulating learning in living organisms.
A paper by Mariya Oda and Kahei Nakamura of Nagoya University will discuss a learning-control system in which the system itself decides whether data is useful, and accepts or rejects it on that basis. Regulation. and control in biological systems will be discussed by A. S. Iberall and S. Z. Cardon of General Technical Services, Inc. , of the United States. They will compare the body's controls with those employed in electronic systems.
There will also be sessions on system design, stochastic systems, optimum controls, simulation, identification procedure, public utilities, multivariable and multilevel systems, identification of systems, and systems in general.
Circle 17 on reader service card-+

Micro Solutions ...from Bourns!

Microcomponents

J ,l
\ II
M icroresistors

I
Microcapacitors

·n·", '
I
~

~" '
Microtransformers

Microinductors

Microcircuits

Want design freedom? Take your choice of a wide selection of microcomponents ... or we will make custom microcircuits to your specifications! All products available now!
Write for complete ·technical information

J30URNS

All units shown actual size

1200 COLUMBIA AVE .· RIVERSIOE, CALIF. PHONE 684-1700 ·TWX: 714-682 9S82
CABLE: BOURNSINC .

MANUFACTURER: TRIMPOT~ & PRECISION POTENTIOMETERS. RELAYS: TRANSDUCERS FOR PRESSURE. POSITION . ACCELERATION. PLANTS: RIVERS IDE. CALIFORNIA: AMES. IOWA: TORONTO . CANADA

·MOS· MOS· MOS· MOS· MOS· MOS· MOS· MOS·· MOS· MOS· MOS· MOS
II
·11 II II
(The New Generation of MOS Monolithic Shift Registers)'
18 Electronics / August 23, 1965

·MOS· MOS· MOS· MOS· MOS· MOS· MOS· MOS· MOS· MOS· MOS· MOS·

MOGISTERS ARE:

GENERAL INSTRUMENT'S NEW MOS MONOLITHIC 21-BIT SHIFT llEGISTERS
With Gl 's new MOGISTERS, pronounced "mo'-jisters, " the much discussed advantages of MOS (metal-oxide-silicon) circuitry are now a practical, commercially available reality. This availability represents a significant milestone in MOS technology, not only because of the unique design possibilities offered by MOS units in general, but also because of the unconditionally assured voltage stability of these GI devices in particular.
MEM-501- New General Instrument MOGISTER, 21· bit MOS shift register, magnified 70 diameters; operating from DC to 500kc. This is the first of a complete line General Instrument will announce shortly. Also available, MEM-521 operating from DC to 1 me.

COST SAVINGS
If you ' re concerned with lower costs (and who isn 't), you'll find MOGISTERS can help you trim equipment costs three ways :
· Lower cost per bit ... substantially less than individual double-diffused JK flip-flops or single shift registers.
· Fewer packages required . . . MOGISTERS are available in register lengths up to 21 bits (16 -4 -1), all in a single T0 -5 or flat pack.
· Fewer interconnections within your system · ·· only one hook-up, instead of 21.
VERSATILITY
Each MOGISTER provides three separate and distinct multibit shift registers on one monolithic chip. These may be used as parallel registers , each with its own push -pull output stage; or as 21 bits serially, by simply connecting the output of each register to the input of the next.
In addition , you may directly buffer into double -diffused integrated circuits merely by grounding the - V0 pin and applying + 3V or + 5V to the ground terminal.
SUPERIOR PERFORMANCE
In terms of in -system performance, MOGISTERS offer a line-up of advantages that just won 't quit. Here are a few of the more significant ones:
· capable of operation down to DC
· high fan -out capability; 25 or more
· high noise immunity; 3 volts or more
· large voltage swings; 10 volts or more

MOGISTERS are available um? from your authorized

General Instrument Distributor.

Call or write today for fuli data and specifications.
GENERAL INSTRUMENT CORPORATION SEMICONDUCTOR PRODUCTS GROUP

....... ... .~·,.~.r...·_..G.(.N..:..·'..:.~......~.~S,.-;.-A·UMENJ

600 West John Street, Hicksville, New York

.

Electronics I August 23, 1965

Circle 19 on reader service card 19

-'. -·~ ·-· /·.·

· ····. ·· '
~ ...........~ .....--···
7

3

i· ·

4 6

SWEPT FREQUENCY

· f ··
,-
INDUS TRIES INC.

Frequency response can be measured by no better method than with instrumentation generating frequencies covering the total spectrum of interest. This is the function of the sweep generator- and nowhere is it more effectively realized than in Telonic instruments.
Designed to facilitate test procedures by providing fast, meaningful data, Telonic Sweep Generators and accessory equipment are both laboratory and production line proven . With models in every frequency bracket to 3 GHz, and the universal SM-2000 for maximum versatility, selection of the best instrument for your application is no problem. Performance and dependability factors are inherent, as thousands of users have already discovered.
Telonic Sweep Generators are of many basic design types. Several different sweeping mechanisms are used, assuring the best possible approach for each instrument. All are available with integral or external frequency marking systems to further simplify response testing procedures.
The equipment shown and described here is but a partial listing of Telonic's complete product line. Catalog C-100 covering all Telonic instrumentation in detail is yours on request, Write, wire or call ...
TELONIC INDUSTRIES INC.
60 North First Avenue, Beech Grove, Indiana Tel: (317) St. 7 - 3231-TWX-810-341 - 3202

"See Telonic Products at Wescon, booths 4114-4118"

20

Electronics I August 23, 1965

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INSTRUMENTATION

1. HD-1A

1 MHz to 900 MHz

Sweep Generator

Design and testing of broad band 1-F, R-F, and video amplifiers.

2. SM-2000

20 Hz to 3 GHz

Sweep Generator (Depending on

Control Chassis Oscillator Head)

For lab or production testing throughout its frequency range. 22 plug-in oscillator heads available.

3. VR-50M Oscillator Head

500 MHz to 1000 MHz Testing broad band video, 1-F and R-F amplifiers.

4. LH-2M Oscillator Head

400 KHz to 110 MHz For testing narrow and wide band amplifier and similar circuits.

LA-IM 5. Oscillator Head

20 Hz to 20 KHz

Testing audio amplifiers, filters, telephone equipment and lines, modulator circuits.

6. SH-1M Oscillator Head

.5 MHz to 460 MHz

Covers radio and TV Broadcast bands, navigational devices, airport control equipment, and other communications equipment.

7. SD-3M

440 MHz to 920 MHz Alignment and adjustment of UHF television tuners.

Sweep Generator

8. PD-8

20 MHz to 1000 MHz Aligning and testing passive devices such as R-F net-

Sweep Generator

works, transmission lines, attenuators and R-F filters .

9. SV-13

20 MHz to 225 MHz Alignment, adjustment and inspection of R-F chan-

Sweep Generator

nels, 1-F Sections of VHF TV receivers.

10. SK-1 Skan-A-Skope

11. TAB-50 Turret Attenuator DC to 900 MHz

12. TG-650

DC to 250 MHz

Toggle Attenuator

13. TS-103 A
coaxial Switch

DC to 1000 MHz

Used with sweep generator to simultaneously display frequency characteristics with reference lines. Attenuating R-F signals - In 1 db steps up to 59 db.
Attenuating R-F signals - In 1 db steps up co 42 db. Switching R-F signals.

Broad center frequency range - Continuously variable
Sweep or CW functions - Variable rate
500 MHz sweep width Variable rate
Multiple octave sweeps - Continuously tunable
Provisions for 8 frequency markers - Flat output
Wide frequency coverage - 200 MHz sweep width
Portable or bench versions - Up to 8 frequency markers
High power - 4 watts output
13 changeable plug-in channels for U.S. and foreign frequencies
Capable of displaying 5 traces at one time
Direct readout dial Low insertion loss
Negligible insertion loss - Accurate attenuation
Negligible cross-talk Minimum insertion loss

$995.00
$775.00
$695.00 $550.00 $995.00 $575.00
$895.00
$2750.00 $625.00
$1495.00 $190.00 $65.00 $100.00

Electronics I August 23, 1965

"See Telonic Products at Wescon, booths 4114-4118" Circle 21 on reader service card 21

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MAKES THE DIFFERENCE!

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FOR PRECISION, COMPACT POWER

The PWR Design Group comprises line and load regulated power modules incorporating the Kepco patented " Flux-0-Tran" line regulating transformer and the Kepco patented "Bridge" output regulator. Designed for use on the bench , in systems or proprietary products, mounting choices include chassis, bench or rack panel arrangements. Unique overload current cut-off provides unusual degree of loadprotection. Output externally programmable 0-100% with linear derating (see graph for operating region).

· less than 0.005% output voltage · 60 cps ± 1 cps single phase input,

REGULATION

change for 100-130V line change

standard models

· less than 0.05% for no load to · 50 cps ± 1 cps units available,

0.005o/o LINE - 0.053 LOAD

full load change

for 104, 115, 208 or 230V AC

· 0.05% or 3 mv (w.i.g.) long term stability
· less than 0.5 millivolt rms ripple

line voltages
· Overload protection, unique current cut-off

MODEL

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OUTPUT IMPEDANCE OHMS MAX
DC to 100 cps 1 kc to 100 cps to 1 kc 100 kc+ uh

· 50 microsecond recovery time

· ± 5% output vernier voltage

PWR 12-7 0-12 0-7 0 .005 0.001 0.1 + 0.5

· - 2o·c to +65°C uncased, +55°C adjustment

PWR 15-6 0-15 0-6 0.005 0.002 0.1+ 0.5

cased, ambient temperature range

· Open/cased/rack mounting
choice, single, dual, treble rack mounting adapters available

PWR 24-4 0-24 0-4 0.005 0.003 0.05 + 0.5' PWR 28-3.3 0-28 0-3.3 0.005 0.004 0.05 + 0.5

OUR NEW CATALOG

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CONTAINING COMPLETE SPECIFICATIONS AND

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KEPCO, INC.· 131-38 SANFORD AVENUE. FLUSHING, N.Y. 11352. Phone: (212) 461-7000. TWX #212-539-6623. Cable: KEPCOPOWER NEWYORK See our Newest Products at WESCON-Booths 4323-4324

22

Circle 22 on reader service card

Electronics I August 23, 1965

Electronics I August 23 , 1965

Editorial
Siren song
for companies . · ·
The easy life is tempting electronics companies again.
Escalation in Vietnam has finally led to steppedup military procurement, after months of slow but steady decline. The one-customer way of doing business is again a possibility for electronics companies that for the past 18 months have been developing new muscles of efficiency, aggressiveness, and independence from the Pentagon (see "The changing face of the W es t," August 9, 1965, page 60).
Nobody is sure just how much additional money th e Vietnam affair will cost; nearly $3 billion ex tra will be spent this year, and similar expenditures are expected in the next few years. But regardless of what the final sum turns out to be, enough spending is in sight so that some companies may forget diversification plans, drop aggress ive marketing strategies and stop putting th eir own mon ey into new products.
If they do, it will be a crime. Th ey'll throw away the gutwrenching efforts of the pas t year and a half. The electronics industry will never be healthy

and mature until it stands on its own feet, and is not supported by the Defense Department. Many in the industry refuse to accept the tenet that the industry must have a war-declared or undeclared - to enjoy prosperity. The progress of the past 18 months supports their feelings , even though many of the plans and programs are just reaching fruition.
Should electronics companies shun the current defense business altogether? They can't-if for no other reason than that the troops fighting in Vietnam deserve the best gear obtainable. If properly handled and assessed, this added business can be profitable. But it should be recognized for what it is: a windfall, unexpected and possibly not repeatable. And it should be treated with caution; Defense Secretary Robert S. Mc amara's passion for economy seems sure to squeeze some of the profits out of production contracts. Competition will be keen and is likely to be on a price basis.
Probably the greatest danger facing electronics companies is that they may be lulled by the old song sung by some defense contractor diehards. Veterans of one cutback after another, these contractors have been saying all along that diversification , modernization, and change were unnecessary because something would come along-it always has. Now th ese men are saying "I told you so.
Not everybody will make the good fight. Some electronics companies will take the easy way out even if they risk long-range catastrophe. But if they remember the hard lessons of the past 18 months, they'll continue to operate the new wayon the basis of their planning, not the Pentagon's.
If they don't, the industry will have it all to do over again as soon as th e Vietnam affair is settled.

. . . and engineers
Engineers can use a word of caution too. Along with th e step-up in military procurement has come a speed-up in engineer recruitment. The advertisements are appearing in all their splendor, again offering dazzling delights of high pay, des irable living, and challenging work.
Many of the engineers who found themselves laid off just a year ago will remember thi s kind of enticement. It is the same lure that got th em in trouble.
At the height of the layoffs in 1964, th e unemployed engineers saw that they had chosen the wrong route. Instead of concentrating on building

a career with a soundly managed company, they had jumped from job to job chasing a higher salary. And despite good pay and easy living, they had been doing technicians' work which did not make th em better engineers.
Though the offerings are tempting, engineers should keep in mind that th e current build-up could be temporary. Our government is exercising every effort to bring th e conflict to mediation ; and if negotiation succeeds, military electronics will b e back where it was at the beginning of 1965. Engineers who have moved to new jobs for a quick salary increase in military work will find the layoffs starting again.
Only you can guarantee your career. When you answer an advertisement, be sure that the job is challenging. Even more important, b e sure it is true engineering and isn't temporary.

23

Is random vibration testing necessary for half-size crystal case relays?

Vibrations of a missile upon launch are far from being a simple sinusoidal affair. They are, indeed, quite random both in amplitude and frequency. It makes only good sense, then, to test our aerospace/military relays for their ability to withstand rand om vibrations. This we do. Few if any other relay manufacturers test in this fashion. All high reliability P&B relays are constructed to tolerate random vibration. A typical oscilloscope trace is shown below.

conservatively rated to withstand 150g shock for 11 milliseconds with no contact opening.
HC Series half-size crystal case relays are built with loving care and precisely controlled processes. Assembly is done at Whitfield-type laminar flow workbenches. They employ absolute filters which are capable of stopping cigarette smoke (or particles as small as .0000118") and provide what many experts consider to be the cleanest environment available.
Over and above all this, our HC relays are designed to be reliable. They have bifurcated contacts, and make use of some superior materials not found in similar relays. All-welded enclosures are available. Our Quality Assurance program keeps production within the scope of MIL-Q-9858A.

' - ~ l

.

..-

Shock testing is important, too. That's why we use a pneumatic shock tester in conformance with MIL-STD 202B. Incidentally, our HC relay is

Remember ... you can buy cheaper relays but you cannot buy P&B quality for less. For more information, call your P&B representative or write us direct.

- - - - - - - - - - - - - H C ENGINEERING D A T A - - - - - - - - - - - - -

GENERAL: Non-polarized half crystal case size.
Shock: 150g for 11 ms. }No contact opening Vibration: 20g to 3000 cps. in ~ither armature
pos1t1on. Random vibration testing to customer specincations is available.
Operate Time: 3 milliseconds max. at nominal voltage @ +25°C coil temperature.

Life: 100,000 operations at maximum rated load. Temperature Range: -65°C to +125°C. Size: .810" long, .410" wide, .410" high !max.I.
Weight: Approx. V. oz.
CONTACTS
Arrangement: DPDT lbifurcoted, gold.plated silver-alloy).
Rated: Dry circuit to 2 amps at 28.0 VDC res.

HC RELAYS ARE AVAILABLE FROM LEADING ELECTRONIC PARTS DISTRIBUTORS

RIDE THE AMF MONORAIL AT THE NEW YORK WORLD'S FAit
24 Circle 24 on reader service card

BRUMFIELD ~POTTER &
T Division of American Machine & Foundry Company, Princeton, Indiana In Canada: Potter & Brumfield, Division of AMF Canada Ltd., Guelph, Ont. Export: AMF International, 261 Madison Avenue, New York, N. Y.
Electronics I August 23, 1965

Electronics Newsletter

August 23, 1965

Radiation, Inc. to design Mark 5 ground terminal

About Sept. I the Anny win announce that Radiation, Inc., has been
selected to dt:velop the ~ark 5, or AN/TSC-54, air-transportable ground terminal to operate with the .military communications satellite system scheduled to be put into orbit next year [Electronics, May 31, p. 86]. Although its bid was reportedly the highest of. three made by finalists picked from a long list of contenders over a.6-month evaluation, Radiation's proposal was chosen because of several technical capabilities the others did not have. Important among Radiation's advances are higher aperture efficiencies and higher gain.
The lowest bidder among the three finalists was the Philco Corp.'s Western Development Laboratories; the Bendix Radio division of the Bendix Corp. was in the middle.
Radiation's antenna will be a cloverleaf consisting of four panels, or petals, that are hinged instead of detached. They can be unfolded without having to be bolted.
Hardware for the system must weigh no more than 17,500 pounds; no package can weigh more than 6,000 pounds. A six-man crew must be able to erect or dismantle the terminal in two hours.
Although the amount of the initial contract is not known, each terminal will probably cost about $1 million ahd at least nine terminals will be ordered over the next few years. Spares probably will cost $6 million more, bringing the total of orders eventually to about $15 million.

Diamonds may be devices' friend

Successful operation of a new type of diamond rectifier is reported by

William J. King, director of solid state physics at the Ion Physics Corp.,

Burlington, Mass. "This is preliminary data and further substantiation

is necessary," King warns.

Surface barrier rectification in diamonds has been achieved for years,

but this is believed to be the first instance of rectification out of a pn

junction in diamonds. The junction was formed by ion implantation,

under a program sponsored by the Air Force Cambridge Research Lab-

oratories.

·

If there is verification of the junction effect it could open the way to

the use of diamonds for active devices. Because of .the wide band gap in

diamonds, semiconductor devices made of this m~terial could operate

at extremely high temperatures. Exceptionally good heat-d!ssipation char-

acteristics would permit such devices to be driven hard without degrad-

ation of performance.

King says the diamond rectifier was made by implanting 1020 phos-

phorus ions per cubic centimeter at a maximum energy of 300,000 electron

volts in a p-type natural diamond.

Eglin radar to feed Spadats

The Air Force learned enough about the capabilities of the phased-array radar being built at Eglin Air Force Base, Florida before fire destroyed it last January so that the installation will be able to skip the experimental period when it is rebuilt. The radar, known as the AN/FPS-85, will become part of the North American .air defense network, as an input to Spadats (the space detection and tracking system) as soon as it is complete.
Original plans were for the radar to be used as an experimental station

25

Electronics Newsletter

for a year after the planned acceptance last January. The rebuilding began

in March; the Air Force has not set a target date for its completion.

The blaze [Electronics, Jan. 25, 1965, page 101] began in the trans-

ceivers behind the face of the giant array; the open area between the

paneling and the electronics created a 13-story "chimney," whipping the

Hames to an intense heat that even melted cables. On the new array, the

area behind the panels will be compartmentalized, to avoid the dangerous

chimney effect.

The Radio Systems division of the Bendix Corp. is the prime contractor

for the radar.

·

Comsat invites satellite bids ..·

The Communications Satellite Corp. is shopping for some more satellites -at least six and possibly 24-and a couple of ground stations.
Last week Comsat asked electronics companies to submit proposals for the design and construction of a 240-pound satellite with a capacity of 1,000 two-watt voice circuits, capable of operating either in a synchronous system at an altitude of 22,300 miles or in a phased system at 6,000 to 12,000 miles. The 85-pound, $3.5-rnillion Early Bird has a programed 240 circuits. .
Bids will be opened Oct. 25 and delivery date for the first six satellites will be 24 months after the contract award.
Comsat was scheduled to request proposals for ground stations to be built at Brewster Flat, Wash. and Paumalu, Hawaii.

. · . and makes a bid of its own

Comsat is preparing its own proposal to the National Communications System for synchronous satellites and transportable ground stations that could be used in the National Aeronautics and Space Administration's Apollo and other programs.
The system to be offered NASA involves four synchronous satellites, two of them orbiting as backup. The proposal, due Aug. 23, is based on the single bid which the satellite corporation received from the Hughes Aircraft Co.

Saturn telemetry to be automated

The telemetry ground station for the giant Saturn launch vehicle, at the Marshall Space Flight Center at Huntsville, Ala., will be completely automated. For the first time, a general purpose computer, with one man at a console, will control all the functions of a telemetry station. The system is being developed by Defense Electronics, Inc. under a $400,000 contract with the National Aeronautics and Space Administration.
If the automated station works well, telemetry at the Manned Spacecraft Center at Houston, and later at Cape Kennedy, will probably be automated. If the entire missile range is automated, a number of engineers and technicians recently hired for the expanded telemetry activity would not be needed.

Prospects bright for night vision

The Army's highly classified night vision progra' m may be very close to
the equipment stage. There are reports that the Army Electronics Command at Fort Monmouth, N.J. has taken over the program from the Combat Development Command in Fort Belvoir, Va. The move could mean that the Army is ready to go ahead with production and procurement.

26

Electronics I August 23, 1965

from SYLVAN IA Electronic Components Group

INTEGRATED CIRCUITS

Announcing SUHt:Il...fastest (40mc/s) saturated logic, in a hermetic plug-in package

From time to time.,-se.veral manufacturers have announced high-speed logic circuits based on a variety of design concepts. But in achieving faster speeds each concept compromised total system performance. Tradeoffs were made in at least one of these important system requirements-noise immunity, logic levels, power drain, temperature stability, fan-out vs. fan-in, or capacitance drive capability. Speed per circuit package was achieved by reducing logic function per package. These approaches required level restoration, fan-out buffering, or bias supply regulators, necessitating extra packages. Hence, not only was package speed lost at the system level, but system power, can count, and costs were increased also .
Now a new line of integrated circuits, SUHL II, solves high-speed system requirements without compromise to any performance characteristic. The SUHL II family consists of totally compatible 6-nsec gates and 30mc J-K flip-flops designed to oper-
·sy1vania Universal High·Level Logic

ate from a single 5-volt power supply. In addition to the universal elec-
trical characteristics, this newest IC line is available in Sylvania's new hermetically sealed plug-in package, important for manual or automatic insertion. The package is also ideal for flow-soldering installation on twosided printed circuit boards.
Every SUHL II circuit, including the single logic level NAND/NOR gate, two logic level expandable OR (AND/ NOR) gate, and the two J-K flip-flops , has high noise immunity, fan-out, and capacitance drive capability. Still another important feature is that additional packages are not required to restore logic levels or noise margin at the system level. Saturated logic has been used throughout to maintain stable logic swings and propagation times over broad operating temperature excursions without recourse to additional bias supplies, complex loading rules, and external clamping and shielding. Low power OR expansion is accomplished with-

out degradation of fan-out or capacitively loading the gate output.
With new SUHL II circuits, output impedance is low and not subject to oscillations. The low power drain is independent of fan-in or fan-out, typically 20 mw per gate function. High noise immunity (-1.5 to + 1.1 volt at 25°C) and high logic swing ("O" = 0.25V, 'T' = 3.5V) are among other notable characteristics.
All circuits in the SUHL II line are compatible with the 18 integrated circuit series of SUHL I. Both SUHL lines are supplied in -55°C to+125°C operating temperature ranges for military applications and, for industrial use, in the 0°C to +75°C range.
CIRCLE NUMBER 300
This issue in capsule
Photoconductors-a black spot
photocell that finds random defects in opaque, translucent and transparent materials.
Diodes-a new low leakage silicon al-
loy series replaces many general-pu rpose diodes.
ReceivingTubeS-special trigger
tube is used in detecting changes in smoke, heat, gas and other phenomena.
Photoconductor- Lamp Assemblies - a new approach to noise-free
switching at audio and video frequencies.
Cathode Ray Tubes-high-resolu-
tion photographic recording with preadjusted and prealigned CRT assemblies.
Microwave Diodes-a new Solid-
Structure concept for germanium tunnel diodes.
Color TV -what to look for in tubes for
damping and horizontal deflection.

This is SUHI: Il
· Sylvania Universal High-Level Logic.

EXPANDABLE DUAL 4-INPUT OR GATE

A

N

B
c
(Vcc)D E

M

L

SG-210

K

SG-211 SG-212

SG-213

J

F

I

G

H

L·(A·B-C·N )+ (E·F·G·H) +--

QUAD 2-INPUT NANO/NOR GATE

A

N

B
c
(Vcc)D
E
F
G C· A·B
G·N

M
L SG-220 SG-221
K SG-222 SG-223
J
H K· H·I N=L· M

DUAL 4-INPUT NANO/NOR GATE

A

N

B
c
(VcclD E F G

L·A· B·C-M K·~

M
L SG-240 SG-241
K SG-242 SG-243
J
H

EXPANDABLE QUAD 2-INPUT OR GATE

A

N

B

M

c
(Vccl 0 E

L SG-250 SG-251
K SG-252 SG-253
J

F

G

H

K·A·N+ C·B +E·F +G·H·I

QUAD 2-INPUT OR EXPANDER

A

N

B
c
(Vee) D E F G

M L
SG-230 SG-231 K SG-232 SG-233 J
H

SINGLE 8-INPUT NANO/NOR GATE

A

N

B
c
(VccJO E F G

M
L SG-260 SG-261
K SG-262 SG-263
J
I
H

DUAL 4-INPUT OR EXPANDER

A

N

B
c
(Vcc:) 0 E F

r--
1 .J
, I I I I -:1 L--

M
L
K SG-270 SG-271 SG-272
J SG-273
I

G

H

J-K FLIP-FLOP (AND INPUTS)

J·K FLIP-FLOP (OR INPUTS)

(Kr) B (CLOCK)
c
(VcclD

M(O.C.RESET)
L (0)
K(Q) SF-250 SF-251 SF-252
J SF-253
I(O.C.PRESET)
H (O.C.SET)

U<rl B (CLOCK)
c
(Vee) 0

L(Ol
SF-260 K (Q) SF-261
SF-262 J SF-263
I (0.C.SET)
H (L2)

Function Expandable Dual 4-lnput OR Gate Quad 2-lnput NANO/NOR Gate Quad 2-lnput OR Expander Dual 4-lnput NANO / NOR Gate Expandable Quad 2-lnput OR Gate Single 8-lnput NANO/NOR Gate Dual 4-lnput OR Expander J-K Fl ip-Flop (AND Inputs) J-K Flip-Flop (OR Inputs)

SUHL II TYPICAL CHARACTERISTICS C+ 25'C, +5.0V)

Type Nos. SG-210, SG-211, SG-212 , SG-213 SG-220, SG-221 , SG-222, SG-223 SG-230, SG-231 , SG-232, SG-233 SG-240, SG-241 , SG-242, SG-243 SG-250, SG-251, SG-252, SG-253 SG-260, SG-261 , SG-262, SG-263 SG-270, SG-271, SG-272, SG-273 SF-250 , SF-251 , SF-252, SF-253 SF-260, SF-261 , SF-262, SF-263

tpd (nsec)
6 6 6 6 6 6 6 30mc· · 30mc··

Avg. Power mw. 30 20 *** 30 20 *** 45 20 7.5 60 60

Noise Immunity + (VOits) -

Military

Industrial

(-55' Cto + 125' CI (O' Cto + 75' C)

Prime FD Std. FO PrimeFO Std.FD

1.1

1.5

12

6

10

5

1.1

1.5

12

6

10

5

1.1

1.5

1.1

1.5

12

6

10

5

1.1

1.5

12

6

10

5

1.1

1.5

12

6

10

5

1.1

1.5

1.1

1.5

12

6

10

5

1.1

1.5

12

6

10

5

· · synchronous clock rate. .. ·Per gate.

INTEGRATED CIRCUITS
New plug-in package for assembly ease

Specifically designed for low cost assembly on two-sided printed circuit boards, Sylvania's new plug-in package is hermetically sealed and tested to a 10-8 cc/sec leak rate. The alumina filled glass package provides extremely low thermal resistance and features Kovar leads formed into a 0.020" diameter for both strength and reliable solderability.

The 100 mil pin centers permit both loose drill tolerances and wide printed circuit lines while the leads provide a 0.035" standoff to prevent solder bridging. Another feature of Sylvania's new package is the handy index notch midway in one of the short sides which can facilitate manual or automatic installation.
CIRCLE NUMBER 300

COLOR TELEVISION

What to look for in sweepers and dampers

In previous issues, IDEAS has pointed out the large strides made in recent months and years in enhancing the reliability and performance of receiving tubes. On this page we take a closer look at how this progress applies to color television, with particular emphasis on newer tubes for damping and horizontal defiection.
New Damper Types
Until recently an accepted, but expensive, means of damping called for circuit designs using two dampers in parallel. The economical, but far less reliable, approach was to design a circuit with a single damper that would be pushed to its electronic limits.
Now there are two new dampers specifically designed for low B+ color TV, where good performance is dependent on high current capability and low tube drop. The Sylvania 34CE3 and 6CH3 individually provide all of the damping requirements at no sacrifice to reliability.
Both tubes are indirectly heated half wave rectifiers within T-9 glass envelopes. Both have excellent emission stability, dissipation ratings of 11 watts and 350ma DC plate current. The 6CH3 has a 9-pin base. The 34CE3 has a .12-pin base with controlled heater warm-up time for series connected circuits.
Arc-free operation is assured in both types because of their high peak inverse ratings. Other important characteristics are high average and peak current ratings, along with low tube drop. Because application heating time is fast, the picture image comes into view quickly and not after the

sound. And emission stability is good throughout the tube's life, a result of high heater power input.
Especially important in both the 6CH3 and 34CE3 is the high heater cathode safety factor with an increased voltage rating between the heater and cathode. In achieving a high plate dissipation rating, Sylvania added a double plate wing design with a copper core multilayer plate. This, in turn, gives the tubes a dissipation capability compatible with current ratings and demanding color set usage. The high thermal conductivity plate also provides uniformity in heat radiation, low tube drop and the high peak inverse voltage rating.
Horizontal Deflection Types
Two newer sweep tubes can be used effectively in combination with the 6CH3 and 34CE3. In addition to their roles as horizontal deflection amplifiers, the 31JS6A and 42KN6 share few other characteristics. Both are pentodes featuring T-12 construction with a 12-pin base. The heater opera-

tion in both is for series string operation. Both have low knees to help assure snivet-free operation and, in case further suppression is needed, beam plates are brought out through separate base connections providing ready access to the element.
The 31JS6A was designed specifically for economy of series string operation. Its lower knee also makes it an acceptable deflection tube for some less demanding (70°) deflection requirements at low B+ voltages.
The Sylvania rugged 42KN6 was specifically designed for low B+ high current operation for deflection of 90° or 70° color picture tubes. The 42KN6 eliminates the need and expense for parallel deflection tube.
The 42KN6 uses the new cavitrap plate design to provide a high peak current consistent with the low knee needed at low B+ voltages for deflection of a 90° tube. Outstanding also is its high plate dissipation rating, high screen dissipation rating and high bulb temperature rating.
CIRCLE NUMBER 301

MICROWAVE DIODES
New... a Solid-Structure Germanium Tunnel Diode

With the industry's first Solid-Structure germanium tunnel diodes, Sylvania has increased diode reliability while maintaining electrical characteristics. The design engineer now has a t'unnel diode line with long-term stability of characteristics, small replacement factor and the ruggedness of solid one-piece construction, all of which make it inherently adaptable to microwave integrated circuitry.
In Sylvania's new technique, an oxide protection is applied to thousands of diodes on the surface of each slice; the contacts are then placed over the oxide. Thin film technology forms the basis for this process. (Traditional tunnel diodes, sometimes likened in cross-section view to "a boulder on a pinnacle," are individually alloyed and etched.)
All units are completely metalbonded; no "glues" are used. The result after dicing is individual tunnel diodes, each 20 mils square and ready for immediate application.
In addition to increased diode reliability, Sylvania's Solid-Structure concept offers the economic advantages of batch processing.
The inherent reliability of SolidStructure tunnel diodes was evident throughout the entire test program. These units withstand cryogenic to
+100°C temperature cycles repeat-
edly. They pass MIL STD 750 mechanical stress testing, i.e. 1500 G shock, 20 G vibration, 20,000 G centrifuge. Exhaustive tests under these conditions prove the long-term stability of Solid-Structure diodes. And, due to the new manufacturing process, they have lower series resistances than standard tunnel diodes. Resistive cutoff frequencies greater than 50 GHz have been obtained.
The Solid-Structure diode line is available in three package styles. Thus, diodes with identical performances are offered in the D-5360, D-5560 and D-5570 series. (See chart.)

Each series offers a wide choice of diode types capable of meeting most tunnel diode requirements. For example, they include resistive cutoff frequencies to greater than 25 GHz

and a peak current range of l.Oma to lOOma. A controlled peak currentto-capacitance ratio aids in circuit design considerations where uniform and stable performance is critical.

CIRCLE NUMBER 302

PASSIVATION LAYER

PASSIVATION LAYER

GERMANIUM SUBSTRATE

L

g
D-5360 D-5360A
D-5361 D-5361A
D-5362 D-5362A
D-5363 D-5363A
D-5364 D-5364A
D-5365 D-5365A

TYPE NO.
~
D-5560 D-5560A D-55608
D-5561 D-5561A D-55618
D-5562 D-5562A D-55628
D-5563 D-5563A D-55638
D-5564 D-5564A D-55648
D-5565 D-5565A D-55658

~
D-5570 D-5570A D-55708
D-5571 D-5571A D-55718
D-5572 D-5572A D-55728
D-5573 D-5573A D-55738
D-5574 D-5574A D-55748
D-5575 D-5575A D-55758

J

Ip Ma ± 20%

ri Ohms
(typ)

R,
Ohms (max)

cj
Pf (max)

F,.
GHz
(min)

1.2

100

1.2

100

1.2

100

8.0

1.5

5.0

4.0

0.45

25

6.0

0.50

20

1.8

67

1.8

67

1.8

67

7.0

2.0

5.0

3.0

0.60

25

6.0

0.70

15

2.7

44

2.7

44

2.7

44

6.0

3.0

5.0

2.5

0.75

25

6.0

1.10

12

3.9

31

3.9

31

3.9

31

6.0

5.0

5.0

2.0

1.00

25

6 .0

1.60

10

5.6

22

5.6

22

5.6

22

6.0

7.0

5.0

1.5

1.40

25

6.0

2.30

7.5

8.2

15

8.2

15

8.2

15

6.0

10.0

5.0

1.0

2.00

25

6.0

3.30

5.5

084

082

048

CRTs
A complete, plug-in CRT assembly for high-resolution .photographic recording

Cathode ray tube assemblies, fully preadjusted and prealigned, are of special interest to display designers and users alike.
Consisting of a high-resolution tube, deflection coil, focusing coil, alignment magnets, mu metal shield and supporting hardware, these selfcontained packages are individually engineered and custom-built for specific systems. Front end mounting plates are also supplied to specification. Engineers are finding that the assemblies are particularly well suited to high-resolution photographic recording and flying spot scanner usage.
Both installation and servicing are easy. The units can be quickly installed by nontechnical personnel. They are simply plugged in, wfrh no further alignment or adjustment necessary. Should servicing ever be required, disconnecting is easily accomplished and, if necessary, the entire package can be quickly replaced by another assembly. Engineering costs and time are thereby cut to a bare minimum. Since components are prealigned, there is greater assurance

of immediate optimum resolution. The newest packaged assembly,
Sylvania's AT-SK-6000, is designed for use with electrostatic focus tubes, such as the 5CEP and 5ZP, both 5inch high-resolution CRT's.

The AT-SK-5053 assembly can be furnished with these same two tubes or with any other high-resolution CRT. These other tubes include the 5-inch SC-2782, SC-2809 and SC3168, as well as the 10-inch SC-3890.

CIRCLE NUMBER 303

PHOTOCONDUCTOR-LAMP ASSEMBLIES
Noise-free switching at audio and video frequencies

...#__ - -

Now switching or continuous attenuation at audio through video frequencies can be noise-free.
The new route to the elimination of electrical noise is a PL assembly, actually a glass-encapsulated cadmium sulfide photoconductor optically coupled to a miniature incandescent indicator lamp. The photoconductor and

lamp are sealed in a small, rugged lightproof housing of plastic or metal.
Using the device in remote control applications, critical amplifier circuits are electrically isolated both from the remote station and from cabling. As a result, inductive or stray magnetic pickup is eliminated as well as all noise from physical movement of

wiper contacts. As applied to the broadcast and television industry, the grid circuit, in effect, can be left back in the transmitter complex.
Sylvania PL assemblies are proving effective in other new applications. Among them are electronic musical instruments (for vibrato, tremolo and percussion effects), "OR" and "AND" logic circuits, noiseless volume or swell control, current-dependent or voltage-dependent noiseless switches, and multi-pole, multi-position switches .
These highly reliable assemblies can be made to order in combinations from any of seven cells and 6, 12 or 24 volt indicator lamps. Non-standard lamp voltages can also be used on special order. To the design engineer, this means that a wide selection of PL assemblies is available in parameters to suit many practical applications.
CIRCLE NUMBER 304

PHOTOCONDUCTORS
Black Spot Detector seeks out minute defects before the trouble starts

Finding spots and blemishes in opaque, translucent and transparent materials has not always been easy, let alone practical. Until recently, quality control systems used essentially one of two systems, both costly, most often inefficient and often painstakingly slow-the human eye and/or standard photocells.
Sylvania's Black Spot Detector finds random defects as small as 1/32" for such applications as inspecting laundry for stains, eggs for blood spots,

and glass bottles for air bubbles. Before, the best electronic inspection systems were based on standard cells where it was essential that the entire light-sensitive area be masked by a shaded image projected from the de-
fect. Thus many defects of 112" and
larger would not be detected until a product was in use.
Now an added product plus is that the SRP-3419A Black Spot Detector is available considerably below its original cost. With advanced production techniques turning it out more efficiently, Sylvania can offer the cell attractively priced for critical applications.
This device detects dark images on the surface of opaque materials. In the case of transparent or translucent objects, such as glass or plastic, the cell can look beyond the surface to respond to blemishes either on or within the material. It is generally used in inspecting goods transported on a

conveyor belt. An attendant or automated device can be quickly alerted to remove the defective or unwanted areas.
The Black Spot Detector uses two special photoconductive elements. Each element is made up of a cadmium sulfide strip, which is actually several cells connected in series. Because of this unique dual-element design, varying thermal excursions and changing ambient illumination have little or no effect on the operation of the cell. It also permits the field light source to be operated from AC as well as DC.
The new cell works best in high illumination where its response time is considerably faster than in a low light level. For instance, in taking full advantage of bright light conditions, the SRP-3419A has successfully detected 1/ 16" spots at a belt speed of 150feet-per-minute with 12 FC average illumination.
Like all Sylvania photoconductors, this cell also includes the famous Blue Dot, your assurance that the cell is free from moisture.
CIRCLE NUMBER 305

DIODES
New low leakage series replaces many general-purpose types

For the engineer who wants true versatility in a general-purpose diode, Sylvania's new silicon alloy series can be the perfectanswer. In this instance, versatility is greatly heightened by the extremely low leakage currents

that are typical of the entire new line. Using an industry standard diode
for comparison, where the long-accepted IN459A shows a current leakage of 25 nanoamps at l 75V reverse voltage, Sylvania's new D-6625 is

measured at just 5na, while the

D-6625A shows only lna. At 150°C,

again with a reverse voltage of 175V,

the newer types are measured at 2µ.a

and lµ.a respectively, versus the IN-

459A's 5µ.a.

(continued)

REVERSE CHARACTERISTICS OF 7
1000 El3~~~~

f----+---+--+---+-+---+-- Typical at iso·c__;;;j

I

Minimum at 150"C -t---1

LL
~ 0.01 -40

-so

-120

-160

Rever.;e Voltage (Volts)

-200

100 50
"~ '
8.
E ~ 10
!

FORWARD CHARACTERISTICS OF 7
~
:z
Tl-
717
7_ 1 I
Z --ZMaximum at 25' C =Typical at 25·c :::::: Minimum at 25°C Typical at lOO ' C~=
_L !f:_
t _Ji_
1

0.5 0 'I 0.4

0.6

0 .8

1.0

Forward Voltage (Volts)

Similar improvements are evident in comparing the low leakage currents of Sylvania's D-6623 and D-6624 diode series with those of standard IN457A and IN458A types.
Their outstanding high temperature and high conductance characteristics are other important considerations to the engineer interested in an unusual combination of features.
The new protected junction is applied simultaneously to make thousands of these diodes during batch processing, a prime reason for both ultra-low leakage cw-rent as well as

the series' excellent long-term stability. Inherent also with diode batch processing is uniformity of parameters, assurance to the design engineer of product-to-product compatibility and reliability.
New improved versions of many standard diodes are now available. These products of Sylvania batch processing include:

IN456, ·/A 0 1N457 · 1N458 · IN459
IN461, -/A IN462, -/A IN463, ·/A IN464, -/A
· Available MIL approved.

IN482, -/A, ·/B IN483, -/A, -/B IN484, -/A, -/B IN485, ·/A, -/B IN486, -/A, -/ B IN487, ·/A, ·/B 0 1N816 IN881

CIRCLE NUMBER 306

RECEIVING TUBES
Trigger tube vital to sensing heat, dust, gas, etc.

Systems with the Sylvania SY-1302,

results in a sensor output current

a special-purpose cold cathode thyra- change. A sudden, though small,

tron, can detect sudden changes in change in sensor output current

smoke, heat, dust, gas, moisture, light, causes the SY-1302 to fire, thus acti-

pressure and radiation.

vating the alarm.

Ideal for use with an ionization

Operating life of the SY-1302 is on

chamber or other detectors, the SY- the order of 1,000 hours or more. Con-

1302 has extremely high grid im- sidering that the tube is in use only

pedance of 1012 ohms, an essential

when the system is in operation, its

characteristic for translating changes practical life can be a matter of dec-

that are sudden or minute. Designed ades. Its strong advantage is the

as a coupling device between high ability to work on low current under

impedance bridge circuits and de- adverse conditions. It is not depend-

vices with lower impedances, it ent on ambient light; rather, the tube

features extremely high insulation re- is designed to function in the com-

sistance and flexible solderable leads.

plete darkness that a system's housing

(On order, it can be provided with a provides. There is also no measurable

7-pin base in place of the leads.)

radiation output.

A practical illustration of how the

Until now, the SY-1302 h~s been

tube works is found in a combined primarily used in smoke detection

smoke detection and alarm system. systems in schools, hotels and other

Smoke enters one of two chambers public buildings. But its proven ver-

in the ionization sensor. The heavy

satility promises it a bright future in

smoke particles unbalance the cham- helping to solve many other detection

bers by slowing down the radiation systems problems.

emission hitting the collector. This

CIRCLE NUMBER 307

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --

~~ HOT LINE INQUIRY SERVICE
Use Sylvania's "Hot Line" inquiry service, especially if you require full particulars on any item in a hurry. It's easy and it's free. Circle the reader service number(s) you're most interested in; then fill in your name, title, company and address. We'll do the rest and see you get further information almost by return mail.

BUSINESS REPLY MAIL
No Postage Stamp Necessary if Mailed in the United States
POSTAGE WILL BE PAID BY
SYLVANIA ELECTRONIC COMPONENTS GROUP
Sylvania Electric Products Inc. 1100 Main Street Buffalo, New York 14209

FIRST CLASS Permit No. 2833
Buffalo, N.Y.

Dept. 77

MARKETING V. P.'s CORNER

The ABC's of ECG ... or...What's in a name?

Have you ever considered the size of the alphabetical complexity existing in the world today? Just think of it. .. all sorts of initials and abbreviations, few of which have relatively any immediate meaning. The electronics world is especially inundated, what with initials in place of corporate names, governmental agencies, technical terms, and even products. Does your wife know what a MOS-FET is? Or a CRT, SCR, TWT, or MIL-SPEC? Is it any wonder that people think engineers speak a foreign language?
Silly as initials often seem, in reality they are a useful form of highspeed communications as soon as they gain a functional acceptance. Look at the word "laser." In a relatively brief time it was coined and accepted. Yet it's a fully functional word, one that clearly means Light Amplification by Stimulated Emission of Radiation.
Recently, we at Sylvania dipped into the "alphabet soup" and came out with a few initials of our ownECG. You may have noticed that we've been using these initials in our recent ads and publicity. They stand for Electronic Components Group, and I'd like to briefly discuss what they mean to you.

To hegin with, they represent a complete change in our sales organization . .. a change made strictly in the best interest of our customers.
\Ve've combined the advanced capabilities of our diverse electronic facilities into one marketing team. The result is an engineering-research-sales organization that delivers information and service from an integrated team of specialists in semiconductors, tubes, microwave devices, readout systems and special components. Compare it, if you will, to one-stop shopping. We feel that an organization of this type is the only practical means of fulfilling Sylvania's role as a major participant in the growing demand for research, development, production and maintenance projects for both industry and government.
Prior to this change, we had separate sales teams for our Semiconductor and Electronic Tube divisions. The two sales forces were calling on essentially the same customers. Some customers were dealing with at least two Sylvania representatives and often with separate policies. Now, as a customer, you can discuss your needs with one man who is familiar with policies, prices, delivery, techni-

cal specifications, and applications for all Sylvania electronic components.
ECG also means that less of our customer's time is taken up in buying Sylvania components, a saving that is valuable to any specifier, particularly if he is concerned with diverse needs. In addition, our Product Marketing department has been strengthened to furnish additional technical and application strength on all products.
We in Sylvania look upon our Product Marketing department as a logistics organization supporting our front-line sales group. The sales organization, therefore, represents any and all electronic components made by Sylvania Electric. In so doing, it is in the best position to advise you on which product to use, whether it be solid-state or vacuum. As a result, we're confident that our customers now receive the best product, service, and advice available today.
r&t~ R. G. LYNCH

S Y L V A N I A SUBSIDIARY OF

Gr-r:l E

GENERAL TELEPHONE & ELECTRONICS . J.&

NEW CAPABILITIES IN: ELECTRONIC TUBES · SEMICONDUCTORS · MICROWAVE DEVICES · SPECIAL COMPONENTS · DISPLAY DEVICES

Circle Numbers Corresponding to Product Item
D Please have a Sales Engineer call

~~ HOT LINE INQUIRY SERVICE
Need information in a hurry? Clip the card and mail it. Be sure to fill in all information requested. We'll rush you full particulars on any item indicated.
You can also get information using the publication's card elsewhere in this issue. Use of the card shown here will simplify handling and save time.

WANT TO SAVE MONEY BY USING GUDEBROD LACING TAPE? .
YOU DO IT HERE!

Harness tying may be a relatively minor operation. But it also can be a major cost drain. Lacing tape is one of the smallest costs in the harnessing operation but with Gudebrod Tape you can save dollars in making harnesses. Knots tie easier, workers say they almost tie themselves, knots stay tied, the harness workers can go right on with the harnessing without having to go back for re-tightening. Workers like to use Gudebrod Tape. You cut harnessing time-you have fewer rejects. All of this works for you in saving money on cable harnesses-that's why it pays to specify Gudebrod Lacing Tape, the original flat braided tape. Prove these statements in your own harnessing department-give Gudebrod Tape a comparative test.

-ANOTHER MONEY SAVER
The first hand tool specifically engineered for continuous wire harnessing. Handle holds bobbin, feeds tape as needed, grips tape for knotting. Speeds, eases harnessing. Has paid for itself in a day in many pl ants.

CABLE LACING INFORMATION:
When you need help on knots, on spacing, on the type of tape to use-Gudebrod is your one best source for information. We have over 200 different lacing tapes in stock, for temperatures up to 1500° F. or down to -100° F., bum proof

tapes, tapes that do not outgas in vacuum, color coded tapes, cut lengths, tapes of nylon, Dacron*, Teflon*, spun glass, silica fiber. Ask for a copy of our Product Data Book.
*Du Pont Registered Trade Mark

Area Code 215, WA 2-1122

UDEBRDD BROS. SILK C0.1 INC.
~~~
12 SOUTH 12th STREET, PHILADELPHIA, PENNSYLVANIA 19107

Electronics I August 23, 1965

Circle 35 on reader service card

35

Today,
a general-purpose resistor, a semi-precision resistor, and a precision resistor 1ust became the same thina.

11ew c s111es lrom CORlllll&:

36

Electronics I August 23, 1965

llew CORlllllG®
cs111e Resistors
Dive vou precision stability, reliabililY, 1, 2 and 5% tolerances, 100 ppm T.C.

All of which boils down to this. Only one component to specify, buy and stock. One component you can use for general-
purpose, semi-precision and precision use alike. One component that satisfies two military specs, as a look at the table quickly reveals. And you still get all the performance advantages of CORNING Glass-Tin-Oxide film resistor construction. Now for your tests. At our expense. Return coupon for samples.

PERFORMANCE CHARACTERISTICS

Chorocteristics

New CORNING C-Style Resistors

Mil·R-226848

Te~rature Rating
Wattage C 4 (Rl07S) Resistars. 51 ohms to 150K Wattage C 5 (RL20S) Resistoro, 10 ohms to 499K

70°C 'A Yi

70°C y,
'A

125°C 1/10
y,

70°C 'A Yi

load life l:,. R

1.0%

0.5%

0.5%

2%

Design Tolerance 6. R

-2 to + 4%

- 1 to +2.5%

-1.5ta +~

Temperature Coefficient from -55°C to +175°C

±100 ppm

±200 ppm

Dielectric Withstanding Voltage 6. R

±0.10%

±0.50%

Moisture Resi stance 6. R

± 0.50%

oJ=l.50%

Short Time Overload 6. R

±0.25%

±0.50%

Temperature Cycling 6. R

± 0.25%

± 1.00%

Effect of Soldering t:,. R

± 0.10%

±0.50%

low Temperature Operation 6. R

± 0.50%

± 0.50%

Shack t:,. R

± 0.10%

± 0.50%

Vibration 6. R

±0.10%

± 0.50%

Terminol Strength 6. R

± 0.10%

0.50%

Voltage Coefficient

± 0.001%/Volt

Shelf Lile t:,. R
*for Type-marked, m.il.1tory lead

Mil·R· 10509 E Charactem.t1.c D

+ o.10%/Year Remtors, specify CORNING NA Style ReS1stors

r--------------------------------,

CORNING GLASS WORKS, 3913 Electronics Dr., Raleigh, N. C. 27604.

Send complete data, test samples of new CORNING®C Style Resistors.

Mil·R· 10509E Characteristic D* 70°C
y, 'A
1%
+200 -500 ppm ±0.5% ±1 .5% ± 0.5% ±0.5% ±1>. 5 % ± 0.5% ±0.5% ±0.5%
± 1.0%

Title_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ __ _ Com pony_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _~ Address'- - - - - - - - - - - - - - - -- - - - - - - - -- - - City_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _State_ _ _ _ __..IP_ _ _ __
CORNING
ELECTRONICS

Electronics I August 23, 1965

Circle 37 on reader service card 37

Df GR£f"i CE"llTICiRAOf
+ 6 3 0.5

~)

DISP!...\Y l ME

ERROR GNAL GAl~

U ROA SIGNU

\.t....·.:.:

..
._ ...
DIGITAL THERMOMETER / TCMPCRATURE CONTR0ll£R
MODEL OTS-1

Visit us at booth 4523 and 4524 at the Wescon Show 38 Circle 38 on reader service card

Electronics I August 23, 1965

August 23 , 1965
Electronics Review Volume38 Nu mber 17

Military electronics

Time of trial
The war in Vietnam drags on through dense jungles and swampy deltas, in mountain gullies and over rocky hills and Hat plains-the wrong place to fight an elusive enemy, but the right place to test new weapons and novel equipment.
The United States military is using this rugged proving ground to experiment with scores of new devices, many of them secret. Some have made the grade, some are still being tested, and still others have been rejected as too fanciful or unworkable.
New headgear. One piece of successful equipment is an eight-ounce radio receiver that is mounted on a soldier's helmet. The grey-green A:\T/ PRR-9 receiver-now being manufactured on an experimental production line by the Delco Radio division of the General Motors Corp.-is said to be able to pick up weak signals that have been attenuated by jungle foilage [Electronics , May 3, p. 64]. Within a month or so, Army officials say, squad leaders in Vietnam will be wearing the receiver-helmets. Some leaders will also carry a lightweight transmitter, the AN/ PRT-4, also made by Delco, which can operate on two voice channels at a range of about two miles.
In areas of very dense jungle, where radio signals are too attenuated for voice-grade communication, the Army will use Morse code because a faint dash-dot-dash transmits better than an equally faint voice-grade signal. Combat soldiers won't have to learn how to read Morse code because Army engineers have designed a miniature device that converts the coded pulses into visual signals and displays them on a tube as letters.
Among other combat radios still undergoing extensive field tests

Morse code converter t ranslates dot-dash-dot into letters.

is a lightweight, single-sideband transceiver with many voice channels. It is intended to filter out the extensive radio~broadcast interference that fouls up military communications. For example, some widely used channels pick up programs from both Radio Hanoi and Radio Peking.
Man or beast? Finding the enemy is the toughest job facing Vietnam's defenders. To detect the approach of the Viet Cong, engineers, some at Texas Instruments Incorporated, have developed sensitive seismographs whose tiny transducers pick up the ground vibrations caused by someone walking through the jungle. The equipment is being tried at the perimeters of airfields and near barracks in an effort to avert surprise attacks.
One big problem, still unresolved, is to determine whose footsteps are causing the ground vibrations. The seismograph's au-

tomatic-alarm system must be tuned, for example, to ignore the passage of small animals but not those of guerillas or, in some cases, wandering cows. Getting a device that can distinguish between the footsteps of man and beast is a high-priority task for the engineers.
Other detection devices being tested by the military [Electronics, June 28, 1965, p. 120; Sept. 21, 1964, p. 32], range from trip wires that ring bells and turn on lights when an intruder hits them to an instrument that picks up changes in magnetic field caused by a trespasser.
Of equal interest is a pulse-type loran D navigation system that aII the allied military services in Vietnam could use. The low-frequency system being tested is expected to provide accurate position fixes for both air, sea and ground forces.
Flunked. Some of the experimental electronic devices tested in Vietnam have been disappointing. One

39

Electronics Review

was a portable proximity-fuse jammer designed to explode enemy shells prematurely.
Proximity fuses are radar devices that are carried in some artillery shells. When the shell nears the ground, the radar senses a strong signal and the fuse ignites the shell, exploding it just before it lands. An off-the-ground explosion causes more destruction over a wider area than a shell exploding at ground level.
The experimental portable device, a scaled-down version of a model that's carried on a threequarter ton truck, was designed to confuse the radar by transmitting a wide range of high-power signals. The idea was to match the frequency of the transmitted signal with the frequency of the fuse's radar and explode the shell long before it reached its target. The bigger model does this , Army officials say, but the portable one apparently didn't have enough power to do the job.
Advanced technology
Monolithic computer
In September, a contract that is expected to prove a landmark in the manufacturing of microcircuit computers will be awarded by the Molecular Electronics Branch of the Avionics Laboratory at WrightPatterson Air Force Base.
The million-dollar contract will be to develop the first "computer on a slice," a type of system that integrated-circuit manufacturers have dreamed of making for years.
The computer is to be built entirely of large arrays of integrated circuits. The monolithic arrays are to have no fewer than 100 circuits, and may have as many as 1,000 circuits. All circuit interconnections are to be located on the array.
In the running for the contract are the Autonetics division of
Torth American Aviation, Inc., General Micro-Electronics, Inc., TWR, Inc., Motorola, Inc. teamed with the Univac division of the Sperry Rand Corp., Texas Instru-

ments Incorporated, Westinghouse Electric Corp., the Radio Corp of America, Litton Industries, Inc., and the Fairchild Camera & Instrument Corp.
MOS or bipolar? The contract competition should help settle a controversy: are conventional integrated circuits made with bipolar devices best for computers, or are metal-oxide-semiconductor (MOS) circuits? Bidders were allowed to choose either, or a combination of both. But they had to be competent in both technologies and justify their choices in terms of reliability, cost, performance and applicability to integrated arrays.
The project officers expect to spend a month evaluating the proposals, which were submitted the week of Aug. 9. But a preliminary reading indicates that most bidders preferred a mix of both types and that they apparently favored MOS for the memory subsystem.
Coincidence. Each bidder was free to chose the type of research system he builds, but the Air Force suggested that it be a general-purpose digital computer that could be used for navigation or to control terrain-following radar in aircraft.
Two of the Molecular Electronics Branch's most important programs are a low-cost inertial-navigation system that will include a low-cost computer [Electronics, May 17, 1965, p. 108) and an airborne phased-array radar made of inte-

grated circuits [Electronics, March 22, 1965, p. 122).
The contractor will have up to three years to build the computer, spending most of the time researching and proving out techniques of making the arrays. The main goals are techniques that will improve system reliability 10 times over systems made with packaged microcircuits, while improving performance and reducing cost.
This should be possible, project officers think, because the intrinsic reliability of an integrated circuit is 10 times as great as the reliability of a system after IC's are packaged and interconnected with wiring. And, they add, packaging doubles the cost.
Computers
Bookbinding
The Alert, the microcircuit Hight computer introduced by Honeywell, Inc., this month [Electronics, Aug. 9, p. 17), has a fast add time of 2 microseconds-but the company is also proud of its fast repair time. vVhere similar computers require an average of 30 hours to repair, Honeywell says, Alert can be made fully alert again in about an hour.
Honeywell's secret is an open book. With 1,199 logic circuits and

IN f - - - - - - - ' IN 2 - - - - - - " " IN 3 - - - - - - - " " IN 4 - - - - - - - -
Typical logic circuit in the Alert. This is a four-input NANO. Multiple·emitter transistor at left replaces usual diodes at input.

40

Electronics I August 23, 1965

Electronics Review

Memory stack (above) can be repaired by using spare words in each plane. Stack is built by wiring board edges (right) and folding up the planes.

a 4,096-word memory packed into less than a cubic foot, the problem was in gaining access to the subassemblies. Honeywell mounted six multilayer logic circuit boards and eight memory boards on hinges, so they can be Hipped like pages for easy tes t and repair.
Quick clip. Isolation of a faulty board is performed by test equipment which itself is computerized. The operator then removes the board and tests it for the bad circuit with another computer that gives him step-by-step instructions. An integrated circuit can be removed by clipping the flatpack leads, and a new one put on with . an automatic welder. Robert Acker, a Honeywell engineer who helped design Alert and now sells it, says a technician can learn to weld in a few hours.
The logic circuits are a new family of high-level transistor-transistor logic (HLTTL) integrated circuits. Instead of the diode logic usually found in front of the transistors in diode-transistor logic (DTL), HLTTL has a multi-emitter

transistor that acts as a high-speed cluster of diodes. Circuit speeds are 40 nanoseconds or less. The configuration is illustrated on page 40. The circuit output is of the bidirectional type known as "totem pole," which increases speed. The top output transistor drives the signal level up; the bottom one pulls th e level down.
Folded memory. The memory, of 4,096 words of 24 bits each , is a read-only, nondes tructive-readout type made of Biax cores. There are eight memory boards , joined end to end with wires, folded up and put into a hinged housing.
Each plane has 32 spare words. A repair job usually consists of finding th e bad word with the tes t equipment, disconnecting it by removing one of the exposed wires at the board edge, and wiring in a spare word. If the memory stack were badly damaged-for example, Acker says, if a bullet went through it-it would take four hours for disassembly and 12 hours to make repairs and put the stack back together.

Book packaging was never a best-seller in conventional computers, because large numbers of circuit boards meant cabling problems. But books are catching on in microcircuit computers, which have relatively few circuit boards. Another computer with a book is the MSP-24 built by Sylvania Electric Products Inc., a subsidiary of the General Telephone and- Electronics Corp. The MSP-24 has 4,000 circuits on 38 pages, in an 18-inch cube. That, plus two memory modules about the same size, make up a computer that can do as much work as Sylvania's old Mobidic field computer, which was housed in a 30-foot van.
Bit of a squeeze
The International Business Machines Corp. has modified its phase encoding technique for storing bits of information on magnetic tape to provide a density of 1,600 bits per inch. Phase encoding was previously used on IBM 's 7340 Hyper-

Electronics \ August 23, 1965

41

Electronics Review

Strips of magnetic computer tape contain equal number of digital bits. Data on shorter tape is encoded with IBM's new phase technique, which doubles digit density.
tape system, which came out in 1961; but the new system, designed as an auxiliary memory for the System 360, can be adapted to take older tapes, with different coding methods-a feature that was not available with Hypertape.
In a phase encoding system, a binary one is represented by a change in magnetic flux from plus to minus, and a zero is a change from minus to plus. The method ensures that a flaw in the tape cannot be mistaken for a mere string of zeroes, as is the case with methods that represent a one as a pulse and a zero as lack of a pulse. Moreover, noise cannot cause a zero to be taken for a one.
However, to represent a string of zeroes, the phase encoding system needs a signal detector that will "blink" at the right times so as not to read a change back to minus as a one.
Timing trouble. Coding systems that represented a one as a change of Aux in either direction and a zero as no change of flux ran into timing difficulties, and the best density IBM could achieve with them was

800 bits per inch-using standard tape.
The new system has nine tracks across the tape, for an eight-bit character and a parity bit. The latter is defined so that there is always an odd number of ones in any character. If one bit should drop out because of a tape flaw, a count of the remaining bits will indicate whether the missing bit was a one or a zero.
The new tape units will rent for from $950 to $1,535 per month, depending on the model. This is about $50 a month more than the comparable 2400 series units previously announced for System 360, and compares with the $950 a month IBM charges for its 729 Model VI tape drives, the workhorse that has been around for several years. Delivery of the new series is scheduled to begin in the spring of 1966.
For an extra $25 a month, the user can have equipment that will allow him to use his old tapes with the new units. This equipment has an old-style detection circuit in parallel with a phase-encoding detection circuit. A signal on the leader of the tape tells the equipment which circuit to use.
Solid state
FETswitch
"It's the switch we've all been looking for," says James Patmore, an engineer at Electronic Associates, Inc., a major producer of analog computers. "It's the first solid state device that can switch as well as a relay at low speeds, and as fast as diode and transistor switches," he adds.
Patmore was talking about field effect transistors and their ability to solve one of the toughest problems in solid state circuits-producing a hybrid analog switch.
Another important consideration, Patmore notes, is that FET's at their current prices of $3 to $5 are cheaper than high-quality relays.
Switching. Electronic Associates will introduce a combination an-

alog-digital computer on Sept. 1 that uses FET's for the key hybridoperation switches. And Beckman Instruments, Inc., recently brought out a computer that uses FET switches.
One of the first to switch to FET's was th e Comcor division of Astrodata, Inc., a relatively small producer of hybrid machines. Comcor beat th e bigger companies by about two years with its FET model. Now, all the big producers are switching with FET's.
Isolation. Low leakage is needed to hold voltages "memorized" on capacitors at various times during hybrid computation. "We found that the high input impedance gives us the same isolation between the switching signal and the signal being switched that we obtained with relays," explains EAi's Patmore.
About the only drawback to FET analog switches is the large "on" resistance. However, according to Patmore, this is not a problem in the hybrid application because the FET switches are inside an implifier feedback loop. The resistance, roughly 100 ohms, is small compared with the amplifier's input resistance. EAi said it is using FET's made by Texas Instruments Incorporated and Amelco, Inc.
In the Beckman computers, the FET drives a double-emitter type transistor switch; while it's more expensive, the combination provides switching signal isolation with low output resistance-less than 10 ohms.
Beckman is using FET's produced by the Raytheon Co. and double-emitter switches made by the Sperry Rand Corp.'s Semiconductor division.
Communications
The silent world
Now that man is developing techniques for working and living in the ocean [see story on p. 111], he is finding the need for talking under water more pressing. For short ranges, sound itself, which

42

Electronics I August 23, 1965

TRW I ner!i
tage 1rre11ula 1v.

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See for yourself what science knowsI Here are results
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ID -T-RW-ZE~ N-ER--..v Mt-F~ R. " C" MFR!v -"B-" -t::.oMFoR.-" A-" ----

,0 --~z ~~ ~~ ~~~-:__z,:,,.:+--~~~+--~~--

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.

2

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8

e "Va CHANGE FROM Va tmA

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Electronics I August 23, 1965

Circle 43 on reader service card 43

Electronics Review

travels through water better than through air, may be more practical than radio waves; the problem is in devising ways of transmission and reception.
Jetronic Industries, Inc., has developed sonic communications gear for Tavy skindivers, which has a range of about one mile, several
Talking under water with Yack· Yack, an inexpensive device for the hobby market ...
times farther than earlier sonic
equipment. This month, Jetronic
received a $165,000 contract to build 210 sets. The 2112-pound, battery-powered device, called the AN/PQC-lA, consists of a microphone and a transceiver, built into a helmet; atop the helmet is a dish antenna that radiates and receives sound waves.
Jetronic engineers decided to transmit the sounds at between 8,000 to 11,000 cycles per second because sound at that frequency travels farther through the water than voice-range frequencies-30 to 3,000 cycles per second. The transmitter boosts the frequency of the speaker's voice, and the receiver tones it down.
The avy has developed shipboard equipment, not made by Jetronic, to communicate over the side with any skindiver wearing the instrument.
For fun , too. Jetronic currently has no plans to produce the device for the commercial or hobby fields

- largely because of the price, about $800 a set. But another company, Y Square Marine, Inc., has developed a simpler and cheaper underwater set for the hobby market. Y Square's device, called the Yack-Yack, costs about $100. It doesn't boost the frequency of th e voice and its range is limited to about 100 feet. On the other hand, the person being talked to doesn't need receiving equipment to hear the message. The sounds are heard through bone conduction, the way some near-deaf persons hear.
The developer of the Yack-Yack, Yujiro Yamamoto, who is president of Y Square, says the major problem that had to be overcome before sound could be adequately radiated into the water was the design of a speaker system. Cone-type speakers are nearly useless under water, he explains, because most of the audio energy is lost when the waves
... and with more costly Navy device that has a range of about one mile.
are reflected back by the relatively noncompressible fluid.
Vibrating case. Yamamoto designed a transmitter that is impedance-matched to the water; the entire transmitter case vibrates to

generate omnidirectional audiofrequency waves.
To protect the skindiver from swallowing water while he's talking, the Yack-Yack ceramic throat microphone fits inside a full face mask. All the electronics are solid state discrete components. However, integrated circuits are being considered for future models, the company says.
For an extra $28.J, Y Square offers a transceiver that can be hung over the side of a boat for communication with the diver.
Microelectronics
Testing the MOS
Only two integrated-circuit manufacturers, the General Instrument Corp. and General Micro-electronics, Inc., are selling lines of metaloxide-semiconductor (MOS) circuits. But evaluation programs now going on at several companieschiefly the Sperry Gyroscope Co., a division of the Sperry Rand Corp., and the Autonetics division of North American Aviation, Inc.may change the picture, and bring other manufacturers into the MOS field.
Since December of last year, Sperry has been studying the performance of conventional monolithic (double-diffused) IC's and MOS circuits in identical applications. On Sperry's decision may depend not only on that company's IC purchases, but also on those of other major users.
Swing the scales. Sperry does not at present use MOS circuits, and won't decide on future use for six months to a year. But Sperry engineers are impressed by two advantages of the MOS: its capacity for more functions in the same chip area, and its low power dissipation. Other factors being equal, these two could swing the scales to the MOS.
Sperry recently tested both types of IC's in a frequency division application. A modified Schmitt trigger and a Darlington amplifier, both built with discrete compo-

44

Circle 45 on read er service card-+

Half the cost of conventional multi-position switches and loaded with multiple performance design advantages. Spectrol ' s miniature switches give you performance characteristics tor printed and micro-circuit applications never before available in so small a package at such low prices. Reliable, trouble free operation is assured by the unique construction features of the type 88 rotary indexing switches.
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Price 1to9 pieces....$3.75

Call your nearest Spectrol distributor for immediate off· the-shelf delivery at factory prices, or write for complete specifications. Spectrol also manufactures a complete line of trimming potentiometers and turns -counting dials.

1704 South Del Mar Avenue San Gabriel, California
"See us at WESCON, Booths 2409-10."

Electronics Review

A. ZT Protector Boots let you handle special cabling problems quickly and economically in your own plant. Designed for two or more separate connectors or break-outs, they zip on in seconds and are easily re-opened for inspection or modification . Made of polyvinylchloride, ZT Protector Boots can be permanently seal ed if desired.
B. ZT SPLICE COVERS protect spliced cable areas and zip closed. Ends can be clamped or taped to the cable to create an effective moisture barrier.
If you 'd like more information on ZT Splice Covers or assistance on intricate design con figurations requiring special cable protection, just call or write. Zippertubing®engineers are at your service!

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46

Circle 46 on reader service card

nents, were used as controls; th e IC's were used as flip-flop counters between them. Both MOS and conventional circuits performed well, despite fluctuations in the supply voltage and variations in temperature from -50° to +125° C. But the conventional integrated circuits used 80 milliwatts of power, compared with only 20 for th e MOS. Both circuits are rated at 10 megacycles.
The comparative power consumption bore out the results of recent activity at General Micro-electronics, which put MOS circuits into a navigational computer originally built with conventional monolithic circuits. The MOS's cut power consumption from 65 watts to 7.
Autonetics has already decided to use MOS integrated circuits, but it declines to say where. It has b een building its own MOS circuits as well as buying them , and is currently looking at MOS circuitry containing complimentary transistors.
A close look. Litton Industries, Inc., the Hughes Aircraft Corp., and the Nortronics division of the Northrop Corp. are also evalu a ting MOS circuits , as are the Raytheon Co., the Lockheed Aircraft Corp., Astrodata, In c., and th e American Machine and Foundry Co. But none of these companies is condu ctin g a program as intensive as Sperry's.
Migratory gold
The use of gold-aluminum bonds in high-reliability military circuits has been severely criticized. The bonds are due to become even more unpopular at \Vescon.
Reliability experts from the Autonetics division of orth American Aviation, Inc., will strongly recommend that such circuits eliminate gold-aluminum bonds. Autonetics made a comprehensive study of bond failures, using electron microprobes and x-ray diffraction analysis as part of the Minuteman-2 reliability program. The findings will be discussed at a \i\Tescon symposium.
Hidden failures. The study veri-

fied the long-standing susp1c10n that the migration of gold into the aluminum is a more serious cause
of failure than purple plague [sec related article on p. 98]. Plague problems caused some circuit manufachirers to get off the gold-aluminum standard.
Plague can be kept under control by careful processing and temperature control, but migration is "cancerous," says Donald Cummings, head of high-reliability component engineering in Autonetics ' Data Systems division. "Once migration starts, it will continue."
The formation of gold-aluminum intermetallics between the lead end and the aluminum bonding pad causes stresses and cracks to appear around the intermetallics. The interface apparently is the path along which th e gold migrates by diffusion from the edges of th e intermetallic bond into th e adjacent aluminum stripe that connects the bond to circuit components.
Time-sequence photos show th e gold diffusion creeping along th e stripe. As th e gold migra tes, it leaves a void around the bond which may separate th e periphery of the lead end from th e stripe and in time completely separate th e lead from th e circuit.
If th e lead is separated from the stripe, but not from the circuit, the failure may b e difficult to de tect and analyze. A voltage pulse, such as a tes t pulse, can temporarily heal th e failure.
The cure. Th e problem was discovered, Cummings says, b efore Minuteman systems were produced for operational use, and a cure has b een found. If the aluminum is oxidized before th e leads are bonded, th e bond failure rate is only 0.000025% per thousand hours at 50° C. Apparently, the oxide blocks migration of the gold into the aluminum. Depositing a third metal atop th e aluminum can also block the migration.
This finding resulted from an investigation of why circuits made by some manufacturers failed far less than others. All suppliers were baking out th e circuits at 425 ° C in nitrogen before bonding, but some of them also used air. Bonds made to unoxidized aluminum failed 100

Electronics I August 23, 1965

times more frequently. Nevertheless, Cummings says,
"Now it is recognized by all suppliers that you don't use gold-aluminum in high reliability circuits." Using other metals is the only sure cure for both purple plague and gold migration. All of Autonetics' suppliers have switched, or will switch soon, to gold wires on gold films, or aluminum wires on aluminum films .

Instrumentation

Under pressure
'What began as a quest for a transducer that would measure the pressures of dental fillings as they dried and expanded, ended with an instrument that can withstand up to 75,000 pounds per square inch of pressure and temperatures up to 400°C. Conventional transducers break clown after pressures of 40,000 psi.
Frank F. Stucki, an engineer at the Lockheed Missiles and Space Co., did more than develop this rugged transducer that's no bigger than a pinhead; he's walking around with two of them in his teeth. They were placed there by a researcher at the University of California Dental School, where the whole thing started when someone began wondering about the properties of dental fillings.
The Lockheed transducer is made from a ferrite material and shaped like a doughnut, 30 mils in diameter. A drive coil and an input coil are wound around the core and the drive coil is also connected to either a square-wave or sine-wave current pulse source.
Digital output. Aside from its ruggedness, several other features make the miniature core transducer unusually attractive for some measuring jobs. For one, the device generates a digital output and can sample rates up to about 350 kilocycles; conventional transducers, on the other hand, produce an analog output, hence their response is inherently slower.
Secondly, the core device has no mechanical hysteresis, so it could make a series of accurate readings even if the pressure were to rise and then fall; all semiconductor
Electronics I August 23, 1965

Sangamo offers 72 hour delivery on all prototype encapsulated inductors.

With Sangamoencapsulated inductors, your assembly time is shortened. There's no need to solder individual

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SANGAMO ELECTRIC COMPANY. P.O. BOX 359. SPRINGFIELD, ILLINOIS 62705
Circle 47 on reader service card 47

Electronics Review

Amelco FET Differential Amplifiers combine high input impedance with minimum tracking error!

Until now, poor tracking was the price of high input impedance when using field effect transistors. Now Amelco is producing the 2N3921 with tracking better than 1011. Vj°C and input offset of less than 5 mV. The price for this high input impedance, with tight tracking, is extremely reasonable. Where less stringent temperature characteristics are allowed, the lower priced 2N3922 is available with tracking better than 25 µV j°C.

Prices
2N3921 2N3922

1-49 $30.00 $22.00

50. 249 $20.00 $14.50

GUARANTEED VALUES 2N3921
a TRACKING= 10 p.V/°C
a OFFSET = 5 mV a LEAKAGE= 0.25 nA
a TRANSCONDUCTANCE""'
1500 µmhos
A NOISE FIGURE= 2.0 db

AM ELCO SEMICONDUCTOR
DIVISION OF TELEDYNE, INC.
1300 TERRA BELLA AVE., MOUNTAIN VIEW, CALIFORNIA

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48

Circle 48 on reader service card

and tunnel diode pressure transducers are a!Fected by hysteresis to some degree.
Internal pressures. In one in-
house application, Lockheed is using the device to keep tabs on the pressures that build up inside the protective plotting materials which arc used to encapsulate complex circuits. ·with knowledge of the various internal pressures, the circuit designers can safeguard delicate diodes and other devices from being crushed as the potting material hardens.
Lockheed also plans to use the transducer in airplane tires; by vulcanizing them inside the rubber, and attaching probes to the devices, aeronautical engineers would be able to measure the pressure exerted on the tires when a plane lands. Conventional crys tal tran sducers wouldn't stand the heat during vulcanization of the rubber.
Customers. Although Lockheed
has no current marketing plans, engineers there foresee a potentially large market in the field of natural resources. Since the device has a low cycle time (as little as 10%) and doesn't use much power (as little as 50 milliamperes), small solar cells would be sufficient to power the transducers in out-ofthe-way lo cations. For instance, water conservation officials might use the device to predict the amount of spring run-off in a watershed area.
Electronics notes
· Coaxial cable. The Bell Tele-
phone Laboratories has developed a coaxial cable with twice the capacity of any long-distance broadband system now in commercial use. The system, called the L-4, can handle 32,400 voice channels over routes several thousand miles long, using transistor repeaters every two miles.
· Mortar radar. The Army Elec-
tronics Command at Fort Monmouth, N. J., is seeking bids for a radar system, weighing no morE' than 400 pounds, that can track enemy mortar fire and calculate the launcher site.
Electronics I August 23, 1965

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Electronics I August 23, 1965

CUBIC
CORPORATION
SAN DIEGO, CALIFORNIA 92123

Circle 49 on reader service card

49

45689723 75938216 24867513
s 13.e~~l'I
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Circle 50 on reader service card

Electronics I August 23, 1965

Washington Newsletter

Robbing Peter to pay Paul?

August 23, 1965
Headed by Brig. Gen. Hal D. McCowan, a special task force is making an on-the-spot check of United States military supplies in S~mth Vietnam. Reporting directly to Defense Secretary Robert S. McNamara, the team will check on the need for emergency equipment, assess the time required to supply it, and spot potential bottlenecks.
No complaints of shortages of equipment have come from Vietnam. But there have been plenty from Washington, where Sen. John C. Stennis (D, Miss.), chairman of the Senate ·Preparedness subcommitee, continues to charge that American units in the U.S. and Europe are being stripped of vital equipment to supply Vietnam. Stennis says these units don't have enough backup stock; that they're running low on communications gear, especially radios and antennas; and that there is an inadequate reserve of helicopters, trucks and even firepower equipment.
The administration request for an additional $1.7 billion for defense spending should meet some of the needs. And McNamara says he'll ask for more money in January.

Westinghouse gets Australian contract

Australia's plans for a new type of flexible coastal defense and early warning system has brought a $4.7-million electronics order to the U.S. Two air-transportable, 40,000-pound radar stations will be built at the Westinghouse Electric Corp.'s Defense and Space Center in Baltimore for delivery in late 1967. Australian military officials said last week that the stations will save the cost of rimming the continent with permanent installations. Equipment will be airlifted from one side of the country to the other or set up on interior landing strips as defense needs require. The 30-foot antenna dishes will be inflatable, and the electronics rugged and lightweight. Plessey Radar, Ltd., of England has the prime $15.5-million contract. Westinghouse will build the radar portion of the system, and Marconi, Ltd., will supply computers.

Independents gain in Autovon battle

The Defense Communications Agency this month invited two more independent telephone companies-in Montana and North Dakota-to build and operate sophisticated telephone switching centers, in their respective states, for the Automatic Voice Network (Autovon).
The decision is a small but significant victory for independents who have been battling the American Telephone & Telegraph Corp. for a bigger share of the multimillion-dollar business expected from the Defense Department's worldwide military communications system. .
The stakes are high. Each of the 65 centers to be built in the continental United States is expected to cost between $2 million and $5 million; the revenue from Autovon in the U. S. has been projected at $90 million a year.
Equipment for the AT&T-owned stations will probably be produced by the Western Electric Co., the manufacturing arm of the Bell System. But victories for the independents might brighten the competitive picture for other producers of communications gear.
Originally, 53 centers went to AT&T, five were assigned to independents and the remaining seven were contested. The agency has already rejected the contention of independents in Kansas and Ohio that AT&T

51

Washington Newsletter

has no legal right to compete for the centers, clearing the way for threatened court action. In Minnesota, a suit has already been filed.

Who'll manage federal computers?

Despite the Budget Bureau's assurances to Congress that a new set of interagency procedures will guarantee efficient management of computer use, some congressmen aren't convinced.
A Joint Economic subcommittee wants a congressional review next year of all federal policies on electronic data-processing equipment. The committee says there's disagreement between the General Accounting Office, which wants a central agency to manage computer use, and the Budget Bureau on how much control the central agency should have.

U.S. funds sought for crime study

Even before the riots in Los Angeles shocked the nation, Gov. Edmund Brown of California made a first step toward obtaining some of the $10 million that will be available should Congress approve the Administration's Law Enforcement Assistance Act.
Brown has been circulating the Justice Deparhnent with copies of an engineering study made by the Space-General Corp. on crime and law enforcement in California. He hopes to get federal aid for a follow-on study that will spell out the policies, procedure and electronic hardware needed to remedy some problems cited by the first report.
The systems engineering study, first of its kind, cost $100,000. It emphasized the police need for improved communications systems, computer identification of criminals and stolen cars, and quicker transmission of fingerprint and arrest records from one city to another.

GE reportedly wins C-5A engine pact

Although defense officials aren't talking, industry sources say that the General Electric Co. has won the jet engine contract for the C-5A transport, over the Pratt & Whitney Aircraft division of the United Aircraft Corp. Last week, the Pentagon stopped funding the development and testing of the P&W engines, while continuing funds for General Electric. Three companies-the Lockheed Aircraft Corp., the Douglas Aircraft Co. and the Boeing Co.-are competing for the air-frame contract. Until Defense Secretary Robert S. McNamara chooses one of them, defense officials won't say whose engines they are buying. The airframe contract is expected to be announced in mid-September.

Gemini 5 may hold space lab's fate

The Air Force seems to be depending on Gemini 5 to bolster chances for a military man-in-space mission. It is expected to hold off sending its recommendation on a manned orbiting laboratory (MOL) and on selection of a contractor until the Gemini flight is analyzed.
Two factors will be watched with special care: the astronauts' physical condition and their ability to distinguish objects on the ground. If Astronauts Gordon Cooper Jr. and Charles Conrad Jr. show no symptoms of space sickness after this longest of all manned space trips by the United States, doctors see no human limitation on manned flight.
High reconnaissance ability would give another boost to a military mission. The astronauts will try to distinguish and photograph 14 landmarks and several man-made geometric patterns on the terrain. They will also make general observations of terrain, railroad and highway networks.

52

Electronics I August 23, 1965

~IE'L's

Helps you Hurdle RF Barriers

Newest in LEL's line of antenna pream·plifiers, the RTP-3 offers a choice of RF center frequencies between 10 and 400 me with noise figures of 2.5 to 4.0 db depending on RF frequency. Minimum bandpass is 10 me at 3 db, and wider bandwidths are available. Overall gains are as high as 23 db. Designed for pole mounting,

this preamp is completely weatherproof and operates from a remote power supply. Like all LEL RF equipment ... amplifiers, converters, mu !ti-couplers, receivers ... the RTP-3 offers the advantages of customengineering at close-to-production-line prices.
Send now for full information.

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Electronics I August 23, 1965

Circle 53 on reader service card 53

New N·channel FET by law-noise amplification

+ I2V RF CASCOOE AMPL IFIER

+ 12V + 12V

TO LOCAL OSCILLATOR
1 .001

RF INPUT
figure !. FM front end employs Tl 2N3823 FET's. Circuit developed by H. H. Scott, Inc.

~ TUNED LINE <i0 - 100 u> SHIELD,

~ TUNED LINE <io- 100 !I )

LOC.
osc.
INPUT --~ · 5011

i:.~

!SY

(ADJUST FOR 10 = 4.0·.)

Figure 2. 500 me amplifier using Tl 2N3823 FET gives power gain of 11 db (5 me bandwidth). Maximum spot noise figure is 4.5 db .

IF OUTPUT SO u
Figure 3. 555 me mixer employs Tl 2N3823 FET. Conversion gain is greater than 7 db for 10 me bandwidth . Noise figure is less than 6.5 db.

0
-2
~-4
=<[ -6
0
> 5

0 W ~ W~IOOIW~O~O
TIME- NANOSECONDS

Figure 4. Photograph of active element of Tl 2N3823 FET. Notice symmetrical, interdigitated geometry.

Figure 5. Unretouched sampling scope photograph illustrates zero storage til)le and fast response of Tl 2N3823 FET.

Tl cannot assume any responsibility for any circ11i1s sho wn or represent that they are free from palent i11fri11gem enl.
54

Texas Instruments has made a "significant contribution " in field-effect transistor technology - an N-channel FET capable of lownoise performance from I 0 cycles to more than 500 megacycles. The new FET is priced for consumer and industrial applications while offering the high reliability required for military and space use.
The new FET, designated 2N3823 , is ava ilable in production quantities in a four-lead T018 package. A du al matched pair, typed TIS 25-27, is in a low profile T0-5 type package.
Circuit designers can now take advantage of the unique characteristics of FET's in high frequency circuits and a wide range of other applications when cost is critical. Characteristics of FET's include reduced cross-modulation, low noise and high input impedance.
Reduced Cross-modulation
Since they follow ··square law" behavior, 2N3823 's give very little cross-modulation when used as RF amplifiers or mixers. The H. H. Scott FM tuner front end shown in Figure 1, for example , exhibited JH F sensitivities of 1.6 to 2 microvolts with cross-modulation rejection of from 96 db to more than I 00 db. Two strong signals, equivalent to more than 50 mv per meter and separated by 800 kc, can be fed into the input without having any measurable intermodulation products generated. This performance is at least equivalent to the very best tube front ends and is more than 20 db better than the best bipolar transi storized front ends.
A 200 me cascade amplifier, using 2N3823 's, generated less th an one percent cross-modul ation when a I 000 µ.v , 200 me signal and a 200,000 µv , J50 me signal were combined.
VHF and UHF Performance
The 2N3823 is the first FET that provides useful amplification at vhf and uhf. Figure 2 shows a 500 me amplifier that gives 11 db gain and a bandwidth of 5 me. Typical spot noise figure is only 4.5 db (with an equivalent source conductance of approximately 13 millimhos.) No other FET's can approach this performance. Circle 190 on the Reader Service card for an application note describing this circuit.
FET's also make excellent vhf and uhf mixers. Figure 3 shows a 555 me mixer that gives conversion gain of more than 7 db and a bandwidth of l 0 me. Local oscillator frequency is ,600 me and output to IF is 45 me. Noise figure is 6.5 db (measured with 12 db image rejection and an IF amplifier with 3.5 db noise figure).
Low Noise
Figure 6 shows optimum noise figures for the 2N3823 at various frequencies. Notice that the FET is better than two of industry's most
Electronics I August 23, 1965

Texas Instruments gives from 10 cps ta beyond 500 me

widely used bipolar transistors at all frequencies up to more than 500 me. The amplifier shown in Figure 3 has a maximum spot noise figure of only 4.5 db at 500 me.
High Input Impedance
Input impedance of the 2N3823 is high. This high impedance, plus the low leakage of 10 picoamps typical at 25 °C, with Yes of 10 volts, gives circuit designers many benefits.
In switching applications the high input impedance of FET's permits a virtually infinite fan-in - leading to important reductions in component requirements.
FET's also simplify design and reduce component requirements in both linear and switching applications. In choppers, untuned amplifiers and similar applications, interstage transformers can be eliminated, reducing weight and cost as well as permitting improved performance. Coupling capacitors can be greatly reduced in size or eliminated altogether, particularly in low-frequency applications.
Symmetrical Geometry
Symmetrical geometry (Figure 4) means that drain and source leads are interchangeable. This allows both electrical and mechanical replacement of older devices with non-standard lead configurations.
Zero Storage Time
In Figure 5 a sampling scope photograph shows the zero storage time of FET's. This characteristic is important in switching applications such as digital logic gates.
Other electrical characteristics of this device include high transconductance (3500 to 6000 micromhos) and low input capacitance (4.8 picofarads typical). Extremely small, interdigitated geometry and an epitaxially deposited junction area make possible the exceptional performance. Circle 191 on the Reader Service card for 2N3823 data sheet.
Tl Offers Complete FET Line
TI. a pioneer in field-effect transistors, offers 16 families of P-channel and eight families of N-channel FET's. You can select a device from this broad line to meet any requirements.
New Book on FET's
Here is the first definitive work devoted exclusively to the theory, application and behavior of field-effect transistors - the latest addition to the TI Microlibrary of electronic books. It is cloth bound ; 130 pages with 140 illustrations. The title: Field-effect Transistors. Author is Leonce J. Sevin, Jr. Publisher is McGraw-Hill and price is ten dollars. Send orders to : Texas Instruments Incorporated, TI Microlibrary, Mail Station 7, P. 0. Box 5012, Dallas, Texas 75222.
Electronics I August 23, 1965

!Or-~~~~~~~~~~~~~~~~~~~~~~~~~~~-,
9

BIPOLAR /HIGH

BIPOLAR FREQ. Tl FET's~HIGH GAIN _ _ _,__ _,

2N3821

BIPOLAR

2N3822 2N3823
R, =IM n

HIGH GAIN

Tl 2N3823 FET
R, =IOOO H

10

100

!KC

!OKC IOOKC IMC IOMC IOOMC !KMC

FREQUENCY IN CYCLES

figure 6. Optimum noise figure vs frequency Tl 2N3823 FET vs widely used bipolar transistors.

LINEAR

APPLICATION DC ampl1f1ers
Low frequency amphf1ers
Opera t ional ampl1 f1ers
Medtum and high frequency amphf 1er s
Mn:ers- 100 me and up
logic gates

ADVANTAGES OF FErs
Zero TC low dnft l ow notse Small couplmg capacitors Low device noise High mput impedance Summing point essen tially zero Low device ne»se Less loading of transducers Low cross·modulat1on Low device noise S1mphf1ed ci rcuitry low mixing noise low cross·modula11on
SWITCHING
Virtua lly 1nf1n1te fan -in S1mphf1ed circuitry Zero storage time Symmetncal

APPLICATION Choppers
A·D converters multiplex switch· ing (arrays) and sample hold
Relay contact replacemen t
Voltage vanable resistor

ADVANTAGES OF FET' s
Zero offset Low leakage currents S1mpl1f1ed circuit ry Ehmmates mput transformers
Improved 1solat1on of input and out put
Zero offset Symmetnca l S1mphf1ed c1rcu11ry
Sohd·state rehabt l1ty Zero offset Symmetnca l No inductive spiking No contact bounce High repetition rate
Sym metncal Solid -state reliabihty Functions as variable resistor Low na1se Improved resolution

Figure 7. Advantages of using FET's in various applications.

TEXAS INSTRUMENTS
INCORPORATED
13500 N . CENTRAL EXPRESSWAY
P. 0. BOX 5012 · DALLAS 22 . TEXAS

S EMICONDUCTOR PLANTS IN BEOFORD, ENGL.ANO · N ICE, FRAN CE· CALLAS, TEXAS

21414
55

there are 500 people
standing behind this connector
to assure you of the reliability, depth of experience and service you want from your connector source
Progress Webster Corporation has long been a supplier of MIL Spec (10544, 12520) audio and power connectors to the electronics, communication and defense industries. Now they offer this same kind of dependability in their new line of PW Series (MIL-C-26482) miniature connectors. The same rigid testing procedures, the same exhaustive quality control, the same scrupulous attention to customer service and requirements stand behind the new PW Series. If you require MIL-C26482 connectors, your first order with us could well change your buying habits!
MIL-C-26482
PROGRESS WEBSTER

PROGRESS WEBSTER CORP. 5 Bridge Street, Watertown, Mass. (617) 926-2100

56 Circle 56 on reader service card

Electronics I August 23, 1965

Here Are The First Low-cost Plastic Silicon Transistors With ..No compromises" In Performance
And Reliabilitr !

There's a lot of "low-cost" transistors around

Bu_t, reliability is only part of the "no compromise"

these days that got that way by virtue of sacrifices story!

mI in performance and packaging quality. That's why I \ it's refreshing to find devices like Motorola's new 2N3903-6 series silicon annular Unibloc* plastic transistors - " no compromise" units that offer

Each of these four new Motorola annular plastic transistors is a full-spec , full-performance device . .. with no compromises to cost.
For example, the 2N3903-6 series offers such features

Actual high performance with topnotch reliability . . · as;

Size and at low cost, too!

· Gain (Beta) - Specified from I 00 µ.A to

Take, for instance, the rugged , high-pressure-molded

100 mA .. . and points in between!

plastic construction used to form the single-unit encapsu-

· High Voltage - 40 Volts (BYcEo)

lation of " Unibloc" devices. It provides a uniform, dense,

· Complete h-parameter specifications

solid plastic package free of voids (and leaks) in which

· Completely specified switching limits

moisture can accumulate. It also provides unusual physi-

. . . including t.., ti1, t, , and tr!

cal strength for intern al leads and connections and im-

You'll find the Motorola 2N3903-6 series literally sets

proved heat transfer characteristics. Because they use the the "performance standard" for low-cost transistors for

solid transfer molded single-unit package approach , there industri al and consumer product applications.

ca n be no incompatibility between header and poured ep-

You can also take advantage of the fact that this key

oxy capping. (You may be familiar with the separation series features device-to-device complements - the NPN

that sometimes occurs at the interface of a two-part plas- 2N3903 and PNP 2N3905 and the NPN 2N3904 and

tic package under thermal cycling.)

PNP 2N3906.

Type

h,. @ BV«o 10 mA/1 V

c ··

fr

100·

@

@

Up

5V 10 mA/20V Price

One more point.They're made by the annular process. That means you get the low-leakage, long-term stability that will set your equipment performance apart from the

2N3903 40V 50-150 4 pf 250 me $ .50

crowd.

2N3904 40V 100·300 4 pf 300 me

.55

2N3905 50V 50·150 4.5 pf 200 me

.50

2N390Ci 40V 100·300 4.5 pf 250mc

.55

Try these devices in your most demanding circuits. Your local Motorola representative would be happy to supply samples for evaluation and complete specifications
on each type.

Electronics I August 23, 1965

Circle 57 on reader service card 57

Credit's good here ... over 1,000,000 times

This new, attractive card reader can register over a 1,000,000 insertions of various credit-type cards and translate the card information to electrical output circuits.
It's fast . .. it's reliable · · · it's foolproof!
Compact and rugged, the A-MP* Credit Card Reader can be used as an input device for credit handling sys· terns, validating systems, security systems or other data collection and control applications. Available in either desk top or rack mount models, this versatile reader is supplied with either manual or automatic operation . Long, trouble-free operation is assured by the quality features built in this rugged unit. Electrical and mechanical interlocks provide foolproof operation. Redundant contacts with exclusive double wiping action insure a clean electrical surface for reliable sensing.
Here's a sample of other quality features which are engineered into this new product.
58 Circle 58 on reader service card

· Semi-automatic or automatic card ejection
· Reads plastic credit-type cards 2 Ys" x 3%" · 250 ma, 500 V operation
· Pre-wired or wired to customer's specifications · Redundant contacts with double wiping action for
reliable sensing · Long life-over 1,000,000 cycles · Compact size-5" x 6" x 2%"
Check the applications this item might find in your system, then write for complete information.

·Trademark of AMP INCORPORATED
Ir -A- - - -l- -\-l- -l- -p- - - - , -l - - - - - 1I 1NDUSTRIAL

I

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I I N C 0 R p 0 RAT E D I DIVISION I

I Harrisburg, Pennsylvania I

I

l----------------~------J

A·MP* p1oducts and enaineerina assistance avai lable through subsidiary companies in: Australia ·

Canada · Enaland · France · Holland · Italy · Japan · Mexico · Spai n · West Germany

Electronics I August 23, 1965

August 23, 1965 I Highlights of this issue
Technical Articles

Good teamwork from scr's:
page 60

During the past year, the silicon controlled rectifier has moved into a variety of new applications that range from golf carts to steel mills. But about all the current a single pellet can handle is 300 amperes. One way around this limitation is to connect scr pellets in parallel. In one assembly, 30 pellets, each rated at 20 amps, were able to handle 550 amperes, extending the potential of the scr.

Measure it, but don 't touch:
page 65

Optical interferometry has rarely been used as an industrial measuring technique because it has so many limitations. A microwave interferometer, on the other hand, is not bothered by such limitations. A new microwave device can precisely measure objects that can't be touched because they are too hot or too delicate, or are vibrating at high frequencies, or are in a vacuum.

Specia l reportThe over lay transi stor:
page 70

As communications, telemetry equipment and data links are pushed into higher frequencies, they outstrip the capabilities of conventional solid state components. The overlay transistor has suddenly sprung into prominence because it handles relatively high powers at high frequencies-for example, as much as 10 watts at 400 Mc. In this three-part article: Part I examines the multiple-emitter geometry that gives this power transistor high-frequency capability; Part 11 describes some typical circuits and applications of the device; Part 111 reports on other geometries such as the interdigitated approach to high frequency at high power.

Million dollar 'screwdrivers':
page 88

----- -·E·..l.·e-c···t~r.-..o.·.. nics

Electronic equipment has grown more complex; so have the instruments to test it. To perform the required tests in a rC'ascmablc

amount of time, the military has turned to

computerized test equipment. :\'ASA also

uses automatic equipmC'nt, and industry is

leaning that way too. For this issue's cover,

Richard Saunders photographed the auto-

matic checkout equinment the Navy puts

on aircraft carriers to test avionics gear. This system was

built by PRD Electronics, a division of Harris-Intertype Co.

Coming · Safeguarding tantulum capacitors against a-cripple September 6 ·An optical computer for instrumentation
·An electronic way to examine reconnaisance pictures · Raising the frequency ceiling on solid state
power switching
59

Solid state
Good teamwork from scr's

Parallel operation of small silicon controlled rectifiers and resistors gives more current handling capability than possible with largest commercially available single scr

By Reuben Wechsler
Motorola, Inc., Phoenix, Ariz.

About all the current that the largest single-pellet silicon controlled rectifier can handle is 300 amperes; a limitation that has often been a problem. Higher currents, however, can be controlled by using a technique often employed with conventional rectifiers-parallel operation. In a test, one parallel arrangement of 30 controlled rectifier pellets, each rated at 20 amperes, handled 550 amperes.
Parallel operation of a number of small scr's nwans not only higher current handling capabilities b11t better thermal characteristics and potentially lower cost. In the case of conventional small-pellet rectifiers, high-volume production brought their cost way down and now it is sometimes less expensive to combine a number of small pellets rather than use one large one. This will probably happen with small scr's as their use increases.
Small low-value resistors (typically 5 or 10 milliohms) are also needed to use an assembly of scr's effectively; one resistor is placed in series with the cathode lead of each scr.
Current sharing
Some of the problems that were solved in the case of conventional rectifiers (by close matching) still exist for scr's; the principal one is current sharing during forward conduction. In addition, scr's have the problem of simultaneous gating and current sharing during the turn-on interval and while several techniques, involving transformers

The author

Reuben Wechsler was recently appointed section manager, appliance applications and is currently assisting customers in the design and use of power control circuitry. Prior to joining Motorola, he was with the Standards Laboratory of the Electronic Industry Association.

and reactors, overcome these difficulties they are not entirely satisfactory.
Using small resistors in series with the cathode leads of the scr's in the parallel assembly is a simple and economical solution to both the current-sharing and the gating problems. A typical multicell arrangement containing only two controlled rectifiers is shown on page 61. The controlled rectifiers, although selected for similar characteristics, were not identical. The equalizing (compensating) resistors are designated R.. The arrangement was tested with and without the equalizing resistors.
The group of curves, opposite, depicts operation with and without equalizing resistors. One pair shows that with a total load current of 40 amperes, the anode current of one scr is 18.9 amperes while that of the other is 21.1 amperes.
A second pair of curves shows how two 10mill iohm equalizing resistors improve performance; with them the respective scr currents arc 19.4 and 20.6 amperes.
By using conventional copper wire, wound into coils to form nonlinear resistors, the difference between the two current levels can be reduced to less than 1.5%; this is seen in the bottom two sets of the group of curves. In these circuits, the resistors present a low impedance until a specific current level is reached; above this value of current the resistance increases sharply, thus directing some of the curren t from one scr to the other. All the curves show that as current sharing improves, the total forward-voltage drop increases. This means a greater power loss and the generation of adclititonal heat in the resistors. If the assembly is to be packaged as a unit, the heat crea'.ed by the power dissipated in the equalizing resistors must be removed. Another way to overcome mismatch between scr's is to add extra scr's to the assembly; they operate below the assembly's maximum capability, eliminating the possibility of failure caused by unequal current sharing. These are

60

Electronics I August 23, 1965

Resistors improve scr performance

u; 22
w
.aw.:.
::E 21
<l

aaIzw-:: 20
::> u

w

Cl
0 z

19

<l

18

WITHOUT EQUALIZING RESISTORS

u; 22
w
.aw..:
::E 21
~

Iaazw-:: 20

u::>

w

Cl
Cz l

19

<l

18

R : 10MILLIOHMS, LINEAR
11.244 I

u; 22
w
wa:
0..
::!: 21
<l

Iz aewr: 20
::> u

w

Cl
0 z

19

<l

18

FORWARD VOLTAGE DROP (VOLTS) Re.= 5 MILLIOHMS1NONLINEAR

FORWARD VOLTAGE DROP (VOLTS)

~ 22r-------------------~ w
a:
w
0.. ::!: <l

1z aaw : :
u::> w
~ 191--- - - - - - - - - - - - - 1,i-.-.,,,...,..- - - - - - - - - - - l

<l

I

1a.___ _ _ _ _ _ _ ___..___:=_10M_ILLI_ OHM__S:1_ NON_LIN_E_A__R_.

FORWARD VOLTAGE DROP (VOLTS)

FORWARD VOLTAGE DROP (VOLTS)

Fo;.ir sets of curves illustrate the operation of a pair of para! lei-connected silicon controlled rectifiers. Those at the top, left, show that operation without equalizing resistors produces considerable current unbalance-one scr carries over two amperes more than its companion unit. The other curves show how equalizing resistors reduce the current unbalance. The MCR808-2 is a commercially available dual scr manufactured by Motorola , Inc.

factors to be considered when deciding on the trade off between the closeness of the match, the number of scr's, and the size of the equalizing res istors.
The value and type of equalizing resistors is importan t in a parallel arrangement for although their purpose is to aid in dividing the total anode current equally among all the multicell scr's in parallel, they are not essential if no individual device is operated beyond its limitations. Ideally, the resistors should have zero resistance for currents up to the maximum that the device is capable of handling, and infinite resistance above that value of current. Although such ideal characteristics are not attainable, they can be approached with copper resistors, wound as coils. It can be seen in the comparison curves on page 63 that the nonlinear characteristic provided by a coil-shaped copper resistor is considerably superior to the linear char-
+v
Equalizing resistors connected to the cathode leads of the scr's help distribute the current load more evenly .

acteristic obtained with conventional resistors. Because of their coil construction, the copper
resistors are self-heating. The positive temperature coefficient of copper is moderately high (approxi-
mately 0.04% I 0 C). Other materials with higher
positive temperature coefficients could be us ed to make resistors with voltage-current characteristics that have sharper knees than provided by copper.
Halting thermal runaway
If a number of controlled rectifiers are parallcleci without the use of equalizing resistors there is the possibility of thermal runaway and it is most lik( ly to occur with a poor heat-sink arrangement. \\ 'Ji.: n thermal runaway occurs, the scr having the lowest forward drop will receive the greates t share of the current; its temperature will be high er than that of the other devices. This increase in heating could decrease the forward drop which, in turn, would cause a greater share of th e current and additional heating. Under certain conditions this process could become regenerative. In any case, it is undesirable because of the inequality of the stress on the devices.
The use of equalizing resistors with positive temperature coefficients tends to prevent th ermal runaway. If the increased voltage drop across the equalizing resistor, caused by an incremental increase in current, is made equal to or greater than the decrease in the forward drop of the scr with which it is associated, thermal runaway is impossibl e.
In des igning equalizing resistors, there is much

Electronics Aug t!st 23. 1965

61

Array of scr's is shown with resistors attached to cathode leads of individual rectifiers. The entire unit is covered by a metal case.

freedom in the trade oH between resistor length and diameter. Reducing the wire size, of course, reduces the length of wire necessary for a given resistance. But reducing the wire size also reduces the power handling capability of the resistor. For safety, the resistor power-handling capability should be greater than that of the scr.
\Vhen choosing th e cathode resistor, current equalization is not the only factor to be considered. The resistors also help assure triggering of all of the scr's in the assembly; this function can be understood with the aid of the characteristics

-=.1ov

o,

+

V6T=1.00V

!GT= 20mA

In this dual-scr circuit, D1 has a lower triggering voltage than D2. After D, turns on, its gate-to· cathode voltage rises, helping to trigger D2.

shown on page 63. One set of curves is for a typical scr operated without a cathode resistor. When the scr turns on, the gate-to-cathode voltage jumps to a level determined by the anode current. The gate current then has little influence on the gateto-cathode voltage. The curve for a one-ampere load shows that th e gate-to-cathode voltage increases by only 90 millivolts under this operating condition. This increase, even though it is small, is useful , since it helps trigger the unfired scr.
Suppose two scr's, both having characteristics similar to those shown in the set of curves just discussed, are connected in a parallel arrangement like the one at th e left. The gate trigger voltages for the devices are matched to within 50 millivolts. If the gate source voltage is increased slowly, scr D1 will trigger when the source voltage reaches 1.02 volts. Its gate-to-cathode voltage will then jump to 1.09 volts. The gate of D 1 will th en act as a trigger for the gate of D~, turning on D 2. Even if more than the minimum drive is provided, this step increase in the gate-to-cathode voltage is important since it tends to unload the trigger source

62

Electronics I August 23, 1965

MCR 808-2
10
8
<
E
Iz -
LU
a: a:
::>
u 6
LU Ict Cl
4
2

ANODE CURRENT= 1 AMPERE 5 10 20

--ANODE CURRENT WITHOUT EQUALIZING RESISTORS
ANODE CURRENT WITH 10-MILLIOHM EQUALIZING RESISTORS

5 10
20

0.2

0.4

0 .6

0 .8

1.0

. 1.2

1.4

1.6

GATE-TO CATHODE VOLTAGE (VOLTS)

Typical scr gate charatceristics: The level to which the gate-to-cathode voltage goes after triggering depends on the anode current and the equalizing resistors.

as each scr fires, steering the trigger current to the other unfired scr's.
The mutual gating effect of the equalizing resistors can be increased by making them inductive since the di/ dt during the turn on of each device will cause an even greater voltage drop across the n:'s istor.
0.80r----------------------.

0.70

0.60
"~' 0.50
0
> - 0.40 w
(!)
c':ti 0.30
0
> 0.20
0 .10

10 (LINEAR)
5

00

4

8

12

16

20

24

28

CURRENT (AMPERES)

Characteristics of equalizing resistors: The selfheating copper resistors provide sharp increases in resistance at high anode currents. This accounts for the high voltage drops which they produce at high currents.

Examining the gate voltage-current character· istics when a cathode equalizing resistor is used (see the characteristic curves on this page), shows that the inclusion of the resistor further increases the gate voltage to the other scr. The increase, of course, is greater at higher currents since it is a voltage drop. A greater gate voltage step is desirable since it reduces the gate trigger-voltage matching necessary to insure gating of all devices in an assembly. For this reason the resistor value should be chosen not only on the basis of a forward-drop matching trade off, but also to improve gating characteristics.
Another effect of the equalizing resistor is worth mentioning. At very high gate currents, the resis tor tends to equalize gate currents in much the same way that it equalizes anode currents. This is important for assemblies where a large amount of total gate drive is applied from a low impedance. Too much drive could cause excessive gate current in some of the scr's.
Both the physical arrangement and the method of assembling the scr's in parallel are important. It is desirable to keep them closely coupled th ermally so that with an adequate heat-sink arrangement, they all will be at approximately the same temperature. Individual scr's should be mounted

Electronics I August 23, 1965

63

on a single plate with a low thermal resistance between devices.
One of the principal advantages of the multicell over the single-cell technique is its better thermal characteristics. In a multicell assembly, the heat sources are separated and spread out over a fairly large surface area that provides much better heat removal. For example, in a single stud package the single die would be mounted directly over the stud, the longest thermal path to the heat sink. In a multicell stud assembly the scr's may be arranged in a ring over the heat transfer surface.
Improved di/ dt capability is another advantage of the multicell approach. The paralleling of many small devices, each having its own gate contact, is essentially a distributive gate that overcomes the principle gating problem present in large singlechip devices.
Precautions
Cathode equalizing resistors can prevent the possibility that one scr will remain in the off state while the other scr's are on, but they do not assure that all the devices will turn on at the same time. Simultaneous turn-on is important to avoid

D1

· WITH MINIMUM GATE DRIVE
· WITH GATE OVER DRIVEN
2 3 4 s s 1 e 9 10
TIME (MICROSECONDS)
With minimum gate triggering-voltage applied to the MCR808-2, one scr turns on and reaches a peak current of 300 amperes before the second unit is fired. This potentially damaging condition may be avoided by increasing the gate drive.

;:;;

I~- 300 > ~ 250

PEAK ANODE CURRENT= 500 AMPERES

:;C( g 200

.... g 150
:r
I-
C(
.u 100
0

.....-IGr=17 MILLIAMPERES

~ 50

0
~ OOL_-,J.~_l_~...L~L:~=:;~;;;;;;;;~::::::i~::;;;:!;;;;;;;;;;;J

0.5 t.O t.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

TIME (MICROSECONDS)

Increases in gate drive-current increases the speed at which the anode-to-cathode voltage falls off following triggering of the scr.

high currents or high di/ dt that can cause hot spots in some of the scr's during the turn-on interval. This is illustrated by the current characteristics figure. If two scr's are connected in parallel with equalizing resistors and the gate source voltage is increased slowly until one triggers, the first reaches a high peak-current value before the second is turned on.
Simultaneous turn-on can be assured by increasing the gate drive. The second set of curves in the figure shows the two cathode currents for the same scr's, but with the gate drive current increased by a factor of 10. The devices now share the total current very closely at all times. It isn't enough to make sure that there is enough current to trigger the scr's simultaneously. Gate drive effects on turn-on time and the anode-to-cathode voltage fall time must also be considered. Each scr should receive enough drive to minimize delay time; an approximate value of total drive for the assembly is about five to ten times the gate trigger current of the least sensitive scr multiplied by the number of scr's in the assembly.
Rise time
Still another gate-drive consideration is rise time. To keep delay time at a minimum before turn-on occurs, the required drive must be applied to the gate quickly. Trigger amplitude and rise time may be traded off. A rise time no slower than 50 to 100 nanoseconds is recommended.
At this point it would be wise to discuss holding current, which is the minimum current level required to sustain conduction. It is not desirable to match holding current as well as the voltage drop and triggering voltage, because the additional testing would increase the cost of the assembly substantially. When an assembly, built with devices that do not have matched holding currents, is operated at very low gate currents some of the scr's may drop out of conduction while the others remain on. 'i\Then this happens, the anode currents of the conducting devices will most likely trigger the remaining devices into conduction.
By closely matching gate trigger voltages, it is possible to prevent those scr's with higher holding currents from turning off when their anode currents fall below the holding level. If the voltage present at the gates of these scr's is equal to the triggering voltage, scr's operating at currents below their holding currents will not revert to the blocking state.
Should the combination of the gate trigger-voltage match and the equalizing resistors fail to prevent a blocking condition, it would be advisable to avoid operation at very low currents except, of course, when turning the unit on or off.
The disadvantages of high gate drive, minimum operating current and the larger size of an arrangement of scr's operating in parallel seem to be outweighed by their higher current-handling and di/ dt capabilities and their better thermal characteristics.

64

Electronics I August 23, 1965

Instrumentation

Measure it, but don't touch

Improving on optical techniques, microwave interferometer measures objects accurately even when they're too hot to handle-or too delicate, or kept in a vacuum

By Carl F. Augustine and John E. Ebert
Weinschel Engineering Co., Gaithersburg, Md.

As an optical technique, interferometry is more than a century old. It is so well established that, by international agreement, it is used to measure the accepted standard of length, the orange-red radiation of krypton 86; one meter is defined as 1,650,763.73 wavelengths.
But as a laboratory tool the optical interferometer has severe limitations. It requires a good source of monochromatic light. It requires a target whose face is a good reflector, and the light beam must be perfectly perpendicular to the target's face, because the optical system's sensitivity is so low that it needs all of the reflected light. Also, when a light-interference pattern finally is received, it still must be converted into electrical signals before the pattern can be interpreted.
A microwave interferometer has distinct advantages over its optical counterpart. It works with targets of any material, electric or dielectric; alignment is not critical because the electronic instrument is sensitive enough to react only to phase

The authors

Carl F. Augustine is engineering section head at the Weinschel Engineering Co. He is responsible for the design and development of standards for microwave production. He has seven patents pending.

John E. Ebert, executive vice president and chief engineer at Weinschel, has 20 years' experience in the microwave field. He supervises all of the company's research and development.

difference, ignoring the amplitude of reflected energy; its output is electrical from the start, so it doesn't have to be converted; and the microwave instrument is easier to calibrate and to automate.
An interferometer produces and measures the interference between two wave trains coming from the same source.
Precise measurements from a distance
One of the new instrument's most important uses is for precise measurements of objects that can't be touched-because they're too hot, too delicate, or perhaps in a vacuum, or vibrating at a high frequency [Electronics, May 17, p. 30].
The microwave interferometer can detect surface irregularities as small as one microinch, and measure the period and amplitude of complex mechanical vibrations with an accuracy of one microinch at frequencies as high as 20 kilocycles per second. It can also measure, accurately to 10 microinches, gradual dimensional changes that result from stresses or thermal expansion.
The measuring instrument detects changes in the phase of a reflected 35-gigacycle signal. For targets less than one inch away, the signal is fed directly from a waveguide output on the sensing head; for more distant targe t~ the sensing head is attached to an elliptical antenna. In both cases, the energy is focused on a spot approximately 0.15 inch in diameter.
Th e target can b e any surface that exhibits good microwave reflectivity. Modern antennas permit the microwave energy to be focused so efficiently that a targe t surface of only a few square millimeters can be measured accurately two feet away.
The basic instrument
A microwave interferometer consists basically of five parts: a radio-frequency signal source, phase comparator, transmitting and receiving an-

Electronics I August 23, 1965

65

Exterior of microwave interferometer. Module at left contains power supplies, amplifiers, synchronous detectors, volt meter and sweep generator. Micrometer-driven phase shifter, klystron and other microwave components are mounted on rear of the eliptical antenna at right, which is used for distant targets.

tenna, reference path and a micrometer-driven phase shifter; all are shown on page 67. The reference path is the standard against which are measured phase changes along the path between the source and the target and then back to the phase discriminator. This phase change depends upon the target's position; therefore the interfer-
ometer can ·sense and measure small movements of

the target in any direction. The phase shifter provides a method for cali-
brating the instrument so that the target's motion in microinches can be read out visually on a meter.
An operator uses the shifter, which is a variable short circuit and acts electrically like the target, to alter the incoming signal to correspond to a change in the distance to the target. Then he ad-

35 Ge KLYSTRON

DIRECTIONAL COUPLER

TRANSMISSION

HYBRID

1------ilCAVITY

t--""'~=--tJUNCTION

CIRCULATOR

DIFFERENCING TRANSFORMER

HYBRID JUNCTION

CIRCULATOR

CRYSTAL/ DETECTORS

OSCP. OUTPUTS

100KC SAWTOOTH
GENERATOR

MOVABLE SHORT CIRCUIT

METER ANO RECORDER OUTPUT
Microwave interferometer includes crystal detectors, circulators, difference transformer and a 100-kc sawtooth generator. Transmission cavity determines frequency of input pulse to first hybrid junction.

66

Electronics JAugust 23, 1965

l I

PHASE SHIFTER

i

OUTPUT

Signal related to target distance is developed in the microwave interferometer as a result
of phase difference between signal reflected from the target and that of the reference path.

OUTPUT VOLTAGE

The Hybrid junction
In a microwave interferometer, the second hybrid junction, in combination with the crystal detectors on the output p01ts, acts as a phase detector. It derives an output voltage that is related to the target distance, d. This comes about in the following way:
If the vectors E1 and E2represent the input sig-
nals to the reference and measurement arms of the microwave bridge, then, as a result of the transfer characteristic of the hybrid junction, the signals in the output ports are:
Ea =
Their magnitudes are:

= where e 41T<l/ ft. and ft. is the free space wave-
length of the microwave signal. These signals are then detected by crystal detectors having square law characteristics and subtracted in a .combining network. The final output signal takes
the form:

Interferometer output voltage, plotted against target
displacement, gives a curve that is basically a sinusoid. The length of one cycle is determined by the wavelength of the radio-frequency signal in air. Operation of the interferometer is restricted to the linear regions of the sinewave, sections I and 11 near null, to achieve the best accuracy. At 35Gc, this usable portion
corresponds to a target motion of 0.05 inch.

where k is a second-order variable that is a function of the signal level and detector characteristics. The output voltage is basically sinusoidal. A full cycle of the sinusoid is equivalent to a target displacement of 0.17 inches at 35 Ge, and the peak-to-peak voltage swing occurs during a displacement of 0.085 inches.
.1.

justs the meter so that a full-scale deflection corresponds to the known distance.
In designing the instrument, careful attention must b e paid to frequ ency stability, length of the radio-frequency paths, packaging, and operation of the directional couplers, phase discriminator and calibrated phase shifter.
The complete interferometer
The block diagram on page 66 shows an in strument that operates at 35 Ge. Frequency stability is achieved by sweeping a kl ys tron 's frequency across the resonance of a transmission cavity at 100 kilocycl es; therefore th e input to the first hybrid junction is a narrow pulse whose frequ ency is determined entirely by the transmission cavity.
This hybrid junction acts as a power divider; its properties are not critical. Th e ferrite circulators direct the energy toward th e target and movable short circuit. Energy, refl ected from target and short circuit, reenters the circulators and is

fed to the two isolated ports of the second hybrid junction.
The second hybrid junction may be considered a simple sum-and-d ifference device with the output to one diode detector b eing th e phasor sum of the two r-f inputs while th e oth er output is th e phasor difference. The crystal diodes arc essentially square-law detectors and their outputs are:
Output l= IE1+E2l 2 = h 2+E22+2 E1E2 cos 8 (1)
Output 2= IE.1-E2 12= E12 +E22 -2 E1E2 cos 8 (2)
wh ere E1 and E~ are the two phasor inputs , E1
and E ~ th eir magnitudes, and 8 ' is th e phase angle b etween th em.
The combining network form s the difference between th ese two detector outputs; this difference is direc tly proportional to th e cosine of the phase angle between them. If the phase shifter is set so that this angle is nearly 90°, the cosine approaches zero and becomes very nearly proportional to

Electronics \ August 23, 1965

67

Reso,ution and stability
How small a change in the target's location can the microwave interferometer detect? The answer depends on four factors: klystron power, klystron noise, crystal detector noise and mechanical stability. The effect of noise can be an alyzed as follows:
The phase detector output may be expressed as

E o

=

E; s

.
Slll

4?rd
--,.~ ,

(I)

where E" is the peak input signal voltage. In general, the operating point should be set at the steepest part of the output-versus-displacement characteristic, for example around the null condition. Then small incremental ch;mges in distance, 6d, can be related with sufficient accuracy to output voltage changes by

(2)

Jz rn-5
z
IU
~ rn-6
u
a"'.....
Q. w-7

). (4KTB) 112
l:id= 4.,,. PsM
l:id =MINIMUM DISPLACEMENT
B =DETECTION BANDWIDTH
). =CARRIER WAVELENGTH

I..U... ~ 10-8
It.> IU I-
~ 10-9

z

i 10-10.__~----:'::------'----..l.-----1

10

100

1,000 10,000

DETECTION BANDWIDTH -CYCLES

Resolution capability of microwave interferometer is limited by the detection bandwidth, as is shown by graph relating the parameters of equation 5. The figure of merit of 40 was selected as typical for the crystal detector.

= To find the apparent displacement caused by
crystal nQise, let 6Eo En and, rearranging equation 2

ild = -~ En 4 7r E.

(3)

The signal-to-noise ratio at the crystals is

E.

P.M

-E;;- = ~4KTB

(4)

where P, is the signal power incident on the crystal, M is the detector crystal figure of merit (units of amperes, watts-1, ohms!) and KTB is the product of Boltzman's constant, temperature and bandwidth. From equations 3 and 4, the apparent displacement due to noise is therefore

-,., (4KTB)1 '2
ild = 4 ?r MP.

(5)

Equation 5 assumes that the crystal generates white noise. This is not the case for frequencies below about 80 kc. At low frequencies , the noise has a II f characteristic and is larger than the value assumed in Equation 4. The system described in this article utilizes 100-kc modulation to avoid the increased lower frequency noise.
For our purpose, klystron noise can be divided into amplitude-modulated and frequency-modulated components. The over-all effect of klystron amplitude modulation is not severe because of the balanced arrangement of the phase detector.

If the two crystal detectors are well matched, the effects of amplitude modulation of a high quality klystron oscillator is not a limiting factor.
However, the incidental frequency modulation is important when the path length of the reference arm differs from that of the measurement arm. The phase difference and the phase detector output will then be frequency-dependent. To
obtain the magnitude of this effect, assume that the waveguide sections of the two arms are identical and the total path length difference is d, the distance between the antenna and target. The equation relating the pertinent variables is

Llw = Ll{3C
d

(6)

where Aw is the change in klystron frequency, C, the propagation velocity, and 6/3 is a specific change in phase angle for a target displacement
of one-microinch. At 35 Ge the significant constant is 89 kc per
microinch per centimeter. This means that if d is equal to one centimeter, the klystron frequency must change 89 kc to cause the phase detector output to give a voltage change equivalent to one microinch of motion.
In the present system, the largest value for d will be about 43 centimeters when the far field antenna is used. This means that the klystron's long-term stability must be approximately one part in 106 to maintain the interferometer stability at less than 10 microinches. Measurements have shown that the cavity stabilization technique produces the required frequency stability.

901 -e. Therefore, the output varies linearly with
the change in phase angle of either r-f signal input to the second hybrid junction. At 35 Ge, a wavelength in air is 0.338 inch and the linearity of electrical output as a function of target motion is excellent over a range of about 0.050 inch.
The phase shifter is attached to one arm of a microwave phase bridge. External mechanical standards, such as gage blocks, can be used if a more accurate calibration is required.

The output signal for static tests is displayed on a front-panel meter whose sensitivity can be adjusted to a maximum of five microinches per division or set for a full dynamic range of 0.07 inch. For vibration or other dynamic tests, the output signal can be displayed on an oscilloscope.
The noise level for both displays is equivalent to 10 microinches. An external bandpass filter can be used to increase the sensitivity of dynamic tests to about one microinch by restricting the instru-

68

Electronics I August 23, 1965

ments, or with an oscilloscope being used to observe high-frequency displacements. When an oscilloscope is used, the percent modulation of the 100-kc carrier as a function of phase-shifter setting is the basis for calibration. Appropriate filters can be inserted between the instrument's output and the oscilloscope, these filters can also be used with the phase shifter to measure the peak-to-peak displacement of each harmonic of a complex vibration.

Extending range with antennas

Three different antennas can be

used to extend the instrument's

applications. The "near field an-

tenna" is an open-end waveguide

with a wedge of dielech·ic insert-

ed for matching. It is used when

the antenna can be brought close

to the target. An elliptical dish

antenna sharply focuses the radi-

ated r-f energy to a beam about

0.15 inch in diameter at a point

17 inches in front of the dish, so

that if the target is placed at the

point the instrument's full sensi-

tivity is achieved.

A third possible antenna is a

horn. This requires a larger tar-

get than either of the others, but

Elliptical antenna focuses microwave energy to a point 17 inches away. It is used for measurements on targets that are relatively inaccessible. Heat sink, at top of assembly at rear of antenna, dissipates heat from klystron.

target position is less critical. A crucial requirement of any
microwave instrument in precision work is mechanical stability

of the waveguide circuits. Any

ment's bandwidth to a narrower range than its full small changes in a circuit's location or dimension s

capability of d-c to 20 kc.

can cause drift and be indistinguishable from target

One oscilloscope output consists of the 100-kc motions. In the instrument described , rigidity is

carrier whose a mplitude is proportional to phase achieved by milling all waveguide circuits from a

change. The second output is the rectified envelope single block of brass. This procedure eliminates an y

of th e carrier. The synchronous detector output is noise and drift that might b e generated b y micro-

a low-freque ncy signal that can be positive or nega- phonics and thermal exp ansion.

tive depending on th e phase; and is suitable to be There are many more application s for the micro-

the input to a cha rt recorder. If the target oscil- wave interferometer. It can measure expansion co-

la tes, th e recorder must h ave adequate frequency efficients of materials at high temperatures. Al so.

response to follow th ese oscillations. If not, the since it operates independently of the material un-

oscillations can be viewed with an oscilloscope on der consideration , the instrument can b e used to

either output.

measure the thickness of the dielectric coatin gs on

Calibration

metallic surfaces and owr-all thicknesses. and to detect Haws.

vVith the phase shifter, the instrument can be

calibrated easil y a nd accurately in terms of microinches of motion per volt change in output. vVith this techniqu e, accuracy of ca libration is practically unaffected b y vari ations in the a mount of energy refl ected ~rom the target. This direct calibration is applicable when either a recorder or a voltmeter is b eing used to observe low-frequ ency displace-

References
I. W. Culshaw, " H igh Resolution Millimeter Wave Fabry-Perot Interferometer, " IRE Transactions on Mierow.ave Theory and Techniques, Vol. MTT-8, No . 2, pp. 182-189, March , 1960. 2. W. Culshaw, " Further Consideration of Fabry-Perot Type Resonators," IRE Transactions on Microwave Theory and Techniques , Vol MTT· lO, No. 5, pp. 3 31 ·339 , September, 1962 . 3. Proceedings of Symposium on Interferometry, National Physical Laboratory, Teddington , England , June 9 -11 , 1959.

69

Solid State
The overlay transistor, part I: New geometry boosts power

Multiple emitters with high periphery-to-area ratios are connected in parallel to give high current-handling capability for semiconductor operation at high frequencies.

By Donald R. Carley, Patrick L. McGeough, and Joseph F. O'Brien
Radio Corp. of America, Somerville, N. J.

At high current levels, a transistor's emitter current is concentrated at the emitter-base edge; exploitation of this fact has led to new geometries for power transistors that operate at high frequencies. To make the periphery-area ratio as high as possible, the size of the emitter was reduced, and to provide the necessary current-handling capability, a number of emitters were connected in parallel. The overlay transistor has a periphery-area ratio greater than 14 .to 1 in some cases; the device has high current-handling capability as well as low capacitance and short carrier transit time between emitter and collector.
Present commercial overlay transistors have from 16 to 216 emitters, while developmental types have as many as 408. They are so small th:\t a lead cannot be directly bonded to the emitter, and an aluminum layer is used to conduct current to the lead. The device is called an overlay transistor because of the position of the aluminum layer directly above the emitter matrix and base region.

Emitter geometry

The current flowing through the base region of

a ·junction transistor, between the emitter and the

collector, causes a voltage drop that produces maxi-

mum forward bias at the edge of the emitter closest

to the base contact. The center of the emitter, then,

injects almost no current.

This edge-injection phenomenon has led to de-

sign changes of the emitter from the circle type to

the line type to the comb type, and finally to the

overlay structure.

The maximum frequency of oscillation fmnx of a

junction-transistor structure is:

,~ ] ¥. 1

f11111x = (PG) V:. F = 47r [ rbb c Tec

(1)

where PG is the power gain, F is the frequency of operation, rbb' is the base-spreading resistance, Cc is the collector capacitance, and Tee is the emitter-tocollector transit or signal-delay time. The latter two terms are very small.
This equation was derived from analysis of the transistor as a low-level class A amplifier, but it can also serve as a guide to performance in the more usual class C circuit encountered in high-frequency power applications. To a first approximation, the frequency fmux at which the power gain is unity is independent of collector area. Although the collector capacitance Cc is directly dependent on the collector area, the value of rbb' varies inversely with area. For example, if the stripes and base of an interdigitated or comb-type structure are made twice as long, the capacitance Cc is doubled, but rbb' is cut in half. Thus,
The authors
Patrick L. McGeough is currently engaged in the design of a I-watt, I -gigacycle overlay transistor. Since joining RCA in I96I, he has worked on the design and development of high frequency transistors, including the 2N3375. He received an electrical engineering degree from the Newark College of Engineering in I961.
Joseph F. O'Brien is investigating new geometries and structures for high-frequency power transistors. He was responsible for the development of the photolithographic technology required in the fabrication of the 2N3375. O'Brien received a degree in physics from Fordham.
Donald R. Carley received the I965 David Sarnoff Outstanding Achievement Award for the design and development of the overlay transistor. In I960, he was promoted to his present position of engineering leader in the industrial transistor design activity. He joined RCA in I957 after graduation from the University of Michigan with a B.S. in physics.

Electronics August 23, I965

71

1

COLLECTOR

MATERIAL

N+ SILICON -

P SI LICON C=:::J

N SILICON C=::J

ALUMINUMc::::::J

p+ SILICON -

OX/OE

c::::::J

Cross-section of the 2N3375 silicon overlay transistor. The aluminum paths (shown in green) carry the emitter and base currents to the bonding wires. The aluminum path which conducts the emitter current is separated from the base region by silicon oxide insulaton . The vertical dimensions are not drawn to scale.

the length of a transistor can be extended and the power dissipation and current-handling capability
improved without any increase of the r1111' cl" product.
The collector-to-emitter transit time T,.'" has four components : the charging time of the emitter capacitance, the transit time through the ·base, the transit time through the collector d epletion region, and the charging time of the collector capacitance and the collector series resistance. The last term is 1Jsually negligibl e in devices made with triple-diffused or epitaxial construction. Of the remainder, only the emitte r transit tim e T,. is current-dependent, as shown by:

= = - T 0 r,, C00

kT q 1-,.C , . "

where r,. is the emitter resistance, c. a is the emitter
capacitance, k is Boltzmann's constant, T is the temperature in degrees Kelvin , q is the electron charge and I,. is the emitter current. However, if the emitter edge is increased proportionally as the area of the e mitter is increased , the fraction C,." I,. remains a constant. vVith suitable scaling, transistors can be enlarged to increase power-handling capability without deterioration of frequency response.

Overlay structure

The new emitter electrode structure called the overlay was first used commercially in th e power transistor 2N3375. Introduced in 1964, this transistor has 156 emitters tied together b y diffused and metalized regions. This approach provides a considerable increase in the emitter edge-to-area ratio and a proportional reduction in the input time constant. This established a new level of performance for high-

power high-frequency transistors by permitting a 3-watt output at 400 \1c.
The desired overlay structure is fabricated by means of carefully controlled diffusion and by th e use of precise photographic processes. By photolithographic techniqu es, areas are opened in the oxidized silicon surface to permit the subsequent introduction of phosphorus or borDn dopant for the formation of electrical junctions. Vapor-diffused techniques pro~ duce the diffusant profile shown on the next page.
The 2N3375
The 2 3375 is a planar epitaxial npn transistor. It has a collector area of about 400 square mils, an emitter area of 40 square mils, and an emitter edge of 300 mils. The precise toforances need ed to define the patterns on the oxide layer required five separate masks. Spacing between lin es in patterns from th ese successive masks is as small as 0.1 mil. The photomasks must have accurate pattern registration over a large area, edge definition of+ 0.01 mil or less, and high contrast (opaque emulsion areas and clear emulsion-free areas).
Techniques were developed for applying the photosensiti ve material on the silicon wafer in films thin enough to provide hi gh resolution but thick enough to provide protection of oxide during etching. ( Thin coatings of emulsion tend to develop defects.) The design and construction of a precise alignment fixture was also necessary to provide accurate control of movements and sufficient pressure for intimate con tact b etween the wafer and the glass mask.
Fabrication of overlay devices b egins with large silicon wafers with a thin epitaxial layer. Approxi-

72

Electronics August 23, 1965

PHO SPHORUS OIFF US EO EMITTER

EPITA XIAL SUBSTRATE (PHOSPHORUS OR ANTIMONY I

--- - - - . . , / CROSSOVER

I

I

I

1018

I

I

,--- BORON DIFFUSED BASE

I I

I

I

I

1015

--

-

-

I
- -,- -

- -I

COLLECTOR

I

I

0

.02

.07

0.1

0.66

6.0

X jE

Xje

DISTANCE FROM SURFACE (MILS l

Diffusion profile for the 2N3375. Curves show impurity concentrations at various depths below the top surface. The n-material emitter depth for this device is 0.07 mil; the p-material base depth is 0.1 mil. Impurity concentration in collector is uniform to a depth beyond 0.66 mils.

mately one thousand 2N3375 transistors are processed simultaneously on each wafer. ( Another overlay type, the 2N3866, has more than 3,500 transistors on each wafer.) Prior to the etching of patterns into the oxide, the wafers are cleaned and coated with a light-sensitive emulsion, such as one of th e Kodak photoresist materials. A few drops of the resist are placed on the silicon oxide layer coating the surface, and the wafer is mechanically whirled to produce a layer of emulsion 3,000 to 4,000 angstroms thick. A photomask is then placed .in contact with th e emulsion layer and exposed. The clear areas in the photomask permit passage of light to expose and thus polymerize emulsion on the wafer. ·
The wafer is then placed in a solution to develop the image and remove all unexposed emulsion. The remaining resist is furth er polymerized b y h eat to protect the oxide during etching; the unprotected areas are then etched to remove the silicon oxide and produce the desired pattern for the subsequent diffusions.
The five main ste15s in fabrication are shown by the five photographs on page 74. In the first step, a pattern is provided for the base.

grid lines. The low-resistance grid line distributes the base current and reduces the base-spreading resistance rbb', and thus improves the frequency response of the device. Another reoxidation occurs after the p + diffusion .
Aligning the squares
The emitter area is then photographically defined in the oxide. Processing steps are similar to those used previously for the p+ deposition. The emitter pattern consists of 156 squares aligned so _that the squares register in the center of the p+ diffused grid lines. Hegistration and developing techniques must be good enou gh to keep edge variations in the pattern within 0.05 mil ( 12,500 angstroms) so that sub-

Dopant deposited
A p-type dopant such as boron is diffused into the etched-out area of the base. A relatively light concentration of impurity is used. The surface of the base area is reoxidized during the diffusion .
The wafer is then recoated with resist, and the p + mask, which has 0.3-mil grid lines, is aligned inside the previously defined base area. The wafer is exposed, d eveloped, baked and etched before diffusion of a p+ conductive material into the wafer

oscilloscope shows voltage-current characteristics for one pellet on a wafer containing more than a thousand 2N3375 pellets. Each pellet must meet minimum current gain requirement of 30 at 100 milliamperes.

Electronics August 23, 1965

73

Making the 2N3375-a five-step procedure

The first masking operation defines the base region on the silicon substrate.

····························································································································································
Next, the p+ conduction paths, through which the base current flows, are diffused.

The 156 individual emitter areas are aligned inside the p+ grid lines.

In the fourth step, the contact areas to the emitter and the base are etched .

The metallization pattern tor connection of emitters and base contacts (below) . The entire sequence of photos shows the five main steps required for processing the 2N3375. Each photograph was taken after the completion of a masking operation . This device contains 156 square emitters, each 0.5 mil on a side, arranged in a 12 by 13 array. In the photograph below, the emitter contact is the small white square inside the larger blue square, which is the emitter. The red square is a portion of the base region. Th e surrounding purpie region is the p + base conduction area .

sequent alignment of squares and grid is possible. After reoxidation during emitter diffusion, contact
areas for the emitter and base are defined in the oxide by means of the third and most difficult of the pattern regish·ations. The metal contact pattern requites a contact area of 0.3 mil in each 0.5-mil emitter.

Aluminum evaporation
Following the etching of the contact regions, aluminum is evaporated over the silicon wafer, and the wafer is then coated with photosensitive resist and again processed as described previously. Etching of the aluminum defines metal areas in which the emitters are connected to the center bonding area by aluminum stripes 1.5 mil wide. Each emitter metalization stripe makes connections to two adjacent rows of emitters. Contact to the base area is made at the metal base stripes.
The diagram on page 72 shows a cross-section of a completed unit. The dark blue area indicates the p+ conductive grid. The emitter metalizing is insulated from the base by the silicon oxide and con~ tacts the emitter in the open region.
Base current is distributed from the bonding area by the base metalization and by the p+ grid unde1= the emitter metalizing. The emitter metalizing "overlays" the base.
After the wafer is scribed for pellet separation, the transistor pellets are mounted in individual 7/ 16inch double-ended stud packages that have isolated collector termination. Aluminum wires are bonded to the pellet areas and the corresponding terminal posts as shown on page 76 . The cap is sealed hermetically to the stud, and the leads are crimped to complete the package.

Pellet-mounting process. Here, the header is being inserted into a heating chamber. After a 30-second warm-up period, the pellet is placed on the header and connected to it with a gold-silicon alloy.

Testing for performance
Parameters of the sealed units are measured in tests conducted under d-c conditions and at high frequencies. Characteristics measured include junction breakdown voltage, leakage current, current transfer ratio, saturation voltage, thermal resistance, and junction capacitance.
Ultra-high frequency measurements are made in the tuned-line, common-emitter, class C amplifier shown on page 77. In this circuit, the adjustable stubs are tuned until an impedance match is obtained between the device input circuit and the signal source and between the power meter and the collector. The

The completed 2N3866, ready for mounting and bonding. Dimensions are 15 mils by 15 mils by 4 mils. The thickness of the oxide determines the color of the different regions of the transistors and varies from device to device, so that there is a difference in color between this 2N3866 photograph and the other one shown below.

The 2N3866 has 16 emitters, each 0.15 mil wide by 2 mils long. This photograph
shows the device after three areas have been exposed to allow contact to the
base. This is the step conducted prior to defining the metallization pattern for interconnecting of emitters
and contact to the base.

Electronics August 23, 1965

75

The 2N3375 pellet after mounting and ultrasonic aluminum-to-aluminum bonding. The center lead is the emitter connection. The two outer leads are connected to the base. Center metal area of package carries the collector current to the collector riser wire. Emitter, base, and collector are insulated from the Jedec T0-60 stud-mounted case by a thick layer of beryllium oxide (white region) .

inline wattmeter measures both the power delivered to the input of the device and the power reflected back to the driver stage. If no power is reflected, there is an impedance match between the driver and the amplifier circuit. These tuned lines make it possible to obtain impedance matching over a wide range of frequency and impedance values using the same circuit components.
Tests were performed at various frequencies, with 28 volts applied between collector and emitter. The input circuit was biased by means of the parallel RC network shown in the circuit. Curves of typical performance for the 2N3375 in this circuit are shown on page 77. This device is rated for a minimum power output of 3 watts at 400 Mc and 7.5 watts at 100 Mc for 1 watt of drive. The minimum circuit efficiency of 2N3375 units is 40% at 400 Mc and 65%at 100 Mc for 1 watt of r-f drive.
Two pellets in parallel
A power output of 10 watts at 400 Mc can be obtained by parallel operation of two 2N3375's. The 2N3733 uses two 2N3375 pellets connected in parallel and mounted in a 7/ 16-inch double-ended stud package ( T0-60) . Typical d-c characteristics of this device are identical with those of the 2N3375, except that the output capacitance is twice as high.
Curves of typical high-frequency performance for the 2N.'3733 are shown on page 77. For an input power of 4 watts, power output is a minimum of

10 watts at 400 Mc and typically 14.5 watts at 260 Mc. As a result of improvements in photomask fabrica-
tion techniques and photolithographic technology, devices employing tighter tolerances and smallet geometries than the 2N3375 can now be fabricated. The 2N3866, which is used in uhf driver applications, has 16 emitter sites, each 0.15 mil wide by 2 mils long. The ratio of emitter periphery to em itter area is nearly twice that of the 2N3375. In addition, due to a substantial reduction in input capacitance, the frequency response of the device has been furth er improved. Although the fabrication steps used to make this device are similar to those of the 2N3375, about four times as many pellets can b e processed on each wafer. The device has a minimum gain of 10 db at 400 Mc for 1 watt of output power.
Five-step process
Five masks are used to fabricate the 2N3866. The manufacturing sequence is the same as that used for the 2N3375, except that the order of the first two steps is switched. In making the 2N3866, the first pattern defined on the silicon substrate is the set of p + conductive regions which carry the base current from the base to the base aluminum metalization. In the next step, the remainder of the base is formed.
The third step defines th e 16 individual em itters, and the fourth exposes three areas to allow contact to the base. Finally, the metalization patterns for interconnection of the emitters and contact to the base are defined.

76

Electronics August 23, 1965

,,<__rJ

ct
~

,_I

::>
,Q__

::> 0

4

a:

LU

~

0

.Q.._.

ZG =50

a:

OHMS

COLLECTOR-TO- EMITTER VOLTS= 28 CASE TEMPERATURE=25°C TRANSISTOR= 2N3375
2.0 1.5
1.0
o. 75

0.5

300

400

FREQUENCY- MC
Test circuit for determining power output of 2N3375 at 400 Mc. Tuned lines are used for the impedance matching. Also shown are typical power outputs for various power inputs as a function of operating frequency. For a 1-watt input, the 2N3375 has a guaranteed 3-watt output at 400 Mc and a 7.5-watt output at 100 Mc.

15 14

13

12

,V_>

11

I-
ct

;I::

,_I

10

::>

Q_

I::>

9

0

a:
LU

3-

;I:: 0

8

STUB

Q..._.

ZG=50 TUNER

a:

OHMS

7

COLLECTOR-TO-EMITTER VOLTS= 28 CASE TEMPERATURE= 25°C TRANSISTOR : 2N3733
4
3
2

6 100

200

250

300

350 400 450 500

600 700 800

FREQUENCY - MC
Test arrangement for measuring 2N3733 high -frequency power output and typical power levels obtainable. To reduce the effects of emitter lead inductance, a tuned emitter circuit is used . With a 1-watt input at 400 Mc, 7 watts of output power are produced, as compared with 4 watts with the 2N3375.

The 2N3375 can be driven by another 2N3375; but it is preferable to use a 2N3866 as the driver, since at low power levels the 2N3866 provides more gain and higher output impedance. In addition, the 2N3375 is more expensive. In 1,000 lots, the 2N3866 is priced at $3, while the 2N3375 sells for around $14.
The 2N3866 is packaged in the Jedec T0-39 case. Another version of this transistor, now in development, is intended for operation at frequencies up to 1,000 Mc.

of the device has been spurred by the need for increased reliability and efficiency in solid state telemetry systems, where transistors have been required for final output stages, as power sources for varactor multiplication, and in amplifier-multiplier stages.
High-frequency transistors are also needed in output stages of citizens band and mobile radio equipment, and for power switching in military and industrial equipment. The advance in geometry that led to the overlay should have a powerful effect.

Putting the overlay to work
Some applications of the overlay transistor are discussed in the following article. The development

Acknowledgement
The authors acknowledge the many contributions made by Ronald Duclos, George Gilbert, and Stanley Matyckas in the development of the devices de~cribed in this article .

Electronics Au gust 23 , 1965

77

Part II: Putting the overlay to work at high frequencies

New transistors can already handle 10 watts at 400 Mc, and are being designed into solid state transmitters. Frequency multiplication will extend the operating range to the gigacycle region.
By D. Joseph Donahue and Benjamin A. Jacoby
Radio Corp. of America, Somerville, N. J.

The overlay transistor is sure to accelerate the conversion from tubes to semiconductor devices, which has been slowed by the inability of transistors to provide high power at high frequencies. With overlay construction, devices are already being built that can handle a minimum of 10 watts of output power at 400 megacycles; next year, overlay transistors capable of 100-watt output at 50 Mc and 20 watts at 400 Mc will be available. Devices that can provide 10 watts at 1.2 gigacycles will also be on the market by 1967.
The first r-f power transistor, introduced in 1958, provided the rather modest performance of 100 milliwatts of output power at a frequency of 100 Mc. Although major improvements in power-frequency performance were achieved in each succeeding year, by 1963 only a few transmitters had been converted to solid-state-including low-power telemetry, citizens-band equipment, and portable 175-Mc mobile communications sets. Although the use of transistors provided the advantages of increased reliability, lower power drain, elimination of d-c to d-c converters in battery-operated portables, and smaller size, the vast majority of military and commercial transmitters appeared to be considerably out of the range of transistorization.
The authors
In June of this year, D. Joseph Donahue was appointed manager of RCA's industrial semiconductor operations. Since 1963 he had served as manager of engineering for the industrial semiconductor operations group. He joined the RCA Electronics Tube division in 1951, and worked on the development of the color television picture tube. In 1958 he joined the Semiconductor division as manager of advanced development.
Benjamin A. Jacoby was named marketing manager for RCA's integrated-circuit activity in June. He has been with RCA since 1952 and has held positions in purchasing, field sales and product sales administration. From July 1963 to June 1965 he served as manager of market planning for the industrial semiconductor operations group.

Some hybrid circuitry in which semiconductor devices were used up to the final stage were explored in military designs to provide reliability, but a sizable swing to solid-state appeared remote. The major barriers were economics (tubes were still considerably less expensive than transistors) and performance (transistors were limited to low-power, narrowband, class-C applications).
In 1964, the first commercial overlay transistor, the 2N3375, appeared on the market. (The history of the device actually goes back to late 1961, when the overlay geometry was one of several considered for high-power, high-frequency applications. Actual development of overlay devices started in 1963 under funds supplied by the Army Electronics Command, Ft. Monmouth, N. J.) With the introduction of th!{ 2N3375, which could provide a 3-watt output at 400 Mc, circuit designers begin to look seriously at the use of transistors in high-frequency power applications. As more overlay devices became available, it became apparent that many kinds of overlay geometries were possible. A number of designs intended for a variety of uses have resulted.
Solid state transmitters
The availability of overlay transistors is reshaping the outlook for all-solid-state transmitters. A wide variety of r-f power equipment is already being designed entirely with transistors; examples are mobile communications, radiosonde, telemetry, troposcatter, radio relay, radar transponder, citizens band, sonobuoy, commercial and military aircraft communications, rescue beacons, military tactical communications and community antenna television systems.
Frequency modulation is used extensively in telemetry, microwave relay and mobile equipment. The center diagram, page 81 shows a typical threestage power-amplifier circuit suitable for telemetry application. The input stage uses a 2N3553 overlay transistor operated as a common-base 100- to-200-Mc frequency doubler. The second stage uses a 2N3375 overlay transistor as a 200- to-400-Mc common-emitter frequency doubler, and the final stage consists of

78

Electronics August 23, 1965

Technician tuning a 35-watt 175-megacycle transmitter power amplifier built with six overlay transistors. The transmitter operates from a 13.5-volt battery and requires only 100 milliwatts of input power to produce 35 watts of output power.

95%is achieved by modulation of the supply voltage to all three stages. The separate input matching network for each output transistor permits drive adjustments to equalize collectox currents.
Transistor frequency multiplication, which had been used for many years at low signal levels, has recently been extended to power levels. In this type of operation, the collector-to-base junction of a transistor is used as a varactor diode to obtain frequency multiplication at the output. Frequency doubling coupled with power gain is becoming commonplace and has begun to eliminate the use of varactor diodes at operating frequencies below 400 Mc.
Of even greater significance are the transistor frequency-multiplication studies now underway which extend the operating range of transistors into the gigacycle region. The 2N3375, 2N3553, and 2N3866 have been found to be particularly suitable for this mode of operation as doublers, triplers, and quadruplers. Substantial power output has been obtained at frequencies approaching 2,000 Mc.
The bottom circuit on page 80 is a 500- to 1000-Mc transistor doubler circuit. Lumped elements are used for the input and idler circuits; a coaxial cavity is used for the output circuit. The 2N3375 transistor is connected in a common-emitter configuration and is located inside the cavity in a position of maximum field strength. Power is taken out through an inductive coupling loop near the shorted end of the cavity. An input of one watt at 500 Mc produces an output of 2.3 watts at 1000 Mc. A 2N3866 in the same circuit provides an output of one watt at 900 Mc from an input of 0.25 watt at 450 Mc.
Higher frequency operation can be obtained with the combination oscillator and frequency multiplier shown in the bottom circuit on page 81.

two 2N3375's in parallel. This amplifier is capable of providing a power output of 10 watts at 400 Mc. An over-all power gain of 16 db is obtained.
The center diagram on page 80 shows a 35-watt 175-Mc f-m mobile transistor amplifier. This transmitter uses a family of overlay transistors which have been specially designed to operate directly from 13.5volt automobile batteries; thus there is no need for a d-c to d-c voltage converter. The output section of the transistor contains three 40282 transistors (selected 2N3632's with their emitters internally connected to the lead to reduce lead inductance). A separate matching network in the base of each output transistor permits drive adjustments to equalize collector currents.
Amplitude modulation is commonly used in the 27-Mc citizens band. The top circuit on page 81 shows a typical 5-watt ( d-c input) transmitter, which can handle three watts of carrier power, and can deliver up to 10 watts of peak power under 100% modulation.
Amplitude modulation is also used extensively in aircraft communications. The top circuit on page 80 is for a 10-watt, 135-Mc a-m transmitter used in small aircraft. Amplitude modulation greater than

The outside story
Packaging is extremely important in building highfrequency transistors. Low lead inductance, good thermal conductivity, and isolation of the collector are all-important. Most overlay transistors are packaged in a 7/ 16-inch double-ended isolation-stud case, the T0-60. Lower-power devices come in a T0-39 case with a solid steel header for good thermal conductivity. New cases are being designed to provide higher resonant frequencies and lower parasitic inductances.
Largely because of the small size of the overlay silicon transistor chips ( 0.03 by 0.03 inch for the 2N3375), the device can be manufactured inexpensively. The size results in higher yields because of the lower probability of imperfections, and also permits more transistor chips per wafer. As penetration of the commercial communications market increases sales volume, and as new techniques are perfected with experience, r-f power transistor prices should drop even more.
The use of overlay transistors also provides further opportunities for cost reduction in equipment design as a result of increased gain per transistor stage, higher power per transistor, and elimination of voltage converters in battery-operated sets.

Electronics August 23, 1965

79

Typical circuits using overlay transistors

40292
C5
C9 L11

Cs L7

C10

PIN= IOOMW

Vee 13 .5V (MOO)

Vee 13.5 (MOD)

-=

A 135-Mc amplifier circuit for an aircraft communications system. The 4-transistor amplifier increases power from 100 milliwattts at the input to 10 watts at the output.

Vee 13 .5 (MOD)

P=IO W

Pout 35W

A 175-Mc f-m mobile amplifier circuit. The circuit operates directly from a 13.5-volt automobile battery, eliminating the need for a d·c to d·c voltage converter. With only the first three stages active, the circuit can function as a 12-watt amplifier. The entire circuit can provide 35 watts of output power. The over-all d·c to r-f efficiency of the transmitter is approximately 60 % . Components for this circuit are listed below.

Vee =13.5 v

Turns Wire

size

Inductor

L4 , L7 L.

3

16

1

16

L io

2

16

L, ,, L ,,, L,4 L, 0, L, ·· L2o

5

16

2

16

Lis. L,., L"

2

18

L,

2

16

L2, Ls. Lo: ferrite choke, 450 ohms

L3, L·. L. , L 11 : 0.1 microhenry

Inside dia.
(inch) 3/16 1/ 4 1/ 4 1/4 1/4 1/8 3 / 16

Length
(inch) 1/ 4 3/8 5/ 16 1/ 2 1/ 4 1/ 8 1/ 4

-=-

-=-

Capacitors
C,: 3-35 pF
c·. C2, C,., C " , C10. C, 9, Cv : 8 -60 pF
C3, C, , C11 : ceramic disk, 0.1 µF
c·. Co, C,2 , C2· · C2J , C2s : feed-through, 1500 pF Cs, c·. C1 0. C,3, C,., C26 : 7-100 pF
C,s: 1.5-20 pf
C20, C22 , C2, : ceramic disk, 0 .2 j..F

This frequency-doubler circuit combines multiplication with
power amplification, and eliminates the varactor
diode normally used. The circuit converts a 500-Mc, 1-watt input to an output of
2 .3 watts at 1,000-Mc.

80

Electronics August 23, 1965

40080
o,

510 5.1K

15µ.H

120

RFC1

MILLER

tSµH
RFC2 MILLER

RL 50

4624

4624

A 0.01

B

ARCO 429

0.01

24pF 90-400pF

27- Mc CRYSTAL

....._~~~~~~~-<1>--+11TO15V

L,.L2 : 0.75-1 .2µH

L4 : 0.2t-0.34µH

0.01 TO MODULATOR TRANSFORMER

Three overlay transistors are used to form a five-watt 27-Mc citizens-band a-m transmitter. This circuit can handle three watts of carrier power, and can deliver up to 10 watts of peak power under 100% modulation . In citizens -band applications, overlay transistors are competing against coventional silicon planar transistors.

LT

200Mc

TRAP

C13
-=
R4

C15

L10

t--

!IN =100 Mc P1N~ o. 2sw

RFC4
four=400Mc Pour =10W

C7

C12

TO GROUND

+28V

A three-stage power amplifier circuit designed with four overlay transistors for use in telemetry equipment. This circuit serves as both a frequency quadrupler and as an amplifier. In the final stage, two 2N3375's are operated in parallel. The circuit converts a 100-Mc, 0.25-watt input signal into a 400-Mc, 10-watt output signal. The over-all power gain is 16db.

,--- - -------- --------- - ---------,

I

2N3553

I

I

I

I

I

RFC

I

RFC

I .

I

C

Rb1

I

I

I

I

I

I

Re

I

Cb

Ct

I

I

I

I

v

L----------- - ---------------- ~

In this frequency-multiplier circuit using a 2N3553, the transistor oscillates at 420 Mc. The frequency is quadrupled to 1,680 Mc by the circuit. Power output is 250 milliwatts.

1680-Mc 250 mW

Electronics I Au gust 23 , 1965

81

Part Ill: Combing the field for ways to match overlay's performance

Several companies have followed RCA into the production of multiple-emitter high-frequency transistors, which have captured NASA's fancy. Yet interdigitation has its supporters

By Jerome Eimbinder
Solid State Editor

Overlay geometry is currently the most popular design for achieving high-frequency performance in a power transistor. Since the Radio Corp. of America put the first overlay transistor, the 2N3375, on the market last year, three other companies have made overlay devices available; they are Motorola, Inc., the National Semiconductor Corp., and the Vector division of the United Aircraft Corp. General Electric Co., Texas Instruments Incorporated and the Transitron Electronic Corp. have overlay devices similar to the 2N3375 in development.
But two other producers, ITT Semiconductors, a division of the International Telephone and Telephone Corp., and TRW Semiconductors, Inc., a division of TRW Inc., both intend to stick with interdigitated geometry. In this configuration, the emitter is built like a pair of interlocked combs. lnterdigitation was one result of the search for an emitter with a high periphery-to-area ratio (see Part I of this series).
NASA likes overlays
The National Aeronautics and Space Administration backs the overlay construction. One NASA official says that overlay transistors are definitely the agency's top choice for high-frequency power applications.
NASA is presently funding the development of a 20-watt, 435-megacycle overlay transistor by RCA, and a 10-watt, 1.2-gigacycle device by both RCA and National Semiconductor. It may award a c~ntract next year for a 5- to 10-watt, 2.3-Gc transistor, but as yet there are no plans to restrict the bidders to overlay geometry.
The interdigitation story
Yet ITT and TRW have both been getting good results from "combs." ITT is already selling an interdigitated 2N3375 and plans to market its versions of the 2N3553 and the 2N3632 shortly. ITT also claims top performance for its 3TE220, which can

handle 50 watts of r-f power at 150 Mc; only specially selected overlay transistors can match those figures.
ITT says the 3TE220 is "resistor-stabilized"; the industry calls it "the centipede," because it has a resistor deposited at the end of each of its many fingers, and a connecting wire attached to each fingertip. The purpose of the resistor is to keep current distribution even at each finger. (RCA is also using a form of resistor stabilization on some developmental overlay devices.)
The 156-emitter overlay geometry used by Motorola to build the 2N3375. With a 28-volt supply at 400 Mc, the 21':13375 handles 3 watts of r-f power with 4.8-db power gain . It is packaged in the T0-60 case.

82

Electronics August 23, 1965

Vector's experimental VX168-10 is a 168-emitter device with a power output of 1 watt and 6-db power gain at 800 Mc. It can dissipate 12 watts.

Another Vector experimental unit, the VX256-10, has 256 emitters. At 500 Mc, it provides 10 watts of r-f power with 8-db gain. Dissipation is 20 watts.

Overlay transistor characteristics

Type

Typical FT
(Mel

Power Output

Min. at

at

Emitters (watt~ Mc volts

DissiMax. pation Co· at 25 ° C Jedec (pF) (watts) case Status Use

Mfr.

2N3375

500

VX3375

500

2N3553

500

2N3632

400

2N3733

400

2N3866 800

40279

500

40280

550

40281

400

40282

350

40290

500

40291

500

40292

300

40305

500

40306

500

40307

400

40330

500

40331

500

40332

400

40337

500

40338

500

40339

500

40340

125

40341

125

40342

400

40343

400

TA2657B 125

TA2658A 800

VX168-10 1,000

VX256-10 800

156t
156
156t
312t
312 16
156 156 156 312 156 156 156 156 156 312 156 156 312 156 156 156 180 180 312 312 180
16 168 256

3.0 400 6.5'' 250 2.5 175

28.0 28.0 2 8 .0

8 11.6 T0-60 Com

8 11.6 T0-50· Com

8

7.0 T0-39 Com

13.5 175 28.0

15 23.0 T0 -60 Com

10.0 400 28.0

15 23 .0 T0-60 Com

1.0 400 28.0

3

4.0 T0-39 Com

3.0 400 28.0

8 11.6 T0-60 Com

1.0 175 13.5

10

7.0 T0-39 Com

4 .0 175 13.5

20 11.6 T0-60 Com

12.0 175 13.5

40 23.0 T0-60 Com

2.0 135 12.5

8

7.0 T0-39 Com

2.0 135 12.5

8 11.6 T0-60 Com

6 .0 135 12.5

15 23.0 T0-60 Com

2 .5 1-75 28.0

8

7.0 T0-39 Com

3.0 400 28.0

8 11.6 T0-60 Com

13.5 175 28.0

15 23.0 T0-60 Com

3.0 135 24.0

8

7.0 T0-39 Dev

3.0 135 24.0

8 11.6 T0-60 Dev

8.0 135 24.0

15 23.0 T0-60 Dev

2.5

27 12.0

8

7.0 T0-39 Com

3 .0

27 12.0

8 11.6 T0-60 Com

3.5

27 12.0

8 11.6 T0-60 Com

25.0

50 13.5 120 70.0 T0-60 Com

30.0

50 24.0

85 70.0 T0 -60 Com

13.5 175 28.0

15 23 .0 T0-60 Com

10.0 400 28.0

15 23 .0 T0 -60 Com

50.0

50 28.0

80 55.0 T0-60 Dev

1.0 400 28.0

3

4.0 T0-39 Dev

1.0" 800 28.0

8 12.0 T0-50· Exp

1.0''' 800 28.0

10 20.0 T0 -50· Exp

GP
GP
GP
GP
GP Driver Hi -Rel FM FM FM AM AM AM Hi -Rel Hi -Rel Hi-Rel AM AM AM CB CB CB FM FM Hi-Rel Hi-Rel GP GP GP GP

MOT, NAT, RCA, VEC VEC MOT, NAT, VEC MOT, NAT, RCA, VEC RCA, VEC RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA RCA VEC VEC

t NAT version has 216 emitters t NAT version has 432 emitters
· Typical value
· Case is similar to T0-50
fT = Gain -bandwidth product

Cob = Output capacitance GP = General purpose Hi -Rel = High reliability FM = Frequency modulation AM = Amplitude modulation

CB = Citizens band Com = commercial Dev= developmental Exp = Experimental MOT = Motorola, Inc.

NAT = National Semiconductor Corp. RCA = Radio Corp. of America VEC = Vector Division , United Aircraft Corp .

Electronics I August 23, 1965

83

175-Mc transistor under an Army contract. The Semiconductor division of the Fairchild Cam-
era & Instrument Corp. has an interdigitated device, the MT1038, which can compete with overlays in the 1- to 2-Gc range; but the company has no immediate plans to go after the 2N3375 business. The MT1038 is capable of handling 1 watt at 1 Ge.

National Semiconductor's 2N3375, an overlay device, has 216 emitters; other manufacturers use 156. However ratings and specifications for National Semiconductor's device agree with those published by Motorola , Vector and RCA.
Silver striplines
At Wescon, ITT is introducing a new line of devices called stripline transistors. They come in a stud-mounted package with an epoxy cap; the stud is the emitter.
The name "stripline" comes from the two flat ribbon leads, made of silver, which extend from the top of the unit.
One stripline transistor, the 3TE440, will handle 20 watts at 400 Mc, with 8 to 10 decibels of power gain. Tom Ciochetti, ITT's transistor marketing manager, calls it the world's more powerful transistor. So far, no price has been set on it.
Like the 3TE220, the 3TE440 has fingers which are resistor-stabilized. The 3TE450, another sh·ipline device which will be shown at Wescon, does not have resistor stabilization, but nevertheless can supply 5 watts at 400 Mc with a low voltage supply. It will cost $28.
TRW's line
TRW also plans to market an interdigitated
2N3375 - a PT4690 pellet packaged in a Jedec T0-60
case. With a 28-volt power supply, the PT4690 provides a typical power output of 6 watts at 400 Mc, and a power gain of 5 db. TRW's other competitor to the 2 3375, the 2N3502, has a typical output of 3.5 watts at 400 Mc.
Another TRW developmental unit, the PT5690, will handle 40 watts at 175 Mc. Where overlay transistors have emitters connected in parallel, the PT5690 has complete transistors, known as cells, in parallel; 24 cells are used, each built with interdigitated geometry. TRW acquired the technology to build the PT5690 last year when it investigated multiple-cell structure while developing a 50-watt,

Overlay configurations
The 2 3375, with 156 emitters, is the oldest and most popular of the overlay h·ansistors; but a number of new overlay configurations will soon be on the market. RCA is already selling a 16-emitter device, the 2N3866, and will put out 180-emitter and 408-emitter transistors soon. Vector has experimental units with 168 and 256 emitters; National Semiconductor is developing a 280-emitter device for operation at 1 Ge and above.
RCA has extended the power of the 2N3375 by putting two of them in a T0-60 case and labeling the product the 2N3632. Vector is also making the 2N3632 this way, but it feels that this type of construction could result in uneven current-handling if there were too large a mismatch between the chips. This company's approach to power extension is a 256-emitter device which has four quadrants of 64 emitters each (see photo on the preceding page). Vector claims this transistor has more uniform current distribution than the 2N3632, and dissipates heat better at the same or higher power.
The 2N3733 is two standard 2N3375's in one case; it provides a minimum of 10 watts at 400 Mc, more than b·iple the performance of the single 2N3375 but it requires four watts of drive power.
Tl's dilemma
Even though Texas Instruments is developing an overlay transistor, the company is not firmly committed to manufacturing it. "The overlay concept looks very promising," says Richard J. Hanschen, assistant vice president of Tl's Semiconductor-Components division, "but we have another totally different approach which also looks good."
TI is considering a majority-carrier device similar to a field-effect transistor, and won't decide which way to go until it completes an investigation of the production feasibility of such a device.
Future geometries
Even the overlay advocates believe that other geometries will find a use in high-frequency power transistors, but many engineers believe that these new geometries will be based on the overlay concept. Richard H. Moyer, chief of the Vector Solid State Laboratories, says that "The most significant contribution of the overlay transistor may turn out to be that it was responsible for a new school of thought concerning transistor construction."
Yet Jack E. Kindregan , sales manager for the Vector lab, says "We feel there is no better way to make high-frequency power transistors than the overlav method, at this time." For the present, the overlay is supreme.

84

Electronics I August 23, 1965

Circuit design
Designer's casebook

Designer's casebook is a regular feature in Electronics. Readers are invited to submit novel circuit ideas, packaging schemes, or other unusual solutions to design problems . Descriptions should be short. We'll pay $50 for each item published.

One-transistor multi
delays digital pulses
By Richard A. Karlin
Linear Alpha, Inc., Evanston, Ill.
Digital pulses can be delayed by a circuit that is much simpler than the usual delay line or monostable multivibrator.
Delay lines are stable and reliable, but expensive and bulky. And because they attenuate the delayed signal, delay line outputs must often be amplified. Another disadvantage is that their delay-time-torise-time ratio is limited so that pulses of very short duration may be distorted.
Monostable multivibrators are compact and they allow much larger delay-to-rise ratios. But since they have two transistors and a number of resistors and capacitors, they are more expensive than the circuit shown in the top diagram at the right. This simple inverter circuit has only one transistor, two resistors, and a capacitor.
Normally, transistor Q1 is biased on by R1 and
the circuit output is at approximately ground poten-
tial. The base of Q1 is a few tenths of a volt nega-
tive with respect to its emitter. A negative-going input signal is coupled through the input capacitor
and injects excess charge into the base of Q1 with-
out causing any change in output. A positive-going
input signal VA cuts off Q1, whose collector imme-
diately goes to -6 volts. The base voltage immediately starts to decrease according to the R1C1 time constant. When the base voltage again be-
comes negative by a few tenths of a volt, Q1 again
conducts and the output returns to ground potential. Thus, the output is negative for the duration of the delay.
Because the circuit inverts the input, successive delays can be provided by cascading several delay stages. Each delayed output acts as the input for the next delay stage.
The delay time of the circuit is determined by the values of R1, C1, and the magnitude of the input voltage VA, and supply voltage E 1111·
The value of R2 must b e low, so that it will not load the output. R1 should be chosen according to the following relationship:

Eee

Ecc

-GV

-GV

R,
3K Ct 4.7pF VA----tl t-----------1--i
Jl

a,
2N3638

Transistor inverter with capacitor input delays digital pulses with delay-time-to-rise-time ratios of 30 to 1.

Eee

Ecc

-GV

-GV

R1
2.2K Ct 6.2pF
Jl. VA--1 t---+o,-~---------+-< 1N914

OUTPUT

tGV
Eoo
Delay circuit isolates the base of Q, from input. This circuit should be used if input voltages exceed rated BVEso of Q,.

R - f3min R2 (EBB - vb.)

1 -

2 Ecc

where f1111i11 is the minimum current gain when Q1 is in saturation (usually about 10) and Vbc is the base-emitter voltage drop. This value of R1 will insure that sufficient base current flows for both static (steady-state) and dynamic (turn-on) load conditions.
After R1 is calculated, the value C1 necessary to produce the desired time delay can be calculated from:

T =

R1 C1 VA

(EBB - vb.)+ o.5 vA

If E1rn is the same supply voltage as that for the stage producing the input signal, the delay time will be approximately independent of E BB and can

Electronics I August 23, 1965

85

be calculated from T=R1C 1/l.5. The collector current Irno, which flows when
the collector-to-base junction is reverse-biased and the emitter is open, should be low compared to Enn/R1. The charge stored in the base junction during the delay interval should be low compared to VAC1. Also, VA should not exceed BVEno, the maximum rated emitter-to-base reverse voltage with the collector open-circuited.
If the last requirement cannot be realized, then the circuit must be modified as shown in the bottom diagram on page 85. This circuit isolates the
base of Q1. Diode D 1 should be a low leakage type.
Speedup capacitor C 2 is optional. The design equations for this circuit are:

J R _ (EBB-Vb.-0 .6)

- - - + - I - [ 2Ecc

EDD

fJ,,.,,. R2 R~

and

+ 1' =

Ri Ci VA

(EBB - Vbe - 0.6) 0.5V A

Since a change in b ase voltage of less tl1an 0.2

Rt

3K

Dt
IN914

Ct 5.1pf

VA-----+---t t-+--------f-{

JL

Cz
0 .0 2 µ F

Delay circuit prevents C, from loading collector of Q, and also decreases noise sensitivity.
volt is sufficient to switch the tran sistor completely, the delay-to-rise ratio is greater than v .\/0.2. For a 6-volt pulse, this gives a delay-to-rise ratio of 30 to 1. Th erefore, for delays of up to 0.3 microsecond, only th e transistor and load time constants limit rise and fall tim es. For a 6-volt sys tem that can tolerate a rise or fall time of 50 nanoseconds, delay times as long as 1.5 microseconds can b e r e a lize d.
The coupling circuit shown above prevents C1 from loading the driving coll ector and decreases noise sensitivity. If H._, = Rd 2, the circuit recovery time will be twice the delay time.

Simple multivibrator
operates at 5 Mc
By Velimir M. Ristic'
Electronic Laboratory, Faculty of Electrical Engineering Belgrade, Yugoslavia
An oscillation frequency of 5 megacycles per second can be obtained with th e multivibrator shown in th e diagram at the ri ght. Output pulse amplitude is 4 volts, and th e pulse rise and fall times are about 20 nano second s each.
Transistors Q~ and Qi are constant-current gen-
erators which always conduct. Th e bases of Q2,
Q:i and Q4 are held at a constant d-c voltage by th e time constants C ~R~., C 4 R4 and C:iR:i. respectively.
During one half-period, timing capacitor Ci ch arges throu gh Qi and Q4, both of which are in the saturated state. In th e nex t half-period, Ci discharges through Q~ and Q:i, which are also both s a t u r a t e d.
Th e timing capacitor docs not affect th e rise and fall tim es of th e output waveshapes because it is coupled through th e emitters of Q 1 and Q:i.
Output pulse rise and fall times can be deter-

C4 Ff'
0.033µJ_

+18 VOLTS

Rs

R3

45K

14K

C5

C3

0.033µF 0.033µF

I I

c,
500pF
OUTPUT

11
Rise and fall times of high-frequency multivibrator are not dependent on timing capacitor C,, because of emitter coupling through Q, and Q·.
mined from
+ 1' = '>C' R6R1 - be R6 R1
where C'1w is the total collector-to-base capacitance of Qi and Q 3.

86

Electronics J August 23, 19

The approximate duration of the multi's period

can be expre-ssed as

T = T1 + T2

~04 + where T1 = C1R04 ln ( R7

RCi2 x Rb R04 )
Rb+ RCi2

R02 and R04 are the output impedances of the con-
stant current generators Q2 and Q4, resp ectively.
Output pulse amplitude can be calculated from

+ Vo =

V.c [

Rb Rb Ro4

+

RsR+1 R-;

X

and

( Rb R+o4flo4 - Rb R+02R02 )]

Multivibrator provides
bidirectional output pulses
By F.C. Ruegg
National Bureau of Standards, Washington , D.C.
A flip-flop that produces bipolar output voltages with respect to ground is often required in transistor log ic circui ts. (A positive voltage V1 represents
logical "zero" and nega tive voltage V:! represents
a logical "one.") The circuit shown below, has a bipolar output; and its ground potential can be varied continuou sly between th e two voltage limits, while th e voltage difference be'!:ween the. levels remains constant.

Transistors Q:! and Q3 form a bistable multivibrator. Transistor Q1 is an invertin g amplifier for
the output of one side of the bistable multi. When
Q:! is on, the output at A is - 10 volts , and when
Q2 is off, Q1 is saturated, causing its collec tor (output) to b e at ground potential. Transistors Q4 and
Qn are a cascaded noninverting amplifier that es-
tablishes a positive d-c level. ·when Qa is off, the output at B is approximately at ground potential; when Q3 is on, th e output at B is +10 volts. The potentiometer connected between circuit points A and B allows th e symmetry of the output voltage
levels to be adjusted. This flip-flop , coupled with a pulse generator,
provides a clean square wave that is symmetrical with respect to ground, and which can b e used to
tes t the frequency response of many transistor cir-
cuits. This simple circuit is useful for a large number
of applications in the laboratory.

+12v

INPUT

A

:-12v
Re
100K R11 5.6K
R10 27K

+12v
R11 14
B

02 2N404

03 2N404

R1e
fOK
Flip-flop output voltage is bidirectional. Potentiometer R,. allows ground potential to be varied with respect to output voltage limits. The difference between the output voltage limits remains constant as the potentiometer is adjusted.

Electronics I August 23, 1965

87

Military electronics
Automatic test equipment: a million-dollar 'screwdriver'

Electronic systems have grown so complex that even a skilled technician can't perform all the necessary checks in a reasonable time. The military has spurred the development of computerized testing

By W.J. Evanzia
Avionics Editor

T here was a time when a good electronics technician could test a radio with a screwdriver, but today even the simplest receivers require elaborate test equipment. Correspondingly, where a typical World War II bomber had about 2,000 electronic components with few if any circuit test points, today's combat aircraft has more than 100,000 components and some systems have more than 50,000 test points.
Even though today's maintenance personnel are far better trained than their World War II counterparts, they simply cannot check out such complex systems in a reasonable time with standard multimeters, oscilloscopes and bridges. All three branches of the military have been developing automatic equipment to make faster tests that are more complete and more accurate than a single technician can perform.
A technician will trace a fault logically. If a system fails, he will check the subsystems; if a given subsystem works, he need go no further, for he knows that a good subsystem must have good components. When he has isolated the faulty subsystem, he performs similar logical steps on modules or circuits until he has isolated the faulty component or components. Sophisticated automatic equipment does not always take such syllogistic steps; it is usually programed so that if a system fails, it will switch serially through the entire system and print out the location of the faulty components.
Costly systems
Automatic test equipment is now a $400-milliona-year business. By far the largest spender (for systems which cost more than $250,000 after de-

velopment) is the National Aeronautics and Space Administration, with $150 million budgeted for checkout on Apollo and the Saturn rocket. The Air Force is spending about $50 million on three systems, the Army about $15 million and the Navy $5.9 million for their basic automatic test equipment.
Industry spends only about $10 million annually. The balance of the money is spent by the services on a variety of special purpose test programs, such as the Navy's BACE (Basic Automatic Checkout Equipment), which was provided for the Grumman Aircraft Co. to check out the E2A radar picket plane.
Spending on automatic test equipment will continue to increase, so that by 1970 the market should be about $500 million. NASA's share will drop to about 20% , but Air Force spending should be up to around $75 million. The Army and Navy together should contribute another $125 million. Industrial electronics firms, with a $200 million investment, will thus represent a significant share of the dollar volume.
Feasibility study
Nearly 10 years ago, the Army's Missile Command conducted a study to determine whether or not there were enough common test requirements among missile systems to permit some degree of equipment standardization. The study was specifically aimed at the problem of test equipment becoming obsolete as prime equipment changed.
The study showed that neither the character nor the art of testing changed radically from one system to the next. The testing requirements for new missile systems could be predicted with a

88

Electronics I August 23, 1965

The Polaris missile guidance system is tested by General Electric's MK 462 Autotester. Results are printed on a Flexowriter, and can also be recorded on punched tape for later analysis.

COMPUTERCONTROLLER GROUP

HIGH-FREQ STIMULUS GROUP UNIT UNDER TEST

CONTROL

LOW FREQ STIMULUS GROUP

DC STIMULUS GROUP

POWER SUPPLY GROUP

Diagram of a typical automatic test equipment system. Control of both stimulus and measurements is by computer. Measured values are compared with the limits stored in the computer and displayed in decimal form.

high degree of reliability, and the nature and the number of testing parameters changed only 10% to 20% from one system to another. Most fire control radars operated at X-band, and their intermediate-frequency amplifiers were at 60 megacycles; search radars had i-f's of 30 Mc; moving target indicator systems operated at 10, 12 or 15 Mc; and other special purpose radars had i-f's of 120 Mc. In other words, a common denominator in most radar sets is the i-f amplifier, which usually operates at some multiple of 15 Mc.
Many out of one
The first really automatic equipment was the Air Force's programed GS-1 system, built in 1955 for the Navaho intercontinental missile. From GS-1 came the specifications for the first production sets, called the AN/GJQ-9. Since then, more than 100 kinds of automatic test equipment have been manufactured for the military.
Typical examples of the Army's automatic test equipment are the systems being developed by the

Electronics I August 23, 1965

89

Radio Corp. of America's Aerospace division in Burlington, Mass. The Multisystem Test Equipment (MTE) is being built for the Missile Command at the Redstone Arsenal in Alabama, and the Depot Installed Maintenance and Test Equipment (Dimate), for the Electronics Command, at Fort Monmouth, in New Jersey.
MTE is a computer-controlled, special-purpose system designed to test electronic, pneumatic and hydraulic components in a variety of missile systems. Dimate, which is mainly built of MTE components and is being bought by the Electronics Command for the Electronics Material Agency at Tobyhanna, Pa., is designed principally to test communications equipment. Both systems are capable of automatic, semiautomatic and manual operation, and will perform both maintenance testing and fault location. Like many other automatic test systems, they are made up of functionally related building blocks; a computer-controller, measurement equipment, low and high frequency stimuli, d-c current stimuli, and power supplies.
Three independent test groups in individual portable shelters, which are carried aboard Army trucks, make up the MTE system. The nrst group, called ETS-1 (for electronic test system), contains a solid state computer-controller, signal generators with a frequency range from less than one cycle to 100 Mc, and programable d-c supplies. The ETS-1 shelter also houses peripheral equipment such as a manual test input keyboard, a magnetic tape transport that carries the programed test instructions for the computer, and a printer to record results, as well as a control director, switching buffers, an address distribution unit, a comparator time delay, memory units and a visual instructor.
The second group, ETS-2, has microwave signal generation and measurement capability from 1 gigacycle to 18 gigacycles. It contains the same basic input-output equipment, paper tape reader, manual input and printer that is in the ETS-1 shelter, but has no computer. Stimulus signals are harmonically derived to accommodate missile systems using continuous-wave, c-w-doppler, pulseddoppler, or conventional pulsed radars.
The third group, HTS (hydraulic test system), automatically tests hydraulic, pneumatic and mechanical systems. It also contains a paper tape reader and controller. Individual or joint operation of the three groups are possible, since both the ETS-2 and the HTS have controllers that may be slaved to the master computer-controller in the ETS-1 shelter.
Controlling the test
The ETS-1 console (see photo on page 92) not only provides the basic control for the entire set, but also a work surface for the unit under test. The computer-controller is the fundamental source of intelligence for operating the test equipment. The four lower chassis in its rack-the control assembly, arithmetic assembly, input-output, and memory assemblies-are the heart of the computer, while

the four upper chassis are the peripheral control, which provides the input-output digital interface between the stimuli, the measurement units, and the display devices and tapes.
The operator nnds the measurement instruments he needs in a panel just to the right of the control console. There are digital multimeters, an analog adapter or signal conditioner which buffers input signals to the multimeters, and waveform analysers.
The technician can control the test by means of magnetic tape housed in a transport assembly. This tape contains the basic test program information in binary form. The tape's output is fed to the computer, where it is stored in a ferrite core memory; the specinc output data is processed by the controller and sent to the various stimuli and measurements units.
Another input that is sometimes used in the manual typewriter keyboard, which gives the operator direct control over the equipment being tested.
He can get test instructions from the visual instructor, which is located at the upper left side of the control console. The visual instructor is a miniature projector whose information is contained on reels of 35-millimeter Rim that is projected onto a ground glass. This device is not automatic; the number of the particular frame that contains the program information for the unit being tested is given by the printer, the operator dials the number, and the film roll turns to the correct frame. The operator sees on the ground glass the schematic of the particular unit that he is testing.
The "test results" panel is also located on the control console. Here the operator can see a digital display of the test signal voltages in addition to displays of pertinent data such as time, resistance and frequency. The printer gives the operator information about the fault found, identifies specific sequences in the test program, and tells the technician to make particular measurements or adjustments.
Field testing
During the last quarter of 1963, the Missile Command decided that it needed a less complex, more mobile tes t setup, one that could service some systems at forward field positions and that would be easily transportable by helicopter or truck. In March 1964, the command awarded RCA a contract to develop the Land Combat Support System (LCSS), which would be used to test Shillelagh, a surface-to-surface, tank-mounted field support weapon; Lance, a vehicle-mounted Bre support weapon; and Tow, an antitank guided missile. Preliminary design of the system began in November 1964; tests of the prototype equipment are scheduled to begin during the last quarter of this year.
LCSS consists of two basic equipment shelters, the ETS-3 and the Repair and Storage Shelter 1 (RSS-1). RCA will build three ETS-3's and one model of the RSS-1. The first ETS-3 will remain at RCA Aerospace in Burlington, and be used to

90

Electronics I August 23, 1965

Army's "Dimate" automatic test system.

OPERATOR COMMANOS

,-----,
TEST RESULTS

~

. - ,.-------.,

hj STATUS

ETS - 1

MONITOR CONT

VI

z~ rl

.. !2

VI

VI

-' 1-

z

-:::>'

c";'; ~

..1-
-:::>'

.l.E..
1-
(/'J

VISUAL INSTRUC
'-----

AUTO . REAOER
'-----

MANUAL INPUT
....__,...-
.VI
z 0
lE :I! u 0
..a:
0 I-

PRINTER '-----c--
V>
~
:::> V>
"a-: '
I-

MAG TAPE
..T.R.A_N,S_
.lE
a:
"a0 :'

"'- >-

VI

lE

"-'
1-
(/'J

VI
0 z

a: "-'
Q.

V..>..
I-

Q.

0

>-
VI

~l<gl

l

e i:H LS 8~1
er'1>1
~~~~~III CON

.....--

fil.------++--+--ttpER1-

MEMORY DATA DATA

PHERAL CONT

ojU>j

....____.

.._...

~

TAPE
..R..E_A,_O.E..R...
..lE
a:
0"'
er
Q.

.., rs,...-L--, 1-
z 0

1 'r=-!'!1CONT

t--CO_N,,..T_-ttlNPUT I DATA OUTPUT

f~5 :~:E

u.....--~ ~ DATA DATA

L..+ CONT

BUS

DIRECTOR

CONT COMP/

Iir- ten;

ARITH. CONT

TIME U...'.::====+t=::::;IDELAY

u~e~n 'IL-C~O~NT!...________'.::=::=::~--.+J

<-----J

..---
PRIMARY POWER CONT

PRIMARY POWER CONT

"...'.
"~ '
0 >
"z '
~
.e..r.
Q. 0
:::.
"-'
1-
(/'J
>-
VI
r FSRTDEQ ~ DISTR IB AMPL

DATA

CONTROL

TIME

~INTERVAL
r FREQ CONY

MEASUREMENT DATA

DATA OUTPUT

SWITCH r-1CONT

VI V>
.t--~ 0 0

t-----------------~BUFFER DIGITAL

:a::l>c<
ENCODED VJ-~

MULTI-

MEASUREMENT

ADDRESS ~o

METER

ANALOG ADAPTER

14----1

DATA

SUBAODRESS ANO SWITCHING

ADDRESS DISTRIBUTION

."ger-'i:":z' ~
03 l!5V>

DATA

§~

1-----1 RF 14-----1 SYN TH

14----1

AF / RF GEN

RF IMPEDANCE

14----1

u:i::
I-

ADAPTER

t--1

i
VI

"':;:z::

SWITCHING SUBSTATION

oc<
DECODED ADDRESS

:";:z:'

:::>

.e0 r

-'
z

14----1

AC FIL TRANS

.e..r.

I-

~

SINGLE SIDE BAND

14----1

:::> 0er

ADAPTER t--1 I:z-

1 .:":.-:...'

STIMULI

a:

:::>
VI

STIMULI OR RESPONSE SELF -

.14----1 AM-FM
t--1 ADAPTER

"::-:.'

~--------~ TEST
.----------~REF

__ ~ ....._ _,

14----1 DC
STIMULUS
0-9.99VOC

j:: .------.

._ ___,' ·n: ct
~ TRANS
~a:I 0sc

!+--1
L---.J

,.....__c_o...,NTROL _I RESPONSE

MONITOR r::P""o"'w~ER::--""'

MONITOR

ADAPTER

LOAD

ADAPTER t-+iLOW

CONT

FREQ

SWITCH

SWITCH

0.99 DB ATTEN/ AMPL

AUDIO AMPL

~
RATIO TRANS

DC
H STIMULUS
0-9.99VOC

.z....
2
LLJ Q:
e:::n>

~ - lcoNTROL RESPONSE

]..J HIGH

-==-

FREQ

CONNECTOR PANELS

J MONITOR RESPONSE1----:~:---:=--_=---------.:--,.------~---l

OC
~STIMULUS
250-850 voe

ct

RESPONSE STIMllLUS

LLJ

::E

DC

STIMULUS

Dimate was especially designed to test

250-850 voe

Army communications, navigation , and

identification sets. It is now being

UUT

used to check out manpack radios. A

photo of the equipment is on page 94.

L

RF VERNIER

i.1

VHF
EXTEND 14'
ANO MOO

r FREQ STD
l
PULSE GEN
I
DC STIMULUS 5-36 voe

DC STIMULUS
5-36 V DC .:.:.E..

Ienc>n-

a:I

DC STIMULUS

c:::n>

5- 36 voe cn

:::>

~

:::>

2

OC

I-

STIMULUS ui,

20-300

voe

. ~ .......

Electronics I August 23, 1965

91

-

-
~11

--·]

.f.:-IJJ.

ETS-1 shelter for the Army's Multisystem Test Equipment. Units under test are connected to the panel above the operator's work bench at left. The visual instructor, as well as a test result panel and printer, are also located over the test bench. Measurements chassis are housed in the rack at rear left, to the right of the test bench. Power supplies are at right foreground and low-frequency stimuli at right rear.

develop and validate the test program for the Shillelagh. Sets 2 and 3 and the RSS-1 are expected to be delivered to the command about the last quarter of 1966.
LCSS sacrifices some automatic fault isolation in return for simplicity. The system must be transported to the field, and once there, it must be used by technicians who may not be as skillful as laboratory specialists. Although the equipment is capable of a wide range of performance tests, it does not have the sophistication of the parent .\1TE system. It does not contain a computer, and program information is fed to the controller by punched paper tape or manual keyboard. Unlike .\1TE, the manual keyboard which is usually operated by a skilled technician is not stored in the LCSS shelter. Automatic fault isolation is carried out only to the major chassis level. Fault isolation at the subassembly level is performed in the RSS-1 by standard test equipment.
Because LCSS engineers converted much of the .\1TE design to integrated circuits, the LCSS is much smaller. One LCSS test reference chassis takes the place of a whole rack of equipment in the parent MTE system. Integrated circuits were also used in the digital multimeter, signal generators, pulse generators and power supplies. The power supplies are programable and can deliver up to 40 volts and 2 amperes, with an accuracy of 50 millivolts.

Dimate keeps troops talking
Troops in the field rely on good communications equipment to help them stay alive. Making sure that they get this equipment in top operating condition is the responsibility of Army supply depots spotted around the country. The Materiel Agency at the Tobyhanna Signal Depot is using Dimate to check out radio sets as fast as th ey can be pulled from stock. [Electronics, July 12, 1965, p. 49].
Much of Dimate is identical to MTE. It contains low and high frequency stimuli, a control console, computer-controller, measurement equipment, and power supplies. Magnetic and punchcdpaper tapes are used to supply test instructions to the computer-controller.
Dimate programs usually consist of a combination of computer instructions and controller instructions. Program control is shared. Special computer instructions are necessary to transfer the program back and forth ; in some cases the system can be programmed so that the computer and controller operate concurrently.
These instructions set up voltage reference levels, power supply voltages and other test stimuli for the units under test. Visual instructions for some tests are also given to the operator by the same projector used in MTE.
There are three basic test sequences. The first is a survey to see whether the Dimate system can

92

Electronics I August 23, 1965

provide the correct stimuli to perform the test and to check out the Dimate system itself; the second is a static test in which the radio equipment is checked for short circuits; the third is an acceptance test.
To permit quick testing of a large number of sets, the acceptance test has two parts. For example, a check of transmitter power, signal quality, and receiver sensitivity can provide go-no-go information for a transceiver. If any factor is b elow the acceptable limits, the operator can elect to put the set aside, rather than hold matters up by further testing.
When he does complete the test, he can read the results-the kind of defect, and the unit numb er, manufacturer's number, ordnance number, and federal stock number of the defective componenton an alphanumeric tape printer.
Airplane checker
Another area where th e Army is effectively using automatic test equipment is for th e avionics systems of some of its surveillance aircraft. In 1961, RCA designed for the Electronics Command a completely automated preflight and operational status test set that could assess the condition of all communications, navigation, instrument landing and identification equipment then installed or planned for the '60s and '70s. The set can be operated by one man and does not require exten-

sive removal of equipment from the aircraft; indirect coupling by radiating techniques reduces complicated test connections.
The finished version is called the Preflight Test
Set (PTS) ; the Army designation is the AN I ASM-
88. It can perform an over-all dynamic check of the complete avionics system of an Army surveillance aircraft. For example, when the PTS is used to check out the ARC-73 radio, the operator gets into the cockpit carryin g a portable remote control and display unit. H e plugs into th e audio jack of the ARC-73, and turn s on the power to both th e test set and the radio. He then adjusts both sets to the same frequen cy and pu shes the start button, and the PTS transmits a signal to th e receiver in the plane. If th e receiver is operating satisfactorily, a go-light shows on the remote control unit. The transmitter portion of the receiver can be similarly checked. PTS makes an over-all sys tem test; it won 't tell which part of the receiver or transmitter is bad. Therefore, if a no-go signal is obtained, the entire set mu st be pulled and sent back to the service shop for repair.
Because most airborne radar operates at microwave frequencies, PTS n eeds a frequ en cy range extender, to ch eck out th e APS-94 surveillance
radar, the A I APN-129(V) naviga tion radar; the
AN/ AP -22 radar altimeter ; and the AN/DPN62(V) radar tran sponder, aboard the Army's OVlB Mohawk aircraft. Tes t of this C, X, and Ku

Quick testing

· measurii1g the potential between Pl-14 and Pl-15. The voltage

measured should be approximately

When a no-go condition is indi- -52 V d-c. An absolute measure-

cated by the RCA's Multisystem ment of less than 44 volts indicates

Test Equipment, certain diagnostic that either R1 or C1 and K, is

tests must be made to isolate the shorted. If R1 shorts , the reading

fault. MTE performs them auto- will be approximately -35 volts and

matically. The illustrated circuit, if C1 or K, short, the reading will

which is part of a Nike-Hercules, be approximately -39 volts. Test

interval timer, is being checked for 45 differentiates between these two

shorts and opens; 61 tests are re- conditions.

quired to check out all the com- " Tests 46 through 48 check that

ponents in the timer. Pages 3- C1 is not open. These tests take

5 of the test manual for the timer advantage of the fact that the coil

describe the manner in which of K1 in parallel with filter capaci-

some of them are performed:

tor C1 form a tank circuit with a

"Test 44 and 45 check that R1, resonant frequency of approxi-

or C1 and K1 are not shorted. This mately 135 cps. The -100 V d-c

is accomplished by applying a is applied through R2 to the net-

-100 V d-c stimulus between R2 work in order to forward bias the

in the adapter box and Pl-15 and selenium rectifier CR1 to a point

where its resistance is very low. A variable frequency a-c signal is then applied through R:i and C2 to the same circuit and, since the diode is forward-biased , the a-c signal (without rectification) is impressed across the tank circuit. Test 46 applies a 40 cps signal
and an a-c measurement is made across Pl-14 and Pl-15. This measurement is called TV-1 and is stored in the computer. The test is repeated at successively higher frequencies . The computer compares TV-1 with TV-2 and TV-3. If C1 is open , TV-3 will be greater than TV-2."
The equivalent circuit diagrams for these tests are shown below MTE perfo1ms the tests in less time than it takes to read about them.

P1-14

-=- 48V E=IOO
+

V 52 V

Pl-15
Electronics I August 23, 1965

K1 -- - E=100
+

V A-CV

c,

Pl-15
93

.] ~
.Ill
.-i! j

Dimate, the depot installed maintenance automatic test equipment being supplied to the Army Electronics Material Agency, is a modularized test system capable of automatic, semiautomatic, and manual operation.

band equipment is carried out by the Mohawk adapter test unit with no physical connection being made to the aircraft's transmitter or receiver.
Navy saves men and space
The Navy has special space problems which shape its need for automatic tes t equipment. An aircraft carrier is huge, but its space is strictly allotted. The 48 rated electronics technicians aboard have to be proficient in all kinds of surface radar and avionics. At present, th ere is a shortage of technicians ; the Navy hopes that automated equipment

will perform better testing with fewer men. The first big automatic test program for the Navy
is Project VAST (Versatile Automatic System Test). VAST is an outgrowth of the N avsea studies, which were carried out in 1961 to determine what was required to service fleet avionic equipment, and to devise a more automated method of testing. On July 1, the Navy signed a $5.9 million contract with PRD Electronics, Inc., in Westbury, . Y., for a developmen tal model of the VAST test sys tem. How many systems will be purchased during the entire program is still b eing decided, but the Navy

Name
AN/GJQ-9 Robotester
Di mate
DACE
MTE
VATE
Saturn Checkout VAST

Comparison of typical automatic test systems.

Manufacturer
Bendix Support Lavoie
RCA
North American, Autonetics div. RCA
Hughes
RCA
- PRO Electronics, Inc.

Status
operational operational prototype operational operational operational operational · prototype

Program Sequencer
paper tape
paper tape

Comparator
digital analog

magnetic or paper tape
paper tape

digital analog

magnetic or paper tape
magnetic drum
magnetic drum
magnetic drum

digital
digital
digital
"
digital

Service Application
Air Force Mil. and commercial Army (depot)
Navy (A6A, EZA, RA-SC) Army missile systems Air Force
NASA (Cl and CS) Naval avionics

94

Electronics j August 23, 196S

expects to have at least one aboard each large carrier. This would mean about 50 VAST sites, including shore repair bases. Each VAST station will cost about $2 million.
Despite its name, the VAST system is not physically as large as some of the other major automatic test systems. But it is designed to test about 85% of the avionic systems that are now in the inventory or are expected to be included by 1970. Until now, most of the Navy's avionic test systems have been custom-designed and delivered by airframe manufacturers.
Two-station tester
The VAST system is divided into two main sections: the test station and the computer station. The computer station, which contains the CP 789/UYK (Univac model 1218) computer and mass memory unit (Univac model 1240) serves as the prime source of control commands, and performs all computations and comparisons. One computer station can be time-shared to run as many as six test stations. The test station itself is divided into two subsections: the data transfer unit and the stimulus and measurement section. The data unit acts as the interface between the computer station and the measurement section; it processes signals that pass between the measurement section and the computer, and sets up the test system operating modes.
About 50 independent programable stimulus generators and measurement units are available for use in the measurement system. These modules include 17 signal generators, with a frequency range of 0.1 cycle per second to 18 Ge; pulse and pulse code generators; noise and pressure generators; 14 monitors that measure frequency, impedance, voltage, waveforms, and signal spectra; 6 power supplies; 3 test switches (r-f, video, and power) ; and miscellaneous amplifiers and standards.
Each generator, measurement block, power supply and amplifier contains a special black box called a universal decoder. Since all the system's addresses are carried by a single instruction line, the decoders are set to respond to a single address. This response then allows the unit to receive subsequent instruction commands from the computer.
Testing at sea
A VAST operating manual designates the correct adaptor cable, hookup instructions, special requirements and test instructions for each set that may be tested by the system. A technician puts the prescribed test connections into the test point switch panel and requests "program start" on the data transfer unit. The computer finds the needed test program on the magnetic tape in the Univac 1240 memory unit and transfers it from the tape memory core matrix.
The computer uses the information stored in the core to set up the test stimuli for the unit being tested, as well as to evaluate the test results. With the data transfer unit, the technician may inject any special steps which he may think necessary to

complete the testing sequence, or to pass over a particular parameter-that is, to continue testing without stopping to repair the fault.
Keeping Polaris on course
The Navy also has an automatic tester for its Polaris guidance system. Designated the MK452, it is built by General Electric's Defense Electronics division in Pittsfield, Mass. Although it was specifically designed to test the Polaris MKl and MK2 inertial guidance system, it can be adapted to test other kinds of inertial guidance or control systems.
Program information is fed into the MK452 computer by a standard perforated tape. The instructions read by the tape reader set up the equipment for each test, set the limits in the measurement system, set the gains of torque amplifiers, and select the earth rate (the apparent angular motion of a space-stabilized gyroscope caused by the earth's turning on its axis at 15° per hour) input and other inputs appropriate to the location and test.
The computer completes the test by evaluating and printing out the test results on an electronic typewriter called a Flexowriter. It then transmits a "pass or fail" signal to the measurement subsystem and terminates the test.
Air Force spends most
The Air Force's three big programs, VATE (Versatile Automatic Test Equipment), GPATS (General Purpose Automatic Test System), and the ground support system for the F-111 fighterbomber [Electronics May 31, 1965, p. 37] represent the largest dollar volume spent on automatic test equipment by any of the three branches of the military. The F-111 ground support equipment is special-purpose, designed to test the complete avionics system of this supersonic fighter. The test system consists of 15 Agerds (Aerospace Ground Equipment Requirements Data), or test stations. Each Agerd is designed to test a particular portion of the plane's avionics. Special stations check out infrared trackers, optics, radar, communications flight controls, and power systems. The A T/ GJQ-9 will be used to program each Agerd test.
The Air Force and the General Dynamics Electronics division in Rochester, manufacturers of the F-111 ground support equipment, have revised the initial special-purpose concept. The new concept, called TASC (for Total Avionic Support Capability), in effect makes the equipment general-purpose, and able to support other systems such as the advanced Mark II avionics system for the F-111, the avionics systems for the C-5A jet transport and the F-4C fighter, the integrated helicopter avionics system, and the integrated light attack avionics system.
Building blocks for GPATS
GPATS began in 1958 as an Air Force study to _determine to what extent automatic electronic checkout could be applied at Air Material areas and depots. The study, conducted by the Dayton

I Electronics August 23, 1965

95

Air Force Dep., resulted in a modular approach which could be made flexible enough to meet the requirements of a variety of airborne systems. The hardware development contract was awarded to the Emerson Electric Co., in St. Louis, Mo., which designed a system that consists of a programercontroller, 49 building blocks, a tape preparation and verification device, 12 universal equipment racks, and other accessories.
GPATS can isolate faults at five levels; system, subsystem, line replaceable unit, module, and piece part. The system was certified in September 1964, and since that time has logged more than 3,500 hours of test time.
Missile system
The hundreds of defensive missiles, with their complex guidance systems, and the shortage of trained service personnel helped to convince the Air Force that an automatic missile checkout system was necessary. In December 1961, the Air Force contracted with the Hughes Aircraft Co. to build and install the Versatile Automatic Test Equipment (VATE) system at its centralized special repair activity at the Newark, Ohio, Air Force Station. The Air Force wanted VATE to test the Hound Dog, Atlas, Titan II, Minuteman, Skybolt and other missiles.
VATE is a computer-controlled automatic tester that trouble-shoots faults by deductive logic and isolates them to the plug-in module or component level. The VATE system has two or more subgroups, known as HCM-lll's, consisting of a general-purpose, high-capacity computer and up to eight test stations. The computer has a 2,300-rpm rotating magnetic drum for its basic memory of 40,000 22-bit words. A number of magnetic core shift registers supplement the system for quickaccess temporary memory.
To facilitate programing, all electronic input
+ and output actions at the test stations are per-
formed by direct command. A "2 l" address order is used; that is, one command contains the operational instruction, such as "add," plus two memory locations containing the numbers to be added. The command also designates the analog input.
Making all stations 'Go'
'i\Then American astronauts take off for the moon, everything in and on their rocket, command module and lunar orbiter will have been checked out by one of the most complex automatic test systems ever devised. Called ACE-S/C, for Acceptance Checkout Equipment/Spacecraft, the system is being built by many different companies, chiefly North American Aviation Inc., the Grumman Aircraft Co., Boeing Aircraft Co., General Electric Co., Control Data Corp. and the Radio Corp. of America.
Tests on the S-lC, the first stage of the Saturn V Apollo launch vehicle, will be controlled by an RCA HOA general purpose digital computer. More than 150 relay racks will house the test equipment.

A separate system, consisting of a Control Data 924A general-purpose computer and a number of test stations, will check out the second stage. Tests arc planned on completion of manufacture and both before and after the static firing tests. With both a core working memory and magnetic tape bulk storage, the computer can transfer information at a 200-kilocycle rate, making it capable of an on-line analysis of system operation.
Like the Army's MTE and Dimate automatic systems, this system is capable of performing diagnostic test as well test routines for complete system analysis when performance variations are determined by the computer program. It uses automatic, semiautomatic and manual methods to locate a fault. Which mode is chosen depends to some extent which test stations are in use; some have only manual systems and some only automatic. When the operator has a choice, the complexity of the equipment under test and the reliability requirements will be the determining factors.
Semiautomatic methods
Semiautomatic techniques may be used when the operator wants to save time and yet maintain some personal control over the test procedure. In this technique, the computer generates the primary commands to the circuit under test, while the operator watches displays to verify the test. The operator may command certain tests manually, ancl have the computer monitor the events; or he can manually operate a circuit and monitor the events on displays. In any case, the signal inputs will go by the same paths.
Extensive self-checks are used to assure correct operation of the test system. For example, echo checks are used to verify the integrity of the signal paths between the computer and the checkout station under control. The computer is programed to transmit a data word which energizes both the computer and test station's input-output circuitry. The original data word is retransmitted to the computer, where it is compared to the original. Signal quality, and checkout station measurement are also computer-tested. For measurement checks, the computer sends a calibrated signal, which is both a command and a reference, to the device under test. The computer then compares the measurement with the known signal input. If the measurement is out of tolerance, the computer proceeds with analytical tests to isolate the fault.
Commercial equipment
The most popular piece of off-the-shelf automatic test equipment is the "Robotester," made
by Lavoie Laboratories, Inc., of Morganville, N. J.
This universal automatic tape-programed te<>t set is being used by all branches of the military, as well as by commercial companies, for all types of static and many dynamic diagnostic tests. To date, more than 700 sets have been delivered.
The Robotester can perform up to 100 tests per minute on any two of 250 randomly selected circuit

96

Electronics I August 23, 1965

A truck containing the Mohawk adapter test unit (AN/ASM-88) drives up to an Army OV·lB to check its radar. No connection to the receiver or transmitter is necessary.

points. Programed acceptance standards cause automatic operation to stop when an out-of-tolerance value is met. The system measures resistance, a-c and d-c voltages and impedance. Faulty circuits are identified by digital readout.
No cure-all
Automatic test equipment creates a number of problems even as it solves others. Since the test equipment itself is complex, and sometimes has more component parts than the equipment it is testing, its mean-time-between-failures may be low. Moreover, it may cost as much to program the system as it does to produce the hardware.
The program of a digital device is an orderly configuration of bits-binary ones and zeros. This information, which is stored on magnetic tape or cores, causes the testing device to perform in a desired manner. The total program is a mixture of commands and data and includes three major classes of operation: input-output operation, such as printing and reading information from storage devices; data processing operations, such as arithmetic comparison of digital numbers, and digital message formats; and decision operations, such as go-no-go.
Getting the machine to perform these three operations logically is the function of the programer, who must translate the test requirements into a language from which the machine will operate.
Machine language itself, the form in which a computer actually sees instructions, is seldom used by programers because its complexity makes it

unwieldy. Instead, they work in symbolic or problem-oriented languages which can be translated into machine by a special compiler.
Now Berton West, of the Battelle Memorial Institute in Columbus, Ohio, is working on a project called "Place," in which a compiler could be programed to translate into machine language directly from English. Such a system could work with several kinds of automatic testing equipment and would cut programing cost.
For many years, prime equipment users have complained that the equipment manufacturers ignore maintenance problems in their designs. Testing had been hard to perform; testing areas were physically inaccessible, packaging methods split circuits at sensitive and unnatural points, and circuit-sharing schemes did little to reduce prime equipment cost but doubled test cJrnrges. Now "testability" in equipment design must be placed at the same level as any other functional operation of a proposed system, and government purchasing agents specify test access provisions.
Automatic equipment can bypass accessibility problems, but since it is relatively inflexible with respect to its acceptance or rejection limits, the test needs of the prime equipment must be carefully calculated. In addition, the military's interest in general purpose equipment that can check out many different prime systems will require standardization of jacks, connectors, and other interface components.
In short, the screwdriver has become as complex as the radio. But now it does a better job.

I Electronics August 23, 1965

97

Manufacturing

Aluminum bonding is key to 40-watt microcircuits

High-power silicon devices run too hot for regular gold bonds. Thick aluminum leads prevent purple plague, while aluminum mounting alloy keeps the chips cool

By Edward M. Ruggiero
Norden division, United Aircraft Corp.. Norwalk, Conn.

New aluminum bonding methods and a new alloy have breached the thermal barriers which prevented the operation of integrated circuits at very high power. Proof of this is the circuit on page 99, a 40-watt servo amplifier. Probably the most powerful microcircuit ever made, it can directly drive the motors of heavy electromechanical equipment.
By comparison, previous microcircuit amplifiers. even those made with several silicon chips, have been considered high-power if they operated at a few watts. Amplifiers rated at 5 to 10 watts have been hailed as breakthroughs.
The 40-watt circuit owes its high power rating to the use of a new method of bonding aluminum leads and to an aluminum alloy for mounting the dice (silicon planar chips). Both techniques were recen tly developed by the Norden division of the United Aircraft Corp.
Norden is now using aluminum leads on all circuits in production and will soon use the die-mounting alloy in a line of integrated amplifiers. These will include Class A amplifiers rated at 1 to 8 watts [Electronics, July 12, p. 127) and Class B servo amplifiers rated at 3 to 40 watts. Initially, these are being made in the multichip form shown,

The author

Edward M. Ruggiero, a chemist, has devoted his professional career to the assembly and packaging of specialized integrated circuits at Norden. He joined Norden's solid state engineering section in 1961. Ruggiero earned his B.S. degree at Fordham University and his master's degree at the City College of New York.

but development work on single-chip versions has begun. Both types are packaged in a modified T053 case, a type normally used for high-power transistors. The package is about 0.8 inch square and 0.35 inch high.
Beating the heat
Power ratings can be higher with the aluminum techniques than those with conventional gold bonding for three reasons:
· Gold bonding causes purple plague,1 which can result in catastrophic failure of a circuit (see panel on page 104). Aluminum leads prevent it.
· As circuit power rises , more heat is generated. The heat must be removed from the package to make circuit operation efficient and extend circuit life. The new mounting alloy, principally aluminum and germanium, avoids plague; but its chief advantage is a thermal resistance far lower than those of gold alloys and other conventional materials.
· The aluminum-based packaging system enables silicon devices to be processed, sealed and tested at higher temperatures, which promotes higher reliability. The Torden circuits now withstand 1,000 hours of storage at 300°C. A new package, in which aluminum-coated feedthroughs replace gold-plated feedthroughs, is undergoing thousand-hour storage tests at 400°C.
Such high-temperature capability is desirable in · low-power devices. It is essential to high-power devices, since junction temperatures may reach nearly 200°C.
Aluminum lead bonding
Norden uses l 1h-mil-diameter (0.0015-inch) aluminum wire as leads. They are thermocompression-

98

Electronics I August 23, 1965

Forty-watt servo amplifier is made with three silicon chips, two carrying high-power transistors and one for control circuitry. Leads are aluminum wire; chips are aluminum-bonded to molybdenum.

bonded to the aluminum thin films on the chips and to the fecdthrough posts of the package header. The posts arc gold -plated in the present package.
The bonding machine is a modified bird-beak bonder made by the Kulicke & Soffa '.\1fg. Co. The technique is so named because the wire is fed through a two-jewel bonding tool. The Jorden modifications ancl their use arc shown below. The bonding and wire-holding jewels, of synthetic ruby or sapphire, arc not heated. The silicon chips arc

h eated to 350°C in nitrogen, which prevents oxidation of the aluminum.
The underside of th e bonding jewel is shaped so that it forms a rib, about 1 mil in diameter, on the wire as the bond is made. The rib adds mechanical strength and current-carrying capacity to the bond, while th e flattened underside of the wire makes for excellen t adhesion and electrical contact to the underlying thin films.
Once the bond is made, the vacuum clamp holds

WIRE SPOOL

WIRE

FEED GROOVE AT REAR OF JEWEL

HOLDING ~ JEWEL

-

BJ.EO-WN-DEIL-N-G-----_,~.-_~-----~-

ALUMINUM
TH IN FILM

___________.l...- cH IP

- - - - BONDING

~

JEWEL

W..L-- - -- WIRE

RIB IN WIRE

Bird-beak bonding method employed by Norden. Strengthening rib is formed in wire as it is bonded to thin film.

Electronics I August 23. 1965

99

-
Bond made with aluminum wire supports entire weight of 10-lead header. The wire is too small to see.
the wire. The wire breaks cleanly at the edge of the bond when the tool is moved horizontally away from the bond. This avoids short circuits due to tails or loose ends on the bonded wire. Double bonds are made on the posts befor~ the wire end is broken free.
Bonding pressures vary from 25 to 125 grams and bonding times from 1 to 6 seconds, depending on the thickness, purity and physical conditions of the aluminum film on the chip and gold plating on the posts. The right wire
Avoiding purple plague was the main reason aluminum leads were selected. The choice of material, wire dimension and bonding technique were also influenced by requirements of strength, conductivity and compatibility with the aluminum thin film on the chips.
The wire diameter, l % mils, is the largest that can conveniently be used. It results in a bond area about 4 mils square, as big as most bonding pads can take.
The diameter is ample for the wire to meet military specifications for vibration, shock and acceleration. Since aluminum is lighter than gold (2.7 grams per cubic centimeter for aluminum, 19.3 for gold), the 1%-mil wire weighs less than the conventional 1-mil gold wire. The aluminum wire won't move during 50,000-g acceleration; 1-mil gold wire does move, which can cause one lead wire to short another during periods of violent stress.
Pure aluminum (99.99%) and aluminum with 1% silicon have been used successfully. Pure annealed aluminum's tensile strength is 6,875 pounds per square inch compared to 19,000 psi for gold. The

pure aluminum wire is strong enough for military specifications; adding 1% silicon makes the tensile strength about as high as gold's.
The 1%-mil diameter also provides enough material for the bond rib. The rib makes the bond stronger than conventional wedge bonds, which squash the wire. (The other type of conventional bond, nailhead or ball bond, has not been made with aluminum). The strength of a rib bond is indicated by the photo at left.
The !112-mil diameter can safely carry an ampere of current. Aluminum's resistance is slightly higher than gold's, but because of its larger diameter, the 1112-mil aluminum wire is far more conductive than 1-mil gold wire. The rib retains this advantage in the bond.
Plague at the post?
Does bonding aluminum wire to gold-plated posts transfer the plague problem from the chip to the post? No; one photo on page 102 shows a post bond after 1,000 hours at 300°C, and the small amount of discoloration indicates relative freedom from plague. Another photo on page 102 shows what happens when gold wire is bonded to a chip.
On the chip, the problem apparently is consumption of the aluminum thin film and loss of adhesion.3 The film is only about 1 micron thick, while the wire is about 375 microns thick. Even doubling the film thickness wouldn't help much if the 250micron (1-mil) gold wire were retained. Also, the gold on the post is fairly thick, approximately 6 microns, and has excellent adhesion to the Kovar base material of the post.
The bond shape reduces wire thinning (squashout), which slows plague formation by limiting the diffusion area. Bonding the wire twice to each post further combats failures due to plague.
Furthermore, silicon-which may promote plague formation-is essentially absent at the post. Even the 1% silicon added as a wire strengthener is apparently too little to be detrimental. Nevertheless, ways of strengthening the wire without using silicon, and of using aluminum posts, are being investigated by Norden.
Plague at the header
Switching to aluminum leads, which is not new, solves only half th e plague problem and does virtually nothing to relieve thermal problems in highpower planar devices. The Norden die-mounting technique attacks both these problems simultaneously.
Gold is eliminated from the mounting area of the package header by use of the aluminum-germanium alloy to mount the silicon chip on a molybdenum pad. The usual technique is to use a gold alloy for mounting, often gold-silicon eutectic solder, and make the header of gold-plated Kovar, molybdenum or alumina metalized with molybdenum.
A gold alloy, particularly gold-silicon, and a goldplated surface should not be used with aluminum lead wires if the metals are to be subjected to high

100

Electronics I Auaust 23. 1965

Types of bonds: left to right, wedge, bird-beak and ball,

Thermal resistance of dice mounts

alloy and header

Resistance (°C/watt) run 1 run 2 run 3

Gold-silicon alloy

gold -plated Kovar . . ... ..... 6

6

5

nickel-gold -molybdenum. . . 2

4

5

Aluminum alloy

unplated Kovar...... . . . ... 2

3

2

unplated molybdenum·.. . . < 1

<1

<1

temperatures. Often, to provide a base or ground connection, a lead must be bonded to the header. The chances of plague forming at the bond are high. The aluminum is likely to touch the smeared gold alloy. The header is also likely to be hot, since it is the heat sink for th e device. The higher the device's wattage, the higher the temperature here.
Aluminum leads, aluminum alloy and the b are molybdenum header eliminate the causes of plague.
Thermal resistance lowered
Molybdenum is u sed as the die mount becau se fts thermal expan sion nearly matches silicon's. The

aluminum-germanium alloy enhances this match b ecause it is soluble in molybdenum (Kovar could be used, but the alloy is less soluble in Kovar). The alloy is also soluble in aluminum, which is alloyed into the underside of the silicon chip to prepare it for mounting. The mounting is done at temperatures above 400° C, without Hux and in a nitrogen atmosphere.
The solubility is needed for adequate cooling of the dice by the header. Without solubility, interfaces would be created between the dice and the alloy and the alloy and the header. Such interfaces act as impediments to heat How, raising thermal resistance between the device junction and the case.
Thermal resistance is negligible with the Norden
technique. It is less than 1° C per watt in one de-
vice (see table above), but this is an approximation because the resistance was too low for accurate measurement by the method used. The thermal resistan ce is several times higher when a gold alloy is used, as th e table indicates . The gold alloys with the silicon and with the gold plating on the header, but there is an interface between the plating and

Failure rates of gold and aluminum wire bonds

Bond location

Standard gold-wire bonds

wedge

bird-beak nailhead

Both types on same chips gold bird-beak Norden aluminum

Interconnections

Wires bonded ....... . .... . . 94

139

165

60

60

failures .. . .... .. ... . . . ... . . . 14

12

9

5

0

percent of failures ..... . ... . 14.9

8.6

5.5

8.3

0

Contacts

wires bonded .............· 91

132

113

60

60

failures .. .. . . . ..... . .....···

9

7

4

4

0

percent of failures .········

9.9

5.3

3.5

6.7

0

Eectronics J August 23, 1965

101

After 1,000 hours storage at 300°C

Gold bonds made to alloyed contacts (right) show more purple plague than gold bonds to interconnections (left).

Purple plague surrounds gold bond (left), but aluminum bond (right) is undamaged.

Gold bond to alloyed contact (left) survived despite plague. Loss of film adhesion made bond at right fail.

Aluminum bond made to top of a gold-plated post. Plague has formed, but not enough to destroy the bond.

the base material. A plating just sits on its base; it doesn't a11oy with it.
The tabulated data was obtained from a multicollector, silicon power transistor similar to those in the amplifier shown on page 99. Dice size is 87 by 47 by 5 mils. Each run was conducted over a power range of 1 to 20 watts, giving an average thermal resistance for that range. Junction-to-case thermal resistance was calculated by using transistors as the heat source and for temperature sensing.
A measured amount of power was applied to the transistor. It was switched off momentarily to measure the forward base-emitter drop, which had been calibrated as junction temperature. Internal case temperature was obtained from a reference base-emitter junction mounted close to the power junction. From these measurements, thermal resistance in degrees centigrade per watt was calculated. [Thermal resistance was discussed in a report on transistor cooling in Electronics, Sept. 7, 1964, p . 92].
Dice were mounted with gold-silicon alloy on

two kinds of headers: gold-plated Kovar and nickelflashed, gold-plated molybdenum. Identical dice were mounted with the aluminum-germanium a11oy on unplated Kovar headers and molybdenum headers.
As previously noted, th e higher th ermal resistance of gold-plated Kovar is du e to an interface. The lower figure for nickel-gold-molybdenum may be due to a difference in interface res istance. The low figure for aluminum-Kovar and the lowest figure, for aluminum-molvbclcnum, results from the mounting alloy's solubii°ity in those metals. The interface in the first case, and the absence of it in the latter, can be seen in the photos on page 103.
Processing benefits
The aluminum-germanium alloy also has processing advantages. Its melting point, above 400°C, makes safe the use of sealing temperatures higher than with gold-silicon a11oy, which melts at 376°C. The circuits can also be aged and stabilized more rapidly at the higher temperature. Often, a l0°C temperature rise will double a chemical reaction

102

Electronics I August 23, 1965

..-GOLD-SILICON MOUNTING ALLOY AND GOLD PLATING
~KOVAR

SILICON
0ALUMINUM-SILICON / ALLOY ~ALUMINUM MOUNTING
ALLOY
""ALUMINUM-MOLYBDENUM SOLUTION
""--MOLYBDENUM

Cross-sections cut through chips mounted on headers by the conventional method (left) and with the aluminum alloy (right). The absence of an interface between the aluminum and molybdenum lowers thermal resistance.

rate, while a 25°C rise will double the rate at which impurities diffuse in silicon.
An alternate mounting material is Pyroceram, made by the Corning Glass Works. It does not contain gold and is good up to 425°C. However, Pyroceram gives very high junction-to-case thermal resistance, is not as strong as metal and is an insu-

Reliability tests

Tests

Test conditions

Wire bonds

Dice mounting

High-temperature storage
Shock MIL-STD-750
Vibration MIL-STD-750
Acceleration MIL-STD-750

1,000 hours at 300° C
Method 2016 (5 blows each direction, 500 g, 1 millisecond)
Method 2056

1,000 hours at 300° C
Method 2016 (5 blows each direction, 800 g, 1 millisecond)
Method 2056

Method 2006 (20,000 g in all six directions)

Method 2006 (20,000 gin Y axis)

lator, preventing electrical contact to the mounting surface.
Like the gold-silicon alloy, the aluminum alloy does not match the thermal expansion of silicon. Both, however, are soft enough to absorb thermal strains that might otherwise fracture the chip.
Reliability of wire bonds
Comparative tests of the reliability of gold-wire bonds and Norden's aluminum-wire bonds show a failure rate of 6.7% for gold bonds and no failures for aluminum bonds (see table on page 101).
Test units were Norden integrated circuits which have aluminum-silicon alloyed contacts and aluminum thin-film interconnections over silicon dioxide. The dice were mounted with gold-silicon alloy on T0-5 headers. The gold bonds were made of 1-mil wire with standard bird-beak bonders, the aluminum bonds with 1112-mil wire and the modified bonders. After bonding, caps were welded to the headers in nitrogen.
To prevent processing differences from clouding the results, test units were taken from four produc-

Electronics I August 23, 1965

103

The cause of purple plague
It has long been known that purple plague can seriously degrade the reliability of semiconductor devices. Restating the causes and effects of plague helps put the orden techniques into perspective.
Plague is a compound formed by the intimate contact of aluminum and gold. It forms by diffusion of the metals, slowly at room temperature and rapidly when the metals are hot. A bright purple compound forms almost instantly, for example, when a gold film is vacuum evaporated onto a hot film of aluminum. Silicon also seems to accelerate plague f01mation.
Plague is the price paid for the desirable characteristics of gold leads and aluminum films in silicon planar devices and integrated circuits. Aluminum is a nearly ideal material for thin-film contacts and interconnections. It alloys easily with silicon , adheres well to silicon dioxide and suits the manufacturing process. Gold is a good lead material and bonds well to the aluminum.
However, device fabrication and operation give plague an opportunity to form . Bonding temperatures go up to 350°C, vacuum bakeout for stabilization before sealing requires temperatures up to 300° C, and package sealing temperature may be as high as 400°C.
Jn low-power devices, plague formation can be kept below the danger point by careful processing, methods of strengthening gold-aluminum lead bonds, and restrictions on device storage and operating temperatures. Such avoidance techniques only

postpone the inevitable in high-power devices , whose junction temperatures may be nearly 200°C during operation. The only sure cure is a metal system other than gold and aluminum.
Breeding ground. Plague is a problem at two places on a silicon device chip:
· Alloyed contact. An aluminum film applied to exposed silicon, for example at a transistor c0llector, alloys with the silicon at 577°C. The gold of a lead bonded to the contact consumes aluminum to form AuAb or another Au-Al compound. However, the plague appears "alloyed" down into the silicon along with the aluminum. This may lower the number of contact failures caused by plague, by helping maintain bond adhesion.
· Thin-film contact. In integrated circuits, leads are normally bonded to aluminum films atop a silicon dioxide passivation coating, not to alloyed contacts. As the gold consumes the aluminum film , the film
loses adhesion to the glassy Si02 and the bonded wire can easily tear loose. Plague is a more serious problem in integrated circuits than in transistors for this reason , and the need for more leads on the circuits further compounds the problem.
Norden's tests, discussed on page 103, confirm these failure modes and underscore the advisability of aluminum-aluminum bonds. The present package is not an absolute guarantee against plague, since aluminum leads are bonded to gold-plated posts on the header. However, the chance of a harmful amount of plague is negligible and even this possibility will be eliminated by the planned use of alumi:numplated posts.

tion batches, and both gold and aluminum bonds were made to alloyed contacts and thin films of each unit. T ests conditions are given in the table on page 103.
The aluminum-aluminum bonds did not discolor. There was some discoloration where aluminum wire was bonded to the gold-plated posts, but none of these bonds failed. One photo on page 102 shows an aluminum bond next to a gold bond, where plague was formed.
The discoloration of the gold bonds was greater at bonds to aluminum-silicon contacts, b earing out the theory that silicon helps form plague.2 However, more of the gold bonds to interconnections failed, indicating that loss of adhesion is a more serious problem than plague alone.3 The contacts are rich in silicon, while silicon can be present at the interconnections only through diffusion, or possibly by reaction of the aluminum with the silicon d i o x i d e .4
Tests were also made on similar circuits, with gold bonds made by the three conventional thermocompression bonding methods: wedge, ball or nailh ead , and bird-beak. The table on page 101 gives the results. The lower failure rate of the ball bonds indicates that less squashout of a wire h elps retard plague formation. In ball bonding, the wire end is formed into a ball that is pressed on the film.
Reliability of die mounting
To check whether the new mounting alloy produces detrimental effects, transistors and integrated circuits were subjected to the te~ts tabulated on

page 103. Gold-mounted units were used as a reference. No failures were traced to either mounting method.
Preliminary results of further tests, at a storage temperature of 400°C, indicate that the Norden technique will prove reliable at this temperature. The headers have aluminum posts. Gold-mounted units cannot withstand 400°C; the gold-silicon alloy melts and consumes the dice.
The ability to withstand storage at 400°C is added assurance of long life at normal operating conditions. Moreover, it is desirable for reliability testing. In their report on the median life of silicon mesa, transistors , G. C. Sikora and L. E. Miller show that 33 hours storage at 400°C would equal 1,000 hours at 300°C and llO million hours at 50°C.5 However, their information for 400°C was extrapolated from data obtained at lower temperatures, while Norden is gathering data at 400°C.
References
I. L. Bernstein, "Gold Alloying to Germanium, Silicon and Aluminum-Silicon Eutectic Surfaces," Semiconductor Products, July and August, 1961. 2. T.A. Longo and B . Selikson, " Aluminum Wire Bonding of Silcon Transi~tors , " Semiconductor Products, November, 1963. 3. E.M. Ruggiero, "Gold-Aluminum Adhesion and Reaction on Semiconductor Surfaces," 4th Annual Microelectronics Symposium, St. Louis Section, IEEE, May 20, 1965. 4. J.E. Thomas, Jr., and D.R. Young , "Space-Charge Model for Surface Potential Shifts in Silicon Passivated with Thin Insulated Layers," IBM Journal of Research and Development, September, 1964. 5. G.C. Sikora and LE. Miller, "Applications of Power Step Stress Technique to Transistor Life Predictions," Third Annual Symposium on Physics of Failure of Microelectronic Devices, Chicago, 1964 (sponsored by Rome Air Development Center, Rome, N. Y.J.

104

Electronics I August 23, 1965

... NOW IN A NEW MINIATURIZED SIZE
Hermetically Sealed
ERIE BUTTON® MICAcapacitors
designed for
-55° to +200°C at 2000 Mc.
Actual Size

~
-New Miniaturized Size .410 dia.

dealut:tn'j

~::CHANICAL 508

VARIATIONS TO SUIT

'

ANY HIGH TEMPERATURE-HIGH FREQUENCY CAPACITOR APPLICATION

With the addition of these new miniatures, Erie further broadens · the most complete selection of Button Mica Capacitors in the industry. These new miniaturized micas provide 33% reduction in mounting area.
Erie Button Mica Capacitors are designed for use in radio frequency circuits for tuning, bypassing and coupling. The outstanding properties of metallized mica dielectric combined with the radial current pattern, make Erie Button Capacitors ideal for low inductance, high frequency applications.
Tbese high quality capacitors are designed for microwave and filter applications, for use in carrier equipment, parametric and RF amplifiers, oscilloscopes ... any application where high temperature and high frequency are factors.
The welded hermetic seal of these excellent broad frequency Gold Seal® capacitors for military and commercial use is 100% tested under prd\sure steam/salt water during production to guarantee a positive moisture seal.
Consider the advantages of Erie Button Mica Capacitors in the equipment you are designing. Write for Gold Seal Bulletin 500-2 or Resin Seal Bulletin 318-3.

Capacitance: Tolerance: Working Voltage:

GENERAL SPECIFICATIONS

5 pf. thru 2500 pf. 1% or .25 pf thru ± 20% 500 WVDC for 1(211 dia. units 250 WVDC for ~" dia. units

Frequency Range: to 2Gc and beyond

Operating Temp.:

-ssoc - ssoe - ss0 c

to to to

+ + +

200°C
1so0 c ss0 c

Q: per MIL- C - 10950

MINIATURE BYPASS CAPACITOR SYSTEMS FOR TRANSMITTING TUBES .. .

Designed for the 10 to 3,000 megacycles range-and beyond

Erie now provides effective capacitive bypassing and coupling or filtering of all RFI signals in the range of 10 to 3,000 megacycles. Variety of systems to meet your requirements.

Write for Bulletin 525-R

Formerly Erie Resistor
Corporation

Another Series of Components in Erie's Proj_ect "ACTIVE" Advanced Components Through Increased Volumetric Efficiency

TYPES AVAILABLE

HERMETICALLY SEALED
IGOlO SEAL<!>) .410" 0. 0. or .505" 0. 0.

IESIN SEALED
.375",. .44T er
.65T 0.0·

FEED THRU

FEED THRU FEED THRU (BUSHING MOUNT) !BUSHING MOUNT)
STAND OFF STAND OFF EYELET
FEED THRU
ERIE TECHNOLOGICAL
PRODUCTS, INC.
~::
..___ ___.II
644 Weat 12th Street Erie, Pennsylvania

Electronics IAugust 23, 1965

Circle 105 on reader service card 105

Design for extra performance
... with Mallory high energy batteries

I mproved heavy-duty performance available
Recent refinements in Mallory Manganese Alkaline Batteries increase their ability to deliver long life, and further improve their advantage over conventional zinc-carbon batteries. At 70°F, this Mallory system delivers up to 7 times more life on continuous heavy drain than ordinary batteries (see chart).
At 32°F, the improvement in performance is even better. This added capability is the result of new internal construction which increases the effective anode area in relation to cell volume, providing lower internal impedance particularly at low temperatures. Added refinements have also been made to insure reliability of the case seal under even the most severe vibration.

Leading battery-powered products use Mallory Batteries

2.0

l
1.6

Iii

DISCHAIRGE AT 250 MILLIAMPS, 7d' F

\J~ Cl
<t
~ 1. 2
> 0
o .a

M A L.L.O RY -

Z INC-CA R B ON

MANGAN ESE AL.KAL.IN E

0.4

I

0

2.

3

4

!5

6

7

a

HOURS

New lsoflash-Rapid camera , by AgfaGevaert, uses snap-in loading with automatic film threading and no rewinding. Both this model, with built-in flash, and the electric eye Isomat-Rapid, with accessory flash reflector, use a B-C system powered by a 6-volt Mallory Mercury Battery with life of 2 years in normal service.

Now-Certified Cells for highest rel iability
For applications where maximum reliability is demanded, we are producing Certified Mercury Cells in a separate, "zero defects" manufacturing facility which is unique in the battery industry. All manufacturing operations are performed by skilled technicians. Every component is individually tested and only those coming within optimum specification values are selected. Complete manufacturing controls are in effect during assembly, and test data are permanently kept on each production lot. Each shipment is individually certified to meet the highest level of quality possible under the present state-of-the-art.
Of the many thousands of Certified Cells we have produced, there has not been a single report of premature failure.
One of many inspection operations on .the Mallory Certified Cell line.

FM Wireless Microphone. Small as a cigarette pack, the "Mike-Caster" made by Federal Division, The Victoreen Instrument Company, transmits with high fidelity, free from interference. Two Mallory Mercury TR-165 Batteries supply power for over 30 .hours of continuous service.
Mallory Batteries cost more, but they're worth more because of the extra values of miniaturization, convenience and performance they can add to your product. For a consultation on your specific requirements, write or call Mallory Battery Company, a division of P. R. Mallory & Co. Inc., Tarrytown, New York.

106 Circle 106 on reader service card

MALLORY
Electronics I Aug ust 23, 1965

Series 2-The original Series 2 introduced modular construction in lighted pushbutton switches. Choice of round or rectangular display. Snap-in mounting. Ava ilable with RFI shield, and solenoid pull-in and/or hold-in coil for remote control.

Serie s 2C200 -Snap-in mount. Re -lamp without tools. Optional RFI shield, and solen oid p u ll -in and/or hold-in coil for remote control.

Serie s 2N -Shock res i stant spring-lock mounting. Hold -in coil . Re-lamp without tools.

Now, more design freed om with Modular Lighted Pushbuttons

Many advantages in design, installation, operation and maintenance are available in the expand ed line of MICRO SWITCH lighted pushbutton switches. Examples of the basic assembli es are shown. Each series offers a wid e choice of interchangeable snap-on modules.
GENERAL FEATURES :
Pan el seals. Choice of colored buttons or col or f ilters; slide-on caps for easy legend chan ges. Choice of 1- to 4-section buttons and 1 to 4 lamps providing up to 4-color display. Choice of 30 different switch modules; 1, 2, 3 or 4-pol e double-

throw and twin-break contact arrangements; heavy duty and low energy electrical ratings; momentary or alternate action; solder, screw and quick-connect terminals. Optional hold-in coil modules. Matching indicators for lighted display only.
For information, contact a Branch Office (see Yellow Pages, under "Switches, Electric") or write for Catalog 67.
MICRO SWITCH FREEPORT, ILLINOIS 61033
A DIVISION OF HONEYWELL
IN CAN ADA : HONEYW ELL CONTROLS LIMITE D. TORONTO 17 . ONTARI O

H O NEYWEL L IS WO RL D WI D E · Sales nnd servi ce offices in alt principal ci t ies of t he world. Manufacturi ng in Brazil, Ca nada, Fr anc e, Ge rm any, Japan. Mexico , N e the rlands, Un ited Kingdom, United S ta tes.

Electronics I August 23, 1965

Circle 107 on reader service card

107

TOO SMALL TO BEA
LIFESAVER? *
NOT IF YOU'RE DESIGNING ELECTRICAL CIRCUITS

Jn the race to\\·arcl smaller circuits and higher density packaging, >ome electrical design engineers are sinking in a sea of OYerlarge components. Those in the know are being buoyed up by l\lagnetics' miniature powder core line-moly-permalloy cores as small as 0.110"1.D.
Designers i1woh·ed with highly critical inductor >tability factors arc welcoming another ;\ l agnetics inno,·ation - guaranteed temperature stabili1:ation in miniature powder cores. The "D"' type limits the change in
inductance to ±0.1 % from 0 to +55 degrees C. The
.. \\!" type limits the change from ±0.25 % from -55 to

+85 degrees C. Our new "l\[" type limits the change to ±0.25% from -65 to + 125 degrees C. A wide selection of core siLes and permeab ilities broadens the engineer's design scope even more. And all of these sizes are designed so they can be \\·ound on present miniature toroidal winding equipment.
If )OU are faced with a problem of compacting a circuit design , it will pay you to investigate the condensing po ten ti al of ;\! agnetics' miniature powder cores line. For the complete story, write Dept. EL-30, l\lagnetics Inc., Butler, Pa.
· A ctual si:e of Mag11 elics' 0.1 JO" l.D. powder core

108 Circle 108 on reader service card

mRIJRETICS inc.
®

Electronics I August 23, 1965

Out in Front! New KNOBPOr Senior
Precision Potentiometer with ±0.1% Dial Accuracy

The acclaim and immediate acceptance which greeted Bourns'

original KNOBPOT, a major advance in the state-of-the-art, have

led to the development of a "Senior" version, to .provide higher

resistance values and increased accuracy. You can see in the

photo below that this new unit saves you nearly all the back·

panel space consumed by the bulky conventional type. That's

because it's a potentiometer, knob and turns-counting dial all

in one, mounting entirely .in front of the panel.

-

Most Important of an ·benefits, however, is the name on the package! It means that the product has undergone 100% in· process and final inspections as well as the double-check of Bourns Reliability Assurance Program. You can be "out in front" In more ways than one if you specify the Model 3640, KNOB POT Sr. potentiometer. Write today for complete technical data.

KNOBPOT Sr., Model 3640, a companion unit to the revolu· tionary Bourns KNOBPOT Model 3600, gives you a bonus in accuracy, resolution, and power, too. The whole unit ... includ· ing the integral turns-counting dial ··· is more accurate than the best competitive potentiometer/dial combination.
In your production, KNOBPOT Sr. potentiometers save you time and trouble. For example, they put an end to do-it-yourself installation. Phasing is done for you-with extreme accuracyat the Bourns plant. No separate dial to attach, no complicated mounting procedure. Just drill two holes, put the unit on the panel and tighten the nut. That's the whole installation!

Standard Resistances: 500n to 250K Dial Accuracy (correlation of dial
reading to voltage output): ±0.1% max. Repeatability (ability to return to a pre·
viously established setting): ±0.05% Resolution: 0.03 to 0.006% Power Rating: 2.5 watts at 25°C Max. Operating Temp.: 125°C Dimensions (in front of panel): only
1%" long x 11A" dia.

ONE- HAL F ACTUAL SIZE

Photo below eompares actual-size KNOBPOT Sr. with a Gonventlonal pote.ntiometer and separat.e dial package.

F!OURNS

41
B 0URNS . INC .. TRIM POT DIVISION 1200 COLUMBIA AVE . . RIVERSIDE . CALIF. PHONE 684 - 1700 ·TW X : 714 · 682 9582
CABLE : BOURNSINC .
MANUFACTURER: TRIMPOT41 & PRECISION POTENTIOMETERS, RELAYS; TRANSDUCERS FOR PRESSURE, POSITION, ACCELERATION. PLANTS: RIVERSIDE, CALIFORNIA ; AMES, IOWA; TORONTO, CANADA

Electronics I August 23, 1965

Circle 109 on reader service card 109

Tests prove it ..· Mallory MTA capacitors , deliver big performance for small cost

Results of performance testing of the new Mallory MTA

molded aluminum electrolytic capacitors may change

your ideas about how much quality you can now buy in

a miniature capacitor at low cost.

Q)

·.ucus:

Good low temperature stability

aro.
8

The MTA has good capacity retention for a miniature electrolytic-even at -30°C. Take a look at the chart.

i 50 l
f 40
.$

Good life and reliability at high temperature
Capacitance, DC leakage and dissipation factor show good stability on life test at 65°C-and at 85°C. The chart shows the first 500 hours' data on a production lot of 100 mfd, 10 VDC units. At 85°C, there hasn't been a single failure of any kind during 1 million piece-hours of life test. And at 65°C, we've had only one failure in 2~ million piece-hours of testing.
Both our tests and those by customers indicate that the MTA has reliability superior to many miniature aluminum types, including many metal case models. DC leakage of polar models is less than 0.03 microamps per mfd-volt. We invite you to evaluate the MTA. We believe you'll find its performance applicable to a broad range of entertainment and industrial uses. And we know you'll like its price. For data, write or call Mallory Capacitor Company, a division of P. R. Mallory & Co. Inc., Indianapolis, Indiana 46206.
MALLORY
110 Circle 110 on reader service card

-30°C -20°C -l0°C 0°C +l0°C +20°C LOW TEMPERATURE CHARACTERISTICS

125

250

375

500

HOURS LIFE TEST 100 MFD, 10 V DC

Maximum Ratings-MTA

Case size

Volts WVDC

Maximum capacity-mfd. polarized non-polarized

o/is" x 'l's"

%" x IVs"

x 1 1/ 2 11

1/

11
2

3 to 50 3 to 50 3 to 50

75-8 210-20 800-85

65-4 135-10 5 2 5 -4 0

Electronics I August 23, 1965

Probing the News

Military electronics
Underwater city: Sealab II

Navy outpost on the ocean floor demands a new breed of electronics to support men in a harsh but promising new world

By John F. Mason
Military Electronics Editor

Every morning, ten Navy divers
crawl out of their bunks, brush their teeth, shave, then eat a hearty breakfast. Later, some of them put on "wet" suits and breathing gear, climb down a ladder through the floor of th eir quarters, and swim to work.
Traveling 210 feet below the surface of the sea, two men, on a typical day, might swim off to repair a malfunctioning telemetering station not too far away, while another pair tes ts the range of underwater communications gear.
At the end of the month-long project, called Sealab II, now under way a half-mile off the coast of La Jolla, Calif., the Navy will have made the most extensive tes t yet of man's ability to live and work in

the ocean depths for long periods of time under saturated diving conditions-the pressure in the undersea lab is the same as that of the water outside. The environment in the divers' quarters and in the water surrounding it is severe and every piece of electronic equipment is being watched to see how it stands up.
For Sealab II, the Navy is using equpiment designed for other Navy programs, commercial scuba diving gear and some built especially for Sealab.
Under pressure. Denzil C. Pauli, assistant project officer for Sealab II, says that what is learned from the performance of this equipment may mean a new generation of underwater sensors, data links,

navigation and reconnaissance gear. It will also provide information on tools for building and making repairs, vehicles for transportation, and the "hydronics" these vehicles will need for navigation and communication.
Pressure in th e undersea lab, which is call ed a habitat by the Navy, and in the water is about 125 pounds per square inch, or seven atmospheres of pressure. This environment requires tf'levision and vacuum tubes that w ill not implode, and transistors that cannot be squeezed out of shape. The atmosph ere the men breathe is mainly helium. Because high lmmidity (60 % or more) is essential for physical comfort in a helium environment and because helium

Electronics I August 23, 1965

111

transfers h C'at five times faster than a standard atmosphere, components must be resistant both to humidity and heat.
I. The objectives
There are many reasons for training men to live and work for long periods at depths they normally visit for only a few minutes at a time. Navy divers could rescue men from distressed submarines, install navigation devices, build undersea habitats, repair sonar installations used for detecting enemy submarines, and retrieve space capsules and instrumentation.
Undersea wealth. Civilian groups are exploring the ocean floor for commercial reasons. Jacques Yves Cousteau, the French explorer, believes-and the U.S. Navy agreesthat off-shore gas and oil wells can be drilled cheaper, faster and more safely by divers than from a barge.
Large supplies of fish can be found deep in the sea. Eventually, there may be fish or plant-food farms that divers will tend.
11. Navy's project
Sealab II is the Navy's second experiment in underwater living. Last summer, off the coast of Bermuda, four men stayed in Sealab I at a depth of 193 feet for 11 days. In Sealab II, a total of 18

men will participate for 30 to 40 days at a depth of 210 feet. Plans are to replace eight of the ten men in the habitat after they have stayed down 15 days; two of the original ten will live in Sealab II for the entire experiment.
Participants. The Sealab project, which is part of the Navy's ManIn-The-Sea portion of the Deep Submergence program, is sponsored by the Office of Naval Research in collaboration with the Special Projects Office. Other naval organizations contributing to the program include the Navy Mine Defense Laboratory, which prepared the plans and specifications for the Sealab II structure, tested and evaluated much of the electronic equipment, and under the direction of astronaut Commander Scott Carpenter, trained the divers, or aquanauts.
111. The site
Approaching Sealab II is somewhat like coming into a small town, because of the cables that lead to it and the number of small structures scattered around it. About 100 feet from the habitat there is an automated telemetering station through which television and audio communications and environmental data are channeled. A cable runs from Sealab to the telemetering

station and from there to shore. Vital link. Rising from Sealab,
there is an umbilical cord that extends upward to the support vessel. In this cord there are a gas supply hose, a gas-sampling hose that men in the support vessel use to monitor the gas mixture in Sealab, emergency power cables and cables for communication and telemetry.
IV. Communications
The umbilical cord carries all communications between Sealab and the support ship. Future colonies will undoubtedly want to communicate independently of a cable, by radio or other means.
Cables in the cord provide the links for both a two-way electrowriter system and voice communications. To make the men's voices from Sealab up to the barge intelligible-the helium atmosphere in the habitat makes them sound like Donald Duck-speech unscramblers are being used. Developed by the aval Applied Science Laboratory in Brooklyn, N. Y. for helium diving operations, the device translates the high frequencies of the men's voices to lower, more normal frequencies.
V ideo monitors. Four television channels are carried up through the umbilical cord to the support ship where doctors and scientists moni-

Berry L. Cannon uses the AN/ PQS-lB
sonar t o search the ocean floor.
112

Life on the ocean floor
Electronics engineers are working in steaming jungles, ari<l deserts and the bitter cold of the Arctic. But only one of them is working at the bottom of the sea.
Berry L. Cannon is one of the ten men living in the 57- by 12-foot cylinder ballasted on the ocean floor, 210 feet below the surface, near the coast of La Jolla, Calif. Cannon is responsible for monitoring test equipment; should any of the electronic devices break clown, he will repair them. And, several times a clay, Cannon and another diver swim out to run tests on the intelligibility of various kinds of swimmer-to-swimmer communications. The tests , repeated frequently, are to dete1mine whether there are changes in range over varying time periods, and if so, what factors , such as turbidity and temperature, cause them.
In August, 1963, Cannon was designing underwater electronic devices for the Navy Mine Defense Laboratory at Panama City, Fla. In order to learn more about the job he was doing, Cannon asked to go to diving school. After some deep-water experience he was transferred to the swimmer-diver branch at the lab. Ever since his graduation from the University of Florida in 1962, Cannon had worked on the control section of towed vehicles, designed an intercom system, and aided in a number of underwater projects.
Cannon is enthusiastic about his role of pioneer in a new world and expects to learn a great deal from his two-week stint at the bottom of the sea.
'TU be a much better designer after my stay in Sealab II," he told Electronics shortly before the descent.
In addition to Cannon, project Sealab II includes a doctor, an aeronautical engineer, mechanical engineers, geologists, biologists, physical oceanographers, military oceanographers, a medical corpsman and professional Navy divers. Commander Scott Carpenter, an aeronautical engineer as well as astronaut and skin diver, trained the men at Panama City, Fla. and is now in Sealab II himself.
Electronics I August 23, 1965

Wet submarines travel at 9 knots but are too maneuverable to use
at deep levels where a quick ascent would be dangerous to aquanauts. The miniature sub might be used by surface divers
to take supplies to Sealab.

tor the divers. Two cameras are

inside the habitat and two are just

outside in the water. Commercial

tv and f-m radio piped through the

cord will be available.

Sealab and the Scripps Institu-

tion of Oceanography communicate

directly with each other only by

cable through the underwater

telemetering station. Scripps, a

half-mile from the Sealab II site,

is assisting in the physiological and

oceanographic research.

Swimmer-to-swimmer. The div-

ers have three systems for talking

with each other when they are

swimming:

· The AN/PQC-1, a standard

single sideband, low-frequency (8

Kc) a-m, sonic communicator with

a range of 1,000 feet. The main

drawback is that the mouthpiece

of the breathing unit makes enunci-

ation difficult.

·

· The Aquasonics communicator

is a 42-Kc, a-m, sonic device with

a 1,000-foot range. It doesn't use

a mouth bit, but has a mask, like

an oxygen mask, that fits over the

mouth and is subject to flooding.

· A buddy-swimmer intercom

system developed at the Navy

Mine Defense Laboratory uses

bone-conduction microphones, con-

nected by a 24-foot wire. The mi-

crophone, fastened to the head,

near the ear, picks up the speak-

er's voice and also enables him to

hear. The unit contains an ampli-

fier, switch and battery.

Swimmers talk to the support

ship or to Sealab by using the

PQC-1. The ship uses an under-

water loudspeaker, the AN/BQC-1.

Tape recorder. One tool that the men in Sealab II don't have, but future undersea workers will need, is a watertight tape recorder into which a swimmer can dictate his scientific findings as he sees them.
Lasers have been examined by a number of companies for solving the swimmer-to-swimmer communication problem, but the high attenuation and the narrow beam rule it out for the time being.
V. Instrumentation
To record the ever-changing conditions in the sea, a weather station with conventional electronic equipment is fixed to the sea bottom near the habitat. To measure the height of the waves, some 200 feet above, a Vibrotron pressure sensor is used. Current is measured with a Savonius type rotor. And temperature of the water every ten feet from the bottom up to 50 is obtained with a series of thermistors. Data from the weather station goes to the telemetering station via Sealab and from there to Scripps for recording and storing in the computer.
Visibility is measured by a volume-scattering coefficient meter and by a null balance transmissometer. The amount of light that small marine organisms emit when they are disturbed is measured by a bioluminescent meter that uses a photomultiplier sensor.
Environmental control. Inside Sealab, a number of environmental conditions are constantly monitored: temperature, humidity and partial pressure of the oxygen. Readings of these measurements

are displayed in Sealab, in the ship and in the Scripps lab.
The oxygen content in the habitat is monitored by a device called a Krasberg sensor, built by the Westinghouse Electric Corp. for the Sealab program. In the support ship, another Krasberg sensor checks the oxygen in the samples of air brought up through the tube in the umbilical cord. Other constituents of the gas are analyzed in the support ship by a gas chromatograph. At the Scripps laboratory, a mass spectrometer analyzes the breathing mixture to measure elements not detectable by the chromatograph.
Power supply. Power to keep this elaborate colony of instruments and men going is transmitted from Scripps by cable to a sealed transformer bank near Sealab where the 4,160 voltage is transformed to 450 volts. In case of power failure on shore, 450-volt power can also be obtained via the umbilical cord from the support ship.
Far off shore, future undersea laboratories will require self-contained power sources. Possibilities include fuel cells, isotopes and nuclear reactors. Isotope and reactor sources look very promising because of their useful by-product -heat. Fuel cells are also promising because they provide water as well as heat.
VI. Reconnaissance
Electronic gear helps a diver investigate the ocean floor. vVhen visibility is poor, he uses the AN/ PQS-lB handheld sonar. Produced

I Electronics August 23, 1965

113

Let's spike the rumors that all thumbwheel switches are alike, for here's the new EECo 200 Series that makes panel cutting, and mounting almost as easy as 0-1-2-3. How? Here's how ...

lntercaangeable
EECoSWITCH 200 Series assem· bly design makes for easy inter· changeability with other makesa real advantage when specifying switches.

Compatible
The Series 200 can be installed with 1 up to 34 switching stations as standard assembly. Any number over 34 can be accommodated to order.
Self-Bevel No panel beveling is required for an EECoSWITCH Series 200 installation. Switches, spacers and end pieces form a smoothly contoured bevel of their own that fits flush against the cut-out.
Metal-to· Metal
The upper and lower metal brack.ets of the assembled switch bolt directly to the panel for an extrastrong mounting.

Replaceable
Only two screws need be loosened to remove an individual switch -no long end-to-end alignment bolts are necessary.
And It's EECo-
-with all the advantages of an original EECoSWITCH; wide range of standard or special output codes, circuit card construction, solder terminals or connectors, positive detent action, and long, long service life.

Captive Nuts
Captive nuts in the ena pieces permit quick installation and wide tolerance in locating mounting holes.

Nail down your own designs now by having full specifications on the 200 Series. Write, Wire or call ...

EECoSW/TCH- a division of
ENGINEERED ELECTRON/CS Company
1441 East Chestnut Avenue, Santa Ana, California 92702 Tel: (714) 547·5651 ·TWX (714) 531.5522 Cable ENGELEX

See EECO switches at Wescon, booths 3113, 3114

114 Circle 114 on reader service card

by the Dalmo-Victor Co., a division of Textron Inc., the instrument, under the right conditions, can find a water bucket at 120 yards and a beer can at 20 yards. Although this is good, the Navy would like still greater range with the same resolution plus visual readout. Readout from the present unit is aural only, with pitch denoting distance. An echo returning from an object 20 yards away has a pitch of 2,500 cycles; at one yard it is 250 cycles. The bandwidth is 30 Kc in the 50to 9-Kc range.
Improved sonar. The Mine De-
fense Laboratory has improved the sonar by repackaging it and making it a much smaller unit. To reduce the size of the transducer, the frequency was changed to 200 Kc; the old transducer was one inch in diameter and 8 inches long, housed in a circular cone.
The new unit uses two transducers, one inch in diameter and only a half-inch long, mounted in an end plate one-half inch thick. The original sonar is a 22-pound hemisphere, 15 inches in diameter and 15 inches high. The new one weighs only three pounds, is in the shape of a cylinder, 31/4 inches in diameter and 9 inches long. Both units are fully transistorized. After the new unit is tested, industry will be invited to submit bid proposals for manufacturing it.
VI I. Navigation
To prevent the men from straying up or down too far without realizing it, depth gauges that measure pressure are worn on the wrist. In murky water, however, they can't be read easily. The Navy would like an accurate depth gauge a swimmer can read under any condition.
To help the men find their way back, Sealab operates a pinger that sends out sounds in all directions. Swimmers carrying the PQS-lB sonar can pick up these sounds and -no matter how dark the waterborne in on their habitat.
Future, more elaborate, missions might use pingers at several sites. These could be coded, or transmit at different frequencies, to identify the particular site.
VI 11. Tools and transportation
So little work has been done at great ocean depths that almost
Electronics I August 23, 1965

Now-shrink Y.OUr high power equipment with CBE*design SCRs
by Westinghouse

CBE 175-amp
SCR - no solder joints
You can get extra power-handling ability in the same space as 150-amp devices. Just change to the Westinghouse Type 220. Added bonus: unique solderless compression -bonding construction eliminates thermal fatigue. Ratings are 4,000 amps half-cycle surge, 275 amps RMS, 175 amps average. Voltages through 1,000. Switching speeds to 20 microseconds, dv/dt 200 volts per microsecond, di/dt 200 amps per microsecond . Ideal applications of the Type 220 are in high power inverters, converters, cyclo -con· verters, and similar uses.

CBE 250-amp SCR for water cooling
The Westinghouse 224 is the industry's only SCR specifically designed to help you· get the space savings inherent in water cooling. Its base is designed for high heat transfer and easy mounting to liquid-cooled radiators, heat exchangers, or sinks. Ratings are 5,000 amps half-cycle surge, 400 amps RMS, 250 amps average. Voltages through 1,000. For applications like large motor drives, power inverters, and ignitron and motor generator replacements, the Type 224 may be just the answer you need to solve your design problem.

CBE 300-amp
SCR with integral
heat sink
Only Westinghouse offers you an SCR with a truly integral heat sink. The new Type 223 produces more power at am bi· ent temperature than any corresponding non-integral combination of SCR and heat sink, thus helps you design compact equipment. This efficiency comes from its exclusive construction concept, which eliminates a thermal interface. Ratings are 5,500 amps half-cycle surge, 470 amps RMS, 300 amps average. Volt· ages to 1,000. In industrial systems and other high power applications, the Type 223 is now finding wide use.

A complete line: Westinghouse manufactures a full spectrum of power SCR 's from 10 amps
to 470 amps, 50 volts to 1,200 volts. Get full details. Call your Westinghouse salesman or distributor now. Or write Westinghouse Semi-conductor Division, Youngwood, Penna.

* Compression Bonding Encapsulation

SC ·2 049

You can be sure if it's Westinghouse

Electronics I August 23, 1965

Circle 115 on reader service card

115

Three nice features and a surprise in Heinemann's new Series JA circuit breakers:
1.- Natural shoulder packaging. The slim, Ivy League JA weighs in at just 2.5 ounces per pole, including hydraulic-magnetic actuating element, silver-alloy contacts and an uncommonly efficient arc-quenching device.
2. Pizazz-The JA is the first breaker with snap-on color-coding caps that you can mix or match for functional or decorative purposes. Also included: a very dressy white handle.
3. Convenience. The JA's 'universal' terminals are made to accept soldered, crimped-type, or screw-type connections; you can use whichever you're tooled for-or overstocked with.
4. Economy. This is the surprise. The JA actually costs less, model for model, than our Series AM12 breakers, which it can replace to your advantage. The JA is available in current ratings from 0.100 to 20 amps, at up to 250V AC or SOV DC. With a choice of time-delay or non-time-delay response. SP,ecial-function internal circuits, too. Bulletin 3350 will give you full technical data. Write, wire or shout for a copy.
Heinemann Electric company
2600 Brunswick Pike, Trenton, N. J. 08602
116 Circle 116 on reader service card

Aquasonics communicator is a 42-Kc a-m, device with 1,000 foot range
nothing is known about the kind ol tools that will be needed. The NaV} and the National Aeronautics anc Space Administration are keepin~ an eye on what the other migh1 come up with for working ir weightless and underwater environ ments. Sealab II should furnish re· quirements that the electronics in dustry can try to satisfy.
Wet submarines. More is knowr. about requirements for transporta· tion at deep levels but there is, a! yet, little equipment. The aqua· nauts' average swimming speed i! % knots and this is far too slow There are vehicles called wet swim mer propulsion units with speed! up to 9 knots. These miniature submarines, are powered by batterie! and driven by a propeller. The) won't be used by the divers he· cause they are too maneuverabl( and might take them up above th( safe 33-foot change in depth , or toe far from the habitat; the navigatior gear presently available won'! guide the small craft home. How ever, a wet sub might be used b} surface divers to take supplies tc Sealab and then surface quickly
'Hydronics.' Precise navigatior gear will be needed along with pressure gauges, depth measuring devices and communications. A~ the ocean floor becomes busier and there are more vehicles carrying men faster and over greater distances a new kind of underwater vehicle electronics, or hydronics, will emerge. Undersea exploration offers new vistas to the electronics industry.
Electronics \ August 23, 1965

distribute anv
fr8QU80CY lrom 80 CPS ID 5mc/S

The TRACOR Frequency Distribution System consists of a precision frequency source, the necessary mod· ular units of line amplifiers, receiving amplifiers, distribution amplifiers, and power supplies to dis· tribute one or more precise frequencies to remote locations. Up to 7.0 volts rms output allows trans· mission distances greater than 1000 feet at 5 mc/s. Greater distances are achievable at lower frequencies. A portable bench amplifier, with self-contained power is available.
Modular construction and advanced solid state design , provide maximum flexibility, expandability, and re· liable trouble-free operation.
Up to ten plug-in modules mount in a standard nineteen inch rack mounted chassis.

TYPICAL TRACOR DISTRIBUTION SYSTEM

SULZER FREQUENCY STANDARD AND SYNTHESIZER

7 OR MORE OU.TPUT FREQ.

TRANSMITTING STATION

" 0 c 0 <' c 0
D 0 0 0 0 0 I)

. .. 0 0 0 0 0 0 0

0

~

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c

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BLANK PANEL

890 POWER SUPPLY

OVER 1000 FEET AT 5 MC/S FOUR 50 COAXIAL CABLES
FROM EACH MODULE

REMOTE RECEIVING

" c
\] 0
0 0
" '

0 0
" 0
..0 0
'

"0 '

c
0

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0

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STATIONS
BLANK PANEL

890 POWER SUPPLY

40 OR MORE MODEL SIB DISTRIBUT ION AMPLIF IERS FROM EACH MODULE

SPECIF I CA Tl 0 NS (typical seven frequency system)
Frequencies: The following frequencies are accepted and amplified, one module for each frequency, by the Model 516 Series B Line Amplifier and the Model 517 Series A Receiving Amplifier: 100 cps; 400 cps; 1.0 kc/s; 10.0 kc/s; 100.0 kc/s; 1.0 mc/s; 5.0 mc/s. Each module (ten each) of the Model 518 Series A Distri· bution Amplifier will accept and amplify any of the above frequencies, the desired frequency being selectable by a front panel rotary switch.
Input Voltage to Line Amplifier: 0.5 to 1.0 volt rms, 50 ohms (each frequency)
Output Voltage From Line, Receiving, and Distribution Amplifiers: 7.0 volts rms into 50 ohms
Output Voltage Regulation: Output voltage regulation of each amplifier (line, receiving, and distribution) is better than three percent with line variations from 105·125 volts rms.
Connectors: UG-657/U BNC Type Connectors are used for input, output, and monitor connections on each amplifier.

Number of Outputs: Multiple outputs are available from each line amplifier and receiving amplifier module as follows: Line Ampli· tier - Four separate outputs from each module. Receiving Ampli· tier - Four separate outputs from each module. Each output will supply ten distribution amplifiers. Each distribution amplifier has all seven frequencies available at a single output jack. The desired frequency is selectable by means of a front panel rotary switch.
Distortion and Crosstalk: System distortion is less than three percent at 7.0 volts rms output from the distribution amplifier, with a sine wave. input to the line amplifier. Total crosstalk does not exceed three percent of total output.
Power Requirements: Each amplifier module operates from :t 20 volts de, 150 ma.
Size: 19" width x 3.5" height x 12" deep
Weight: 15 pounds

For technical data sheets and complete information telephone 512·476-6601 or write TRACOR, Inc., 1701 Guadalupe Street, Austin , Texas 78701.

TRACOR, Inc. Instruments/Coznponents/Systems

® Electronics \ August 23, 1965

Representatives in principal cities.

Circle 117 on reader service card

117

Manufacturing

A plug for microcircuits

Bigger packages, easily plugged into ordinary boards, get industrial manufacturers' approval
By George Sideris
Manufacturing Editor

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118 Circle 118 on reader service card

Next to the tiny, shiny flatpacks that set microcircuit packaging styles for two years, the integratedcircuit package introduced in March by the Fairchild Camera & Instrument Corp. seems big, crude and ungainly. But assemblers of commercial and industrial electronic equipment have learned to love the dual in-line package known as DIP. Fairchild claims that its customers are "fighting for deliveries" of DIP-packaged circuits because DIP cuts equipment assembly costs to as little as 10% of flatpack assembly costs.
Fairchild's success has not gon<' unnoticed. Most of the other leading integrated-circuit manufacturers are now offering packages that resemble DIP and are interchangeable with it.
I. All join in
Sylvania Electric Products Co. will be selling military as well as

commercial circuits in DIP-style packages. Sylvania's package looks like Fairchild's, but, Sylvania contends it is better and cheaper because the circuits are sealed in glass in a single fabrication step. Fairchild seals its circuit .in a ceramic sandwich which takes two more steps. Sylvania says its design resulted from an independent analysis of the market.
The \Vestinghouse Electric Corp., when requested, makes a package interchangeable with Fairchild's, and Motorola, Inc. offers the same service. Neither has revealed design details. Both the Signetics Corp. and Transitron Electronics Corp. have promised customers they will make a DIPstyle package.
Thomas A. Longo vice president in charge of integrated circuits at Transitron, says, "Undoubtedly, some time in the future we will make an in-line package. I have

Sylvania's new plug-in package and a flatpack straddle a wafer of circuits.
Electronics I August 23, 1965

not decided on when or what type. Obviously, the package will be interchangeable with the Fairchild type."
Since equipment assemblers don't like to be tied down to a single source for circuits, they pressure their suppliers to adopt similar package styles.
Holdout. Not all big integratedcircuit producers are switching to DIP. Texas Instruments Incorporated is sticking with the industrial plug-in package it announced last May that, because of the number and spacing of its pins, is not interchangeable with DIP.
TI is aware of Fairchild's head start, but William Martin, of the company's marketing department, says TI isn't convinced that the industry has made up its mind to standardize on DIP. It's his view that it will be another six months before any big customer reaches a decision.
Texas Instruments is now tooling up for mass production of the package and plans to announce, at Wescon, three new lines of industrial circuits that will use it.
11. Sales booster
At Fairchild, Bryant Rogers, disagrees sharply with the TI spokesman. Rogers predicts that DIP will win 60% of the Hatpack market.
Among its major customers Fairchild now counts the Advanced Scientific Instruments division of the EMR Corp., the Burroughs Corp.-both are using DIP's in computers-and the Hughes Aircraft Corp. Fairchild claims that its customers save as much as $30,000 when DIP's are used in large systems.
In addition, Rogers says, "DIP will help open new industries to us, because the impracticality of handling Hatpacks will no longer be a deterrent to potential users."
111. Flatpacks and plug-ins
The reason for DIP's success is its large size and the shape and spacing of its leads.
A DIP is nearly four times the size of a Hatpack, so it's easier and cheaper to handle. The largest
standard Hatpack is about 3/s inch
long and its thin ribbon leads are only 0.050 inch apart. In conh·ast, the plug-ins are longer, broader and thicker and the space between
Electronics I August 23, 1965

szso·11 per a4 Hours
SULZER FREQUENCY
STANDARD

This new SULZER Model 2.5A Frequency Standard is a high quality rugged frequency source of the highest frequency stability available.
Best ·long and short term frequency stability, spectral purity, and reliability (MTBF in excess of 20,000 hours) plus optional varactor tuning makes the SULZER Model 2.5A an ideal frequency source for laboratory measurements, primary frequency and time systems, synchronous communication systems, microwave spectroscopy, and other applications.
The all-silicon, solid state unit provides output frequencies of 2.5 me/ s, 1.0 me/ s, and 100 kc/ s. A 1 pps clock drive output is optional. Operating temperature range is o·c to 35°C.
The crystal and oscillator circuits are mounted in a double proportional control oven which maintains the crystal and frequency .determining elements at the point of zero temperature coefficient within a few thousandths of a degree C.
The cylindrical packaging used in the oven, circuitry, and case design, and the modular construction used make these units withstand a shock of 30G's with a frequency change of less than 1 x 10-s. The unit meets all technical requirements of MIL-E-16400E, and all RFI requirements of MIL-l-26600.
Front panel vernier frequency adjustment permits setting and resetting to a few parts in 1011·
The Model 2.5A mounts in a standard 19" rack or in a system chassis accepting the 4" square front panel and 4" diameter cylinder. A companion power supply (shown in photograph) is optional. The power supply operates from 105-125 volts, 48 to 400 cps and has 8-10 hour nickel-cadmium battery standby power.
Other SULZER Frequency Standards and related products are available.

Telephone 512-476-6601 or write TRACOR, Inc., 1701 Guadalupe Street, Austin, Texas 78701 for complete information.

SULZER PrecJsJon OscJJJators

·

REPRESENTATIVES IN PRINCIPAL CITIES

Circle 119 on reader service card 119

their leads, 0.1 inch, is twice that of the flatpack spacing.
The leads of the new packages are stiff and point straight down for easy insertion in ordinary printed circuit boards. Once a board is filled with packages, all the joints between the leads and the printed wiring can be made simultaneously with conventional flow-soldering machines.
By comparison, flatpacks are usually assembled under a microscope, with special soldering or welding equipment. The leads are not inserted and machine-soldered, but are painstakingly joined, one at a time, to printed wiring on the top of the boards. Flatpack leads can be bent and inserted into boards, but it is tricky work.
Getting a lift. One significant advantage of the DIP leads are their wide tops, which raise the package above the board. This facilitates soldering, board cleaning and cooling. More importantly, it allows the printed wiring to run
The original dual in-line package, made by Fairchild Semiconductor.
under the package, so the whole surface of the board can be used for wiring. Rarely can this be done with other types of packages.
The DIP's two rows, of seven leads each, are 0.3 inch apart. Tl's first package has two rows of eight leads, with the rows 0.2 inch apart; these leads are round pins that come out of the bottom of the package, rather than stamped leads that bend down at the package sides. TI thinks this design feature will be its ace in the hole in the competition between the two package styles. The company believes the round pins stand up better under the strains of automated equipment assembly, and because the pins can't touch each other and short neighboring circuits, the packages can be packed tightly together on the boards.

Space electronics
Live tv from the moon
The Apollo spacecraft will carry a camera that will let the whole world watch the trip and the first walk on the moon

The first American landing on the moon will be a television spectacular. A tv camera weighing less than seven pounds, developed at a cost of more than $21/4 million, will let the whole world watch the Apollo mission. During liftoff, it will be trained in on the faces of the three astronauts; once in orbit, it will make a straphanger out of one of them, who will have to give up his seat so that the camera will have an unobstructed view of the instrument panel. (Since the standee will be weightless, he won't get tired; in fact, he might float.)
The only gaps in transmission during the entire round trip will be the three- to four-hour periods while two of the astronauts descend to the moon in the lunar excursion module (LEM) and ascend to the command module for the trip home. LEM's antennas will not provide enough gain to send pictures.
On the moon, one of the astronauts will set up a 10-foo t parabolic antenna. His companion will stay in LEM with the camera; the first picture viewers on earth will receive of a man on the moon will be of the astronaut standing by the antenna. When the first astronaut returns to the module, the second will step out and take pictures of the spacecraft, the moon, and th e earth, hanging in the sky.
For transmission from Apollo itself, the camera will operate through two antennas-omnidirectional for earth orbit and high-gain directional for the trip to the moon.
The tv signals will be relayed around the world by communications satellites. Except for a few seconds delay at ground stations to convert the pictures from 10 frames per second to the commercial rate of 30 per second, they will be "live".
I. Compact-but overweight
Portable as it is, the Apollo camera still doesn't quite meet

specifications. The $2.29-million contract awarded last October to the Aerospace division of the \Ves tinghouse Electric Corp.'s Defense and Space Center was for a 51/zpound instrument. The first model weighed 91/z pounds; the one to b e delivered this month to th e National Aeronautics and Space Administration weighs 61/z pounds.
To achieve reduction in weight, Westinghouse had to abandon the original idea of a two-piece camera, with a control set installed permanently in the spacecraft and a viewer that could be carried around. All versions actually built were in one piece.
Solid state components, including 55 integrated circuits, reduced weight by keeping the total number of components down to 250 from the 1,300 that Westinghouse engineers es timate would have been necessary otherwise.
11. Survival in space
"One of our big problems was just making the camera survive," says Charles Hoffman, director of engineering for the project at Westinghouse. Specifications called for an instrument that would operate for at least 14 days-two of them on the moon. \Vestinghouse came up with a camera that has a meantime-between-failures of 35 years; the probability that it will fail in any given two-week period is 0.1 %.
The camera will have to operate in the shock and vibration extremes of blastoff and weightlessness, in temperatures of from 250° F during the lunar day to -275° F at night, and at pressures of from 5 pounds per square inch in the spacecraft to almost none on the moon.
To reduce heat, a white titanium dioxide coating on the top of the camera will reflect ultraviolet radiation from the sun, and a silver coating on the sides and bottom will reflect infrared radiation from

120

Electronics I August 23, 1965

Synchronous Motors Don't Wear Outl

...THf CfARINC OOf~!

wd that's

u r81 designed the Gearing First

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Electronics I August 23, 1965

Circle 121 on reader service card 121

RELIABILITY
&PERFORMANCE
PROVEN BY 150 MISSILE
&AEROSPACE
COMPANIES ...

MEPCO FH Series Hermetically sealed,
&lass Enclosed METAL FILM RESISTORS

High reliability resistors for demanding requirements of aerospace and military electronics fields. Conform to MIL·R·55182.

For complete information and detailed specifications, write:

MEPCO, INC.
Morristown, New Jersey Phone (201) 539·2000 TWX (201) 538-6709

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MEPCO

MANUFACTURERS OF PRECISION ELECTRONIC DEVICES
122 Circle 122 on reader service card

the moon. The camera's normal power consumption will guard against cold, as will a special cover that will be used at night. An aluminum container 1/s inch thick
on the top and -h inch thick on the
sides will give protection from micrometeoroids. vVhile it's in Lem, the camera is cushioned within a shockproof case.
Ill. Sunlight and earthlight
Light levels on the moon will vary from blinding sunlight, unfiltered by any atmosphere, by day, to mere starlight and "earthlight" by night. The SEC (secondary emission conductivity) vidicon tube used in the camera is sensitive enough to operate at the night level of about 0.09 foot-lamberts.
The tube is not as sensitive as an orthicon, but it can televise moving pictures at low light levels where an orthicon cannot, since the SEC has faster beam erasure. Moreover, the orthicon requires a bulky package, is sensitive to temperahire variations, and must be mounted in a specific way to operate.
Westinghouse will not give details on its camera's light level capabilities, because of its military applications. However, a similar tube now being produced by the Dalmo Victor Co. , a division of Textron , Inc., in Belmont, Calif., is known to produce 250-line resolution at 10-5 foot-candles.
IV. Getting in focus
The camera has four optical systems, each combining a lens and a fixed aperture:
· An 80° wide angle lens with a focal length of 9112 millimeters will be used inside the spacecraft.
· A telephoto lens with a focal lenth of 100 mm and a fi eld of view of about 7° can be used for shots of the earth or moon from the spacecraft, and for long-distance pictures on the moon.
· A T-60 lens with a 25° field of view and 25 mm focal length is available for the brilliant daylight on the moon, when illumination is about 14,000 foot-candles.
· During the lunar night, a T-1.1 lens with the same field and focal length-but, obviously, a much larger aperture-can be used for pichires in the dark.
The "T" numbers used above are analogous to the f stops on a conventional camera, which give

the ratio of the focal length of a lens to the aperture of the shutter. The "T" number takes into account the light attenuation of the lens as well as the f number.
V. Transmission
The camera will send 320-line pictures at 10 frames per second, although it can be slowed to 0.625 frames per second to transmit pictures of 1,280 lines. The highresolution pictures will come too slowly to show movement; they will be stills.
Still or moving, the signals will be transmitted over two S-band frequencies - 2.272.5 megacycles from the spacecraft and 2.282.5 Mc from the moon. Under the unified S-band system [Electronics, July 26, 1965, page 98) , tv, voice and telemetry can share a single transponder in the spacecraft. The system was chosen because it can transmit large amounts of information with a relatively small amount of equipment. However, the 500kilocycle bandwidth for tv limited the camera to a slow frame rate and low resolution.
Separate frequencies are used for transmission from the spacecraft and from the moon so that th e rece1vmg stations on earth can separate the source. There is only one camera, so there can be no doubt as to its position; but voice and telemetry will be carried on the same carrier as tv. Since one astronaut will remain in lunar orbit while the others descend in LEM, both voice and telemetry will be sent from the moon and the spacecraft at th e same time.
V I. Pay television
It would be hard to put a price tag on that first picture of an astronaut on the moon. Certainly it will represent, to the millions of Americans watching at home, some reh1rn on their investment.
Yet ASA did not buy th e tv camera merely to entertain the public. The main purpose was to provide better communications between the astronauts and the Manned Spacecraft Center.
The next development for space tv is color; NASA is now evaluating proposals for a study contract on a color camera. The one which makes the Apollo trip, however, may find further use in the Apollo Extension System for a space laboratory.

Circle 123 on reader service card-+

1 HAND SIZE AND LIGHTWEIGHT, but with the features of fullsize V-0-M's.

2

20,000 OHMS PER VOLT DC; 5,000 AC (310)-15,000 AC (310-C).

3

EXCLUSIVE SINGLE SELECTOR SWITCH speeds circuit and range settings. The first miniature V-0-M's with this exclusive feature for quick, fool-proof selection of all ranges.

SELF-SHIELDED Bar-Ring instrument; permits checking in strong magnetic fields . FITTING INTERCHANGEABLE test prod tip into top of tester makes it the common probe, thereby freeing one hand. UNBREAKABLE plastic meter window. BANANA· TYPE JACKS-positive connection and long life.

Model 310-$37.50

Model 310-C-$44.50

Model 369 Leather Case-$3.20

ALL PRICES ARE SUGGESTED U.S.A. USER NET, SUBJECT TO CHANGE

THE TRIPLETT ELECTRICAL INSTRUMENT COMPANY, BLUFFTON, OHIO

310-C PLUS FEATURES
1. Fully enclosed lever range switch 2. 15,000 Ohms per volt AC
(20,000 O/V DC same as 310) 3. Reversing switch for DC measure·
ments
MODELS 100 AND 100-C
Comprehensive test sets. Model 100 includes: Model 310 V-0-M, Model 10 Clamp-on Ammeter Adapter; Model 101 Line Separator; Model 379 Leather Case; Model 311 leads. ($67.10 Value Separate Unit Purchase Price.). MODEL 100-U.S.A. User Net .. $64.50
MODEL 100-CSame as above, but with Model 310-C. Net . ..... .. . .$71.50

'' I

FIELD ENGINEERS· ELECTRICAL, RADIO, TV, AND APPLIANCE SERVICEMEN· ELECTRICAL

CONTRACTORS · FACTORY MAINTENANCE MEN · ELECTRONIC TECHNICIANS · HOME OWNERS, HOBBYISTS

I I

\ '

I I

'

' I ; ,· "I 11 I ,·'' : , ) ' ,·, 1 ·"' \

, -

·

No matter how small the ferrite piece,
WHEN MECHANICAL AND ELECTRICAL SPECS ARE TIGHT... SPECIFY STACKPOLE

Stackpole makes them all:

But subminiature size isn't Stackpole's only claim to

Toroids down to .120" OD Cups as small as .250" OD x .130 Hgt. Bobbins smaller than .080" OD Cores of .031" D x .170" Long

fame in ferrites. One customer put it this way, "Your ferrite cores are more consistent from order to order than any of your competitors."
Over 30 grades. Isn't that what you're looking for?

Coil forms below .060" D x .187" Long Sleeves to .075" OD x .028" ID
Rectangular Solids smaller than .120" x .120'' x .218"

f~STWPOLE ELECTRONIC COMPONENTS DIVISION sr. MARYS, PENNSYLVA.NIA

124 Circle 124 on reader service card

Electronics I August 23, 1965

What made this avionic DC amplifier circuit obsolete?

Hamilton Standard's
new Microcircuit Packaging Technology
ACTUAL SIZE

The use of Hamilton Standard microcircuit modules has reduced the size and weight of temperature con trols in the Navy's advanced LingTemco-Vought A7A light attack aircraft. They function as DC amplifiers in two identical controls for the cabin and pilot 's vent suit.
Each module replaces a multi -com · ponent 3 1/ 2 x 4 1/ 2 -inch circuit board ,

resulting in a 16% weight reduction . Design, production and testing are greatly simplified . Reliability is im · proved by electron-beam welding of interconnections within the module, and complete hermetic sealing.
Hamilton Standard 's design team is experienced in custom circuit packag. ing and will assist circuit designers in component selection and circuit layout.

This technology allows flexibility in interconnecting and l'ackaging both uncased integrated circuits and semiconductors for both digital and linear applications .
For more information on this new microcircuit packaging technology, write to Sales Manager, Electronics Department, Hamilton Standard , Broad Brook, Connecticut 06016.

Hamilton Standard u DIVISION OF UNITED AIRCRAFT CORPORATION
Fl

SEE THIS NEW MICROCIRCUIT PACKAGING TECHNOLOGY AT WESCON, BOOTHS 3208-3211

ELECTRONICS · ATTITUDE CONTROLS · STABILIZATION SYSTEMS · ENVIRONMENTAL CONTROLS · FUEL AND AIR INDUCTION CONTROLS ELECTRON BEAM MACHINES · PROPELLERS · STARTERS · TURBOMACHINERY · GROUND SUPPORT EQUIPMENT · OVERHAUL AND REPAIR

Electronics I August 23, 1965

Circle 125 on reader service card 125

This is AE's Class B relay.
Use it where a less expensive relay would cost too much.

The Class B is a premium-quality telephone-type relay. It can give you at least 400 million operations with unfailing contact reliability. And it seldom needs maintenance.
That's why it's probably the most inexpensive relay you can use-where long-term reliability is a must.
In commercial and industrial control applications, the AE Class B delivers just what you'd expect of a telephone relay. It combines good sensitivity with excellent stability. Withstands extreme temperatures. Provides a wide range of practical operate and release timing ... a range much wider than possible with smaller types of relays.
The Class B has two armature ratios (long, for fast acting

or pulsing - short, for slowrelease and chatter-free AC operation). It also features twin contacts to insure against contact failure, a permanent wear-free backstop, pin-type armature bearings - pl us a sturdy, stable heel-piece.
Newest Class B relay is the Series BRM latching version. When pulsed, remanent magnetism keeps the BRM latched without power consumption until it is restored by a second pulse.
Find out more about the Class B relay- the industry standard for long-term economy. Ask for Circular 1993. Just write to the Director, Relay Control Equipment Sales, Automatic Electric Company, Northlake, Illinois 60164.

AUTOMATIC ELECTRIC
GEN GT&E 5 1 ERAL TELEPHONE & ELECTRONICS

126 Circle 126 on reader service card

Electronics I August 23, 1965

· THESE 9MAJOR FEATURES OF
MODEL520 X·Y RECORDER.
FROM
ELECTRO INSTRUMENTS
THAT MAKE IT
THE WORLD'S
MOST
PRACTICAL

TRUE DIFFERENTIAL INPUT-permits measurements from grounded or ungrounded sources.
HIGH SENSITIVITY-to 100 microvolts per inch ... eliminates need for preamplification.
HIGH INPUT IMPEDANCE-from potentiometric in ·microvolt ranges to 10 megohms ... prevents source loading.
TIME BASE-on both axes ... for maximum flexibility.
QUIET VACUUM HOLDDOWN-holds paper securely, does not attract dust, contaminants·.
TABLE OR RACK MOUNTING-without need for modification kits or adapters.
SINGLE SWING-OUT CIRCUIT BOARD-for easier maintenance,
$ I eliminating problems caused by plug-in circuit board connectors.
BUILT-IN EVENT MARKER-for event time recording on both axes.
20 5 REAR INPUTS AND REMOTE OPERATION-at no additional cost. Priced Only

[3 Electro Instruments, Inc.
D 8611 Balboa Avenue, San Diego, California 92112 Electro International, Inc., Annapolis, Md. Electro Instruments s. a., 512 rue de Geneve, Brussels 3, Belgium

Electronics I August 23, 1965

Circle 127 on reader service card

127

TO SUCCESSFUL DATA PROCESSING SYSTEMS
This NEW design aid can cut logic hardware as much as 50°/o

r···········~

I

MAGNETIC SYSTEMS CORPORATION

I

I 2000 Calumet Street

I

Clearwater, Florida

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I

Gentlemen: Please send me my free copy of " Short Cuts

I I

I to Successful Data Processing Systems."

I

I

I

I Name

I

I Title

I

I Company

I

I Address

I

I City

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I State

Zip

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~--········-J

Send for your free copy today!

lhe information in "Short Cuts," a just-published design aid from Magnetic Systems Corporation, will speed and simplify the design and specification of digital logic systems. And it can reduce the number of components required by as much as 50%.
Among other things, "Short Cuts" contains: · Six rules for foolproof implementation of compatible 1Mc NAND-NOR logic. With these rules - and Magnetic Systems' exclusive new compatible logic modules - you can mix NAND and NOR elements in the same logic system, whether it's positive or negative. · Specific examples that show you how Magnetic Systems 1Mc NAND-NOR compatibility cuts component requirements by 10 to 50%. · Detailed specifications for a new, complete line of compatible welded encapsulated modules. · An easy-to-use selector chart for fastest selection and specification of modules for your system. The cost? Nothing. The coupon above or the reader service card in this magazine will get you a free copy immediately.

128 Circle 128 on reader service card

MAGNETIC SYSTEMS
CORPORATION
Electronics I August 23, 1965

New Products

Recorder reduces time-base error by 99%

By eliminating capstan's cyclical error and reducing skew, it cuts error to 2.0 p.sec at 120 inches a second

When recording data on tape, scientists must know the sequence in which the recorded events took place, and the exact times between events. It may be important to know, for exam ple, that the pulse representing a vibration was ahead of a pulse corres ponding to a temperature change. Recorder manufacturers have been sh·iving to reduce time-base erro r-the di parity between the time separation between events and the time as given when played back through a reco r der.
Up to now, the best instrumentation tape recorder had a time-base error of 250 microseconds at a tape speed of 120 inches a second. Now the Ampex Corp., in Redwood City, Calif., has combined two previous techniques and announced a "new generation of instrumentation tape recorders" that offer 2.0-megacycle bandwidth and a time-base error of only 2.0 p.scc at 120 ips-more th an 100 tim es as accurate as th e bes t conventional instruments. This was accomplished by eliminating th e cyclical error of the capstan and by reducing skew-the tape's crossing the capstan at an angle rather than in a straight line. The recorders also offer, for the first time, a tapedrive system with only one moving part (excluding rccls)-the capstan itself. Throu gh novel design techniques, Ampex engineers have eliminated all other moving parts.
Primary causes of time-base error have been capstan cyclical error due to out-of-round machining; tape elasticity, which causes the tape to speed up or slow down infinitesimally as it "stretches" when being pulled across the capstan ; and skew. The new Ampex FR1600 (shown above) and FR-1800 recorders use a unique dual-re-

sponse capstan servo to achieve maximum stability during recording and playback. They do this by placing a reference tone on the tape so that during playback, whenever a dissimilarity occurs in playback signal time and recorded reference tone time, the difference generates a signal that causes a servo to adju st th e tape speed to provide original time-base integrity of th e recorded data. This technique also minimizes pulling or stretching of the tape.
To prevent skewing of the tape across the capstan surface-which disrupts interchannel timing-and further to reduce tape stretching, the new recorders use two-foot vacuum chutes as tape-storage buffers. In the chutes, immediately before and after crossing the capstan, the tape is guided in friction-

less chambers, assuring a smooth, cushioned path with no extran eous disturbances.
The vacuum chambers also help reduce flutter or skipping of the tape across the capstan, because the capstan itself is th e only rotating element and hence is the only su pport of th e tape through the head area. All pinch rollers, idlers, ro tatin g tape guides and other moving elements that contribute to tape-mo tion in consis tency have been elimin ated. The capstan itself has two guiding edges.
By permitting the use of 16-in ch reels instead of the usual 14-inch reels used with conventional recorders , the FR-1600 and FR-1800 increase the uninterrupted playing time 33%- to 20 minutes at 120 i p s.
The complete line includes the stationary FR-1600, a portable model for shipboard or fi eld use called th e PR-1600, the FR-1800, and an airborne recorder called the AR-1600 (for use up to an altitude of 70,000 ft.).

Specifications

1600 Family Tape widths 1/2 or 1 in ., field interchangeable

Tape speeds 3 3,4 ips to 120 ips, electrically switchable

Heads

Bidirectional; p I u g. in interchangeable IRIG standard

Servo

3 separate systems for capstan, supply reel, take·up reel. Cap· stan servo reference frequency 200 kc at 120 ips

Electronics

2.0 Mc direct, 400 kc f·m. Individual record and reproduce modules

Size FR AR/PR

Single 75-in. rack cabinet 25xl9xl3-in. case

Ampex Corp., 401 Broadway, Redwood City, Calif.
Circle 350 on reader service card

Electronics I August 23, 1965

129

New Components and Hardware
Miniature resonant reed frequency selector

Other
BUCHANAN ~
cyclecontrolled cr1· mp1· ng
tools

Resonant reed relays have been widely used as frequency selectors in mobile radio receivers, telemetry and industrial controls. But with the spread of miniaturization, their value has been limited by their relatively large size.
The Micro resonant reed selector developed by Fujitsu, Ltd., of Tokyo, is said to be less than onethird the size of existing devices, and compatible in size with transistors and other small components. It was developed for use with personal paging systems whose receivers are small enough to be carried in a man's shirt pocket, but is suitable for other frequency-sensing applications that require compactness.
The basic components of a resonant reed relay are a vibrator, a driving coil, a permanent magnet, contacts and a sensitivity-adjusting mechanism. Over-all dimensions are determined primarily by the size of the vibrator and of the driving system. Although it's possible to reduce the size of these components, problems arise in manufacturing procedures, including the maintenance of accuracy in parts. In addition, contact currenthandling capacity and contact breakdown voltage are both reduced with size. For these reasons,

Fujitsu approached the problem as one of arranging components within the package.
The first step was to fold the vibrator into a U shape with a square base. The vibrator is made of a thin strip of iso-elastic magnetic material, such as Vibralloy. The base is soldered to two base blocks, leaving the arms as two identical bent cantilevers, acting as a vibrator that resembles a tuning fork.
The electromagnetic driving system, composed of the permanent magnet and the driving coil, is then inserted into the broad separation between the two "tines" of the tuning fork, and soldered to the base blocks.
The relay's frequency extends over 50 channels, from 475.5 cycles to 1207.5 cycles per second, spaced 15 cycles apart. It operates with a standard driving current of 2.5 milliamperes, but its sensitivity can be adjusted to operate at resonance with 0.7 milliampere. Impedance of the driving coil is approximately 280 ohms at one kilocycle, corresponding to an operating power of about 140 microwatts. Approximately, 1.75 milliwatts are required at th e standard driving current of 2.5 milliamperes.
The device is highly selective

130

MANUAL FEED PNEUMATIC TOOLS Portable or Bench Mounted.
for moderate volume production. Crimp .proprietary and Mil-Spec contacts for · 'wire sizes #8 thru #30. Weighs less than 5 lbs. Bench-mounted model avail· able with foot pedal to permit free use of both hands by operator. Meets per· formance specs of MIL-T-22520.

AUTOMATIC FEED PNEUMATIC TOOL

Portable or Bench Mounted.

For high volume, it automatically feeds

contacts from disposable carriers. For

almost any pin and socket contact #12

thru #20. Speed limited only by oper·

ator's ability to insert wires. Crimp

depth automatically selected by inter·

changeable snap-in blocks; accommo-

dates foot valve control. In bench·

mounted units, carrier reel holds 2,000

or more contacts. For portable applica-
. tions, carriers in self-positioning "see·
thru" magazines hold up to 102 contacts;

magazine automatically selects proper

I I

crimp depth.

I I

I

Write today for complete library of crimp-

I I

ing data and

new catalog on full

line .

· I
I

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1077 Floral Avenue · Union, New Jersey (201) 289-8200 · TeleK 1-25471

1
l

-~~-.:~~~~~: .o~~~~~:~~~ -N~~~~~~i~~~~~~~~tc_aj

Circle 130 on reader service card

I Ji t f 111 J; !II I
Crimp any of these contacts with no operator adjustment!

MS Hand Tool
For most contacts
#12 thru #22, MS ·
'and proprietary.

Miniature Tool
For most contacts
#20 and smaller.
Only 6%" long. 10 ounces.

Electronics J August 23, 1965

See us at Wescon, Booth 2924 and 2925 Circle 131 on reader service card 131

New Components

and shock-resistant, and its characteristics are said to be stable against temperature change and aging.

Specifications

Frequency

50 standard frequencies

from 475.5 to 1207.5 cps

spaced 15 cps apart

Coil impedance 280 ohms ± 15 % , at 1,000
cps, 2o·c

Standard driving 2.5 milliamps

current

Selectivity

Inoperative at a current of

less than 7 ma at frequen-

cies more than ± 15 cps

from resonance.

Bandwidth

Frequency ± 1.5 cps min at

2.5 milliamps

Max. contact

10 watts pulse and 100

rating

milliwatts continuous

Life

Over 100,000 operations

when driving current is

turned on for 1 second and

turned off for 2 seconds in

an ordinary circuit, at nor-

mal temperature and humid-

ity

Over-a ll

7.7 mm x 10.2 mm x 16.5

dimensions mm

excluding

terminals

Price, 1 to 50 $8.50

pieces

Fujitsu Limited, Tokyo, Japan . Distributed in the United States through the Nissho American Corp., 80 Pine St., New York, N.Y. 10005. [351]

Metal film resistor
rated at 1/a watt

IN
V.O.M. RECORDERS

Ever seen a Recorder that looks like this? Neither have we-yet! But we've made just about every other modification in the book for our customers-with 1 range, 2 ranges, with push-button zero, with different scales, and with special chart papers. We've painted them custom colors, put a variety of customer designations on them. You name it, we'll do it! Just let us know what, and the quantity. We'll work up a quote that'll be a pleasant surprise to you.
There are a goodly number of people who buy the standard instruments without modification, singly and in O.E.M. quantities. Boring, really, but we do fill these orders along with the specials. The standard Bausch & Lomb V.O.M. Recorder is a 5 inch Strip Chart Recorder that will record volts, ohms and milliamps directly. It has 5 built-in chart speeds, built-in event marker, built-in take-up reel, 5 voltage ranges, 6 linear ohms scales, 4 D.C. current ranges. Full scale sensitivity is lOmv, 2.5mv or 500 microvolts depending on the model selected. It has a number of other advantages, too. And, we have accessories, a variety of them, that make our recorders so versatile it hurts (other recorder manufacturers, that is!).
If you want further information on our standard recorders, so that you can tell us how you want them changed, write for Catalog 37-2068. Bausch & Lomb, 61420 Bausch Street, Rochester, New York 14602.
BAUSCH & LOMB~
132 Circle 132 on reader service card

A miniature metal film resistor, type PME50, has a rating of 1/8 w (MIL rating of Y:?o w). This resistor, only 0.147 in. long by 0.060 in. in diameter, is obtainable in resistances from 10 ohms to 250,000 ohms. Standard temperature coefficients of ±25 ppm, ±50 ppm, and ± 100 ppm per degree Centigrade may be selected.
Excellent protection against moisture and environmental extremes is provided by special end cap construction plus the manufacturer's Pyroclad protective covering.
Pyrofilm Resistor Co., Inc., 3 Saddle Road , Cedar Knolls, N.J. [352]
Circle 133 on reader service card~

FIN£
8
YOUAG£ ADJUST

THEIM Al OVERLOAD

POWEi

1. 20 SILICON CONTROLLED RECTIFIER SUPPLIES AVAILABLE ··· Delivery in 30 days or less.
2. LOW PRICES .·. Starting at $325 <Voltmeter and Ammeter included with no increase in price!
3. COMPACT PACKAGING
4. HIGH EFFICIENCY
5. CONSTANT VOLTAGE REGULATION ··· with continuously adjustable current limiting.
6. CONSTANT CURRENT REGULATION ··· with continuously adjustable voltage limiting.
7. AUTOMATIC CROSSOVER ··· full automatic transition from constant voltage

to constant current operation, or from constant current to constant voltage operation, at any operating point. 8. REMOTE PROGRAMMING ... Voltage and Current 9. REMOTE SENSING ..· At distances up to 200 feet 10. SERIES OR PARALLEL OPERATION 11. VOLTAGE REGULATION ·· ·(as low as ± 0.075% or 15 mvl line and load com· bined 12. CURRENT REGULATION ··· As low as±15 ma 13. LOW RIPPLE 14. RFI SUPPRESSION !Typical within 10 db of MIL-1-26600) 15. COARSE AND FINE VOLTAGE CONTROLS

For complete data on the OCR series and other Sorensen products, send for the new, 140-page "Controlled Power Catalog and Handbook." Write to: Sorensen, Richards Avenue, South Norwalk, Connecticut. Or use Reader Service Card Number 200.

MODEL NUMBER

VOLTAGE RANGE <VOCI

VOLTAGE REG. !LINE & LOAD COMBINED)

OCR ELECTRICAL AND MECHANICAL SPECIFICATIONS:

OUTPUT CURRENT !AMPS.I

CONSTANT CURRENT
RANGE !AMPS.I

CURRENT REG.

CONSTANT VOLTAGE RIPPLE
!RMS)

PACKAGE

SIZE

TRANSIENT

(INCHES!

WEIGHT

RESPONSE WIDTH HEIGHT DEPTH (LBS.I

PRICE

OCR 300-1.25 0 -300 ± .075 % or60mv 0·1.25 0.125 to 1.37 ± 15ma 0.4 % + 300mv 30msec 19 5 14 15 OCR 150·2.5 0-150 ±.075 % or 30mv 0·2.5 0.25 to 2.75 ± 15ma 0.4 % + 150mv 30msec 19 51,4 15 OCR 80-5 0-80 ±.075% or 20mv 0-5 0.5 to 5.5 ± 15ma 0.4 % + 80mv 30msec 19 514 15 OCR 40-10 0-40 ±.075 % or 15mv 0·10 1 to 11.0 ± 20ma 0.4% + 40mv 30msec 19 514 15

52 $325 52 325 56 325
55 325

OCR 300·2 .5 0·300 ±.075 % or60mv 0-2.5 0.25 to 2.75 ± 15ma 0.4% + 300mv 30msec 19 5 14 18 77 525 OCR 150-5 0-150 ±.075 % or 30mv 0-5 0.5 to 5.5 ± 15ma 0.4% + 150mv 30msec 19 5 14 18 77 525 OCR 80-10 0-80 ±.075 % or 20mv 0-10 1.0 to 11.0 ± 20ma 0.4%+ 80mv 30msec 19 5 14 18 77 525 OCR 60-13 0-60 ±.075 % or 15mv 0-13 1.3 to 14.3 ± 20ma 0.4% + 60mv 30msec 19 5 14 18 77 525 OCR 40-20 0-40 ± .075 % or 15mv 0-20 2.0 to 22.0 ± 25ma 0.4 % + 40mv 30msec 19 5 14 18 77 525

OCR 300-5 0·300 ± .075% or60mv 0·5 0.5 to 5.5 ± 15ma 0.4% + 300mv 30msec 19 7 OCR 150-10 0-150 ±.075 % or30mv 0-10 1.0 to 11.0 ± 20ma 0.4 % + 150mv 30msec 19 7 OCR 80-18 0-80 ± .075% or 20mv 0-18 1.8 to 19.8 ± 25ma 0.4% + 80mv 30msec 19 7 OCR 60-25 0-60 ±.075 % or 15mv 0-25 2. 5 to 27.5 ± 25ma 0.4 % + 60mv 30msec 19 7 OCR 40-35 0-40 ± .075 % or 15mv 0-35 3.5 to 38.5 ± 35ma 0.4 % + 40mv 30msec 19 7

18 95 710 18 95 710 18 98 710 18 100 710 18 102 710

OCR 300-8 0 -300 ± .075 % or60mv 0-8 0.8 to 8.8 ± 20ma 0.4% + 300mv 30msec 19 7

18 115 825

OCR 150-15 0-150 ± .075 % or30mv 0-15 1.5 to 16.5 ± 25ma 0.4 % + 150mv 30msec 19 7

18 115 825

OCR 80-30 0-80 ± .075 % or 20mv 0-30 3.0 to 33.0 ± 30ma 0.4 %+ 80mv 30msec 19 7

18 120 875

OCR 60-40 0-60 ±.075 % or 15mv 0-40 4.0 t o 44.0 ± 40ma 0.4 % + 60mv 30msec 19 7

20 130 900

OCR 40-60 0 -40 ± .075% or 15mv 0-60 6.0 to 66.0 ± 60ma 0.4 % + 40mv 30msec 19 7

20 131 925

OCR 20-125 0-20 ± .075 % or 8mv 0-125 0 to 125 ± 125ma 0.4 % + 20mv 30msec 19 101h 20 169 1050

s@-
A U NIT OF RAYTHEON COMPANY

Vector
Solid State Laboratories
New package improves RF characteristics ...
excellent for strip line mounting

RF PACKAGE VX-3375

· Integrated Structure Distributes Heat Generated At Junction And Increases Reliability.

· Test Data Demonstrates Rugged Construction And Validity Of Package In Variety Of Environmental Stresses.

HIGH FREQUENCY CHARACTERISTICS

SYMBOL RF Output
Po n ~
Cob

TEST CHARACTERISTIC CONDITION

Power as Unneutralized Amplifier at 250 Mc

Vee= 28V

P;n =I.OW

Output Capacitance

~e=UV le = 150mA Vcb=30V
10 = O fo =l Mc

TYPICAL
6.5 watts 55% 500 Mc lOpf max.

ABSOLUTE MAXIMUM RATINGS *

Vcbo Collector-to-Base Voltage 65 volts Vceo Collector-to-Emitter
Voltage with base open 40 volts

Vcev Collector-to-Emitter Voltage with Vbe =-1.5 volts

65 volts

Vebo Emitter-to-Base Voltage 4 volts

le

Continuous Collector

Current

1.5 amperes

Pt

Transistor Dissipation- 11.6 watts

at 25°C heat sink

interface.

At case temperature

De rate I inearly

above 25°C

to Owatts

at 2oo· c

Tj

Operating Temperature

(Junction)

-65 to +2oo·c

Ts

Storage Temperature

-65 to +2oo·c

*25°C, except where otherwise noted

SEND US YOUR REQUIREMENTS OTHER DEVICES AVAILABLE IN THIS PACKAGE Telephone: (215) EL 7-7600

Vector
u
DIVISION OF UNITED AIRCRAFT CORPORATION
R
SOUTHAMPTON, PENNSYLVANIA
See us at WESCON, Booths 3208-11
134 Circle 134 on reader service card

New Semiconductors

Everyman's laser and a thermos jar

For the budget-poor engineer who wants to know firsthand what a diode laser is, how it is se t up, and what it might be able to do for him, Seed Electronics Corporation is marketing a gallium arsenide laser for $75.
Th e " laser for everyman" needs a pulser to drive it, and a S75 companion instrument to do this is available for those whose lab equipment does not in clude a suitable pulser.
The diode laser must be immersed in liquid nitrogen during operation. For the engineer who does not want to spend another $15 to $50 for a liquid nitrogen dewar, Richard Seed, president of the Lexington, Mass ., company suggests using a wide-necked coffee th ermos jug. "Just shin e the laser output up through th e open end," he says.
"Any welding supply hou se will sell you a quart of liquid nitrogen for a dollar," Seed adds, "and it will last for about three days ."
No one is going to be able to do anything very profound with the S-27 laser, Seed em phasizes. "It's for investigation of laser applications, rather than for the applications themselves. There seems to be a good market for a cheap unit for engineers to play around with and learn something about laser operation." One research customer, however, is using it to stimulate fluorescence in materials, an-

other in studies of point-to-point

ground communications.

According to Seed, a seconcl-

unexpected-market seems to be

emerging. "\Ve sell one or more of

these inexpensive units with almost

every one of our more expensive

devices," he says. "They use the

less expensive one to check experi-

mental setups, try out mounting

fixtures, tes t pulser and current in-

put limits, and in general bang it

around the lab-something they

don't want to do with a device

that costs something between $300

and $9,000." In other instances

·s eed says, companies and indivi'.

duals want to try out the inexpen-

sive unit first to help them decide if

th ey need a laser in th eir proj ect~.

With the S-27 laser, the Seed

corporation includes five pages of

instru ctional materials. "Most en-

gineers don 't know how to go about

using a laser," according to Seed.

Th e S-27 is operated with pulsed

direct current and emits at approxi-

mately 8,400 angstroms, in the in-

frared. It is a p-n junction diode

made from a small chip of gallium

arsenide, a chip smaller th an its

which is in wire contact.

fTahct~

chip is mounted on a T0-5 header

without a cap, and th e coherent

output is emitted radially from the

T0-5 header in th e direction of the

wire contact. Seed describes the

S-27 as "fallout" from manufacture

of medium-power c-w laser devices.

Characteris tics at 77°K are listed

b elow.

Specifications

Minimum

average

coherent

power output 1 mw

Maximum

average

input power

400 mw

Peak power

output,

2 !LSec pulse at

20 amps

0.5 w

Threshold

current

3-6 amps

Junction

material

Zinc diffused

Base material Gallium arsenide, tellurium

doped

Diode size

0.005 x 0.005 x 0.020 inch

Availab i lity

Off shelf

See~ Electronics Corp., 258 East St., Lexington, Mass., 02173. [371]

Electronics I August 23, 1965

command control and telemetry antenna systems

DESIGNED ... ENGINEERED ··· AND MANUFACTURED AS A COMPLETE PACKAGE

Andrew antenna systems are designed as complete packages.

Antenna and positioner engineering are integrated to guarantee

system performance.

Andrew positioners are available with a wide choice of low,

medium and high gain telemetry antennas to meet your require-

ments. HELIAX® coaxial cable provides the most reliable con·

Standard single or dual axis posltloners offer electro-manual control, solid state power supply, 125 mph design, and permanently sealed and lubricated motors. Optional features Include optical equipment for aligning eleva-

nection between transmitter or receiver and the antenna. ONE SOURCE-ONE RESPONSIBILITY... Contact your Andrew sales
engineer or write for complete system information and delivery.

tion and azimuth axis, servo controls, mechanical stops and adaptors, special mounts and counterweights.

28 YEARS OF ENGINEERING INTEGRITY

' · o. IOX '°'.CHICAGO, ILLINOIS U. S. A. · 60642

EUROPEAN OPERATIONS: ANDREW CORPORATION, H·JSGAARDS-A&.&.E 82, HE&.&.ERUP, DENMARK

Electronics \ August 23, 1965

Circle 135 on reader service card

135

You get better results with high speed
integrated monolithic circuits
that are packaged riuh!

New Semiconductors
Controlled-avalanche silicon rectifiers

The manufacturer's line of silicon rectifiers now includes 100-amp alldiffused junction units with controlled avalanche characteristics. Th e new rectifiers , 1 3289-1N3296, which have peak inverse voltages to 1,000 v, offer the circuit designer a wide selection for the most exacting requirements. Operating and storage temperature range is -40° to +100°C.
Welded construction, accomplished in a controlled atmosphere, assures hermetic sealing of the contamination-free D0-8 size package. The units are suited for industrial applications, such as motor and power distribution controls.
The devices are priced from $9.50 each, in lots of 100.
North American Electronics, Inc., 401 N. Broad St., Philadelphia, Pa., [372]

SEL 8500 Series Micrologic Modules

Here is the answer to your digital logic design and assembly problems. Whether your requirements are for an entire system or a single demonstration unit, you will appreciate these operational and packaging advantages: Easily accessible test points, ELCO connectors for quick and reliable wirewrap inter-connecting. Card shape and size minimize flexing. One power supply voltage is required, and operation speeds are in excess of 5 me. Noise immunity is excellent. A full line of SEL trays and files is available for compatible packaging.

Write for SEL Bulletin 9031

BYBTEMS ENGINEERING LABDAATORIEB, INCORPORATED

P . 0 . BOX 9148

FORT LAUDERDALE . FLA. 33310

Telephone 305-587-2900

TWX 305-587·1079

Immediate openings for logic design engineers · An equal opportunity employer

136 Circle 136 on reader service card

Silicon transistors
usable to 2.5 Ge
Two new silicon transistors, with frequency capability to 2.5 Ge, are available. The TIXS12 and TIXS13 make possible the replacement of low-power klystrons, bwo's and vacuum-tube oscillators in microwave applications. Broadening the scope of solid-state microwave applications, the transi stors are designed for use as microwave power sources from 500 Mc to 2.5 Ge. Guaranteed oscillator power output is 250 mw at 1.5 Ge, and typical current gain-bandwidth product is 1.4 Ge. Both transistors are furnished in a coaxial package that allows maximum power operation at high frequencies. The devices are useful in military and industrial circuitry.
Texas Instruments Inc., 13500 North Central Expressway, Dallas Texas. (373)
Electronics I August 23, 1965

speeds production-line sealing at lower cost

Get General Electric silicone rubber adhesive sealants These RTV compounds are ready to use with no mixing

in a better package! Get G-E white RTV-102 and trans- required. Their new cartridge-pack makes it a cinch to

lucent RTV-108 at a new low price! And get a handy get into confined areas and hard-to-reach spots. RTV

dispenser gun FREE with your trial purchase!

sets in minutes, cures in a few hours ... will not sag, flow,

RTV-102 and RTV-108 are now in new 6 and 12 shrink, crack, harden or peel ... at temperatures from

ounce cartridges designed for use in standard or air- -75°F to above +300°F. These RTV compounds meet

powered caulking guns to speed and simplify production- Federal Food and Drug Administration requirements for

line sealing operations. Ideal for electrical, electronic, use in any application where they might incidentally

aerospace and general industrial applications such as come in direct contact with food. All in all, there are

sealing terminal connections, weatherproofing, caulking, probably 1000 production problems you can solve ..·

patching ... and virtually any application requiring a permanently ... with these RTV's.

flexible, durable adhesive bond.

r--------------------------------

SPECIAL INTRODUCTORY OFFER

e
GENERAL ELECTRIC

Handy adhesive/sealant dispenser gun FREE with your

trial purchase of one 12 ounce cartridge RTV-108

(translucent) or RTV-102 (white) at the new low $3.27*

price. Get yours by sending company purchase order

to General Electric Company, Silicone Products Dept.,

P. O. Box 385, Schenectady, N. Y. Only one free dis-

________________________________ penser gun to a customer. Offer expires Oct. 31, 1965.

,

*Plus applicable state or local tax.

Electronics I August 23, 1965

Circle 137 on reader service card

137

New Instruments
Portable scope meets lab specs
TYPE 453 OSCILLOSCOPE

3}{"

INDUCTION
Model 3000
PAMOTIR
Miniature Axial "fans + · 20,000 operational
hours at 45°C · All metal construction · Low-cost design · Maximum air delivery at
higher back pressures · Unexcelled performance
and reliability · 50-60 cycles at 110 or
220 vac · In stock for immediate
delivery
Write for technical data on the Model 3000 and other PAMOTOR axial fans to:
PAN{~ QJ'OR, INC.
312 SEVENTH STREET · SAN FRANCISCO, CALIF
138 Circle 138 on reader service card

As electronic gear becomes more prevalent and more complex, there is increasing need for a portable oscilloscope that has all the capabilities of laboratory models. Such a scope would be valuable for testing electronic installations in aircraft, aboard ships, at remote missile sites and computer complexes.
To meet this need, Tektronix, Inc., is introducing a portable oscilloscope, called type 453, at W escon. The instrument is a 50 megacycle, dual-trace oscilloscope that offers all th e features and performance of a laboratory instrument in a 28pound package that measures only 6 by 10 by 19 inches.
Designing a scope of this type gives rise to some conflicting requirements that Tektronix engineers had to resolve. An ordinary portable scope was not the answer; a laboratory scope had to be made about one-quarter of the usual size, with reduced power consumption, and capable of operating in a variety of environmental conditions.
One innovation in the type 453 oscilloscope is a four-inch rectangular cathode-ray tube. An overall accelerating potential of 10 kilovolts results in a short rapid-writing

tube with relatively large graticule area. To simplify th e horizontal and vertical amplifiers and reduce the instrument's weight, the Tektronix engineers added a frame grid in th e crt between the post accelerating fi eld and the deflection plates to increase th e tube's deflection sensitivity. Illuminated internal graticules eliminate parallax. And a mesh-like filter, which can b e clipped in front of the crt, improves the contrast so th e traces can be viewed under high ambient light.
The dual-trace vertical amplification system has a bandwidth greater than 4 megacycles, with a deflection sensitivity of 5 millivolts to 10 volts per division. Th e display can be chopped, or the scope can show the two inputs alternately or added. An optional trigger pickoff provides a means for viewing th e time relation in the chopped and alternate modes.
A delayed sweep is included in the horizontal amplification system. This provides sweep speeds from 5 seconds down to 10 nanoseconds per division, with calibrated variable delays from 50 seconds to 0.1 microsecond.
Strength and reduced weight

Electron ics I August 23, 1965

DAILYrll NEWS NEW YOaK'I PIC1Ual NIWIMPIR e N'tw York 11. N.Y.. Friday, M·Y '1 . 1954

lA RG fSJ CIRCUl.AJION IN AMERICA

When this headline was current news . .. digital recording tapes
had a packing rate of 200 bpi.
Today, 800 bpi is standard; improvement in tape and base is the reason.

In analyzing the sensational development of EDP over the past decade, most of us naturally talk in terms of improvement of hardware. But when you stop to examine them, the contributions made by tape manufacturers have been quite ~emarkable .
The tape of today looks like the tape of 1954 ... but think of the differences: improved oxide coatings to increase total capacity, reduce fluctuations in performance; much stronger binders to reduce dropouts and flaking, lengthen tape life; smoother surfaces to give longer, errorfree wear; thinner coatings and better production controls to guarantee reel-to-reel uniformity.

Working hand in hand with the tape manufacturers during this time has been Du Pont. Improvements in the uniformity, stability and overall reliability of the base of MYLAR*have played a vital role in making possible the sophisticated tape in use today. Continuing cooperation of research and development facilities assures continuing improvements in the fu- · ture. Your guarantee of Du Pont's regist ered tr adema rk for its pol yes ter fdm .
:~et~eos~::':r~~~~:::.: ~

brand and a base of

............. ...

MYLAR polyester film. Beller Things for Beller l iving ··· through Chemi·lry

At the base of all tape improvements: Mylar®

Electronics I Aug ust 23, 1965

Circle 139 on reader service card 189

WHAT'S THE LATEST IN DISC CATHODES? ASK SUPERIOR.

V. power for 300 ma heater applications

Shielded full power for better temperature uniformity in 600 ma heater applications

Shielded low power for 12.6 volt 85 ma heater applications

Widest choice of disc cathode designs
There are three basic types of Superior disc cathodes. Each has its own advantages. All feature close control of the E-dimension (distance between top of cap and top of ceramic), flare at the shank opening to facilitate assembly, shadow groove in the ceramic to inhibit electrical leakage and are available in wide choice of both cap and shank materials. Available in 0.121 ", 0.100" and 0.090" outside diameter shanks. Ceramic diameters can be either 0.490" or 0.365", with either round or triangular center hole.
New shielded disc cathodes~~ Full power and low power
In the full power design the emitter is separated from the ceramics by a shield which minimizes the conducting X-section from the shank to the ceramic. In the low power design, the slender shank, thermal shield and thin ceramic permit low heater power consumption and fast rise time. The shield also acts to eliminate leakage if sublimation takes place.
Widest choice of disc cathode materials
Superior's disc cathodes feature separate nickel cap and shank alloys. Hence you may choose the most suitable materi al for each. The Cathaloy® series, developed and controlled by Superior Tube Co., offers alloys with high strength, high activity, low sublimation, freedom from interface impedance, or any desired combination.

Cathaloy A-31. Approximately twice as strong as tungsten-free alloys at high temperatures.
Cathaloy A-33. Combines the high emission of active alloys with freedom from sublimation and interface impedance.
Cathaloy P-51. More than 100% stronger than X-3014 at high temperatures.
X-3014. Powder metallurgy pure nickel for resistance to sublimation. Suggested for shanks.

X-3015. Special shank alloy for strength with resistance to sublimation and for nonemitting characteristics.
Nickel 220, Nickel 225, Nickel 230 and Nickel 233. Suggested for caps requiring normal emission with rapid activation.
Driver Harris 599 and 799. Provide rapid activation plus high level d-c emission. For caps only.
For your copy of our Catalog 51, write
ISuperior Tube Company, 2500 Germantown Ave., Norristown, Pa .

®. Superior W/Je The big name in small tubing NORRISTOWN, PA. 19404
West Coast: Pacific Tube Company, Los Angeles, California
Johnson & Hoffman Mfg. Corp., Carle Place, N.Y.-an affiliated company making precision metal stampings and deep-drawn parts

140

Circle 140 on reader service card

New Instruments

were achieved by using alnminum alloy castings for the main frame and side rails. The solid state circuitry is mounted on six glassepoxy boards. The instrument cover is designed to provide storage space for the power cords and measuring probes during transit. The carrying handle doubles as a stand to position the scope for easy viewing. A few of the less commonly used controls are on the side of the instrument which gives more room for the basic controls on th e front pan el.
Specifications

Sensitivity

5 mv/division to 10 v/

division in 11 steps

Frequency response D-c to 50 Mc for sensi-

tivity greater than 20

mv/div

Input resistance

1 meg paralleled by 20

pf

Maximum input

600 v combined d·c an<l

voltage

peak a-c

Trace drift

Less than 1 division/

hour at 5mv/ div

Sweep rates

0.1 microsecond / div to

0.5 second/div in 21

steps

Trigger sources

Internal, line, external,

external divided by 10
Temperature range - 15° to + ss· c (operat-

ing)

Shock

30 g's

Power requirement g6 to 127, 103 to 137,

192 to 254, or 206 to

274 v a-c, 45 to 440 cps,

100 watts

Price

$1,950

Availability

90 days

Tektronix, Inc., P.O. Box 500, Beaverton, Ore., 97005. [381]

Air-insulated supply delivers 500 kv

A high voltage assembly, model BAL-500-5.5 uses air as an insulating medium. Output is 0 to 500 kv d-c at 5.5 ma d-c. The unit offers
I Electronics August 23, 1965

reversible polarity. Ripple is 2% rms. Load regulation is approximately 20% for no load to full load changes of 5.5 ma d-c when measured at 500 kv d -c. Output will vary directly with lin e; however, a line voltage regulator is available. The high voltage assembly, mounted on cas ters, measures 3 ft. wide by 8 ft. high by 18 ft. long. Controls measure 22 in . wide b y 16% in. high by 18 in. deep. H eight will increase b y .30 in. if a lin e voltage regulator is included in th e package.
This equipment has application in tes ting of electroni c cabl es, rectiilers and capacitors. Its chief advantages are found in maintenance, mobility and p erformance. The air design is readily accessible for serviceability and does not requ ire th e pumping and pressurizing equipment that is necessary for oil. Th e equipment may easily be moved by two men around a laboratory and may also be disassembled in a short time for transportation purposes. Th e modular construction of the high voltage componen ts lends itself to extension to approximately a million volts a t some later date.
Universal Voltronics Corp., 17 S. Lexing ton Ave., White Plains, N.Y. [382]

ANTENNA
and
TOWER INSULATORS by LAPP

Position transducer
in 2 configurations
An improved series of displacement or position transducers is available in a range of standard sizes, from ± 112 in. to 140 ft. , to meet most requirements. These new transducers incorporate many of th e improvements that have been developed for units built to meet NASA's and other government agencies' specifications for aerospace environment.
Electrically, the transducers are available in two different confi gurations. The A circuit provides outputs in the magnitude of 7 to 270 mv per v per in. The B circuit provides outputs in the order of 0.05 to 0.23 mv per v per in. Proper selection of either circuit will provide a transducer capable of driving at highest efficiency the particular equipment available that can read out.
Lockheed Electronics Co., 6201 Randolph St., Los Angeles 22, Calif. [383]
Electronics \ August 23, 1965

Lapp insulators support most of the world 's large radio towers, both

self-supporting and guyed masts. Lapp has designed and built base

insulators from 80,000 lbs. to 9,000,000 lbs. ultimate strength. Lapp

strain insulators have been made from 1200 lbs. to 620,000 lbs.

ultimate strength. D Lapp is also a dependable supplier of entrance,

spreader and stand-off insulators for transmission lines. Other Lapp

insulators and our gas filled capacitors are used in transmitters and

coupling networks. D Difficult insu-

1ating problems are welcome here at

Lapp. We've been solving them for almost a half century. Write Lapp Radio Specialties Division, Lapp Insulator Co., Inc., 235 Sumner St.,

Lapp

LeRoy, N. Y. 14482.

Circle 141 on reader service card 141

Want to design for
INSTANT STARTING? ..·
SPLIT· SECOND ACCURACY ?
REVERSIBILITY? .. . MIXED SPEEDS? .. .

New Subassemblies and Systems
Detector checks explosive bolt firing

'.turn the job over to
SYNCHRON® MOTORS!
No matter whether you want a motor to withstand swiftly changing tempera· tures, meet fast-reversing stresses, turn a small part with exact accuracy to 1 Rev. per week or 600 Rev. per minute, there's a SYNCHi<.ON Motor that can do it! It can do a hundred other things as demanding as these - if you tell us how you want it to function. Before you start any design that calls for small drive or timing motors, think of SYNCHRON Motors, and call or write us at Hansen Manufacturing Company. We'll be there at once to help - with experience. Bet· ter still - don't wait till you face a problem. Write us now - let us tell you about SYNCHRON Motors and the ways we design them to work for you.
HANSEN REPRESENTATIVES, CAREY & ASSOCI· ATES, Houston, Tex .· R. S. HOPKINS CO., Sher. man Oaks, Calif., EICHORN & MELCHIOR, INC., Son Carlos, ColH., THE FROMM CO.· Chicago, Ill., H. C. JOHNSON AGENCY, INC., Rochester, N. Y., WINSLOW ELECTRIC CO., Essex, Conn., and New York, N . Y. EXPORT DEPARTMENT, 64-14 Wood· side Ave., Woodside, N. Y. Handled exclusively in Canada by Sperry Gyroscope Ltd., Ottawa, Conoqo.
142 Circle 142 on reader service card

The systems for firing explosive bolts, or squibs, on missiles or other space vehicles must be very carefully checked in the factory and before launching. If a single squib does not fire, or fires at the wrong time, stage separation will not take place properly and the entire mission may fail.
In testing, it is necessary to know if the firing command signal was initiated, when it was initiated, whether it was recognized, and when the reaction occurred. The tests usually require a separate wire connection between each squib location and the checkout equipment, but a system developed to test Gemini's 70 to 90 squibs gets rid of much of the wiring and saves on checkout times.
Dummy squibs are used in the tests; they are resistors with the same general characteristics as the thermal wires in the actual squib. The system consists of one detector module for each squib to be monitored (up to 125 in the present design) and a decoder assembly to provide multiple readout. (The detector modules are the small cylinders at the left in the photo above. The decoder is the large panel.)
Each detector operates on its

own frequency, at increments of one kilocycle between 175 and 300 kc. It is connected in series between the squib simulator and a current probe which is slipped over the common lead of the missile battery that powers the squib. \Vhen the missile programer closes relay contacts between the battery and the squib, a crystal oscillator in the detector begins to rise to full potential. The command initiation is thus recognized.
As long as the squib remains intact, it presents a nearly zero ohm d-c resistance, and a gate between the oscillator and the battery line remains deactivated. But when the squib has blown, the oscillator signal is passed through the gate and an adjustable current driver back to the line.
The signals are picked up by the current probes, and all 125 are sent along a single cable back to the decoder. Here the signal is demodulated into the individual frequencies, and the data is read out for test operators.
Tridea Electronics, a subsidiary of the McDonnell Aircraft Corp., developed the system to test squibs on Gemini; the company is now making it available to other space

Electronics I August 23, 1965

Etching solder plate boards with chromic acid?

Switch to ammonium persulfate. Get 21/ 2 times as many boards for your etchant dollar.

Use ammonium persulfate on solder boards and save 60% on every dollar you now spend on etchants.
Standardize on persulfate-for both copper and solder boards-and get further savings on storage and purchasing.

clean boards etched with chromic acid.
For full information (including our bright dip formula, ea sily mi xed with standard chemical s), or for a demonstration in your own plant, write deoartment 1088R.

Get clean, shiny, ready-to-u se solder boards with our new bright dip formula, for no more than it costs to

Electronics I August 23, 1965

143

New Subassemblies

contractors. The cost is $9,510 for the decoder and ancillary gear, plus $310 for each detector-which would make the price of a complete system, with all 125 channels, $48,260. Tridea is wo1king on a leasing plan for companies which do not want to make such a large investment.
Specifications

Channel capacity Frequency range
Time delay Signal current
Detector size
Detector weight Decoder size
Decoder weight

125 175 kc to 300 kc (1 kc spacing) 20 msec±2 msec 0.1 ma to 5 ma (each channel, adjustable) approx. 2 in. in diameter x
5 ¥., in. long
less than 8 oz. 19 in. rack mount, 24 in. high 150 lbs.

Tridea Electronics, 1020 Mission St., South Pasadena, Calif. [401]

Also 200 other Models of Power Supplies & Battery Chargers· Write for Cata1og CHRISTIE ELECTRIC CORP. 3400 West 67th Street, Los Angeles 43, Calif.

Tiny preamplifiers are rfi-protected

COMINCO
high-purity metals

Available forms in 99 .999% and /or
99 .9999% purities

~ ::::> 2
~ ::::>
....I
ct

>
2 0 ~
i==
2
ct

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a: ct

:r
I::::>
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iii

~
::::>
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0
uct

a: awa... u 0

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..J
0 Cl

BARS

x x x x x x

SHEETS

x

x x x

WIRE

x

x x x

POWDER

x x x x

SHOT

x xxx

ROD

x

x x x

RIBBON
x PREFORMS
SALTS

x x x x

Available forms in 99 .999% and /or
99.9999% purities
BARS

~ ::::>
Ci
-z

0
cw t
....I

a: w
>
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iii

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2
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x x x x x x x

SHEETS

x x x

x x

WIRE

x x x

x x

POWDER x x x x x x x

SHOT

x x x

x x

ROD

x x x

x x

RIBBON

x x

x

PREFORMS x x x

x x

SALTS

x

COMINCO PRODUCTS, INC.

ELECTRONIC MATERIALS DIVISION

818 West Riverside Ave.· Spokane, Wash. 99201

Phone 509 747-6111

Telex 032 610

...,.

TWX 509-328-1464

144 Circle 144 on reader service card

Circle 207 on reader service card

Low noise, solid state preamplifiers are available packaged in ultraminiature, ruggedized housings. Offering power drains of 0.2 w , less than 3 cu in. volume and a weight of 2 oz, these units are ruggedly constructed for missile and aerospace applications.
Units are conduction cooled and will operate from - 55° to +100°c. They are designed to withstand shock of 35 g, acceleration of 15 g, and vibration and acoustic noise from 5 to 2,000 cps. They are rfi protected with MIL-I-26600 as guideline. Standard center frequencies include 30, 60 and 70 Mc with bandwidths to 30 Mc. Prices start at $395 with delivery of stock to 30 days.
RHG Electronics Laboratory, Inc., 94 Milbar Blvd., Farmingdale, L.I ., N.Y. [402]
Electronics I August 23, 1965

Hitachi germanium power transistors
288471 and 288472

ELECTRICAL CHARACTERISTICS (Ta=25 "C)

lcso lcso (sat) hFE VsE VcE (sat) fas

(Vcs= -30V, IE=O) (Vcs= -0.5V, IE=O) (VcE=-2V, lc=-lA) RVcE= -2V, le= - lA) (le= - lOA, Is = - lA) (VcE=-2V, lc = -lA)

2S8471

2S8472

min - typ - max

min - typ - max

-

-

-0.5

-

-

-0.5

mA

-

-

-0.l

-

-

-0.1

mA

50 90 165

50 90 165

-

-0 .3 -0.5

-

-0.3 -0.5

v

-

-0.4 -0.75

-

-0.3 -0.5

v

-

300

-

-

300 -

KC

HITACHI SALES CORPORATION : 33':3, N . Michigan Avenue, Chicago 1, Ill., U.S.A. Tel: 726-4572/ 4 / 666, 5th Avenue , New York , N.Y. 10019, U.S.A. Tel : 581-8844 I 12715, S. Daphne Avenue , Hawthorne, Calif., U.S.A. Tel : 757 ·8143 HITACHI, LTD ., DUESSELDORF OFFICE : Graf Adolf Strasse 37, Duesseldorf, West Germany Tel : 10846

Electronics J August 23, 1965

Circle 145 on reader service card

145

New Microwave
Lightweight microwave relay

J
. I

Flat Glass Packages
· In volume production
Ultra Carbon' s "quarter-by-quarter" -fi e:: glass package in standard 10-lead con-fig uration has been placed in volume production. This package can be purchased with the pad coplanar with the leads or depressed pad arrangements. Leads and pad are gold plated. Either natural or black glass available.
· Nearing volume production
Ultra Carbon's "quarter-by-threeeighths" flat glass pack with 14 leads is in advanced stages of development. To be released for volume production soon, this package will be available with depressed or coplanar pads; gold plated pad and leads; and, in either natural or black glass.
· Whatever your glass pack needs
ULTRA/FGP 8 glass pack is a completely flexible technique of providing rugged protection for integrated circuit devices. Final seal made in your plant .. . assures proprietary security.
Ultra Carbon welcomes the opportunity to work with you in applying ULTRA/FGP packaging to your microcircuit needs. Write P.O. Box 747, Bay City, Mich. 48709.
ULTRA CARBON
CORPORATION
146 Circle 146 on reader service card

When mountain climbers inched
their way up the Matterhorn several weeks ago, the action was televised by two technicians who aocompanied the mountaineers. One technician took the pictures, the other carried a portable relay system on his back that transmitted them to the bottom of the mountain.
The solid state microwave relay system, model MA-7A, was developed by Microwave Associates, Inc. It is capable of operating in the microwave relay band-6,000 to 7,000 megacycles. It weighs 30 to 40 pounds, about one-third the weight of relay systems that use klystron tubes in the transmitters' output stage.
Microwave Associates' system uses a transistor capable of several watts output in the ultrahigh frequency range, and a varactor multiplier that gets the transmitter output frequency up into the microwave relay frequency band.
The transmitter's radio-frequency output is 0.5 watt minimum from only 35 watts input. The receiver, which has a crystal-controlled, stable local oscillator, requires only 25 watts. Because it is solid state, the relay system requires no warm-up time. Receiver noise is 10 decibels maximum, but can be reduced to 5.5 db with a preamplifier, which is optional equipment.
Besides monochrome and color-

tv signals, the system can relay multichannel telephony and wideband data signals.
The transmitter and receiver are contained in separate weather-tight cases that include integral interchangeable power supplies that can accept 12 volts d-c, 24 volts d-c, 110 volts a-c or 220 volts a-c. Each rack mount is 19 by 8112 inches. The transmitter, model MA-8565, is shown above.
Microwave Associates says the MA-7A system is in production for fall delivery. Price is about $9,500.

Specifications

Transmitter Differentia l gain Differential phase
Transm itter frequency Video bandwidth Tuning

Model MA 8565 0.2 db typica l Less than 1· at 3.58
Mc 6,000 to 7,000 Mc 6 Mc Selecting oscill ator frequency only

Receiver Noise figure Frequency stability Price

Model MA 8564 10 db m axi mum With i n 0 .005 % About $9,500 for both transmitter and re· ceiver

Microwave Associates, Inc., Burlington, Mass. [421]

Frequency extender
uses VIG preselector
Type FE-1-2 frequency extender tunes from 1 to 2 Ge in a single b and. It employs a four-section YIG preselector that is tuned electronically throughout its range, avoiding

Electronics I August 23, 1965

CONSIDER COLORADO . .. where research and education are industry's partner...
Directly. Indirectly. From government, university and private sources ... Consider 103 research organizations located in the state . .. headed by a
total of 3500 graduate scientists who guide the efforts of 23,000 employees to discover the unknown. Everything from economics and marketing to cryogenics and advanced nuclear research and neutron generator performance.
In close support of science, research and industry are Colorado's educational institutions: 12 colleges and universities; 7 junior colleges. Plus an increasing number of vocational and trade schools whose primary mission is to serve the needs of Colorado and the nation's industry.
If research and education are important to your business, consider industrial Colorado for your expansion or relocation . Complete information is available from Dwight E. Neill, Director, Division of Commerce and Development, 14 State Services Building, Denver, Colorado.
INDUSTRIAL COLORADO

Electronics I August 23 , 1965

Circle 147 on reader service card

147

You get what you see with a
FAIRCHILD SCOPE CAMERA

The highest precision and clarity in oscilloscope photography are insured by a long

list of Fairchild design features. Pinpoint focusing at any object·to·image ratio

within lens range is one. Heavy duty synchro shutters with jam-proof activation are
others. With Polaroid Land Back, 6 x 10 cm field can be recorded 0.9 actual size.

Option of f/1.9 or f/2.8 lens. Prices start at $350.
For specifications or a demonstration, contact l=AI R C 1-t I L..C

your local Fairchild Field Engineer, or write to
u Fairchild Instrumentation, 750 Bloomfield Avenue, 1N STR ME NTATI ON

Clifton, N. J.

A DIVISION OF FAIRCHILD CAM(AA ANO tNSIAUM(Nf CORPOAAflOH
Circle 204 on reader service card

MIDGET
IN SIZE

New Microwave
complex mechanical drives. Signals are converted to a 160-Mc i-f output, and fed into a series 900 vhf receiver or other unit that tunes to 160 Mc. The 160-Mc output can also be connected to a type IFC-21 converter for further reduction to a 21.4-Mc intermediate frequency, acceptable as input by a demodulator system such as the type DM-4. The tunable, four-section YIG preselector assures low oscillator radiation and high image rejection (70 db minimum). Solid state devices are used throughout, with the exception of a ceramic triode in the highly stable local oscillator. As a result, average power consumption is kept to 25 w, and the FE-1-2 requires just 51.Af in. of rack space. The unit operates from a 115-230 v power source, 50 to 400 cps, and weighs approximately 20 lb. Price is $4,000, delivery in 60 days.
Communication Electronics, Inc.. 6006 Executive Blvd., Rockville, Md. [422]
Band-pass filters
are extremely rugged

IN POWER
NOWI
New and Smaller Sizes TYPE LK Rectangular High Voltage
CAPACITORS
"The little one" with the tremendous power! 4 times the life of Mll-C-25A in case sizes reduced up to 80%! And you also get: superior resistance, better power factor, withstands greater overloads, may be
operated to 125° and voltage ratings from 600 to 500,000 volts.
Write today lor Bulletin LK Also ask lor FREE pocket size "Comparator" and "Conversion" chart

148 Circle 148 on reader service card

,Custom ~Engineering at
J'roduction Prices

Two lines of coaxial band-i.:>ass filters feature improved pass-band performance with extremely rugged construction. The BK series filters are 10% bandwidth comb line filters; the BL series filters are octave bandwidth intcrdigital units.
Maximum pass-band vswr is 1.5; maximum insertion loss, 0.5 db. The units are available in the 0.25 to 8 Ge region and are supplied with various combinations of passband frequencies, connectors, and polarities. Priced from $125, the units are available on 4 weeks delivery.
Microlab/FXR, Livingston, N.J. [423]
Electronics \ August 23, 1965

©~IT®®IT® ®uo ~Ou® ouo®w® ouo solid state electronics

The Advance Electronics Department of the Douglas Missile & Space Systems Division offers challenging opportunities for physicists with
---------------------------~ Mr. 0. R. Snodgrass, Douglas Missile & Space Systems Division, 3000 Ocean Park Blvd., Santa Monica, California.
I am interested in career opportunities at Douglas MSSD.
NAME·-------------------~ ADDRESS_ _ __ _ _ _ _ _ _ _ _ _ _ _ __ __

Degree(s):_ _ _ _ _ _ _ __ __ _ _ _ __ __ _ Field(s):_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Specialty(ies):._ _ _ _ _ _ __ __ _ _ __ _ _ __

U.S. Citizen:

Yes D

No D

interests and backgrounds in solid state devices. Since the work is of a fundamental nature, publi-
cation of results is encouraged. Specific areas of interest are:
Semiconductor and Thin Film Transport Phenomena · Electronic and Magnetic Measurements · Electronic Materials Properties· Device Concepts.
Please send us your resume or the coupon. You will receive a prompt reply.
You gain by going to:
DOUGLAS
MISSILE & SPACE SYSTEMS DIVISION An equal opportunity employer

Electronics J August 23, 1965

Circle 149 on reader service card 149

THERMOELECTRIC
COOLERS
Stan dard !tne . .. for immediate delivery'

New Production Equipment
Solder sniffer in production

MODULE 3950-1
For spot cooling-e specially in electron ic components. Heat pumping capaci ty 6 8
watts ; voltage 2.6 voe, cur-
rent 7 amps DC . Module mounted between aluminurr; plates for mechanical r-o'I!!~~ strength, uniform junction tempera lures .

MODULE 3951-1
Similar in configuration to 3950·1 , but with higher 20· watt heat pumping capacity Voltage 6.4 VDC ; current 7 amps DC .

MODULE 3952-1
Very low curren t require· ments (1500 m1ll1amps), high heat pumpmg capacity (2000 milliwatts) - ye t very small
(.786" sq. x .196" thick) and
light (less than I/· oz.). Ideal for hot spot problems in circu its w1lh Ion avJ1l able power .

1 /

MODULE 3953-1
New annular ring provides high 20 watt heat pump. ing capac ity (68 BTU's per hour). Runs on low 6.5·7.0 amps current rating . Cold plate diameter is 17/a" with an ID of 'la". Four mounting taos are
located at 90 ' increments on the base plate. Tabs
include one 6·32 machine screw feed through hole . Modules special ly intended f or cooling in a variety of unusual circuit applications.
ASSEMBLY 3970·1
Complele TE cooling sysl am cold plate hea t sink . fan and b1acket. High 40·.vatt hea t pumping capaci ly , low 7-amp DC curren l load. Unit measures only4~ 11 1. S"x 4Vz".
~r?·~~b~~~v~:1~e2o~0-1 ~idi;9!!111~~
fC'rs 1rt :q 1rhr· :. 1 lartte ar t>a ccld surh'"" f;' x l ·h;. r tr - 15"C - y<t r.· a11 s "· I; I amp oo sl· nd» d I IO· I ll VA~. 60 \ le cu rre nt'
Send for comple te data now!
" DIAL- A-PA RT" SERI/ICE St ,r d ar~.10 co CAMBIO'<
The Guarant e0 d E! ectrc"1 c Corl'pcnents CAMBRIDGE THCRMIONIC CORPORATION 401 Concord A··enu e. Cambridge, Ma ss. 02138
Tel· (61 li 876·2800
150

"Where can we buy a solder sniffer? "
Sc\'cral readers, including one in Canada and another in Japan, wanted to know after an article on the Hoeing Co.'s homemade clesolderi11g tool appeared in the April 5, 1965 issue of Electronics, on page 114.
SinCL' then Boeing has licensed Thermo Industrial Products, Inc., to pwducc the sniffers for sale. That company r ports production underway and says that the tool will cost about ~10 re tail.
The sniffer is a hollow adapter and tip which fits onto a pencillypc sol<l ring iron. Suction is crcalul in the lip by a small rubber bu lh attached to the adapter hy a nwtal tub.:.
To remove a componcllt from a prinle<l circuit board, the tip is pressed against the soldl'r joint, melting th e solder. 111L' solder is sucked up into the tip and th en npcll rd int,1 a n'C'Ppta ble by . q1 Pczmg the bulb again
1 li c lips arc m:iclc in st,vcral different !>izcs ,md shapes tor use on

different kinds and shapes of solder joints.
Thermo Indu stria l Produ ct s, In c., 918 Centra l Build ing, Wic hit a, Kan. [451]
Sniffer catches waste solder
A British enlry in th e solckr-smfTing fiel<l is <l new de-;okkri11g tool made by Auk" Ltd. It usl's tlw Ven turi principle to suck up tlw molten solder and th l'n dcposi ls thl' waste in a recep tacle tlut is part of the tool.
A h1be e, rrying compressed air passes th10ugh the tip and into a stainless steel container. The air

I Electronics Au g ust 23, 1965

Tung-Sol

Bead-Out

Lamp

Saves

ACTUAL

SIZE

Customer

Two

Operations,

Cuts

Shrinkage

Our customer's problem stemmed from handling. The bulbs he bought went first to a wiring company to have lead wires attached. (Shrinkage here due to lead wire damage). After the leads were attached the bulbs went to a molder to have bases added. (More shrinkage due to bulb damage and lead wire breakage). Shrinkage in both operations ran as high as 15 per cent.
Now Tung-Sol does the whole job and the customer has benefitted 4 ways : (1) two processing steps eliminated. (2) valuable production time saved . (3) inventory reduced. (4) gets 1000 usable lamps for every 1000 purchased.
Tung-Sol can harness to any specifications and mold to any configuration. Describe your application to us for free suggestions about how Tung-Sol can solve your problem at a saving.

If your application requires only bulbs , ask for a quotation from Tung-Sol. The Tung-Sol line of miniature and subminiature lamps is extensive. Quality is the best that more than half a centu ry of know-how can produce.
TUNG·SOL
INSTRUMENT LAMPS
Tung-Sol Electric Inc., Newark, N. J. 07104
Circle 205 on reader service card

ELECTRO
... EXACTLY THE PO\NER SUPPLY
VDU NEED!
Conservatively-rated components ... overload protection. Top quality construction , long life ... guaranteed one year.

1.

2.

1. Need good but not super regulation? . .. you can save 8250 to s550,
Electro "NFB" Power Supply ... one of the industry's lowest cost-per watt-output, priced at only $250. Reg ulation: 13% at maximum output; 0-32 vdc up to 15 amperes; ... Low de impedance: 0.3 ohms, no load to full load. (Rack model NFBR ... $275.)
2. Need low ripple, high voltage: ... Electro has both for only 8150.
Electro "EFB" ... a low cost power supply delivering up to 128 watts, with top-load ripple less than 0.1% at only $150. Low cost-per-watt-outp ut. Two ranges, continuously variable 0-32 vdc up to 4 amperes; 0-16 vdc to 8 amperes. Regulation: 1.25 volts for each ampere of load current change between 0-4 amperes in 32 volt range; 1.0 volt for each ampere of load change between 0-8 amperes in 16 volt range. (Rack model EFBR ... $175.)
3. Need others?
. . . 18 standard models, 6 to 500 vdc from $27.50 stocked at your electronic distributor ; custom designs for O.E.M . and special applications.
Write for complete line catalog
Since 1936-Pioncers in Low Voltage DC Power Supplies · Proximity Switches · Magnetic Pickups · Tachometers · Pres-Con Contrcls · Dynamic Micrometers
ELECTRO PROOUCTS LABORATORIES, INC .
6125 - F HOWARD, CHICAGO, ILL. 60648 · 312/775-5220
Circle 151 on reader service card 151

thin I<
BIG
(also small)

Now engrave anything from 6 ft. panels to tiny n~meplates

Engravograph tackles them all. Right in your own

I

shop, effortlessly, speedily- ideal for unskilled

workers. Adjustable ratio engraves 21 different

sizes.

---=-==~~~~~~~

Write for illustrated catalog# 114

new hermes engraving machine corp.
154 WEST 14th STREET, NEW YORK 11, N. Y. Chicago, Atlanta, Dallas, Los Angeles, Montreal

Production Equipment
is expelled through the back of the container.
As the air passes a vent which runs to the front of the tip, suction in the vent draws up solder heated by the tip. The air stream carries the solder to the receptacle.
Two models are available, a 25watt model for radio and television assemblies and an 18-watt model for smaller work, such as computer modules and hearing aids. There are two types of adaptors, one for use with compressed air from an air line and another for use with a foot pump. Versions for llO, 220 and 240-volt operations are available. Each model costs 84 shillings (about $ll.75).
Antex Ltd., Grosvenor House, Croyden, Surrey, England. [452]
Power supply welds
through insulation

NYLAFIL® molded coil

Amerline Corporation, Chicago, pro-

duces a complete range of stock and custom injection molded coil bobbins

for motors, relays, solenoids, transform-

ers, etc. They say, "Our reasons for selecting Fiberfil 's NYLAFIL (fiberglass reinforced nylon) in these applications

are:

1. Better dimensional stability and better

moisture characteristics than the unre-

inforced material.

-

-- ... . ._.,...,

- .~ .,-

-~-- -,.,...,..

JEi,[.:J.t:EJi EI [.

.., t "!fff> ~ N ~ ,~·~ / ' i

»;

bobbins stay in shape!
2. Better rigidity which prevents the bob· bin from distorting during and after the coil winding operation.
3. Increased resistance to heat, especially for soldering."
When you want high physicals not available in an unreinforced thermoplastic, specify Fiberfil FRTP ... "reinforced insurance for all injection molding!" Write for technical data.
F I B E R F I L, I N C.
EVANSVILLE 17, INDIANA

152

Circle 152 on reader service card

An a-c power supply now available - th e AC-10-is capable of welding through the insulation on small wires or soldering all the leads of a flatpack in one operation. It can put out more than 1,000 amperes with an unlimited duty cycle. Discharge times range from 0.1 to 3 seconds; other discharge times are available by changing a simple plug-in circuit module. The output transformer is provided with a convenient tap switch to allow for a wide range of output impedances. The power supply measures 10 in. by 103/s in. by 12 15/ 16 in. It is usable with practically any welding, bonding, or soldering head, on an adequately rated llO v, 60 cycle line.
I Electronics August 23, 1965

The company provides, without charge, a sampling service to show the manufacturers of miniature motors, coils, solenoids, and memory boards, how to use th e new power supply to bond class A or class B insulated magnet wire without stripping it. The time saved by using the new technique is said to be substantial.
Model AC-10 is priced at $650. Matching welding or s.oldering heads range from $220 to $725. Delivery time is three to four weeks.
Weltek, a division of Well s Electronics, Inc., 1701 S. Main St., Sout h Bend, Ind., 46623. [ 453]
Hand tool
strips shields

The \VT-700 hand lool is designed for stripping th e braid on shielded or coaxial conductors nea tly and quickly. It is simple and convenient to use and will not nick or damage conductor insulation.
Coaxial or shielded conductors with braid diameters ranging from 0.053 in. to 0.202 in. can he stripped with this tool. Individual die sets to cover any specific shield size may be obtained as needed to accom modate imm ediate requirements.
To use the WT-700 stripping tool, the shield is inserted into the male die side of th e tool. Th e die set used is a function of th e outer diam eter of the sh ielding and is in' talled in th e tool by means of wing nuts on th e jaws of th e tool. The knurled holding disk is rotated to secure the shield and the tool is ooened to expose a short length of shielding. The opposite holding disk is then secured and the tool closed, cutting and stripping the shield.
The Thomas & Betts Co., 36 Butler St., Elizabeth 1, N .J. [ 4 54 ]
Circle 153 on reader service card --+

Taber Teledyne ®AmPlitier built
into Polaris tire control bY Ii. E.
Developed by the Navy and General Electric, Mk 84 Fire Control Systems receive, interpret and transmit essential position, flight and target data for rapid-rate firing of Polaris missiles in ranges up to 2500 nautical miles. Shown above is the supervisor's console aboard the U .S.S. Lafayette from which the entire operation of the Mk 84 System is monitored and controlled.
Serving as a pre-amp in an electro-mechanical resolver servo, Taber TELEDYNE® Model 214-12 Solid State Amplifier is part of the inductosyn servo used by the Fire Control System in fine al ignment of the inertial guidance platform.
Often selected to meet stringent operational and maintenance standards in applications such as these, Taber Amplifiers are reliable under extremes of temperature and vibration. Available to meet a wide range of AC and DC amplification requirements, they can be combined with Taber TELEDYNE Strain G age Transducers to provide high level pressure sensing packages. They can also be used for signal conditioning in conjunction with many other sensing devices.
For detailed information, write: Aerospace Electronics Division. Taber Instrument Corp. , Section 851, 107 Goundry St., N . Tonawanda, N. Y .

New Books

If yothe starting from scratch this way...

e

Check the advantages of Radiation's pre-engineered packaging and plug-in modules

· Packaging density compares with integrated circuits
· Cold solder joints and complex wiring eliminated-all components are welded and interconnections made by manual or automatic wirewrap
· Spare parts and logistics reduced drastically
· Circuits are individually encapsu-

lated plug-in units, 0.4"xl"xl.l"
· High reliability-up to 5,330,000 hours MTBF
CUT COST on both logic circuits and mounting hardware. For example, a 1 Mc 4-input NOR is priced at $5.00. Hardware for mounting 400 NOR 's is only $370.00. For more specification data or price information write:

See our complete line of data processing building blocks and communications maintenance/ operation equipment at WESCON, Booths 2207-
2208 and ISA Instrument-Automation Conference Booth 2014.

Products Division· Dept. EL-08· P.O. Box 220 ·Melbourne, Florida· Ph. (305) 727-3711 Circle 154 on reader service card

To order reprints: Fill in, cut out coupon below, insert in envelope and mail to: Electronics Reprint Dept., 330 W. 42nd Street, New York, N.Y. 10036

Reprint order form

For listing of reprints available see the Reader Service Card.

Unijunction Transistors

Send me

reprints of Key no. R-74 at 50¢ each.

For reprints of previous special reports fill in below:

Send me

reprints of Key No.(s)

(For prices, see Reader Service Card)

@ .. .. .. . ¢ each.

Name

Number of street

City, State, Zip code

Solid state
Silicon Semiconductor Technology W.R. Runyan, McGraw-Hill Book Co. 277 pp. $16.50
This book covers all aspects of silicon semiconductor technology except for surface behavior, which the author considers beyond the scope of the book.
It is the third volume in an engineering series by staff members of Texas Instruments Incorporated. The others are Transistor Circ11it Design, 1963, and Field Effect Transistors, 196.5. But unlike the other two, which emphasize circuit applications, this volume disc11sses physical properties and manufacturing processes.
Since silicon technology is primarily responsible for the development of integrated circuits, the need for ready access to information concerning this technology is obvious. Runyan's hook answers this need in two ways.
First, it provides a comprehensive discussion of the key areas: silicon manufachuing, silicon casting, crystal growth an<l orientation, eloping procedures, physical properties, and metallurgy. Second, each chapter is extensively refrrenced for further research by the reader. For example, the chapter on crystal growth contains 112 references. In addition, the hook's compilation of key ohysical and chemical data should prove invaluable to physicists and engineers working in this area.
Runyan thoroughly explores the tonic of diffusion, pointing out that diffusion process has two basic requirements: a method of heating the slices and a source for impurity. Various diffusion processes that meet these requirements are discussed in detail. Both closed-h1he and open-tube approaches to diffusion are covered.
In describing sili~on structure, an analysis of gross crystallographic defects is given, and the orienting of silicon crystals. by Xray is exolainecl. One interesting photograph shows a defect in a silicon epitaxial layer magnified approximately 700 times. Runyan also mentions various techniques for

154

Electronics J August 23, 1965

close control of diffusion during the growth of epitaxial layers.
The optical properties of semiconductor material are discussed in depth. The use of optoelectronic phenomena in integrated circuits, although quite new, appears to have one important advantage: ex-cellent isolation. For example, an optoelectronic integrated circuit can prevent the transfer of noise in coupling subsystems [Electronics, July 26, 196.5, p. 52] , and this timely discussion of semiconductor photoconductivity will prove useful.
The impressive list of references -nearly 600 au thors are given in the index-attests to the author's diligence in his search for source material. The index simplifies the search for references by glving both the page on which a reference appears and the reference number.
Recently published
Electromagnetic Field Theory, R.D. Stuart, Addison-Wesley Publishing Co., 214 pp., $8,gs
Time-Domain Analysis and Design of Control Systems, R.C. Dorf, Addison-Wesley Publishing Co., lg4 pp., $8.gs
Probability, Random Variables, and Stochastic Processes, A. Papoulis, McGraw-Hill Book Co., 583 pp., $12.75
Progress in Radio Science 1960-1963, Volume II: Radio and Troposhere, Francois du Castel, American Elseiever Publishing Co., 291 pp., $16
Introduction to Electron Tubes and Semiconductors, C. Alvarez and David E. Fleckles, McGraw·Hill Book Co., 294 pp., $6.95
Electronic Information Handling, Edited by A. Kent and Orrin E. Taulbee, Macmillan and Co., ltd., 364 pp., $11
Electronic Instruments and Measurements, P.B. Zbar, McGraw-Hill Book Co., 106 pp., $3.95
International Telemetering Conference Proceedings 1965, Washington, D.C., Volume 1, International Foundation for Telemetering, 802 pp., $20
Electrical Machines, J. Hindmarsh, Pergamon Press Inc., 523 pp., $4.90
Physical Networks, R.S. Sanford, Prentice-Hall, Inc., 576 pp., $17.25
Quantum Electronics and Coherent Light, C.H. Townes and P.A . Miles, editors, Proceedings of the International School of Physics, Aug. 19-31, 1963, Italy, Academic Press Inc., 371 pp., $16
Microwave Tubes, Proceedings of the 5th International Conference on Microwave Tubes, Sept. 14-18, 1964, Paris, Academic Press Inc., 528 pp., $50.
Electronics I August 23, 1965

A

NOW AVAILABLE!! A complete seri es of switching matrices

for analog or digital switching up to 5 me., and coax or twin ax video switch-

ing up to 60 me. Th e matrices allow any input or series of inputs to be

connected to any output or multipl e of outputs . They are available in 1 by 2

up to 20 by 20 crosspoint version s. Also available are multiple pole (up to

25 points) single and multiple throw coaxial switches . Switching control

can be accomplished by a remot e control panel, pre- programmed punched

card or tape, or computer control for automatic checkout applications.

COAXIAL SWITCHING MATRICES
(remote controlled pre-programmable matrices and switches)

Circle 155 on reader service ca rd

155

Physicists and Electrical Engineers for research into
NEW COMPONENT PART
CONCEPTS

Unusual opportunities now exist in the field of component development and performance analysis, due to a conceptual approach developed by our Research and Development Laboratories. These positions demand the ability to perform laboratory evaluation on existing components and prepare a critical analysis of their performance. Where the state of the art is a limiting factor, new approaches must be proposed and development work initiated to provide the required component performance.

In the process of developing new approaches to the solution of component problems, papers must be prepared which will be used as the basis for proposals.

Well equipped laboratories are provided in which the applicant can employ the latest techniques in devel-
opment and instrumentation to assist in the exploitation of his ideas.

Qualifications should Include at least a BS degree from an accredited university in Physics or Electrical Engineering. In addition, the applicant must be able to demonstrate 5 to 10 years of progressive creative experience through issued patents or publications in technical journals.

Please airmail your resume to:

MR. ROBERT A. MARTIN Head of Employment Hughes Aerospace Divisions 11940 W. Jefferson Blvd. Culver City 59, California

r------------------, Creating a new world with electronics

I

I

: HUGHES:

IL------------------JI

HUGHES AIRCRAFT COMPANY

AEROSPACE DIVISIONS

An eoual opportunity employer.

156

Technical Abstracts

Harmonic sampling
Chromatron tv color processing using semiconductor circuits Larry Blaser, Derek Bray Fairchild Semiconductor, Mountain View, Calif.

formation from the demodulators with the color switching grid.
Presented at the 1965 Spring Conference on Broadcast and Television Receivers, Chicago, Ill .. June 14.

A transistorized version of the onegun Chromatron color tv receiver has been built using harmonic sampling for its color decoding rather than the more common chromagate decoding. Harmonic sampling has the advantage of better color purity, though alignment is easier and circuitry simpler with chromagate.
In both systems, a 3.6 Mc sine wave voltage is applied across the color switching grid near the face of the tu be so that electrons hit the red, blue and green phosphors in the sequence R-G-R-B-R-G-R-B.... In chroma-gate decoding demodulation takes place along the R-Y, B-Y and G-Y axis. These signals are added to Y (luminance) in the cathode in the sequence corresponding to the color grid switching so that R, G and B information reaches the appropriate phosphor.
In harmonic sampling, demodulation takes place at fundamental, second, and fourth harmonics of the 3.6 Mc chroma signal along the axes chosen so that R, G and B information appears at the cathode in the appropriate sequence without gating.
Since dwell time on the red phosphor is half that of the blue and green, the color switching sequence, in terms of equal time increments, is R-G-G-R-B-B-R-G-G. This may be thought of as three periodic square waves-one for each color. A Fourier analysis of these waves gives an expression for each color in terms of harmonics of the subcarrier. Adding these expressions together and solving for the separate harmonic terms (up to the fourth) in terms of R-Y and B-Y coordinates give the required demodulation axes and gains.
The color receiver has a demodulator for each harmonic, which operates on the prescribed axis. The cathode of the tube is fed with the sum of the demodulator outputs. Gating is not needed to synchronize the sequence of color in-

Compatible DTL's
High Speed Integrated Monolithic Thin-Film Compatible Diode Transistor Logic Circuits N. Fuschillo, J. Krobath, T. Pardue Melpar Inc., Falls Church, Va .
In large commercial machines, such as scientific computers, the information cost per dollar is approximately proportional to the half power of the clock speed of the machine. Therefore, there is a strong economic incentive to develop computers with as high a clock rate as possible. In this paper the author describes monolithic diode-transistor-logic circuits made with compatible thin film technology. They are especially suitable for achieving a high speed. low power system of integrated circuit logic, and have the added advantage of increased reliability.
The compatible technology combines the best features of pure monolithic technology with those of the pure thin-film approach. Photolithographically processed thin-film resistors and capacitors are used for both passive components and interconnections. This produces a system with low parasitic capacitances and a wide range of capacitor and resistor values.
In the DTL logic system, the basic repeating structure is the single AND gate, and most other DTL logic functions can be derived from it. Dual, tri and quadNAND gates are simple repetitions of the single-NAND gate. An RS flip-flop is made by interconnecting two single- TA D gates; and a binary counter can be made by interconnecting six single-NA D gates. Topologically, the DTL layout is based on a master die approach. Such a die could have 19 components; and the various circuits, dual- A D, RS flip-flops, and others, are simply made by changing the interconnection mask.
Presented at the 1965 Aerospace Technical Conference and Exhibit, Houston, Tex .. June 21-24.

Electronics I August 23, 1965

You can figure on designing more compact products. As a matter of fact Globe has developed 2 new MIL spec motors-one for a.c. called Type CC, and one for d.c.
named VT. Both motors are only %" in diameter, weigh
11h ounces . Type VT uses a system of planetary gea ring that multiplies torque up to 50 oz . in .
Choices for designers are fantastic ; we have 83 standard gear ratios. Type VT can be wound for any voltage up to 50 v.d.c., and we can furnish them with speed governors. Type CC is a hysteresis synchronous motor. And if you need a smaller or larger power unit, come to the can-do manufacturer. Request Bn. 58.

---- ---- ---- - -- - -- --- --- ---- - ---- - -- ---- --- ---- ------

'

Reprint order form

Send to: Electronics Reprint Dept.
330 West 42nd Street New York, N. Y. 10036

' ' ' ' ' ' ' ' ' ' '

For listing of reprints available see the reader service card. To help expedite mailing of your reprints please send cash, check or money order with your order. For reprints of the latest special report:
Automated Trains: Whose on the right track?
Send me . . . . reprints of key no R-76 at 50¢ each.

For reprints of previous special reports fill in below:

Send me no.(s)

reprints of key at ... .. . ¢each.

For prices see the reader service card.

Name Number & Street City, State Zip code

Electronics I August 23, 1965

TYPE VT-Produces .0025 HP in the 8,000 to 17,000 rpm range. Size : %" x 13/s'' long. 1.48 oz. To 50 v.d.c. Planetary gearing in 83 ratios. TYPE CC- Produces .07 oz. in. max. sync. torque. Size: %" x lKt long. 1.5 oz. 26 v.a.c. (115 v.a.c. with series capacitor), 2 or 4 poles, 400 cycles.
Booth 2717 WESCON
Globe Industries, Inc., 2275 Stanley Avenue Dayton, Ohio 45404, U.S.A., Tel.: 513 222-3741
Circle 208 on reader service card
- KIT OR ASSEMBLED!
World's Best Values In Electronic
Instruments ··· HEATH KIT®

5" Lab Oscilloscope

VTVM

Audio Generator

Ki t 10- 12, 24 lbs.. $ 76.95 Kit IM - 11, 5 lbs.. .. $24.95 Kit IG-72, 8 lbs . ... $41.95

Assembled IOW-12 $126.95 Assembled IMW -11.$39.95 Assembled IGW-72 .$64.95

laboratory AC VTVM

"Service Bench " VTVM "Solid -State" Regulated

Kit IM -21, 5 lbs .. ... $33.95 Kit IM - 13, 7 lbs .. .. $32.95 OC Power Supply

Assembled IMW-2 1. $52.95 Assembled IMW-13 $49.95 Kit I P-20, 13 Ibs... $ 72.95

RF Signal Generator

Variable-Voltage

Assembled IPW-20 .$114.95

Kit IG -102, 6 lbs. $27.95 Regulated Power Supply Battery Eliminator

Assembled IGW -102 $54.95 Kit IP-32, 17 lbs. .$56.95 Kit IP- 12, 18 lbs. $47.50

Condenser Checker

Assembled IPW-32 $84.95 Assembled IPW -12 $59.95

Kit IT-II, 7 lbs..... $29.95
As:_~!~·~~~~-~~-~.:·.:~----- -------~ hrnxd<!f;l ___1

HEATH COMPANY, Dept. 67-8 Benton Harbor, Michigan 49023

I I

In Canada: Daystrom ltd., Cooksville, Ontario

I

O Pl ease send my FREE Heathkit Catalog.

I I

o I Enclosed is $_ _ _ plus shipping. Please send model(s)_____ \

I Name_____ - - - - - - ----------- -- :

Address

I -------- I
I

, , City

State

Zip ____ \

J_P_ri_ce_s_&__sp_e_ci_fi_ca_ti_o_ns_s_u_b_je_c_t t_o_c_ha_n_g_e_w_it_ho_u_t_n_ot_ic_e_. __________T_E-_1_3_8 _I

Circle 157 on reader service card

157

Investigate your career now in missile-defense radar; ad-
vanced sonar engineering at General Electric.
G.E.'s Heavy Military Electronics Dept-whose capabilities include the design, development and fabrication of the world's largest and most advanced ASW and radar systems-announces long-term career openings for continuing contributions to large military contracts.
l-IMED offers you stability oased on its broad capability for handling large programs and the experience that goes with front-rank performance on this decade's most advanced projects. Your growth is tied to that of a lean, highly professional engineering group backed by top-flight facilities - both within HMED and throughout General Electric.
At G.E., you'll be treated as a professional who's expected to handle well -defined, delegated responsibility. In most instances you'll deal directly with your customer's organization.
You will be given every opportunity to develop yourself professionally through continuing :ompany-taught ·~ourses and advanced tuition -paid study at nearby Syracuse University. And, in the cou rse of your work, you'll have access to information developed by other G.E. faciliti es throughout the country.
WHY NOT MATCH YOUR EXPERIENCE AND CAREER DESIRES AGAINST THESE REQUIREMENTS?
SONAR: Advanced Sonar Engineers; Array Beamformer and Signal Processing Development Engineers ; Digital Logic Engineers; Sonar Solid-state Circuit Design; Transducer Development; Solid-state Transmitter Development; Pattern Recognition Analysis; Adaptive Filtering Research; Display Development; Propagation Analysi s; Sonar Subsystem Development.
RADAR: Monitor and Control Analysis Engineers; Digital Control Eqpt. Engineers; Microwave Component Design Engineers; Consultant, Circuit Design and Development; Instrumentation Circuit En gi neers; ME's for Signal Processing Modules; Consultant, Array Radar Subsystem Requirements.
INVESTIGATE NOW! For full information, send a resume of your experi-
ence in confidence to J. L. Wool ,
Professional Placement, Heavy Military Electronics Dept., Section 107, General Electric Co., Court St., Syracuse, New York.
177-65
An Equal Opportunity Employer

living space

One of the plea sures of working at Grumman is li vi ng o n Lo ng Island. Here Grumman engin ee rs are surrounded by 43 golf courses within a ten mile radius. Five beautiful public courses are in Bethpage - two minutes from the plant. White sand beaches stretch for miles along the Atlanti c. (12 minute drive) . The famed sailing reaches of Long Island Sound are o nl y eleven miles away. Yet, homes in this fine sectio n of Long Island are priced well below the nation al average!
So much for living space - now for outer ... Gru mm an, rea dying the LEM (Lun ar Excursion Modul e) fo r its histo ri c landin g o n the moon in the late sixties, is see king th e services of tal ented engineers and scientists to help speed the laun ching date. Superso ni c aircraft of a revo lutionary character compound the chall enge. If you' re qualified, why not exp lo re immediate openings listed in the space below.

Aircraft Navigations Systems Engineers-BSEE with a major in con· trol theory and 3·8 y ears experience with sm a ll ana log co mputers, inertial sensors and solid·state circuit design. Knowledge of aircraft navigation systems, required ; capable of designing small analog computer and investigating total navigation system problems.
Inertial Navigation Systems Engineers-BSEE (MSEE preferred) with major in control theory and 3-8 years ex perience in the desig n & development of navigation systems hardware. Sh ou ld be ca p ab le of directing major systems redesign progra m . Circuit de sign ex p e· rience desirable but not essential.
Vendor Liaison Engineers-Space Guidance & Control SystemsBSEE with major in control systems with 3.5 years experience in Guidance and Control, Design and Development. Will conduct tech· nical liaison with vendors to assure compatibility between hardware and specifications, and be responsible for techn ical interface control.
Senior Illumination Engineers-BS in EE or Physics wit h a minimum of 10 years ex peri ence in Aircraft or Spacecraft Conso le and Fl oo d Lighting including measurement of lig hting parameters.
Microwave Standards Measurements Engineers - PhD o r MS in EE. Physi cs o r El ectro physics, with a minimum of 5 years ex p erience in electro magnetic-e lectronic instrumentation & measure m ents. Strong theoretical background is required. Will be part of Measure· ments Science team in estab lishing state-of·the·art Microwave Standards Measurements & Consultation Services.
Measurements Science Engineers - BS in EE or Phys ics, ex p erienced in electrica l-electronics or microwave standards Measurements & In strum entation. Duti es will inc lude technical adequacy of Measurements techniques & procedures, & measurements advisory consult ants.

R&O Electronic Flight Test Engineers - B .S. in E.E. or Physics plus test ex perience in Electronic Airbo rn e Systems including Radar, computer, navigation & guidance, stabilization & control & communications equi pm ents for appli cation to sp ace p rograms.
Guidance & Control Integration Engineers- BS or advanced degree with ex perience in design, analysis and integration of vehicle guidance & control systems. Applicants shou ld possess a working knowledge of both analog & digital f eedback system & design tech niques . System test or hardware d esig n experience d esi rabl e. Position entai ls conceptu al work in defining guidance & control syst ems, establishing subsystem and component requirements, system development and veri fi cation .
Guidance Dynami cists - BS or MS in AE. EE. or Appli ed Mechanics with a minimum of 2 year~ experience 1n the analysis of guidance systems for spacec raft. To analyze and eva luate f unctional configurations and dynamic systems com po sed of radar, IR , optical and inertial guidance loops; signal processing and prror analysis. Back· groun d in sa mpled data & nonlin ea r controls systems.
Control Oynamicists - BS or MS in AE. EE or M E with a minimum of 2 years experience in analysis of control systems. Will evaluate automatic flig ht control system requirements and performance. Fa miliarity with no nl i near techniques, d igi tal cont ro l techniques and adaptive control techn iq ues is desirable.
Space Oynamicists - BS or MS in Physi cs, Aerospace Engineering, Appli ed Math or Applied Mec hanics, with a m inimum of 2 years experience in the analysis of flight dynamics. Experience in space dyn a mics, e.g. disturbance torques . orbital m ec h a ni cs, lunar trajectory analysis, and separation system dynamics is desirable.

(Additional opportunities in space as well as aircraft & ASW programs, o n following page)

Electronics I August 23, 1965

GRUMMAN
AIRCRAFT ENGINEERING CORPORATION Bethpage ·Long laland ·New York
An Equal Opporlun1ty Employer

159

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(Continued from previous page!
Aerospace Value Engineers-B.S. in Engineering or equivalent tech· nical ability with experience in one or more of the following: Value Engineering, aircraft design, electronics design.
J>rogrammer-Analysts-2 years experience in test data reduction programming, using large scientific Programmer. Experience with FORTRAN & machine language on either the IBM 7090 or CDC 3000 series computers essential.
Data Engineers-B.S. degree with a minimum of 2 years experience in test data reduction, planning for digital computations, semiautomatic data reduction systems & data reduction stations. Oat~ Engineers will be assigned primarily to Field Test Sites at Houston, Texas, & Cape Kennedy, Fla .
Ground Station Systems Engineers-B.S. degree with 2-3 years experience in an operational telemetry data reduction ground station . Experience should include the use of magnetic tape recorders & playback equipment; FM/FM discriminators; PCM, PDM & PAM Decoms; Oscilligraph & Pen recorders; analog to digital converters ·&familiarity with digital computer technology.
Flight Operations-BSEE with experience in telemeter and magnetic tape. Assignments involve interesting work with airborne analog & digital data acquisition systems & their use in flight testing.
Instrumentation Applications - BS in ME, EE or Physic· with 4 years experience in instrumentation measurement problems. A good theoretical and practical knowledge of transducers, their specifica· lions and application to measurement of temperature, pressure, flow, acceleration, rater force, is required .
ASW Research Scientists-M .S. or Ph .D. in Math, Electronics or Physics to carry out odginal research in signal processing, infrared wake detection, ocean reverberation, underwater acoustics, and advanced detection t:ichniques. A well equipped.ASW Research Laboratory is available for experimental work. Opportunities are excellent for applicants with initiative and imagination.
ASW Electronics Systems Engineers-B .S. or M.S. degree with a minimum of 2 years appropriate experience. Duties will include conceptual design and sub-system performance analysis, including trade-off s~udies, for: sonar, radar, ECM, MAD, IR, sensory and signal processing equipments; aircraft navigation systems; tactical communication systems; integrated data processing, display and control systems .
EMC Systems Engineers-With ability to perform system analysis, state-of-the-art reviews, and develop advanced EMC techniques . Will be responsible for generating design data; control plans, test plans, directing tests, analyzing results, generating fixes, and preparing reports for systems in accordance with MIL-E-6051C. Familiarity with WR-27 and MIL-STD-449 is essential.
Radar Development Engineers - BSEE with a minimum of 4 years experience in the analysis, design and development of airborne radar systems. Should be capable of analyzing the radar system with end view :>f integrating the equipment into a complex space vehicle system. Will tully participate in laboratory and flight development program conducted in the finest facilities available in a professional atmosphere.
Electronic Component Parts Engineers-BSEE preferred plus experience in electronic component part evaluation & applications of semi-conductor devices & other electronic components. Responsibilities will include, part selection, determination of part reliability requirements, establishing derating & establishing test & procurement specifications.
ASW Reliability Engineers-B .S. or M.S. & a minimum of 2 years appropriate expe·ience including systems prospectus & an understanding of mission requirements. Some design background is desired. Responsib.ilities include: Developing system models, defining mission objectives, performing reliability & maintainability tradeoffs & hardware evaluation. Working knowledge of applied statistics, probability & the methods of operations research is essential.
Senior Programmer-Three to five years programming experience on general pllrpose equipment with an applications background in the scientific fields <A systems simulation, real time programming , math, modeling, systems analysis and differential equations. BS in science, Mathematics or Physics as a minimum. Desirability for a strong engineering orientation in systems analysis. Complete programming knowledge of the IBM 7094 including FORTRAN, and FAP languages.
Programming Analysts-Over 5 years experience in programming scientific problems on general purpose and special purpose com puters. Competency in real time system programming, problem formating, mathematical modeling, assemblies, compilers, executive control routines, and simulation techniques. BS or MS in Science, Mathematics or Physics, Systems engineering orientation and space project background most desirable. IBM 7094 experience in depth.
NOTE: Positions also available in the above areas to February or June '65 Engineering Graduates
Use the attached inquiry form to arrange a mutually convenient interview.
GRUMMAN
AIRCRAFT ENGINEERING CORPORATION Belhpage ·Long Island· New York
An Equal Opportunity Employer
Electronics I August 23, 1965

·······························
ambitious?

go where the GROWTH is!

10 Fold .. . in 10 Years

Texas In struments In corporated ha s grow n fro m a compan y of 2293 peopl e in 1954 to more than 28,000 today. Continu ing increase in Tl ' s professional employment (25 % for the past fi ve years) provides outsta nding oppor-
t unities for career development in such areas as

Multilayer

Circuit Board

Process Engineer

Th e person qual ifyi ng for thi s position will be res ponsi bl e for process opti mizati on and th e evaluati on of new production t echn i ques and material s in th e manufactur e of hi ghly sophist ica ted multi la yer ci rcuit boa rds. Re -

.······

· quires BS i n ME , EE or Ch E, plus 2 to 5
years experience in printed circu it boa rd

man ufacture.

Sa lary commensurate wi th experience . Excel lent benefit program includ ing pro f it sha ri ng. Outstandi ng advancement opportun iti es.

Plea se send confidential resume to Shelly Leva, Dept. C-179 .

MATERIALS & CONTROLS DIVISION

.···
· · · ·

TEXAS INSTRUMENTS
INCORPORATED
P. 0. BOX 5474 · DALLAS, TEXAS 75222

:··

An
····

Equal
·····

Opportunity Employer
·····················

INSTRUMENT TECHNICIANS
THE OAK RIDGE NATIONAL LABORATORY
Highl y sk i lled instrumen t technici ans t o ass ist in th e inst allation and maintenance of process cont rol instrum entati on system s and devices fo r chemi cal pi lot plants, nucl ear reacto rs and other large exper imental installation s.
High schoo l educati on, plus add i tiona l tra ining in either t he physical sciences, in st rumentation , or electr onics, an d at least 4 yea rs exper ience in installation and ma in tena nce of complex i nstru· mentation and control system s. Ent rance rate $3.39 per hour; $3.45 per hour after si x mont hs. Rea sonable intervi ew and re location expenses pa id by Company.
Excellent Working Conditions and
Employee Benefit Plans
An Equa l Opportunity Emplo yer
Send detailed resume to:
· Central Employment Office UNION CARBIDE CORPORATION Nuclear Division P. 0 . Box M
Oak Ridge, Tennessee 37831
POSITION VA CANT
Electronics Eng inee r for design of air traffic co mmunicatio n a nd navigati o n a i d system s. M u st b e qua lifi ed fo r pl annin g , d es i g n, and spPcificatio n s". P- 7 1 17 , E lec t ro ni cs.

II PROFESSIONAL SERVICES II

GIBBS & HILL, Inc.

Consulting Engineers

Systeme: En1ineering Operations Research · Denlopment

Field Studtea · Deaign · P rocurement

P ower · T ransportation · Com mun ications

Water Supply · Wute Tr eat ment

393 Seventh Avenue

New York I . N. Y.

I Electronics August 23 , 1965

Data Handling and Communications Engineers/Information Theorists
data squeeze
compacting data to increase the transmission capability of the Eastern Test Range
To meet the future demands of range users for transmission of large amounts of trajectory, telemetry, bioastronautic, and color television data from space vehicle to central control at the Cape, Pan Am engineers are studying various compaction techniques that may permit essential information received at the rate of over 1.5 million bits per second to be transmitted over existing narrow-band channels with a 3000 bit/sec capacity. Th e feas ibility of some 20 compaction methods are being analyzed, including combinations of data adaption, pulse compression , multiplexing, etc. Models are being set up using simulated and real data to determine the necessary trade·offs on compaction vs accuracy. Graduate engineers who can contribute to this effort and to the development of other systems fo r data processing and real -time computing, digital data transmission, range safety display, target acquisition, and analog-digital conversion are invited to write in confidence to Manager, Professional Employment.Dept. 24H-4.
GUIDED MISSILES RANGE DIVISION
PAN AMERICAN WORLD AIRWAYS , INC . 750 S. ORLANDO AVENUE , COCOA BEACH , FLORIDA An Equal Opportunity Employer
161

HIGH SPEED
Communications &
Computer Engineers
BuShip.::; ht.:ad11uartcr:i ha::i a le\\' :-irl("\'l up L' ning::i fur e nginc~r~ l'ap.Lblc r.f din"'1·ting prugram:i jn ath-J.nL'e<l milit..u y 1·1)m111uni1·3tiuns . Cn lll· puk1'. comrna nd &:. l;U nl1 ol ~y~t1 · m .. d·'\t·lop11u·nt. \\hill· tht.. ;,t .1n not k ::il·br n1 h job:-, it i::i impurta11t th.ll )llU h 3\t"' th e i-J1g1nt' c:1mg bad.. !)<uund lO handl e an) number vf b1oacl-gaugc' as.ignmcnlo . .. an) thing from the ROT&F: ot" c'luipmtn ls to the inotallatiun .md maintenance uf operating S)::ilcni:; in liH:' following r atcgorir:;;
Submarine & Satellite
Antennas · Transmitters
& Receivers · Terminal
& Security Equip1nent
(bant1"idth co mprr os ion , modulation tcr hniqurs, opccch processi ng. pallcrn r rcogmtion , rn t.:::i::i.1ge & lin e S'\il r h tnj!, multiplexing, td rmdry, fa u, i111il1.~; lim r &. frrqw ·nC) diri sion, cryplu <le\iceo, d e.)
Data Transmission
Systems
(co mrna11d & cunlrol ::iuh::i y::i lt'lll :-, hi gh l·apacity t.:u ti '-' ..d co rnmunll'..1tivn~. aulvm..1.lit! m1.1d1int· 1.111µt13 f!t' <o llllllttni l al i n n ~, f II'.)
Shipboard Co1nn1and
& Control Syste1ns
(oyote n1s <l eo ig11, intl'µra1ion , and s hipboard instali3ti u11)
Since man) of thc;,e projects relate to the entire national militar) and ;,ccurit) picture, ) ou "ill h e c~pcc t c d lo coordinate with o ther N1n y and DOD acth itieo , , , at all lcYclo and locatiuns .. , as well ao "ith NASA. These au solid opportunities in the Sl0,250 to 8 L.>,000 starting range (pluo regular increases and full Carc<'t" CiYil :,,, ,,ice b e n e fit s). with intrrf' , t ing po. · iLilitt f'" for th e right ·nrl of pcoplf',
If yuu h.wc appmpri.uc <du tal1o n .111cl pro1en cxpcricnt:c, sc n<l prufr~ !'> ion .d llualitH .1li1J ll:::O (or SF-57) tu: Mr . W. N. V.1ill.1ncuurt, Cude 26:.llt-:!:l
Bureau of Ships
Main 1 .wy Bldg . R nom 2422
Wa~hinglon. D.C.. 20360
An Equal Opportunity Employer
162

APPLICATIONS ENGINEER
To perform applications analysis of custom e r systems and to establi!i.h the de!i.ign of hybrid integrated circuitry . Require 8.5.E . E. and experience in circuit and systems analysh .
CIRCUIT DESIGNER
Analysis and design of hybrid integrated circ uitry and associated sy!i.fems; dete rmine pockaging feasibility and t e~ ting methods Desire graduate E.E . with four or more years of circuit design experience
DEVICE DESIGNER
To apply theoretical knowledg e to develo p designs for new e lectr onic passi ve and active d evices. At least M.S.E.E. or M.S. Physics d es ired with experience in s::>lid state d esign techniques.
MATERIALS ENGINEER
In a dva nced dev e lopment involv's pro cCS!i. and materials investigation relating I.,, el ectronic applications. Require M.S. in inoraanic or physical chemistry. Some solid sla fE cncm · istry desirable.
Well d efined work objectives provide an ex .. cellent opportunity for ind ividual recognnion and personal development. Contralab IS a leading manufacturer of componenis for e lectronic systems; primarily industrial applica· dons. Location is on Milwaukee's north side near desirable living areas . Write in con fi .. dence, your background and qualificati on s to Technical Recru iting.
CENTRALAB
A Division of Globe-Union Inc .
900 East Keefe Av enue
Milwaukee, Wisconsi n 53201
(At the WESCON Show , contact Dr. E. M. Baldwin at the Fair mont Mot el, 950 Mason Str~e t . )
" An Equal Opportunify Employ er"

"Put Yourself Ln the Other Fellow's Place"
TO EMPLOYERS
TO EMPLOYEES
Letters written offering Employment or applying for same are written with the hope of satisfying a current need. An answer, regardless of whether it is favorable or not, is usually expected.
MR. EMPLOYER, won't you remove the mystery about the status of an employee's application by acknowledging all applicants and not just the promising candidates,
MR. EMPLOYEE you, too, can help by acknowledging applications and job offers. This would encourage more companies to answer position wanted ads in this section.
We make this suggestion in a spirit of helpful cooperation between employers and employees. This section will be the more useful to all as a result of this consideration.
Classified Advertising Division
McGRAW-HILL, INC.
330 West 42nd St., New York, N. Y. l 0036

SEARCHLIGHT SECTION

· · CLASSIFIED ADVERTISING · BUSINESS OPPORTUNITIES

iiiJiil~...

USED OR SURPLUS EQUIPMENT

. -- - - - -I SEMICONDUCTOR

J

MAJOR BRANDS

INHRGRATED CIRCUITS e Dlf, AMPS DAR-
LINGTONS · POWER DIODES & TRANSISTORS
· SPECIAL DEVICES Wr ite for Catalog 5-1

SEMICONDUCTOR SALES OF CALIF.

1063 Perry Annex

Whittier, Calif.

(213) 696-7544

-

... .._-~·-.

WRITE FOR NEW ©KEYSTONE

free c..-·alog

We are the lta d1n9 produ cers of BATTERY HOLDERS, TER-
. . . . . .. MINALS, TERMINAL BOARDS & ELECTRONIC HARDWARE .
KEYSTON E ELECTRON ICS CORP " llHCtc:U U NEW YOH 12 N 't'

Watch~ the Searchlight Section for
Equipment Opportunities

RADAR AUTO-TRACK & TELEMETRY ANTENNA PEDESTALS 3 & 10 CM. SC" SU AUTOTRACK RADARS. M-33 RADAR TPS· lD SEARCH . APS ·45 TPS· lOO HT. FINDERS. WX RADARS . FPN -32GCA. APS· lO APS·lSl!I Af"S· 27 CAMTI) SEARCH . · · Af"N -102 DOPPLER. DOZENS MORE. CARCINOTRONS . PFN' S. .25·. S-1-2-3 ·6 MEGAWATT PULSE MODULATORS . CAVITIES. f"ULSE TRANSFORMERS. If STRIPS. WAVEGUIDE. BENDS 200 MC. l KMC . 3 KMC . 6 KMC . 9 KMC . 24 KMC . RF PKGS.

RADIO RESEARCH INSTRUMENT CO.

550 STH AVE., NEW YORK 36, N . Y.

JU 6-4691

CIRCLE 954 ON READER SERVICE CARD

SEARCHLIGHT RATES
DISPLAYED
Tli1 ;u h P 111-.in ..:. 1:1t t"' i ... ~:!;.;!.) p l 1· lllt'h, 1111 .111 adu ·111 ...1n ,.:. , tp Jh'.llin~ on CJtltt·r 1han a eontr.\l·t h.1..b. l '11 11tnll0l tat1 ·-. 11lhH1d o il H·q111·:-.t.
An advertising inch i:-; 11wa ~urt:d 1ri .. w11ira ll~ on a
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UNDISPLAYED $2. 70 per lin e. minimum 3 lt11CS. To flgu1 e paymen t
coun t 5 average words as a line. Box nu mbers,. 11 n t ... ;h I lllW.
P o'i it io n Want ed ads, 1,.! n r ilhO\I' 1.11t·
Oi scn unt o r 10° 0 if full na~mn1t "111.111 1· 111 .ld\,111·
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~111 S11hJ· r t to .\J.:1·n ry Cnmn11 .....10n
Send NE "..V ADS and Inqui ries to Classified Adv. Division of El ectronics, P . O. Box 12 . N. Y. 36, N. Y.

Electronics \ August 23, 1965

New Literature

Tiny d -c motor. Globe Industries, Inc., 1784 Stanley Ave.. Dayton, Ohio 45404. Bulletin A-1000 contains complete de· tails on the type VF subminiature motor rated at 0 .0025 hp in the 8,000 to 17,000 rpm range and available for use at 3 to 50 v d -c. Circle 461 on reader service card.
Connectors and cables. Gulton Industries. Inc., 212 Durha m Ave., Metuchen , N.J. The Glennite C-21 series of miniature multiconductor shielded connectors and cables is described in bulletin A2la. [462]
Telephone-type relays. C.P. Clare & Co., 3101 Pratt Blvd., Chicago, Ill. 60645. Engineering data sheet 552 covers types LB and LBP miniature telephone type relays. [463]
Microminiature connectors. ITT Canno n Electric, 3208 Humboldt St., Los Ange les, Calif., 90031, offers a pictorial bro chure, MMBS-1, illustrating its microminiature connector designs. [464]
Microwave tuners. Watkins -Johnson Co., 3333 Hillvi ew Ave ., Stanford Industrial Park, Palo Alto, Calif. 94304, has avail able a technical bulletin on the WJ-195 to WJ -198 family of voltage-controlled m1crowave tuners. [465]
0
Remote programing dvm. Dana Laboratories, Inc., Irvine, Calif. Data sheet 464 describes the model 5603 remote programing, 5-digit digital voltmeter w;th 22-msec reading time. [466]

Ferrite toroidal cores. Indiana General Corp ., Keasbey, N.J. An engineering data bulletin describes in detail the use of low-loss, high-frequency ferrite toroids in bifilar-coil baluns. [471]
Spectrum analyzers. Tektronix Inc., P.O. Box 500, Beaverton , Ore . 97005. An eig ht-page illustrated brochure is entrtled " Getting Acquainted with Spect1 um Analyzers." [472]
Operational amplifiers. Zel tex, Inc., 2350 Willow Pass Rd ., Concord, Calif. An eight-page catalog gives specifica tions for the manufactu rer 's standard line of operational amplifiers. A custo m capability is also described. [473]
Nylon strapping and accessories. Weckesser Co. , Inc. , 4444 W. Irving Park Rd ., Chicago, Ill. 60641. Bulletin 805 contains detailed specifications and physical characteristics on both perforated and nonperforated strapping, as well as Strap-Tite buckles, stud buttons, nylon mounting tabs and mounting cradles [474]
Metal film resistors. Hi-Q division , Aero vox Corp., Olean , N.Y. A data sheet covers low temperatu re coeffi cient, pre cision metal film resistor types. [475]
Multiplex system. Lenkurt Electric Co., 1105 County Rd ., San Carlos, Calif. An eight-page brochure describes the 46A multiplex system, which provides multi channel service for a wide variety or applications. [476]

Random access drum. Brydnt Computer Products, 850 Ladd Rd ., Walled Lake, Mich . 48088. A 4-page brochure describes the PhD-170 and tells how it offers computer users independent, simultaneous multiple access to the en tire information store of over 170 million bits. [467]
Ceramic capacitors . V1tramon, Inc., P.O. Box 544, Bridgeport, Conn. 06601. The complet e line of CK05 and CK06 ceramic capacitors is described in two µage data sheet Cl3. [468]

Digital data systems. Beckman Instruments, In c., Berkeley division , 2200 Wright Ave., Ri chmond , Calif. Bulletin 5Bl28 discusses capabilrties for th e manufacture of digital data systems. (477]
Time delay relays. The A.W. Haydon Co ., 232 North El m St. , Waterbury, Con n. 06720. Bulletin ESF312 describes electroni c trme -delay modules featu rin g facto ry preset or extern ally adjustable delays fro m 0 .10 se c to 400 sec. [478]

Pcm deeommutator. I eler11e tri cs. In ., 2830 S. Fairvi ew St.. Sa nt<> Ana , Calif. Data sheet 348 gives descriptron and specification intorm atron on the mod el 621 single -channel pell! decommutator, which provides economical check -out of pc111 telemetry sy stems and subsys t e111s. [ 469]
F-m demodulato rs . General Electroni c Laboratories . In c.. Simon and Ledge Sts. Nashua, N.H. Two pag e data sheet describes two high -capture, solid state f-m demodulators. [470]

Mrcrowave equipment. PRD Electroni cs , Inc, 1200 Prospect Av e., Westbu ry, N.Y. 11590. A t wo- pag e data sheet covers types 130 and 1100 series fi xe d coa xial attenuators, ty pe 139 series ter1111nat1ons, and typ e 1203-12 13 series of ferrit e isolators. [ 479]
Hybrid junction . Ada m s-Rus se ll Co ., 280 Bear Hill Rd Waltham , Mass . 02 154.
A data sheet on a subrnrnrature , h1gh -
isolat1on hybrid that offers exce ll ent phase and amplitu de balan ce from 40 to 400 Mc. [4801

Electronics August 23, 1965

very often come
in small packages

NEW!
multichannel
reed
from S & G Electronics
Here 's a printed circuit plug -in module that's no bigger than a pair of dominoes.
S&G El ectronics ' new Multi Channel Reed is avai lab le for either two or three channel operation. Its extensive fre quency range allows over 40 channels of operation . This tiny reed relay module is ideal for portable applications like pocket paging- as well as for telemet ry and remote control use. WRITE us now for full details.

multi- channel
A nother fine product from th a lea ders rn the reson.:int reed field.

.lll.fiA.E~LEMC"TR"O' N/ChS
SARGENT & GREENLEAF. Inc.
RO C HESTE R, NEW YORK 14621

Circle 163 on reader service card

163

STORAGE OSCltLOSCOPE

New Scope of Versatility
accepts more than 20 plug-in units for DC-to-30 Mc operation, or for
storage applications

as a storage scope
Enables holding single-shot events, and low duty cycle waveforms, for detailed analysis.
features include:
unparalleled writing speed-up to 5 cmlµsec, with enhancement, split-screen storage-storage on either upper or lower half of crt (with other half for conventiona! displays, if desired), automatic erase feature-with selectable viewing times from 0.5 seconds to 5 seconds .
Storage feature adds a new dimension to sampling applications and spectrum analysis- permitting displays not possible with any other oscilloscope.
164 Circle 164 on reader service card

as a conventional scope
Accepts more than 20 plug-ins-either the Tektronix letter-series units or the newer 1-series units.
features include:
calibrated sweep delay from 1 microsecond to 10 seconds, single sweep , 5X sweep magnifier, and full-passband triggering facilities.
Adaptable and reliable, the Type 549 can handle almost anv laboratory application in the DC to 30 Mc range. Type 549 Oscilloscope (without plug-ins) . . . . . . $2375
U.S. Sales Price f.o.b . Beaverton, Oregon
Tektronix, Inc.
Electronics I August 23, 1965

August 23, 1965
Electronics Abroad Volume 38 Number 17

Argentina
Bridgehead for Secam
France is making a powerful bid in Latin America for her Secam system of color television. Her technique is an old one: free samples.
By the start of 1966 she is expected to install about $467,000 worth of broadcasting and receiving equipment for a six-month trial in Argentina. If Argentina adopts Secam, the tv gear would remain as a gift from the French government and industry; if she should decide against Secam, the equipment would be removed without cost.
Angel Lapieza, Argentina's director general of broadcasting, says his country has agreed in principle to the French offer. All that's needed, he says, is the signing of a decree by President Arturo Illia.
Lapieza says the agreement gives the French a big advantage over the United States' TSC and West Germany's PAL systems. "We would like to see the United States system," he adds, "but we have not had any offer."
The offer. The French offer, as described by Lapieza, is to install broadcasting equipment wherever desired by Argentina, and to place 30 to 40 receivers in government offices. Some 300 to 400 more receivers would be sold duty-free to clubs, department stores and other public establishments. Secam broadcasts would start about Jan. 1.
In Paris, a spokesman for Compagnie Fran~aise de Television (CFT) describes the offer as a test of Secam. CFT will offer circuits in Argentina for converting NTSC sets to Secam, charging less than $10 apiece, he says. He does not indicate, however, the charge for the extensive rewiring that would be required. CFT owns rights to the Secam system.
Mission to Paris. The big break in negotiations seems to have come

last March, when a four-man Argentine delegation, including Lapieza, spent eight days in Paris as guests of the French Government. They looked at all three color-tv systems; Lapieza says he "was impressed especially that under Secam broadcasts can be received by black-and-white sets" with "minor" adjustment. About a million tv sets are in operation in Argentina, twothirds of them in and around Buenos Aires.
The Argentine broadcasting chief says he came away with the impression that the French are not seeking tests elsewhere in Latin Am erica. "They do not have money for mass production," he explains.
New channel. Lapieza says Argentina plans to create a new tv channel to carry Secam programs. Asked whether this bars any chance that NTSC may be tested simultaneously with Secam, he says, "I cannot comment on a nonexistent offer." The Argentine Government does not allow any existing channel to broadcast in color.
Elsewhere in Latin America, two private stations in Brazil are reported to be installing NTSC, and the Latin American Free Trade Association Committee has recommended that its nine member adopt the U. S. system.
Edward L. Bonin will discuss optical coupling at Paris symposium.

France
Opto-electronics symposium
A relatively obscure arm of the North Atlantic Treaty Organization is sponsoring a symposium in Paris next month that is ath·acting as much civilian interest as military. A tutorial meeting on opto-electronics will be conducted Sept. 6 to 9 by ATO's Advisory Group for Aerospace Research and Development.
Attendance at the symposium is by invitation only; about 300 scientists and engineers from nearly every NATO country have been asked. Only a handful of Am ericans will attend, but United States technology will dominate; 14 of the 24 papers will be given by Americans, 4 by the French, 3 by Britons, 2 by \Vest Germans and one by a Canadian.
The first paper will be given by Pierre Aigrain, a professor at the Sorbonne and an adviser to President de Gaulle on arms development. His paper is on "Perspectives offered by opto-electronics."
Optical coupling. Edward L. Bonin of Texas Instruments Incorporated will discuss the use of electro-optics in integrated circuits. One device he will describe combines a gallium-arsenide lightemitting diode with a silicon photodetector [Electronics, July 26, p. 52]. The device is a low-noise coupler.
He will also describe a transformerless low-level chopper switch with an isolated driving circuit, a photon-coupled transistor switch, and a photon-coupled pnpn switch.
Avionics. The military interest centers largely on avionics, where designers are interested principally in the construction of circuits with a greater degree of input-output isolation.
Applications include altimeters,

165

Electronics Abroad

an image intensifier for radar, and electro-optical processors for phased-array antennas and for transmission of infrared information.
Roger Voles of EMI Electronics, Ltd., in Britain, will discuss the use of an image intensifier to derive the doppler spectrum of radar returns while preserving range resolution. The returns are painted as brightness modulation along the vertical diameter of a cathode-ray tube whose phosphor decay time is in the order of the interval between pulses. This vertical line is projected onto the photocathode of an image intensifier whose horizontal deflection circuit sweeps the resultant image across an output phosphor that has a long delay time. Voles will show that the output phosphor's brightness represents the radar energy-vertical brightness pattern for range and horizotal for doppler.
Altimeters. Optoelectronic altimeters have been built in prototype, but none is in general use. James E. Hopson of the Raytheon Co. will describe an altimeter based on an injection laser diode, an optical transmission medium and a silicon photodetector. Altitude is calculated from the time required for a light beam to travel to the ground and back.
Two methods are under investigation. One employs continuous sine-wave modulation of a cryogenically cooled injection laser. The light beam's transmit time is measured in terms of a shift in the modulation phase between the outgoing and incoming light waves. The second mode of operation uses an injection laser with a fast-rise optical output; the laser is pulsemodulated at room temperature.
Italy
GE stakes its claim
Although they didn't begin officially until late last month, the General Electric Co.'s operations in Italy have been increasing quietly but steadily since last August, when

GE agreed to acquire the computer business of Ing. C. Olivetti & Co.
In September, 1964, a few weeks after Olivetti-General Electric S.p.A. was conceived, Olivetti began to sell GE's new 400 and 600 series computers, which are bigger and more expensive-about $500,000 apiece-than any previously offered by the Italian company.
Olivetti-GE is owned 75% by GE and 25% by Olivetti. The joint operation was delayed a year while the companies awaited passage of a law that saved them almost $1 million in taxes on the merger.
New markets. GE's foothold in Europe was made almost simultaneously in Italy and in France. Last August the American company invested $43 million in the French Compagnie des fachines Bull. Between them , Olivetti-GE and Bull-GE have already taken orders for more than fifty 400's, a GE spokesman says.
The deal also seems to have helped sales of Italian-made computers by opening foreign markets to them. Last year Olivetti installed only about 50 computers; a 50% increase is predicted this year, and the company expects next year's orders to climb to 300. Two-thirds of next year's computer installations should be made abroad, according to an Olivetti-GE spokesman. The company expects further gains soon when it introduces another member of its series 4,000 line.
To cope with the expected surge in sales, Olivetti-GE is expanding the production capacity of its plant in Caluso.
A world power. In Charlottesville, Va., Louis T. Rader, a vice president, masterminds the transition of GE's data-processing operations from a domestic to an international effort (process-control computers remain entirely a domestic operation). As general manager of the Industrial Electronics division, Rader considers Olivetti-GE and Bull-GE as "departments" on the same level as GE's domestic operations, each to specialize in a particular product area. OlivettiGE for example, would specialize in small computers and peripheral

equipment under Rader's plan. How strong a factor has GE be-
come in Europe? According to Arthur D. Little, Inc., an industrial research company in Boston, Olivetti controlled about 15% of the Italian computer market at the end of 1963 and Machines Bull had 21 % of the French market and 7% of all European computers. With Machines Bull, GE also acquired representatives in 52 countries, with either subsidiaries or agencies in 27 nations.
In France. A spokesman in Charlottesville says Machines Bull's first-quarter installations this year were up 20% from the 1964 period, and that subsequent installations have been "well ahead of all budgets and forecasts."
The French-made Gamma 10 computer, which was introduced last fall, has received more than 700 orders with "no sign of a letup," according to Bull-GE. The Gamma 10 costs $75,000 to $100,000.
GE is still a long way from rivaling the International Business Machines Corp. in the international market-a prospect that GE has never even mentioned publicly. But in one year it seems to have carved a deep niche in the European computer market, a solid accomplishment even for the world's fourthlargest corporation.
West Germany
Mail sorter
West Germany's first electronically controlled mail-sorting center has been in operation since May 31 at Pforzheim. It handles 200,000 letters daily.
The principal missing link, an electronic address-reading machine, is still under development at Siemens & Halske AG. The company says a flying-spot scanner that recognizes zip-code destinations on 18,000 letters an hour is "under test." Its speed is about the same as that of a machine developed by the Philco Corp. for the United States Post Office [Electronics, Jan.

166

Electronics I August 23, 19 65

Electronics Abroad

11, p. 131). An improved version of Philco's alphanumeric reader is said to handle 36,000 letters an hour; Siemens says it is working on a reader with comparable speed.
Typists in funnels. While the electronic scanner is being perfected, girls perform part of its task at the $1.1-million Pforzheim postal center. Streams of mail, both outgoing and incoming, are funneled automatically through 14 special typewriters. As each letter passes through a machine, a girl reads the zip code on the envelope and punches the figures on the typewriter keyboard.
The typewriters generate signals that are passed through an electronic memory and logic register, where they are translated into a form that will cause the typewriter to print on the envelope, in magnetic ink, a line pattern that represents the zip code; this pattern will later be recognized by magnetic pickups at a sorting station.
Luminescent ink also can be used, to be read later by photoresistors, or phosphorescent ink for reading by photomultipliers.
Forks in the road. From the typewriters, a conveyor system carries the letter along a route past dozens of forks, or sorting stages, at which groups of letters are separated according to their destinations. At each fork, an electronic reader scans the letter and sends its reading to the memory rack; here logic circuits generate signals that open and close gates to conveyor chutes, thereby steering each letter along its proper path.
To save space, the final sortinginto as many as 100 locations- is done in a revolving tower whose surface is lined with letter pockets; each pocket is entered via a door controlled by a reed relay. The relays are actuated by multiple magnets that rotate past the relays.
Tower suite. \i\lh~n each letter drops into the tower from an overhead conveyor, its address signals have already set up combinations of polarizations on the magnets. When the letter passes the slot representing its destination, the magnets actuate the reed relay and the letter slips into a slot.
The memory-logic rack serves

Mail sorting is masterminded from central electronic rack at left, which provides memory and logic. Girl at right stamps zip-code destinations on envelopes, which are sorted in the chandelier-like tower to her right.

many coding stations and the final sorting towers simultaneously, for both outgoing and incoming mail. At present, 3,000 printed-circuit cards of the central electronic rack are considered sufficient to translate the line patterns on the envelopes into destinations for Germany's 2,800 postal addresses.
To set up address codes, signal wires are inserted by hand through the apertures of large magnetic cores. The signal wires receive their pulses from printed-circuit cards, in racks above the cores.
The scanner. The electronic scanner, under trial at the German Postal Institutes, uses a cathoderay tube and a photocell to read the zip codes that correspondents have written on the envelopes. The crt beam is deflected in two directions, through lenses, to read codes on two rows of letters at a time. The signals are then picked up by the photocell.
Each letter passes the spot-scanning beam twice: the first time for coarse resolution, the second for higher resolution. The first scanning is horizontal, the second vertical.
Analog signals from the photocell are digitized; for recognition, the digital signals are compared with a set of signals representing the various postal destinations.

Great Britain
Great expectations
One of the Labor Government's first moves upon taking office last October was to create a Ministry of Technology whose job was to bolster Britain's economy with new industrial processes and advanced technology.
After 10 months and two national financial crises, the ministry and its chief, former labor leader Frank Cousins, are targets of increasing criticism in and out of government. A Parliamentary investigating committee has charged it with being slow, inefficient and topheavy. The electronics industry and the trade press generally agree that the ministry has fallen far short of achieving its goals. But many industrial officials concede that the problems of organizing a new department during a period of economic trouble are difficult and that final judgment should be withheld.
The criticisms. Critics point to Cousins' headquarters staff of 500, which is expected to expand to nearly 700 by March; they compare this with the ministry's list of successes, and charge that seldom has so little been owed to so many.
Last November, Cousins ap-

I Electronics August 23, 1965

167

Electronics Abroad

pointed task forces to study problems of four sectors that he considered basic to his modernization program: electronics, telecommunications, computers and machine tools. None of the studies is complete yet, the critics charge. ·worse, they add, the teams are made up of the wrong people; instead of looking to industry, Cousins drew his advisers from the civil service.
The accomplishments. Cousins' most ambitious efforts have been directed at the computer industry. Last March he arranged a $15-million loan for International Computers and Tabulators, Ltd., to develop its ICT 1900 computer system to compete with the IBM Series 360. Th e T echnology Ministry also has placed a $266,000 research contract with a leading university to develop ways of using digital computers in printing and in type corn position.
At th e National Engin ering Laboratory at Glasgow, a division has been established to find uses for numerically controlled machine tools in British industry. A computer advisory panel has been form ed to study computer requirements in the public sector of the economy. Research into computer techniques and development of special equipment also have been initiated. The ministry is now considering creation of a national computer center.
Even in the computer industry, however, there is a feeling that the Technology Ministry is not doing enough to increase th e awareness of what automation can do for th e economy. Industry officials have called repeatedly for tax incentives to spur the development of new equipment.
New body. A private organization has been formed to coordinate elec tronics research in Britain. Under the leadership of Lord Mountbatten, who recently retired as Chief of the Defense Staff, the National Electronics Research Council is an association of industry, government and university representatives.
Mountbatten says he has conferred with Cousins and assured him of the council's help in every way possible.

Changing allegiance?
Until this month, Britain was considered a solid supporter of the NTSC color-television system used in th e United States. Now the government and private tv companies are showing increasing interes t in \Vest Germany's PAL, a slight variation on the American system.
A switch by Britain would make PAL th e leading contender for an all-European sys tem. Th e third method under consideration is France's Secam.
Some officials of th e Tv Companies Association are predicting a British switch. Th ey say the big reason is a lack of support for NTSC in Europe; only Britain, Scandinavia and th e Netherlands have backed th e American system.
"Th ere's no point in going it alone and supporting a sys tem which has little or no chance of becoming a common one for Europe," says one British executive.
Another indication that the government is wavering is th e fact that the British Broadcasting Corp. conducted compatibility tes ts Aug. 10, transmitting NTSC and PAL in color and receiving the programs on black-and-white receivers.
Japan
Automobile pilot
No matter how safe automobiles are made mechanically, drivers can still crack them up. One solution to that problem is to get rid of th e driver entirely-and that's what is being done in a highway control system now being tes ted in Japan by that country's Government Mechanical Laboratories.
The Japanese experiment will be described at a Tokyo symposium on systems engineering Aug. 25 to 28 [seep. 16]. Unlike systems b eing tested in the United States, it employs parametron circuits to control speed and prevent collisions.
Although it has never gained wide acceptance for computer circuits in the West, the pararnetrou circuit has been favored by the

Japanese for nearly a decade. It amplifies small oscillatory signals by pumping them with another signal at twice the frequency, in much the same way that a child pumps a swing to make it go higher.
Easing traffic jams. With an eye on Tokyo's traffic tangles, which rank among the world's worst, the Japanese have devised a system that seems especially suitable for controlling th e speed of a fastmoving, densely packed stream of cars. The system employs inductance loops buried in the 1.25-mile highway, and pickup coils in the automobile that detect the presence of cars ahead and slow th e tes t auto when necessary.
The loops, 15 by 6 fee t, are buried at uniform distances along the tes t highway: their seriesreson ant circuits are th e inputs to stages of a parametron. The loops are activated with 300-kc signals.
One input to th e parametron is a 300-kilocycle signal from one inductance loop; the other input is at the same frequency from another loop furth er up the road, but 180° out of phase. Wh en there is no car crossing either inductance loop, the series-resonant circuit is in its resonant state; the pumping frequency (600 kc) amplifies the original, or zero-phase, signal to overcome the out-of-phase (piphase) signal and produce a 300-kc zero-phase output.
Tracking a car. Wh en a car is crossing a loop, the zero-phase input is detuned and the pi-phase is amplified, resulting in a pi-phase output. The car detectors and their pararnetrons arc connected in series, so that the signal that indicates the presence of a car becomes weaker as the car proceeds in one direction and stronger when the car goes the other way.
Pickup coils in each car detect the pi-phase signals that indicate the presence of cars ahead, and their distance from the test vehicle. The coils supply inputs to the throttle control, which can slow the car to prevent a collision or speed it up when the road is clear.
Steering is regulated more conventionally with a guidance cable buried in the highway and with a steering-control device in the car.

168

Electronics I August 23, 1965

Mix
~· match.

From breadboard to prototype to production.

Sub-miniature coax, standard machined or formed strip contacts can be intermixed instantly in the same connector block.
You can begin wiring your breadboard or prototype with standard wire. If noise develops, just switch signal leads to subminiature coax without changing the connector block.
Here's a t\vist. You can also convert standard leads to twisted pair. In case we forgot to mention it, the sub-minia-

turc coax contacts take twisted pairs as well as coax cable.
And the formed contact is a big money saver in initial and installed costs. Throw in the automatic Burndy Hyfematic:· and crimp up to 3000 contacts per hour. Blocks available for 14 to 152 positions.
Now put it all together. Contact intermixing, economy, universality. Get in touch with Burndy for all the details. Hurry.
Circle 169 on reader service card

BU ANDY

Norwalk

Connecticut

llEW from N1/aos1cs IN NEBRASKA
High Stability
Precision Wire Wound Resistors

NYTRIM Ar(justo/J/e llesistor wit/; /nl/nite lleso!ution
* 28 Turn Adjustment Over 0.10 to 5.0 ohm range.
* Stocked in four standard des igns * Ultra stability and low
thermal noise
* T/C 20 PPM/"C or better * Package size: 1Ya" long by 1f2" diameter

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* Conforms to MIL-R-93
* 1.0 ohms to 6 megohms * Tolerance to .001 % * Stability: to 1O PPM/year * HTC to 0.5 PPMl°C * Axial Size: Va" to 3/4" diameter by
* V4" to 2" in length. Printed Circuit Size: V4" to V2" diameter by 1%2" to 1" in length
For Complete Engineering Data Write Dept. E or Phone (201) 464-9300
NYIRON/CS
550 Spri ngfield Ave ., Berkeley He ight s, N. J.
Design Leaders - STANDARD Components to Meet CUSTOM Requirements
170 Circle 170 on reader service card

HIGH PRODUCTIVITY assures you of
LOWER UNIT COSTS
An officer of one of the nation's largest ma nu facturers with a plant in ebraska recently said: "I don't know of any other region where work has the dig nity that it does in Nebraska ."
Still another manufacturer with plants in Nebraska a nd six other states said: "What really impresses us is the attitude of the people."
This loya l, hi g h ly productive labor force, which is readily adaptable to new ski lls, is one of the major reasons why manufacturers of all types, incl uding producers of electronic components, enjoy low-cost, trouble-free operations in N ebraslw .
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· "Heart of the natio n" location served by major transportation a rteries.
e Progressive communities ready with low-
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For complete information. including individual community su rveys, write to Da vid J . Osterhout, Chief Confidential, ofcou rse.
DIVISION OF NEBRASKA RESOURCES
State Capitol · Lincoln, Nebraska
Circle 209 on reader service card

Electronics advertisers August 23, 1965

· AMP Incorporated

58

Garceau, Hargrave & McCullough Inc.

Amelco Semiconductor, Div. of Teledyne

Inc.

· 48

Sturges and Associates

·Andrew Corporation

135

The Fensohlt Advertising Agency

· Astrodata Inc.

15

Bonfield Associates Inc.

· Automatic Electric Company

126

Tatham-Laird & Kudner Inc.

·Bausch & Lomb Inc.

132

Wolff Associates, Inc.

Bendix Semiconductor Division

9

MacManus, John & Adams Inc.

Borden Chemical Company, Mystick Tape

Inc.

172

Fuller & Smith & Ross In c.

·Bourns Incorporated Allen, Dorsey & Hatfield Inc.

17, 109

· Brush Instruments, Div. of Clevite

Corp.

3rd Cover

Carr Liggett Advertising Inc.

· Buchanan Electrical Products Corp. 130, 131 Keyes, Martin Company

· Burndy Corporation

169

Ted Gravenson Inc.

Cambridge Thermionic Corporation Chirurg & Cairns Inc.
· Christie Electric Corporation Len Woolf Company Advertising
Colorado, State of Buchen Advertising Inc.
Cominco Products Inc. McKim Productions Limited
Computer Measurements Company Charles Bowes Advertising Inc.
Corning Glass Works The Rumrill Company Inc.
Cubic Corporation Phillips-Ramsey Inc.

150 144 147 144
50 36, 37
49

Datak Corporation

10

Einhorn-Stern Inc.

Douglas Missile & Space Co.

149

J . Walter Thompson Company

· DuPont de Nemours & Company Inc. E.I. 139 Batten, Barton, Durstine & Osborn Inc.

Electro Instruments Inc.

127

Teawell Inc. Advertising

Electro Products Laboratories Inc.

151

C. M. Gotsch, Advertising

Engineered Electronics Company

114

Barnes Chase Advertising

Erie Technological Products Company

Inc.

105

Altman-Hall Associates

FMC Corporation, Inorganic Chemicals

Division

143

Muller, Jordan & Herrick Inc.

143

· Fairchild Instrumentation

148

The Wexton Company Inc.

· Fairchild Semiconductor Corporation
Faust/ Day Inc. Adverti sin g

11, 12, 13

Fiberfil Incorporated

152

Tri-State Advertising Co. Inc.

· General Electric Company, Silicone Products Dept. Ross Roy Inc.
General Instrument Corporation Norman Allen Associates Inc.
General Radio Company K. E. Morang Company
Globe Industries Inc. Odiorne Industrial Advertising Inc.
Gudebrod Bros. Silk Co. Inc. Lee Ramsdell & Co. Inc.

137 18, 19
6 157
35

Hamilton Standard Div. of United

Aircraft Corporation

125

Cunningham & Walsh Inc.

Hansen Mfg. Company Inc.

142

Keller-Crescent Company

·Heath Company

157

Advance Advertising Service Inc.

Heinemann Electric Company

116

Thomas R. Sudheim Inc.

· Hewlett-Packard Company Lennen & Newell Inc.

Hitachi Ltd.

145

Dentsu Advertising Ltd.

· Hughes Aircraft Company

156

Foote, Cone & Belding Inc.

Hurst Mfg. Corporation

121

Hathaway Advertising Agency &

General Advertising Associates Inc.

· Kepco Inc.

22

Weiss Advertising

· Lapp Insulator Company Inc.

141

Wolff Associates Inc.

· LEL Division of Varian Associates

53

Snow & Depew Advertising

Machlett Laboratories Inc., The

8

Fuller Smith & Ross Inc.

· Magnetics Inc.

108

Lando Inc.

Magnetics Systems Corporation

128

Neals & Hickok Inc.

· Mallory & Company Inc., P.R. Aitkin-Kynett Company, The

106, 110

Mepco Inc.

122

Ray Ellis Advertising Corp.

·Micro Switch Div. of Honeywell

107

Batten, Barton, Durstine & Osborn Inc.

Motorola Semiconductor Products Inc. 57 Lane and Bird Advertising Inc.

Mystik Tape Inc. Div. of the

Borden Chemical Co.

172

Fuller & Smith & Ross Inc.

Nebraska Resources

170

Ayres & Associates Inc.

New Hermes Engraving Machine Corp. 152 Doner-Harrison Inc., Advertising

North Atlantic Industries, Inc.

16

Murray Heyert Associates

· Norton Associates

144

J .J . Cappo Co . Inc.

Nytronics Inc.

170

Stukalin Advertising Agcy., The

Pamotor Inc.

138

Harry J . Bridge Co. , The

Plastics Capacitors Inc.

148

Sander Rodkin Adv. Agcy. Ltd.

· Potter & Brumfield Div. of American

Machine & Foundry Co.

24

Grant, Schwenck & Baker Inc.

Princeton Applied Research Corp.

38

Mort Barish Associates

Progress Webster Corporation

56

Stern/Frank Advertising Inc.

Radiation Inc.

154

G.M. Basford Company

Radio Corporation of America Al Paul Lefton Co.

4th Cover

Sanborn Co., A Div. of Hewlett Packard

Co.

2

Culver Advertising Inc.

Sangamo Electric Company

47

Winius-Brandon Company

· Sargent & Greenleaf Inc.

163

Wolff Associates Inc.

Sinclair Radio Laboratories Inc.

118

John E. Hayes Company Inc.

·Sorensen Inc.

133

Fuller & Smith & Ross Inc.

Spectral Electronics Corporation

45

Jones, Maher, Roberts Advertising

Sprague Electric Company, The Harry P. Bridge Co., The

5, 7, 14

Stackpole Carbon Company

124

Meek & Thomas Inc.

· Superior Tube Company

140

Gray & Rogers Inc.

Sylvania Electric Products Inc. Kudner Agency Inc., The

27 to 34

Systems Engineering Laboratories

136

Adams & Keyes Inc. Advertising

TRW Electronics

43

Fuller & Smith & Ross Inc.

Taber Instrument Corporation

153

Harold Warner Advertising Inc.

·Tektronix Inc.

164

Hugh Dwight Adv. Inc.

· Telonic Engineering Company Jansen Associates, The

20, 21

Texas Instruments Inc. Semiconductor-

Components Div.

54, 55

Don L. Baxter Inc., The

Tracor Inc. David G. Benjamin Inc.

117, 119

Triplett Electrical Instrument Company 123 Burton Browne Advertising

Trompeter Electronics

155

Writing & Advertising Inc.

·Tung-Sol Electric Inc.

151

E.M . Freystadt Associates Inc.

Ultra Carbon Corporation

146

Church & Guisewite Advertising Inc.

· United Transformer Corporation 2nd Cover Philip Stogel Company Inc., The

Vector Department of Norden Div. of

United Aircraft Corp.

154

Cunningham & Walsh Inc.

Westinghouse Semiconductor Div.

115

ITSM

Zippertubing Company, The

46

Edward S. Kellogg Company

Classified Advertising

F.J . Eberle, Business Mgr.
EMPLOYMENT OPPORTUNITIES PROFESSIONAL SERVICES EQUIPMENT
(Used or Surplus New) For Sale

158·1 62 161
162

Advertisers Index

Bureau of Ships

162

General Electric

158

Globe-Union Inc. Centralab, Div.

162

Gruman Aircraft

159, 160

Keystone Electronics Corp.

162

Pan Am Guided Missiles Range Div.

161

· Radio Research Instrument Co.

162

·Semiconductor Sales of Calif.

162

Texas Instruments Inc. Corp.

161

Union Carbide Corp.

161

· For more information on complete product
line see advertisement in the latest Elec· tronics Buyers' Guide

~~~uJ~v~:6~ciJ~g~:~.c~~~~:~i~c~~~:h~l~~~i-~~'f:>~!~;i::o~f~:ap~~Nba~rr1~d~n~ivTsY~n~~~~11~~df~~:i.t·p~:~d~~~~·v~c!··P1r~~~~·nT::'ef~s0e0p8h A~~8A1?.ind,eo2p1e~~?o~:;3i3c>b!~~erp~o~':~
Administrati on; John R. Calla ham, Editorial; Ervin E. OeGraff, Circulation; Donald C. McGraw. Jr., Advertising Sales; Angelo R. Venezian, Marketing. Officers of the Corporation: Don ald C. McGraw, Pre side nt; L. Keith Goodrich and Hugh J. Kelly, Executive Vice Presidents; John J . Cooke, Vice President and Secretary; John L. McGraw, Treasurer. Title R regis· tere d U .S. Patent Office; © copyright 1965 by McGraw· Hill, Inc. All rights reserved, including the right to reproduce the contents of this publication, in whole or in part.

Electronics \ August 23, 1965

171

........._
· I·
':.·I I ,o.a:
"·'-·1.

Everything you need to know about tapes you can carry in your hip pocket
It's Mystik's new Select-A-Tape Guide. Here, in a pocket-size, full color edition is a complete catalog of Mystik Tapes. It's the fastest way to find the right tape for any given application.
For easy reference, the guide is indexed by type of tapemasking, packaging, protective, printable and special purpose. Over 100 tapes right at your fingertips! Each tape, its backing material and adhesive, is described in detail, along with physical characteristics, advantages and principal uses.
A word of warning. Once people pick up our new pocketsize Select-A-Tape Sample Guide, they can't put it down. They pocket it instead. So watch it. Mail the coupon below and get yours free of charge. Then you won't have to borrow somebody else's.
A DIVISION OF BORDEN CHEMICAL COMPANY
Takes the guesswork out of tape selection. Gives physical characteristics of all Mystik tapes, typical applications, sizes, principal advantages. Send for your copy today. MYSTI K TAPE, INC., 1700 Winnetka Ave., Northfield, 111.
NAME.~--------------~ COMPANY_ _ _ _ _ _ _ _ _ _ _ __ ADDRESS_ _ _ _ _ _ _ _ _ _ _ _ __ CITY_ _ _ _ _STATE_ _ _,ZIP_ __
172 Circle 172 on reader service card

Advertising sales staff

Gordon Jones [212] 971 ·2210
Advertising sales manager

Atlanta, Ga. 30309: Gus H. Krimsier,

Michael H. Miller, 1375 Peachtree St NE

[404] TR 5-0523

. . .,

Boston, Mass. 02116: William S. Hodgkinson

co McGraw-Hill Building, Copley Square

[617]

2-1160

'

Chicago, 111. 60611: Robert M . Denmead, J. Bradley MacKimm 645 North Michigan Avenue, [312] MO 4-5800

Cleveland, Ohio 44113: Paul T. Fegley, 55 Public Square, [216] SU 1-7000

Dallas, Texas 75201: Richard P. Poole, The

Vaughn Building, 1712 Commerce Street

[214] RI 7-9721

'

Denver, Colo. 80202: Joseph C. Page , David M. Watson, Tower Bldg ., 1700 Broadway, (303] AL 5-2981

Houston, Texas 77025: Kenneth George, 2270 Humble Bldg., [713] CA 4-8381
Los Angeles, Calif. 90017: Ashley P. Hartman, John G. Zisch , 1125 W. 6th St., (213] HU 2-5450
New York, N. Y. 10036: Donald R. Furth (212] 971-3615 Frank LeBeau (212] 571-3615 George F. Werner (212] 971-3615 500 Fifth Avenue
Philadelphia, Pa. 19103: William J. Boyle, Warren H. Gardner, 6 Penn Center Plaza, (215] LO 8-6161
San Francisco, Calif. 94111: James T . Hauptli, 255 California Street, [415] DO 2-4600

London Wl: John W. Patten, Edwin S. Murphy Jr ., 34 Dover Street, Hyde Park 1451

Milan: 1, via Baracchini Phone: 86-90-617

Frankfurt/ Main: Gerd Hinske, 85 Westendstrasse Phone: 77 26 65 and 77 30 59

Geneva: Michael R. Zeynel , Joseph Wuensch, 2 Place du Port 244275

Paris VIII: Denis Jacob, 17 Avenue Matignon ALMA -0452

Tokyo: Nobuyuki Sato Shiba, Minato-Ku (502) 0656

Osaka: Kazutaka, Miura, 163, Umegee-cho, Kilta -ku (362] 8771

Nagoya: International Media Representatives,
Yamagishi Bldg ., 13, 2-Chome, Oike-cho Naka-ku

Hugh J. Quinn: [212] 971-2335 Manager Electronics Buyers' Guide

David M. Tempest: [212] 971-3139 Promotion manager

Milton Drake: [212] 971-3485 Market research manager

Wallace C. Carmichael (212] 971-3191 Business manager

Theodore R. Geipel: (212] 971 -2044 Production manager

Electronics I August 23, 1965

Another Brush Innovation in Recording:
··-

I
The Brush Mark 240
If you can't record it with this recorder, chances are it didn't happen!

What we've done is this: We took our famous Mark 200
Recorder and made a 'compact' version for general purpose and medical requ irements. Performance? The new 240 will do everything the Ma rk 200 wi ll do. And as Aerospace people will tell you, that's plenty:
System linea rity better than 1123.
Pressurized fluid writing system assures incredibly crisp traces on low cost cha rt paper. Presentation is true rectilinear and there's pushbutton choice of 12 chart speeds.
Cost? The Mark 240 runs about

half as much as a Mark 200. Still,

If your kind of recording calls for

you have a choice of either four 40 mm analog channels, two 80 mm channels, or a combination * of two

the utmost in resolution, precision and recording flexibility, ask your Brush representative for complete

40s and one 80 . (You can also have details about the new Brush Mark

8-channel event-marker modules). 240. There's nothing else like it

There's a choice of 17 plug-in pre- ·.. anywhere! Brush Instruments

amp lifiers, too. High gain d-c units, Division, Clevite Corporation, 37th

straight-through couplers and straingage and demodulator types. The

& Perkins, Cleveland, Ohio 44114. Just out! Three information-packed

Mark 240 is just 17V2" high x 19" wide x 20 1/ 2 " deep. Mount it vertically or horizontally in stand-

booklets on strain recording, temperature recording and techniques of /ow-level recording. Write us today

ard 19 " racks to RETMA specs, on table-top carts or you name it!

for your copies. They 're yours for

the asking!

·see photo

CLEVITE

- - -IJrush I N sTR u M ENT s DI v I s I 0 N

Circle 901 on reader service card

Two new RCA units-2N3878 and 2N3879-are n-p-n epitaxial silicon transistors, in T0-66 cases, offering designers high-current ratings for high -speed switching appl ications and broad band amplifier circuits.
Available at the low costs you 'd expect for mass production requ irements , RCA 2N3878 and 2N3879 feature:
· Linear beta over a wide range of collector current
· Rated for safe operation without second breakdown
· Immediate availability at low cost.
Employing epitaxial structure for low saturation voltage and improved switching speeds, 2N3878 and 2N3879 are ideal for high frequency power amplifiers and osc illators, high -speed

inverters, pulse-width modulated regulators, and low distortion power amplifiers.
For more detailed information check the ratings in the chart. See your RCA Representative about prices and delivery. For technical data on these types, write : RCA Commercial Engineering, Section IN8-4 , Harrison , N. J.

2N3878 2N3879

l c(cont inuousl

7

7

A

le (peak)

10

10

A

pmax .

35

35

w

VCEO (sus)

50

75

v

VCER (sus)

65

90

v

VcE (sat) 4A

2.0

1.2

v

hFE 4A

20 min

20 -8 0

Also Available From Your RCA Distributor RCA Electronic Components and Devices

Circle 902 on reader service card

The Most Tr.u-sted Name in Electronics
®