Electronics V37 N21 19640727
Thermal transfer works in microcircuits: page 54 Computers cut testing costs: page 76 Receiving weather photos from orbit: page 81

July 27, 1964
75 cents
A McGraw-Hill Publication
Below: new photon-coupled devices find applications, page 58


00-T No. DO-T44 DO-T29 DO-T12 DO-Tl3 DO-T19 DO-T30 DO-T43 DO-T42 DO-T41 DO-T2 DO-T20

Prl. D.C. Ma.t Imp. In Prl.

80 CT 12 100 CT 10

120 CT 10 150 CT 10

150 CT 10 200 CT 10

300 CT 7 400 CT 7

300 CT 7

320 CT 7 400 CT 7

400 CT 8 500 CT 6

400 CT 8 500 CT 6

400 CT 8 500 CT 6





500 CT 5.5

Sec. Prl. Res. Prl. Res. Mw 01-T Imp. 00-T Dl·T lml No.

32 split 40 split

9.8 11.5 500 Dl-T44·














19 20 500 Dl-T19





40 split 46 50 500 Dl-T43·

50 split

120 split 46


150 split

400 split 46 500 split

50 500 Dl-T41'


60 65 100 Dl-T2



31 32 500 DT-T20








600 CT 5




800 CT 5



640 CT 5




800 CT 5



800 CT 4




'1000 CT 4



800 CT 4




1070 CT 4



900CT 4


53 53 500

--=D~O~-T~3=-=-~~l~00~0,..:..:.~-~3~~-=-;;5~0~~---,';1175~'1~10;----;-1;0, 0

DO-T22 DO-T34




1000 CT 3.5 16,000 split 120


1250 CT 3.5 20,000 split

1000 CT 3.5




1330 CT 3.5


1060 CT 3.5




1330 CT 3,5





105 110 100

1500 CT 3




2000 CT 3


1500 CT 3


86 87 500

1600 CT 3




2000 CT 3


Dl-T21 Dl-T3
DI-TS Dl-T22

*DO-T51 DO-T37
*DO-T52 DO-T18 DO-T35

2000 CT 3 2500 CT 3 2000 CT 3 2500 CT 3 4000 CT 2 5000 CT 2 7500 CT I 10,000 CT I 8000 CT I 10.000 CT I

2000 split 195 180 100 Dl-T51* 2500 split

8000 split 195 180 100 Dl-T37· 10,000 split

8000 CT 320 300 100 Dl-T52* 10,000 CT










8.000 CT I

1200 CT 640


10.000 CT 1

1500 CT


9.000 CT I

9000 CT 850


10.000 CT I 10,000 CT












500 CT 600 CT

780 870 100 Dl-T9

DO-TlO 10.000


1200 CT 780 870 100 Dl-TlO



1500 CT


10.000 CT I 12.000 CT I

1500 CT 780 870 100 Dl-T25 1800 CT


10.000 CT I 12.000 CT I

2000 split 560 620 100 Dl-T38· 2400 split

DO-Tl 1 10.000


2000 CT 780 870 100 DI-Tl 1

12 .500


2500 CT

DO-T36 10.000 CT 1 10,000 CT 975 970 100 Dl-T36 12.000 CT 1 12,000 CT
~D~o--=T~ 1 ~-2~0-.ooo·~~-_75~=-o8~00=-'-'~____,8=30=---=8-1~5~~5~o~D=1-~T=1~

30 .000

.5 1200

DO-T23 20.000 CT .5 800 CT 830 815 30.000 CT .5 1200 CT

DO-T39 20.000 CT .5 1000 split 800 30.000 CT .5 1500 split

DO-T40 40.000 CT ,25 400 split 1700 50.000 CT .25 500 split

DO-T46 100.000 CT 0

500 CT 7900

DO-T7 200.000




DO-T24 200 .000 CT 0

1000 CT 8500

50 Dl-T23
25 25 25

DO-TSH Drawn Hipermalloy shield and cover 20 / 30 db


iocMA shown is for single ended useage (under 5% distortion-IOOMW- 1KC) .. for

push pull , DCMA can ~e any balanced value taken by .5W transistors (under 5% distor-






for transistor use only. U.S. Pat. No. - . *Units newly added to series

lSenes connected; HPara1lel connected






Now.I Hermetically Sealed to MIL-T-278

*16 New Items Added to Stoel< Line

High Power Rating ...............................up to 10 times greater

Excellent Response ............................twice as good at low end

Low Distortion ......................................................reduced 80%

High Efficiency .. ............. up to 30% better · .. comoare OCR

Moisture Proof ..................... hermetically sealed to MIL-T-27B

Rugged ........

.. ..... Grade 4, completely metal cased

Anchored Leads ..................will withstand 10 pound pull test

Printed Circuit Use ........(solder melting) nylon insulated leads

Suited to Clip Mounting .............. ....use Augat #6009-BA clip

(2 wdgs.)
· DO-T49
(2 wdgs.)


Inductance HJS (U\ ma


!.075 HY /10 ma . .06 Hy /30 ma


U.018 HY /20 ma , .015 Hy /60 ma


.3 Hy /4 ma , .15 Hy /20 ma


.I Hy /4 ma , .08 Hy /IO ma

1.25 Hys /2 ma , .5 Hy /II ma


.9 Hy /2 ma, .5 Hy /6 ma

3.5 Hys /2 ma , I Hy /5 ma


2.5 Hys/2 ma, .9 Hy /4 ma

6 Hys/2 ma, 1.5 Hys /5 ma


4.5 Hys /2 ma, 1.2 Hys /4 ma

!20 Hys / I ma, 8 Hys /3 ma


HS Hys /2 ma , 2 Hys /6 ma


01 -T 01 -T OCR(} No.
25 Dl-T28 105 Dl-T27 630 Dt-T8 2300 Dl-T26


· DO-T400 Pri 28V 380-1000 cycles, Sec 6. Vr.l\ 60 ma *DO-T410 Pri 28V 380-1000 cycles, 2-Sec .3 iW 30 ma each *DO-T420 Pri 28V 380-1000 cycles, Sec 28V (ill 20 ma (lsol. Electrostatic Shld.)

Write for catalog of over 1,200 UTC HIGH RELIABILITY
IMMEDIATELY AVAILABLE from your local distributor.





Circle 900 on reader service card


New hp 117A VLF Comparator-for.only $1150

Here is an easy, precise and inexpensive way to calibrate your own oscillator against the United States Frequency Standard ... whether it's the time base in your electronic counter or your laboratory frequency standard. The new hp 117A VLF Comparator provides all the features needed for frequency standardization. You need no other instruments.
The 117A makes accurate phase comparisons between local oscillators and the 60 kc U.S. Frequency Standard broadcast by the National Bureau of Standards on WWVB.
This instrument makes comparisons with an accuracy approaching 1 part in 1010 over an 8-hour period. WWVB broadcasts a signal capable of being received at a precision of about 5 parts in 1011 during a 24-hour period.
The 117A employs an electronic servo system that permits the utilization of the WWVB signal to phase lock a voltage controlled oscillator. The local standard is then compared to this phase-locked oscillator and a continuous phase difference recording is made on a built-in strip chart recorder. Templates are furnished for direct reading of recorder charts. A front panel meter shows signal level, satisfactory phase lock with WWVB, or phase comparison, depending on switch setting. The 117A provides a 100 kc phase-locked output accurate enough to use as a
Electronics 1 Ju ly 27, 1964

local standard during stable propagation conditions. External recorder outputs are included for recording phase comparison and signal level.
Check your oscillator requirements and consider the advantages of a fast VLF U.S. Frequency Standard transfer, then ask your Hewlett-Packard field engineer for all the information.


USFS input: Sensitivity: Local standard input: 100 kc phase-locked
output: Phase stability:
Chart width: Chart speed:
Size: Price:

60 kc (WWVB carrier) 1 µ.v rms into 50 ohms 100 kc, 1 v rms into 1000 ohms (1 me option )
20 v rectangular positive pulses into 5000 ohms ± 1 µ.sec, 0 · 50°C 50 µ.sec or 16 ~ µ.sec ( internal switch ) 1 inch per hour, others available upon request 3 ~" high, 11 ~" wide, 16 ~" deep, 15 lbs. $1150 including 60 kc antenna

Data subject to change without notice. Price l .o.b. factory.



· An extra measure of quality


1501 Page Mill Road, Palo Alto, Calif. 94304, (415) 326-7000. Sales and service in all principal areas. Europe, Hewlett-Packard S.A., 54 Route des Acacias, Geneva, Switzerland; Canada,
Hewlett-Packard (Canada) Ltd., 8270 Mayrand St., Montreal, Que.

Circle 1 on reader service card


New Sanborn Tape System
7 CHANNELS plus monitoring track 16 ELECTRICAL SPEEDS without
capstan change 40 db or better SIGNAL/NOISE RA TIO 0.23 P -P FLUTTER
IRIG compatibility
For under$~000

Now you can have precision instrumentation tape system performance at substantially lower cost than ever before, with this completely new Sanborn 3900 Series incorporating a specially-designed Hewlett-Packard transport. The primary objective was to provide a highly flexible, reliably useful system with stable tape motion, simple operation and no maintenance - at a signifi, ...- - .-- cantly lower cost. T hese objectives have been successfully accomplished, in a system which has:
· Greatly reduced interchannel crosstalk with a new magnetic head assembly design using improved shielding. · High signal/noise ratio, gentle tape handling and reduced tape wear, through precisely controlled tape tension, driving and braking torques, and guide element designs. · Plug-in solid-state electronics with record/reproduce amplifiers on the same cards, and equalization plug-ins necessary only for speeds to be used. · No need for maintenance or lubrication, except for cleaning tape path. · Built-in footage counter accurate to 99.953. · Quick, easy snap-on tape reel loading. · Cabinet, rack or portable case mounting.
Check the key specifications here, then call your local H-P Field Engineering Office for complete details and prices. Or write Sanborn Company, Industrial Division, 175 Wyman Street, Waltham, Massachusetts 02154.

SERIES 3907A (7-channel), 3914A (14-channel)


6, electrically controlled, pushbutton selected, H's to
60 ips; other speed ranges optiona l. Max. start 2 sec., max. stop 1 sec.; zQ.25% max. variation in tape speed at nominal lin e freq u ency.
7· cha nn el 1/ 2"; 14·channel l"; 2400 feet1.5 m il, 3600 feet 1.0 mil; 4800 feet 0.65 mi l ; 10'12'' ree ls.


Direct, FM or Pulse Record/ Reproduce via inter· changeable solid state plug·in electronics; 7·channels in 7112" panel space. Single.e n ded i n p u ts, push-p ull
with o ption al coupler. Adjust able input/outp utlevels.

Circle 2 on reader service card




Di r ect (60 ips) 100· 100,000 cps

z3 db

40 db

FM (60 ips) 0-10,000 cps
(Wideband systems avail· able soon - 250 KC direct, 20 KC FM)

:1;0, -1 db

44 db without flutter compen. sation 48 db with flutter compensation

P-P FLUTTER (30 & 60 ips)

0.1 KC, 0.2% max. 0·5 KC, 0.5% max.


Power, Stop, Play, Reverse, Fast Forward, Record ; all can be remotely controlled

PRIC E S (f. o . b. W al t ham, M ass.) (Systems represent two of many choices avail· able. Prices are correspond· ingly lower for fewer speed filters, or where direct record /reproduce electronics are specified, and higher when filters for a ll six speeds are ordered.)

Complete 7-channel system for FM

recording and reproducing, with

filters for 3 speeds, extra (8th)

channel for monitoring, and console



Same system, f o r 14-channels: $13,370

July 27, 1964 Volume 37, Number 21


Page 4 8
10 15 17 43 111 132 135 136

Readers comment People Meetings ahead Editorial Electronics newsletter Washington newsletter New products New literature New books Technical abstracts

Electronics review

Page 27 27 28 28 29 29 30

Instant radar maps Ceramic that foams Numerical sculpture Shocking shrimp The littlest Biax Thin films of glass Thin-film first

30 Out, damned spot 32 Superpower triodes 32 SAC speedup 34 More power 34 Which way is down? 34 No cheating

Probing the news
99 Homemade ground stations 101 The state of the unions 106 Microsurgery in color tv

In this i· ssue
Title R registered U.S. Patent Office;
© copyright 1964
by McGraw-Hill, Inc. All rights reserved, including the right to reproduce the contents of this publication, in whole or in part.

Technical articles

Microelectronics Solid state
Components Circuit design

I. Design
54 Low-frt!quency integrated circuits Thermal transfer makes possible new oscillators, filters and delay networks for below 100 cps W.T. Matzen and R.A. Meadows, Texas Instruments
58 Optoelectronics at work (cover) New components use photon coupling in applications from amplifiers to demodulators, oscillators to mixers Irwin Wunderman , hp Associates
68 Stray signals can't throw this desensitized switch It discriminates between r-f energy and a d-c pulse with an extra zener junction J.M. Gault and R.J . Sanford, Naval Ordnance Laboratory
72 Designers casebook Displaying the contents of a computer register; added transistor decreases multivibrator reset time; nomograph shows phase-shift angle; positive-pulse generator; buffer amplifier supplies bipolar output

Computer Space electronics Communications

II. Application
76 Automatic circuit tester Digital computer saves time and money and increases capability in production testing Kenneth Wakeen , Digital Equipment Corp.
81 Bird's eye view of the weather Meteorological satellites will send cloud pictures Here's a ground station to receive them C.M. Hunter and E. Rich Jr., NASA
88 Tropo goes commercial AT&T prepares to use a new solid-state system that's been proved by the military Alexander A. McKenzie, Communications editor

Editor: Lewis H. Young
Managing editor: John M. Carroll
Senior editors
Technical: Samuel Weber News: George Sideris
Senior associate editor: John F. Mason
Department editors Advanced technology: George V. Novotny Avionics: W .J . Eva nzi a Circuit design: Jerome Eimbinder Communications: Alexander A. McKenzie Components: Michael F. Tomaino Computers: Stephen B. Gray Consumer electronics: V .S. Acunto Industrial electronics: Louis S. Gomolak Instrumentation: George J. Flynn Military electronics: John F. Mason New products: William P. O' Brien Solid state: G.G. Tirel lis Space electronics: Joel A. Strasser Staff writers: Leon H. Dulberger, Peggy Jackson
Regional editors Boston: Thomas Maguire, editor; Susan Turn er Chicago: Cletus M. Wiley, editor; Leslie Krimston Los Angeles: Ha raid C. Hood , editor San Francisco: Laurence D. Shergalis, editor; Mary Jo Jadin London: Derek Barlow, editor
Copy editors Howard Rausch, Sally Powell
Illustration Art director: Howard R. Berry Assistant art director: John C. Wright, Jr. Editorial production: Ann Mella, Sandra A. LeMond
Editorial secretaries: Claire Benell, Lynn Emery, Kay Fontana, Lorraine Rossi, Lorraine Werner
McGraw-Hill news service Director: John Wilhelm; Atlanta: Fran Ridgeway; Chicago: Bruce Cross; Cleveland: Arthur Zimmerman; Dallas: Marvin Reid; Detroit: Donald MacDonald; Los Angeles: Kemp And erson, Michael Murphy, Ron Lovell; San Francisco: Margaret Ralston, Ed. Addeo; Seattle: Ray Bloomberg ; Washington: George Bryant Jr., Glen Bayless, Charles Gardner
McGraw-Hill world news service Bonn: Richard Mikton; Brussels: Arthur Erikson; London: John Shinn; Mexico City: Wesley Perry; Milan: Bruce Bendow; Moscow: Donaid Winston; Paris: Dan Smith; Rio de Janeiro: Leslie Warren; Tokyo: Richard Halloran, Charles Cohen
Circulation manager: Hugh Quinn Reprints: T.M . Egan
Publisher: C.C. Randolph

Electronics: July 27, 1964, Vol . 37, No. 21

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

Sub.s~riptlons are solicited onl~ from those _act~vely engaged in the f ield of the publication.

Pos1t1on and company connection must be 1nd1cated on orders. Subscription prices: United States"
~~~n~~::el~~Qi ~"n~ ~:~~-d~i·n~?e~~gi~~.Y~~~ie~9S~~t~~0a~~ap~·s:;;S~~~har~~ t:~~5<JaA~so,ther

Single copies all other countries $1.50.


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 a ny 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


Readers Comment
3-D electronics
Congratulations on your excellent 3-D reproduction of an electronic module [June 15, p. 26]....
The main weakness in this approach to 3-D is in the confusion as to distance from the viewer, and scale. I recommend that in your next venture you use Jayne Mansfield as reference; she should hold it over h er h eart.
Lawrence A. Shaw St. Paul, Minn.
Your editorial, "The challenge of change" [June 15 p. 15] , brings up an important point. It mentions that on th e average it takes about five years to develop a new product and to establish a capable marketing organization, sometimes even longer. You bring up the importance of diversification in view of the leveling off of our defense spending, and you mention particularly th e field of industrial electronics as havin g great promise.
Many medium-size and smaller companies in th e United States are not aware of one short-cut for diversification. There are thou sands of counterpart companies in Europe and Japan that are eager to cooperate with th eir brother companies in th e U.S. In the process, valuable exchange of knowledge and of products can be achieved.
Electronics companies in foreign countries have not been as dependent on defense spending as have our companies here. Consequently they have developed products which are precisely the kind we are seeking, in consumer electronics and in industrial applications. On the other hand, these companies have not had governmentsponsored research as we know it here. Therefore they are behind in technical capabilities and in basic research facilities.
Evidently a great deal can be gained by an exchange between these two diversely oriented groups of manufacturers. Most Am erican electronics companies, when they sell abroad, think of extending
Electronics I July 27, 1964

Now from Spra uel

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I Electronics July 27, 1964

Circle 5 on reader service card


(A dt'el'liseJJ1<111)
Pulse Network Problems Solved by Experienced Systems Engineers
r -
T ypical Large Pulse-Forming Network designed by Sprague to meet a specific customer need,
Prompt cooperation on customers' pulse network problems is readily available from Sprague Electric Company's Pulse Capacitor and Network Section.
Sprague has much to offer to designers of radar systems, laser systems, tube testing systems, and other specialized systems. A highlytechnical special engineering section devoted exclusively to pulse capacitors and networks includes systems as well as pulse network engineers. S prague can help you with you r problems becau seSprague fully understands your problems!
But Sprague service does not end here. Following up the design aspect, these specialists can quickly and efficiently estimate pulse network sizes and prices for bidding purposes. They are also equipped to give quick reaction capabilities for your breadboard and prototype units.
A pioneer in pulse networks, Sprague i~ a major supplier of custom units from less than 1 KV up to 500 KV over a broad range of power levels.
For application engineering assistance, or additional information, write to Pulse Network Section, Sprague Electric Company, 35 Marshall St,, North Adams, Massachusetts.
6 Circle 6 on reader service card

their m ethod of selling in the U.S.; i.e., through sales representatives. This is why so often opporhmities inherent in coop eration b etween manufacturer s are overlooke d.
If any of the readers of this letter care to have a reprint of our recently published booklet, KnowHow Is Our Most Important Product, we shall be glad to mail a free copy.
S.V. Hart Electronic Engineers International 57 Levant St. San Francisco 14.
Ferroacoustic storage
The article entitled "Ultrasonic Approach to Data Storage" in your May 4 issue [p. 671 has impelled me to disclose proprietary thinking in a comparabl e area. In my view the basic concept involved here holds great promise for future generations of computers.
A configuration I propose for a high-speed, hi gh-capacity ferroacoustic storage consists of a spirally deposited magnetic film on a rod or tube substrate with a characteristic of high acoustic velocity. Longitudinal anisotropy for the film is assumed.
Recent studies of the means to propagate pressure pulses at high velocity for the instrumentation of plasma research has revealed the ability to generate pressure wave fronts of 0.4 microseconds at propagation speed s of nearly 40,000 feet per second in materials such as sapphire and beryllium (Poulter Laboratories T echnical Report 01060, Stanford Research Institute).
The dependence only upon acoustic energization is a significant aspect of th e ferroacoustic storage. Extrapolating this concept to higher orders of logical manipulations, one can speculate on the formation of an integrated arithmetic assembly on an acoustic substrate with transducer-initiated command generating a pseudo clock, as manifested by the traversing compression wave.
Consider a cylindrical surface onto which is deposited thin-film microcircuits and input/ output conn ections to " induction pads." A close-fitting hibe, in near contact, surrounding th e acoustic cylinder over its active length comprises the

interface to wired input/ output elements. The interface is formed on the inner surface of the tube with mating pads to the "induction pads" on the cylinder. It is contemplated that energy will be transferred across the interface by induction through the medium of the traversing compression wave.
Spatial distribution of the microcircuits and conductors in relation to the actuating compression wave provides, for example, predetermined delays and facility for addback and carry-forward functions. P arallel entry with serial-parallel data manipulation for sorting, shifting, or arithmetic operations are suggested.
The advantages envisioned for this design concept are small size, high speed, minimum standing power, minimum wiring connections, and ultimate low cost.
N. A. Moerman Roslyn H eights, L.I., N.Y.
Independent inventor
B. McFarlan e [June 29, p. 4] b emoans the passage of the bill raising patent fees. H e indicates that these fees will " s tifle and starve the independent inventor."
I am somewhat of an independent inventor. Two patents issu ed. About six applications on file. Live in a rented room. Drive a '55 Ch evy. Was glad to see the fees go up. Even wrote my congressman urging approval of the measure. Th e $60 fee paid for a patent is a pittance b eside the $600 fee charged by th e lawyer who files the application. It is not the Patent Office charges which stifle me-it is the argot in which patents are written. That is what is stifling. It forces me to engage an attorney. It raises my cost by a factor of 10.
The judges appointed to hear patent cases should be engineers rather than lawyers. The legal argot would disappear very quickly and patents would b e written in understandable engineering language. I could then prepare by own applications. The patent lawyer would be eliminated.
Let the fees go up. Get rid of the patent lawyers.
George E. Row
Rowco Engineering Co. Indianapolis, Ind.

Electronics J July 27, 1964

There was

a worried

look on Steve's
face as he met my
cab outside the gover11-
ment office building.
"Where've you been?" he wailed.
"We're scheduled in five minutes!"

"What's got you grounded, Dad?" I gave him the presenta-

tion booklets to carry and kept the flip charts. "You look as

if the Russians had just landed on the moon."

"I don't like the way things are going," Steve said gloomily

as we went inside and punched for the elevator. "When the

Ajax crew came out of their meeting, they looked as if they'd been given the deed to the Pentagon.'·

"Have they got anything we haven 't?" The elevator door

opened and we stepped in.

r ···
\ \

"Not as far as I can find out. But we haven't got anything they haven't, either."


"Don't be too sure," I said as the elevator


slowed for our floor. "What kind of shock

l , : /-\ and vibration data did they show?"



"How should l know? The usual shaketable tests. all the required g's and fre-

_1.___.:._:_ ._.l;._·..J., quencies, I suppose. What else could you

do. throw it off the Washington Monument and count the

number of times it bounces?''

The first part of the presentation went as smooth as a jet

at thirty thousand. Then I hit clear air turbulence.

"This is a resume of the shake table results in accordance

with the required Mil Specs,'' l was saying, "As you see, there's

no appreciable distortion of output. And here," I flipped to the

next chart, ''is a record of electrical performance under the

maximum transisnts of the shock and vibration history of

Frontiersman lll1. As you know, that was an earlier version of

the vehicle for which we are quoting this component."

Colonel Walsh leaned forward across the table and his

eyes glinted like fixed bayonets as he said,

"You people had no components on

Frontiersman ill."

"No," I said "this was simulated. But we

asked the Air Force inspector to witness

the tests, and he has certified that we

reproduced the max mechanical inputs

within five per cent."

"l'd like to know how you did that," the colonel challenged.

"You mean you want the technical details?" I asked him.

"If you don't mind," said the colonel. Coming from him, this

was an expression of profound interest.

I shot a glance at Steve. He looked like a little boy who

has just found out there really is a Santa Claus.

"Well, to start with," I said, "on our copy of the Frontiers-

man III telemetry tape they hadn't included the time code. So

we began by re-recording it with time code in modified IRIG B

format from an EECO 858 Time Code Generator/Reader2 ·

Of course, it wasn't the original time. Just an arbitrary indica-

tion for marking and searching purposes."

"Of course," the colonel said. "Go on, please."

"Then we read out the entire tape onto strip charts and eye-

balled them for maximum g's. We selected three time segments

that contained the most severe conditions, and noted the start

and finish times of the segments selected. You know, you can

read hours, minutes and seconds by eye from the strip-chart

trace of the time code. "

"I know," said the colonel drily.

"We rewound the mag tape and switched the EECO 858 Time

Code Generator/ Reader to the reproduce mode. In that mode,

it accepts the time-code channel as input and visually reads out

hours, minutes and seconds on high-visibility Nixie indicators,

at any speed from one twentieth to two hundred times the

recording speed. So with the 858 and the tape deck, we had a

complete manual search system3 . Am I making myself clear?"

"As a cloudless day in May," said Colonel Walsh, "and I

hope EECO is paying you a commission."

"On the contrary,' ' I said, "1 still consider myself in debt to

them for selling us that 858. Anyway, using the 858, we re-

recorded the selected segments of the shock and vibration his-

tory onto a single tape. Then we were all set to read that tape

into the shake table any number of times. Considerably more

realistic, of course, than an artificial program at a limited

number of prescribed frequencies and g levels, or even fre-

quency sweeping."

"Why couldn't you simulate the entire burning period as

your test?" he demanded.

"We did, "I said, "on a couple of articles, just to make sure.

But it wouldn't be feasible to spend that much time on every

article. You see, we're making it part of our proposal that

every article be acceptance-tested this way."

"Mmm," said the colonel. "Miss Roundtree, please remind

me to recommend a similar procedure for critical components

in future RFP'S. "

"Yes, Colonel," Miss Roundtree said.

Steve was beaming as foolishly as a victim of anoxia. I could

see he was already mentally spending his extra-sales bonus.

When the presentation was over Colonel Walsh made the

rare gesture of standing up and shaking hands warmly as we

started to leave.

Later that afternoon Steve and I were

having a martini with Miss Roundtree in

the hope offinding out how we did. A little

underhanded, but strategically sound.

"That was an outstanding presentation,"

she told us. "The colonel was deeply im-

pressed. Especially by the shock and vibra-

tion simulation4 · Too bad you're not going to get the contract."

"We're not g-- Wha-a-a--"

"I shouldn't be telling you this, but Ajax came up with exactly

the same idea. It must be the next logical step in environmental

testing. Funny, they even used an EECO 858 Time Code

Whatchamacallit to process the tape. But their component

happens to be an ounce and a half lighter and point oh

eight cubic inch smaller than yours. Too bad.


Better luck next time."

You can't win 'em al15 ·


1 ··Frontiersman" is a figment o f our copywriter's imagination. o f course. But in reality EECO timing equipment has been used a t missile ranges throughout t he U.S. with every major missile and space program since 1951. including Matador, Bom:irc, Nike, Redstone, Atlas,Titan. Po laris, Minuteman , or you n ame it and we helped time it.

2 This compact unit generates !RIG B-format BCD time code (modified to omit days) and occupies only seven inches of rack space. You wh o have to watch the buc ks (a nd who doesn't, these days) will be happ y to know tha t an EECO 858 costs Jittle m o re than you'd expect to pay for either the generating or the reading fun ction alone.

3 By adding an 859 rape search unit, either right away or later. you can convert your EECO 858 into an automatic search system . Then all you have to do is preset the start and stop times on decimal switches. The system advances at search speed to the preset start time, then automatically switches to playback· and reads out the desired segment.

4 The application described in our story is o ne o f the latest and most interesting. but there a re hundreds o f other technical. scientific. industrial and medical uses for the 858 - wherever you need to time-mark analog data so you can lo ok it up and play it back later. D ynamic testing Jaborato ries fi nd it particularly valuable.

5 But Ajax won with the help o f an EECO 858 Time Code Generator/ Reader. So can you . Circle reader card number for fu ll information. You'll also receive FREE engineering drawing and specifications of Terrific Terri the Test Engineer. ADULTS ONLY. (Minors don' t buy much digital timing equipment.)
EE 3-79R2

Electronics July 27, 1964

Circle 7 on reader service card 7



ML-8534 Ml-8536

Same ratings .. .'/a size

~ 7 10


[~534 G~ID!PJ:~JJ

:::> 0
0 0..1.0




:::z:. 2







0 0

I- 0.1

0 .01





As UHF plate or grid pulsed amplifier

The same fast frequency stable performance-100 times faster than normalis obtained with both the miniature ML-8534 and ML-8536 planar triodes. Both tubes employ the Phormat (matrix) cathode. Both allow use of variable duty cycle operation without noticeable frequency shift. But the ML-8534 and
ML-8536 miniature planars are only 'l3 the size of the ML-7698 and permit
significant reductions in cavity and equipment size. Ratings: ML-8534, plate pulsed, 3500v, 5.0a; grid pulsed, 2500v, 5.0a. ML-8536, plate pulsed, 3500v, 3.0a; grid pulsed, 2500v, 3.0a. For complete data on miniature planar triodes, write: The Machlett Laboratories, Inc., Springdale, Connecticut. An affiliate of Raytheon Company.

Harper Q. North, newly elected president of the Electronic Industries Association, pioneered in semiconductor technology. He received his doctorate in p h y s i c s from the University of California at Los Angeles in 1947, the year before the tran; sistor was introduced. His interest in the new field led him , in 1949, to the Hughes Aircraft Co. where he initiated work on semiconductors. In 1954 he founded Pacific Semiconductors Inc., a subsidiary of Thompson Ramo Wooldridge Inc., and served as its president until 1961 when he was named board chairman of TRW Electronics Inc. Since 1962, he has b een vice president of TR,V, responsible for coordinating all research and development Away from the office, he shares his 12-year-old son's enthusiasm for baseball and occasionally h elps his 16-year-old daughter with chemistry.
John S. Sayer, vice president of the Auerbach Corp., is the principal investigator in a study of the use of scientifi c and technical information being conducted for th e Department of D efense . Sayer plans to interview 1,500 of the 36,000 technical employees of the armed services, to learn the type and use of data acquired by them. The information will then be analyzed to discover how effectively technical data is being used in research, development and engineering. Before joining Auerbach, Sayer was the executive vice president and general manager of Documentation, Inc., where he directed information processing. Previously, at E. I. duPont deNemours & Co., he headed development of critical path method scheduling.

8 Circle 8 on reader service card

Electronics I July 27, 1964

How small can a pin be?

It can be within a mere few thousandths of an inch of the outside diameter of the wire insulation. Or even less. That's the way we engineer our A-MP* Taper Pins.
Anywhere the wire fits, our pins fit. That's the kind of density that gives you the extra design space you need.
With nominal retention strength of 25 pounds, our taper pins assure peak mechanical and electrical characteristics. Even when subjected to temperature cycling of -85° F to +500° F, and being vibrated at 150 cps, 20 g accelerations, these taper pins hold fast. And they become better with age-joint resistance decreases, while joint disengagement forces increase. Combine this with a taper design that makes pins self· cleaning and self-locking and you 've got reliable performance under the toughest conditions.
Want further assurance? Check these features:
Our matched crimping tools eliminate cold solder joints, burnt and brittle insulation
Automatic application for lowest installed cost
Electronics I July 27, 1964

Pre-insulation prevents flash-over and possible shorting
One piece solid molded blocks and two piece for customer assembly
Standard configurations, 10, 20 and 30 cavities

So why look further? We have the most complete line of taper products in the industry. Pins stamped and formed, uninsulated and insulation piercing types, screw machine with insulation support and pre-insulated types. Plus all kinds of companion items, such as vertical entrance blocks, taper bus bar and taper tab blocks. Write today for complete information.

I V I r - - - - - - - - - - - - - - - - , - - - *Trodemuk ol AMP - - - 1 INCORPORATED




I ~~ I


I Harrisburg, Pennsylvania I



A- MP* products and en1ineerin1 assistance are available throu1h subsKtiary comP1nits in:

Australia · Canada · Enalarld · France · Holland · Italy · Japan · Mtaico · West Germtnr

Circle 9 on reader service card


llew from Sprague! Meetings


Research Conference on Instrumentation Science, ISA; William Smith College, Geneva, N.Y., Aug. 3-7.
UAIDE Annual Meeting, Users of Automatic Information Display Equipment; International Hotel, Sepulveda and Century Blvds., Los Angeles, Aug. 12·14.
Quantification of Human Performance Symposium and Workshop, University of New Mexico, EIA M -5.7, Subcommittee on Human Factors; University of Mexico, Albuquerque, N.M .· Aug. 17-19.

Symposium of Ultra Low Frequency Electromagnetic Fields, NBS Central Radio Propagation Lab. and National Center of Atmospheric Research; Boulder Laboratories, Boulder, Colo., Aug. 17·20.

Electronic Packaging International Symposium, University of Colorado Cahners Publishing Co.; University of Colorado, Boulder, Colo., Aug. 19-21.

The tubular polycarbonate film capacitor and the rectangular
oil-impregnated paper .capacitor are both rated 10 pF, 100 VAC, 400 cycles.
· More than 13 times smaller than paper capacitors of equivalent rating. · Unusually high capacitance stability over entire temperature range. · Low dissipation factor - extremely desirable where high current capabilities are required.
· Low dielectric absorption over a
broad frequency I temperature spectrum.
· Extremel y high insulation resistance - superior to many commonl y -used film dielectrics.
· Capacitance tolerances to ± 0.25 % .
· For critical applications such as tuned circuits, analog computers, digital circuits, etc.
For complete technical data, write for Engineering Bulletins 2700 and 2705 to Technical Literature Service, Sprague Electric Company, 35 Marshall Street, North Adams, Massachusetts.
' Spra1ue' ind ·@· ert re11stereo trademarks of th· Spraaue Eltctric Co.

Distributor-ManufacturerRepresentative Conference, WESCON; Ambassador Hotel, Los Angeles, Aug. 24.
AIAA/ ION Astrodynamics Guidance and Control Conference, American Institute of Aeronautics and Astronautics. Institute of Navigation; University of California, Los Angeles, Aug. 24-26.
Ai!.-.>Ciation for Computing Machinery Annual Conference, ACM ; Sheraton Hotel , Philadelphia, Aug. 25-27.
WESCON 1964. 6th Region IEEE and Western Electronic Manufacturers Assoc.; Los Angeles Sports Arena and Hollywood Park, Los Angeles, Aug. 25·28.
International Conference on Microwaves, Circuit Theory and Information Theory, Inst. Electrical Comm. Engrs. of Japan: Akasaka Prince Hotel, Tokyo, Sept. 7·11.
International Exhibition of Industrial Electronics, Swiss Industries Fair; Basel , Switzerland, Sept. 7-11.
International Convention on Military Electronics (MIL-E·CON-8), IEEE; Shoreham Hotel, Washington, Sept. 14-16.
Operations Research Society Annual International Meeting, Western Section of ORSA, ORSJ , University of Hawaii; Sheraton Meeting House and Princess Kaiulani Hotel, Waikiki, Honolulu, Sept. 14·18.

Ceramic-To-Metal Session, America n Ceramic Society. Philadelphia, Sept. 17.
Annual Northwest Computing Conference, Northwest Computing Association, University of Washington Computing Center; University of Washington , Seattle, Wash . Sept. 17-18.
Engineering Management Annual Conference, IEEE-ASME; Pick-Carter Hotel, Cleveland, Sept. 17-18.
AIAA Military Aircraft Systems and Technology Meeting (Secret), AIAA, USAF, and BuWeps; NASA-Langley Research Center. Va ., Sept. 21-23.
Professional Technical Group on Antennas and Propagation International
Symposium, PTGAP I IEEE; International
Hotel, John F. Kennedy International Airport, N.Y., Sept. 22-24.
Annual Communications Conference, Cedar Rapids Section of IEEE; Hotel Roosevelt, Cedar Rapids. Iowa, Sept. 25-26.
Canadian IEEE Communications Symposium, Canadian Region IEEE; Queen Elizabeth Hotel, Montreal, Sept. 25-26.
Call for papers
Allerton Conference on Circuit and System Theory, Universitv of Illinoi s, CTG/IEEE ; Allerto~ H ouse, Conference C enter of U niversity of Illinois, Monti cello, Illinois, Sept. 28-30. August 15 is deadline for submitting 100 \Vorel abstract to
W . R. Perkins , D ept. of Electrical
Engineering, University of Illinois, Urbana, Ill.
Tri-Service Conference on Electromagnetic Compatibility, U. S. Army, Navy, Air F orce; Museum of Science and Indu stry and Ill inois Institute of T echnology, Chicago, Nov. 17-19. August 15 is deadline for submitting 150 word abstract to IIT Research In stitu te, 10 W . 35th St., Chicago. Papers are invited on interference prediction, equi pmen t design, instrumenta tion, measurement techniques, interfe rence reduction measurements, etc.

10 Circle 10 on reader service card

Circle 11 on reader service card-+

Hewlett. Packard sweepers that demand comparison ···

in the complete hp 690 Series Sweep Oscillators ····




POWER (maximum leveled
across band)

ACCURACY (center


691B 692B H01-692B 693B H01-693B 694B H01-694B 695A 696A 697A

1-2 2-4 1.7-4.2 4-8 3.7-8.3 8-12.4 7-12.4 12.4-18 18-26.5 26.5-40

at least 60 mw at least 40 mw at least 15 mw at least 15 mw at least 5 mw at least 10 mw at least 5 mw at least 10 mw at least 10 mw at least 5 mw

±10 me ±10 me ±10 me ±20 me ±20 me ±30 me ±40 me
±1% ±1% ±1%

$3550 ° $3350° $3650* $3350° $3650* $3450 * $3750* $3500 $4500 $6500

Option 01: Internal leveling, 691B/692B, $325; 693B, $375; 694B, $400 extra.


Data subject to change without notice. Prices f. o. b. factory

Designed with you in mind · . . that's why the hp 690 sweep oscillators offer a unique combination of features to simplify and increase the dependability of your measurements. Now these user-designed features are available to 40 gc. The "extras" (not duplicated in other similar instruments) range from exclusive PIN diode leveling and modula· tion to such convenience exclusives as easy x-y recording capability, outstand ing marker visibility; and the instrument, only 8 %" high, fits right into your test stand.
Mu ltiple Sweep Modes
Independent sweep modes for unparalleled versatility:
Start-Stop Sweep: Set end points anywhere in the frequency range on slide rule scale. Sweep up or down just by pushing the Start-Stop button. Markers appear on rf output.



Electronics I July 27 , 1964

··· compare the details with any and all other sweepers!

Marker Sweep: Expand any small area of the major sweep merely by setting independent Marker controls and push ing the Marker Sweep button. End points set on error-free digital readouts. Sweep up or down the Marker range. Delta F Sweep: A symmetrical sweep about a center frequency ... useful for calibrating narrow band devices. Just press the !:::,. F button , and get the industry's only accurately-calibrated narrow sweeps.
Manual Sweep: The 690' s are the only sweepers offering Manual Sweep for detailed investigation of a localized area. For x-y recording tedious setup t ime becomes a thing of the past.
Sweep Speeds
With Sweep Selector in Automatic, the 690's provide recurrent sweeps, continuously adjustable in 4 ranges, 0.01 to 100 seconds. Or you can sync the sweep with line frequency.
For scope presentation , output power, on except during retrace, offers a zero baseline and eliminates transients at the start of a sweep. Automatic pen lift circuit on two slowest speeds permits easy x-y recorder use. Sweep voltages for both scope and recorder are provided concurrent with swept rf.
Modulation, Leveling
Pushbutton selection is standard for external AM or FM or internal square wave modulation, 950-1050 cps. PIN diode modulators are offered in the more popular " B" models. By

absorbing rf in response to the modulating signal they end frequency pulling and other troublesome effects associated with BWO grid modulation.
Two leveling options are offered: external closed loop, which eliminates transm ission line problems and delivers leveled power where you need it, or internal leveling for less critical ap· plications. Maximum usefulness of leveling capabilities is demonstrated in your ability to use reflectometer techniques with· out the conventional ratiometer. For more information on
ratio-meterless reflectometry write for Application Note # 61.
Models listed in the chart include three standard extendedrange instruments for special but popular applications. " A" models differ from ·" B" models only in the elimination of the PIN modulators, slightly increased power output and lower price. Other models with special ranges are available for narrow sweeps or different frequency breaks. All tubes have 2500 hour warranty through 18 gc. The specified accuracy of each model in the 690 Series covers all sweeps, plus rf output in CW mode.
You'll want to put all the capabilities of the hp 690 Series Sweep Oscillators to a rigorous test on your bench . Call your Hewlett-Packard field engineer. He'll make it possible. Or write Hewlett-Packard Company, Palo Alto, California 94304, Tel. (415) 326-7000; Europe: 54 Route des Acacias, Geneva ; Can· ada: 8270 Mayrand St., Montreal.

I Electronics July 27, 1964


Fairchild introduces aunique line of general purpose Zener and reference diodes



6.2V to 33.0V
· Low impedance · Low voltage tolerance · Low leakage at voltages
approaching breakdown level
· Silicon Planar Reliability

*Multi-Current Range

Lo111JC: from lmA to 15mA
· Wide operating current range · Low leakage: 200nA@3.0V,25°C max · High reliability-Silicon Planar · single-chip construction

· Low impedance: 10 ohms


This unique new Fairchild family of Multi-Current


Range reference diodes offers the enginee r new de·

sign freedom . The broad operating cu rrent range

· Wide variety of operating voltage ranges

al lows the designer to select a device which meets

specific circuit requireme nts-rathe r than design a

circuit around available device characte ristics. Low , nearly constant TC allows a sing le off.the-she lf


Fairchild M-CR type to meet many different design

requi rements. Also, cu rrent supply amplitude is no

longe r a critica l design factor.

· Low dynamic impedance

· Low leakage near breakdown voltage


· Variety of packages
Fairchildtemperaturecompensated voltage refe rence
elements provid eawidevariety of reference voltages
with th eadva ntages of red uced instal lation time and


Low TC over wide temperature range
· Low dynamic impedance at 1001..tA · Low leakage at biases approaching · reference voltage


cost, reduced space, and simplified circuit design. Packaged in T0-18, T0-5 or custom epoxy packages, they also offer high thermal and shock resistance.


These single-chip Sil icon Planar devices are temper· ature compensated voltage reference elements

especially designed for applications in which avail·


able power is limited.

3[ T£.>::; 3

AVNET Toronto, Canada, 789-2621 BOHMAN Orlando, Fla., 425·8611 CRAMER ELECTRONICS Newton, Mass., WO 9-7700 DART SALES Clarence, N. Y., 874·1212; Syracuse, N. Y. , GL 4·9257 DENNY-HAMILTON San Diego, Cal., 279·2421 EASTERN SEMICONDUCTOR Syracuse, N.Y., 454·9247 E. C. ELECTRONIC SALES Minneapolis, Minn .. 888-0102 ENSCO Cedar Rapids, la., 366-1591; Wichita. Kan ., MU 3·3751; Kansas City, Mo., EM 1-9600; St. Louis, Mo., PA 6-2233 HAMILTON Phoenix, Ariz., 272·2601; Culver City, Cal., 870-0236; Pa lo Alto, Cal., 321-7541; Seattle. Wash .· 282-3836 HYER Englewood, Colo. 761·0754; Albuquerque, N. Mex ., 268-6744; Salt Lake Ci ty, Utah, 322-5849 MARSHALL Scottsdale, Ariz .. 946-4276; San Marino, Cal .. MU 1-3292; San Diego, Cal., BR 8·6350; Redwood City, Cal., EM 6·8214 NORVEll Dallas, Tex .· FL 7·6451; Houston, Tex., MO 5·0558 POWELL Beltsville, Md., 474·1030; Philadelphia, Pa .. 724·1900 SCHLEY Watertown. Mass ., WA 6·0235 SCHWEDER Westbury, L.1., N.Y., ED 4.7474 SEM I CON· DUCTOR SPECIALISTS Chicago, HI., 622·8860: Minneapolis, Minn ., UN 5.3435 SHERIDAN Cincinnati, Ohio, 761-5432; Cleveland, Ohio, 884-2001; Dayton, Ohio, 277·8911 SOLID STATE Chicago Ill., 889·8033 STANDARD Buffalo, N.Y.. TI 3-5000 TAYLOR Baldwin, L.I., N.Y., BA 3-8000 TEC-SEL Huntsville, Ala .. 534·7304 VALLEY Winter Park , Fla ., 647·1216; Baltimore, Md., NO 8·4900; Cherry Hill, N.J .. NO 2·9337.
HUNTSVILLE, ALA . 536-4428, 4429 SCOTISDALE , ARIZ . 946·6538 PALO ALTO , CAL 321-8780 SHERMAN OAKS , CAL. TR 2·1380; ST8-8701 ENGLEWOOD, COLO. 761·1735 ORLANDO, FLA . CH 1·2596 OAK PARK , Ill. VI 8·5985 COLLEGE PARK , MD . 779-6868 BEDFORD, MASS . 275-8450 MINNEAPOLIS , MINN . UN 6·3301 ENDWELL , N.Y. 754-2600 JERICHO, L I. , N.Y. ED 4·8500 POUGHKEEPSIE , N. Y. 454·7320 SYRACUSE, N.Y. GR 2·3391 DAYTON, OH IO 228·1111 JENKINTOWN , PENN . TU 6·6623 SEAffiE, WASH. AT 2-5344 CANADA OFFICE : TORONTO, ONTARIO 782-9230.




14 Circle 14 on reader service card

Electronics I July 27, 1964

Electronics I July 27 1964

Commercial road for electronics

To diversify or not to diversify? That's the burning question for many suppliers of military electronics.
For those who realize that the answer is "yes" but wonder how to go about it, a measure of help is coming. The Research Institute of the Illinois Institute of Technology, together with Electronics magazine, will sponsor a conference Dec. 1 and 2 in Chicago on "The 'commercial road for electronics". More on this later.
For those who haven't yet decided that they should diversify the arguments continue to pile up on the affirmative side. In mid July, Business Week magazine (July 18) estimated that military procurement would continue to decline 4% a year for the next five years. That's a total slash of close to 15% from current levels, which are already making some electronics companies unhappy-currently military procurement is off $1.8 billion.
If suppliers are to replace this sales volume, it's clear that they'll have to find other markets.
On the other hand, some military suppliers are so used to doing business with the government that they don't know how to get started in other markets. They don't know how to develop commercial products, how to manufacture them, or how to market them.
Early in July, the American Management Association held a conference to investigate conversion of military industry and featured some speakers from the Pentagon. Most of the attendees' purpose in coming seemed to be to find out whether any m4litary contracts were up for grabs. ,They wouldn't even listen to urgings that they start making plans to diversify.
Obviously, management that won't even listen to talk about diversification isn't going to diversify. You can preach until your are blue in the face about responsibility to employees, the community or national economy, but they won't budge.
We feel strongly that suppliers of military electronics should diversify as fast as is consistent with good business practice.
The electronics industry can never be strong as long as it is built on the shifting sands of government procurement. Companies cannot plan their product planning, their engineering or their production as long as their businesses can be wiped out by a whim of a bureaucrat or of Congress.
For a company that does want to diversify, the big question is, "How?"
There are many pitfalls fo r the company and for the individual. Is it possible to retrain an engineer who has spent all of his professional life working on military projects? Can such an engineer-accustomed to complex solutions, damn-the-cost engineering, and way-out-technology thinking-convert to simple, straightforward engineering that uses inexpensive, reliable components and touches advanced technology sparingly?
There are no answers yet. But the December conference may offer a few.
Conference speakers will not discuss whether to diversify. They'll be operating on the assumption that listeners want to diversify and are anxious to learn how. There will b e four sessions: product planning, engineering, manufacturing and marketing. All will present information of th e how-to type.
For example, in the session on product planning, one speaker will compare product planning for military business with product planning for commercial markets. Others will discuss how to plan in consumer, industrial and medical electronics.
As plans for the conference crystallize we'll keep you informed.


These silicon planar transistors are under a quarter*

+ 22V
(2 ma~
- Cartridge capacitance:
1,000 ta 10,000 pf Phono Preamp for Ceramic Cartridge
(Velocity Response · RIAA Equalization l.

0 .1











r - .006




All d1v1ders ident ical to first divider

Moster Oscittotor and. Frequency Dividers .

Type 2N2926 offers 2 to 1 beta spread, tight parameter control, high reliability

The new G-E 2N2926 is a planar passivated, high performance, high value silicon transistor made possible by advanced manufacturing techniques, highly reliable encapsulation, and utilization of the full-line distribution of h10 ·
The 2N2926 is a type provided in 5 beta categories , each with a 2-1 beta spread. Each beta category is color coded, and the per cent of the total order shipped in each category is set.
The 2N2926 is only one of the growing number of types in our "Economy Line" of transistors. Millions of units in use in the field for over two years have proven them rugged and reliable. They are probably the toughest transistors made today.
Find out how you can enjoy high performance with real savings by designing equipment utilizing all 2N2926 beta categories in proportions compatible with this "full line distribution" type. See your General Electric District Sales Manager, or write Section 16G166~. Semiconductor Products Department, General Electric Company, Electronics Park, Syracuse. New York. In Canada: Canadian General Electric,

189 Dufferin Street, Toronto, Ont. Export: International General Electric, 159 Madison Avenue, New York , 16 N. Y.
0 22¢ in 100,000 quantities; 24¢ in 10,000 quantities.


Collector to Emitter Emitter to Base
Collector to Base Current
Collector (Steady State) · Dissipation
Total Power (Free air at 25°C) .. Total Power (Free air at 55°C) .. Temperature

Vceo VEBo Vc10
Pr Pr



5 18

v v







-30 to + 125°C +100°c

Ct Oetermined from power limitations due to saturation volta ge at this current.

0 ·0erate 2.67 mw/°C increase in ambient temperature above 25°C.


16 Circle 16 on reader service card

Electrontcs I July 27, 1964

Electronics Newsletter

July 27, 1964

Around-the-world Scratch another missile project. Project Pluto, the Air Force-Atomic

missile project dies

Energy Commission program for a nuclear ramjet engine, is dead. Pluto was intended to develop a unique missile capable of around-the-world

Hight at speeds up to 2,000 miles an hour. To avoid radar detection, the

missile would have flown to its targets at low altitudes and, presumably,

been guided by terrain-following radar and other advanced electronics


The AEC on July 13 ordered its Livermore, Calif., lab to close down

the reactor development and test effort, ''because of a lack of a firm

military requirement" for the missile. The end came when Defense

Secretary Robert S. McNamara vetoed the recommendation of a Depart-

ment of Defense review group for a minimum Hight-test program. The

Pentagon wouldn't pay for Hight tests. As of July 20, McNamara hadn't

ordered contractors to stop work, hut he was expected to do so at any

moment. Contractors are Ling-Temco-Vought, Inc., for the airframe, and

the Marquardt Corp., for the engine.

Since 1956, the AEC and the Air Force had spent some $200 million on

the program. Ling-Temco-Vought's latest contract involved $12 million

for the year ending September 30.

Three computers run steel mill

The most sophisticated computer network for production control is now operating on-line at the Park Gate Iron & Steel Co., Rotherham, England. The network links three digital computers supplied by English ElectricLeo Computer Ltd. One computer controls the others to produce steel products tailored to the customers' specifications. The system is part of an $88-million facilities development that will step up plant output from 425,000 to 800,000 ingot tons a year.
The English Electric Ltd.'s Metals Industries division coordinated all the electronic systems. The control system includes three KDN2 computers, two with 8,192-word memories and one with a 4,096-word memory. Cathode-ray-tube tabular displays for operator information were supplied by Marconi Ltd. and a solid-state voice communications system was supplied by Marconi International Marine Ltd.
One computer directs over-all plant operations from orders to finished steel. The second is an on-line unit that controls reheating the steel billets and forming and cooling them. The third controls the Hying shear that cuts the steel to the ordered length. A major advantage of interconnecting the computer operations is reduction of waste in the cutting

Flatpack standards After almost a year of work, the Electronic Industries Association's

are nearly ready

microcircuit applications committee is about ready to propose an industry standard for microcircuit packages.

The committee is expected to propose a series of packages ranging in

body area from 3/8 inch square down to 3/16 inch by 1/4 inch, with a

total of 10 to 16 leads on two opposing sides. The standard may be

refined further to specify the dimensions between usable lead areas

instead of body size.

Still undetermined is whether the committee will also propose a series



Electronics Newsletter

of Hatpacks, ~ inch square to % inch square, with a total of 12 to 24
leads on all four sides.

Ion propulsion works in space

The National Aeronautics and Space Administration operated an ion-

propulsion engine in space on July 20. It was the first announcement of a

successful test Hight of an ion e11-gine. The Air Force tried one, unsuc-

cessfully, at least 20 months ago [Electronics, Dec. 28, 1962, p. 8].

The test proved that the ion stream can be neutralized with electrons

after it passes accelerator electrodes. The ions did not flow backward

and reduce thrust. Nor did spurious radio-frequency signals swamp

the command system.


Two small ion engines were sent aloft on a rocket. One, built by

NASA's Lewis Research Center, was turned on and off several times. The

other, built by the Hughes Aircraft Co., failed to operate, apparently

because of short circuits in its power supply.

Similar small battery-powered ion engines can be used to adjust

positions of satellites. Large systems, with nuclear-electric power

sources, could make satellites maneuverable and propel interplanetary-

range spacecraft. The first test of a nuclear-powered ion engine will be

made early in 1965 by the Air Force. Electro-Optical Systems, Inc., is

developing the engine.

Tropo conquers a mountain

The 128-mile Philippine radio link between Manila and Baler, terminus of the new Pacific telephone cable, will be a series of microwave hops and one unusual 78-mile tropo circuit. To span the mountains in the path, Radio Engineering Laboratories, Inc. will supply to General Telephone & Electronics International, Inc., a I-kilowatt, 2 gigacycle tropo system that will be beamed at the ridge and diffracted over it.

GE gets computer allies in Europe

The General Electric Co. has now carved a foothold for its computer business in all three major European market areas. It has just reached a manufacturing and design licensing agreement with Associated Electrical Industries Ltd. Associated will make and sell the GE/PAC 4000 computer in England.
Allgemeine Elektricitats-Gesellschaft will be supplied with GE 412 computers for installation in German steel plants. In France, General Electric is negotiating a deal to buy into La Compagnie des Machines .Bull [Electronics, May 4, 1964, p. 36].
One of the new, and unexpected, results of l'affaire Bull is the formation of a joint subsidiary by two French electronic giants. DeGaulle's government had asked the Compagnie Generale d'Electricite and Compagnie Generale de Telegraphie sans Fil to save Bull's slipping computer business. Then although neither company had been very active in computers before, they put together a subsidiary that will concern itseli with computers and industrial electronics equipment.

Sylvania sells its twt production line

Sylvania Electric Products Inc., is Ketting out of the traveling-wave-tube business. The company, a subsidiary of General Telephone & Electronics Corp., is selling its twt operation in Mountain View, Calif., to the Microwave Electronics Corp., of Palo Alto. Sylvania will continue its klystron production and its other microwave tube lines produced at Williamsport, Pa.


Electronics I July 27, 1964

Unitrode trouble spots

(1) Void in conventional diode becomes contaminated

(4) Delicate construction increases chances of faulty

by trapped impurities, degrading diode characteristics.

assembly - loose solder balls, doub le whiskers, flaking

Unitrode"' diodes have no void - the silicon dice is

gold, defective glass seal, distorted elements. One-piece

high-temperature bonded directly between the terminal

Unitrodes are so simplified, t roub le-free and rugged that

pins, and hard glass is fused to all exposed silicon.

cha racteristic readings do not change through all

Electrical performance is fixed, permanently. And because

MIL-S-19500 environmenta l testing ... and performance

they're simpler, Unitrodes are smaller ... in fact.

will not deteriorate throughout a long service life.

this small:

This kind of reliability has to cost a little more - but it's

(2) Whisker can be burned out by surges, and contacts
broken by vibration. Unitrodes have no whisker - their broad contact surfaces withstand continuous 10-watt power overloads, thermal shock and cycling from -195°C to+ 300°C.

essential for electronic packages that require all the
performance possible in the sma ll est space. Allow our
representative a few minutes to demonstrate the entire
Unitrode line of diffused 3-ampere si licon diodes, fast switching rectifiers, 3-watt zeners, high voltage stacks and bridge assemblies, and ask him for the

(3) Exposed silicon dice can easily be tipped, cracked or

Unitrode Reliability Manual. Just write or call ...

contaminated in assembly. The Unitrode dice -

UNITRODE CORPORATION, 580 Pleasant Street,

sandwiched between terminal pins and sealed in

Watertown, Massachusetts 02172. Te l : (617) 926-0404,

hard glass - is practically invulnerable.

~x, (617) 924-5857.

Electronics J Ju ly 27 , 1964


Circle 19 on reader service ca rd


Our first Microglass diode customer came in a helicopter

The MICROGLASS diode was still · secret. But somehow word leaked out.

So, lo and behold, one sunny morning a helicopter landed at our front door. Out popped our first customer - eager for more information.

He was sworn to secrecy. And given the MICROGLASS story.

There was only one thing that we couldn't then provide : life test data. But

now we can . Today MICROGLASS diodes have successfully completed sev-

eral thousand hours on extended life tests under military standard conditions.

Write for further information: Hughes Semiconductor Division, 500 Superior Ave ., Newport Beach, California. Or just phone. You needn't come in a helicopter.





IL __________________ JI



Electronics I July 27, 1964

_, G



Min . Bv
@ IOOµA (volts)









75 @ 5µ A



75 @ 5µA






50 @5µA



50 @ 5µ A



50 @ 5µA









@ 25 ' C @ 150' C @V


(µA) (volts)































MAX . CAP @ OVolts
3 2 2 2 2 3 2 2 2 3





















S -S




S -S










S -S


S -S




S -S






S -S



Max . Time (nsec)
2 2 2 2 2 2 2 2 2 2

#Additional Reverse Recovery Parameters Which are Guaranteed are : Conditions It = lk from lOmA to 200mA Recovery Current= .lit Recovery Time ::;; 4 nsec


D0 -7

Silver Clad Nickel Leads

Silver Leads

Ribbon Leads



Power Dissipation (mW )







Av erage Rectified Forward Current (mA)



Forward Surge 1 sec (amps)











Forward Surge l µ sec (amps)



4 .0


4 .0

4 .0

Temperature, Storage

-65 C to 200 ' C

Temperature, Operating (ambient)

- 65 C to 200 c

Temperature. Cycling (-65 ' C to 200 CJ Method J05 2 MIL-STD -750
Constant Acceleration. Method 2006 MIL -STD -750
Shock. Method 2016 (1 .5 msec ) MIL -STD -750
Shock . Method 2016 (.5 msec) MIL -STD -750
Shock, Thermal (-65 ° to 200' C Instant Transfer) 5 cycles - J minute dwell
V1brat1on . ( 100 to 2.000 cps) M ethod 2056 MIL-STD -750
Vibrat ion . Fati g ue (60 cos ) M eth o d 204 6 MIL-STD -750

24 Cycles 30 .000g
l ,OOOg !.500g 5 Cycles
30g 20g

H erm eti c Sea l Test (Dye Bomb JOO PSI )

24 Hours

Lea d Ten s io n , Method 203 6 MIL -STD -750

10 lbs

JO lbs

JO lbs




NOTE : Gl as s -Ambient Junction Diodes have exceeded the op erating and storage life test conditions of MIL S 19500/J J6A and MILS J9500 /1 44 :
J,000 hrs Operating Life I, = 50mA LTPD JO J,000 hrs Storage Life = 200 ' C LTPD 10
MICROGLASS diodes a·re .065 '' round x .050 " long. Leaded versions: silver and nickel leads are .020 " round x 1.36" long, ribbon leads are .025" x .003 " x 0.70 " .

Electronics J July 27, 1964

Circle 21 on reader service card 21

DIGITAL MODULES are available from stock in two sets of fully compatible resistortransistor logic circuitry-for bit rates up to 200 kc; for bit rates to 1 Mc. More than a dozen types include: 4-input NOR · Counter Shift Register· Power Inverter· Emitter Follower · Complementary Driver · Differential · Filter (Decoupler)

How's this for digital density!

Compact new logic modules combine flexibility, reliability and economy

Radiation Logic Modules can be used in any configuration, type or number compatible with your digital system requirements. They can be mounted in vertical or horizontal drawers, in standard 19" racks, or on breadboards ... fixed or removable. Because of their compact modular construction, packaging densities up to 137 modules per inch of panel height can be achieved in standard racks. There's no need for design compromise.
RELIABILITY Superior engineering and rigid component selection assure highest reliability: based on extensive tests, MTBF for low-speed NOR Modules exceeds 2,940,000 hours! The units are also packaged for rugged use. Constructed of welded circuitry molded in epoxy and mounted with high-density module connectors on cast aluminum frames. The resulting positive-contact units measure only 0.4" x l" x 1.1" with a 0.25" pin protrusion.


Circle 22 on reader service card

ECONOMY Each module represents a fraction of the entire digital system. Each is designed for easy interrogation. Change or replacement is as simple as plugging in another unit. Thus, expensive downtime is reduced, costly benchwork completely eliminated. APPLICATIONS ASSISTANCE Radiation offers the services of its engineering staff in the application of digital logic modules, or in helping solve your unique data problems. Write or phone for technical data sheets. Radiation Incorporated, Products Division, Department EL-07, Melbourne, Florida. Telephone: (305) 723-1511.


Part Number Description

Unit Price

503815Gl NOR-Medium Speed

$ 10.38

503816Gl NOR-Low Speed


503818Gl Power Inverter-Low Speed


503818G2 Power Inverter-

Medium Speed


503819Gl CSR-Low Speed

8 .82

503819G2 CSR-Medium Speed


503819G3 CSR-Medium Speed


503820Gl MSMV "B" Side


503821Gl Diff (MSMV "A" Side)

9 .68

503834Gl Filter (Decoupler)


503860Gl Campi. Driver-Low Speed 12.55

505694Gl Diode Gate


505703Gl DI A Converter


505704Gl Indicator Driver


506030Gl CSR-Ml


507318Gl Emitter Follower-Low Speed 7.29

507318G2 Emitter Follower-

Medium Speed


508334Gl-G8 Octal Patch

4 .20

508335Gl-G2 Jumper Patch

4 .84

508367Gl 5 Volt Reference


508517Gl Module, Special Component 13.62

509050Gl Indicator Driver (Negative

Coincident Input)


Specifications and prices subject to change with· out notice due to technological advances. Delivery, discount schedules and additional pricing information available upon request.

Electronics I July 27, 1964

Exposed view shows accessibility of components in the Chatham Model R24-10R3 GSE highly regulated, multiple output power supply

Chatham Power Supplies and Frequency Changers for instrument and systems applications are custom-designed with a background of sophisticated experience in the development of ground support equipment. Chatham can deliver the total power supply requirements of any customer, with parameters, circuit requirements and configuration tailored to any set of conditions. Performance


can be held to any commercial requirement, or as tight as MIL-E-4158, MIL-E-8189 or MIL-E-16400 and tighter if the need requires. Design and production capabilities are backed by Chatham's environmental, physical and functional test facilities which are equalled by only a very few independent testing laboratories. Write for complete technical information about Chatham Power Supplies.


LIVINGSTON, N. J. TWX: 201-992-7350


Electronics I July 27, 1964

Circle 23 on reader service card 23

23,000,000 unit hours reliability of commercial

An extensive testing program has shown that commercial capacitors of "Mylar" * are very reliable and readily available from a number of suppliers. Capacitors from six manufacturers had a predicted life of 30 million hours between failures, based on average-size capacitors of' 'Mylar" used in radio and TV circuits.
Du Pont commissioned Inland Testing Laboratories of Cook Electric Company to conduct the reliability testing. The purpose of the tests was to answer these questions, " How reliable are capacitors with 'Mylar' as the dielectric?" and "Are they commercially available?"
The test involved 3,700 capacitors of varying constructions produced by 15 capacitor manufacturers from two
'DuPont 's registered trademark for it s polyest er f ilm .

randomly selected lots of "Mylar", plus 4,000 laboratorywound capacitors produced by Du Pont from 14 randomly selected lots of "Mylar". Large one-half microfarad units were used so that the area of film tested was equivalent to that of 100,000 tubular capacitors of the average size typically found in radio and TV circuits .
Twenty-three million unit hours of testing showed t hat very reliable capacitors of"Mylar" are commercially avai lable. Of the commercial units tested, those from six m an ufacturers had an average failure rate of less t han 0.033 per 1,000 hours , at rated voltage stress, of 800 V DC/mil. In terms of smaller capacitance units, usu ally found in radio and TV circuits , this failure rate can be extrapolated


Electronics I Julv 27. 1964

100 80



.r l~.O f----r---t-~'- ·!-+- - - - ---I
·o J---!---1--.,.~·,,.,_.c.....; -----~

20 f---1---l--4j~__,_ _ _ _ ___j

Io I

; 1,Y"'"c' o" Mm

B 4




~: :,~t-+-----__j

,..i.,,.j I

as·c 0 . 1 i---+--1--~....



;!. 0 5 mid.. 400 WVDC rated ~.::~a:.~:~y~s~: :.~~c

,,. o· l----l---1--41.-_,

" : °

82umts / mfr uch11oltage

1 1 --1--1---.'--'-l-4 300 Ou Pont umh each voltage.



0.01 ..___.__1--.._._ _.__ _ _ _ __,
I00 200 400 800 I000 2000 \IOlTAGE STRESS, VOLTS/ MIL

Average failure rate of V. microfarad units of six manufacturers was less than 0.03% per 1,000 hours-almost equal to the 0.023 rate of the Du Pont laboratory wound units. A valuable byproduct of this test was spotlighting effects of other materials which adversely affected performance of some capacitors. Full details of the test are available. To get your copy, use cou· pon below.

==:...- ~·
Commercial capacitors on test racks at Inland Testing Laboratories of Cook Electric Company in 23 ,000,000 unit-hour Du Pont reliability test.
of testing prove the capacitors of MYLAR®

to 0.0033 or 30,000,000 hours between failures. When a lower voltage stress is used to obtain extra-high reliability, the failure rate can be extrapolated to less than 0.00013 per 1,000 hours.
Other significant and interesting results of the test are included in a comprehensive report which we would like to send you. It will provide data which can help you use low-cost, reliable and space-saving capacitors of "Mylar" . For your copy, simply mail the coupon at right.

~ ~ H. u . t. ,ATO"

only DU PONT makes

Ir-- ---------- - ------------- 1 E. I. du Pont de Nemours & Company (Inc.)
I Film Department-N 10452 B-22 I Wilmington, Delaware 19898

I Please send me the reliability report.

I Name ____________Title ______ I

I Company_________________~


Address ___________________


City_________State_____Zip ____

: Potential Application_____________

Electronics I July 27, 1964

Circle 25 on reader service card


CLARE Stepping and Cam Switches provide millions of steps with minimum maintenance. They are capable of handling extremely complex switching, counting, totalizing, selecting and sequencing operations. Special wiper configurations, shorting together all but one point in a level or leaving alternate points unshorted, are available.
Mechanical life of Clare Spring-Driven Stepping Switches ranges from 50,000,000 operations for switches with from 13 to 16 levels to 280,000,000 operations for from 1to4 levels. Cam switches range from 10,000,000 operations for switches with eight cams to 30,000,000 operations for two-cam switches.

Increased capacity of Clare stepping switches stems from a design which permits not only more levels per switch ... but more levels in less space. For instance, the Clare Type 26 switch can provide twelve 52-point levels within a height of 4 -11/16 in. This is but 11/16 in. higher than a comparable 52point switch of eight levels. This compactness often allows more simplified circuitry when a single Clare switch can do the job which otherwise might require a multiple switch assembly.
) For Complete Information on Clare Stepping
and Cam Switches · S end for Clare Manual 601

'Electrical and Mechanical Characteristics of Spring Driven Stepping Switches and Cam Switches

210 211 20 ·26 200


Points per Level

Levels Points (max) (max)

10, 20 or 30



11, 22 or 33



20 or 40



26 or 52



.Up to 8 cams with up to 6 contact springs per cam and 30, 32 or 36 steps per revolution

Operating Speeds



Interrupt impulse

60 steps per second at nominal

30 steps per second at nominal
voltage with 663 "on~~!bme;

Nominal voltages and
Coil resistances
6, 12, 24, 48, 60 and 110 vdc
1.5-600 ohms

ENCLOSURES : Hermetically-sealed enclosures or dust covers, with solder terminals or plug connectors, are available for all Clare Spring-Driven Stepping and Cam Switches.

Address: Group 7N6 C. P. Clare & Co., 3101 Pratt Boulevard, Chicago 45, llllnols . Cable Address : CLARELAY. In Canada: C. P. Clare Canada Ltd . , 840 Caledonia Road, Toronto 19, Ontario . In Europe: C. P. Clare, Ltd ., 70 Dudden Hill Lane, London NW 10, England.
Relays and related control components


Circle 26 on reader service card

Electronics j July 27, 1964

July27, 1964
Electronics Review Volume37 Number21

Instant radar maps
A display tube that will instantaneously show what an aircraft's side-looking radar sees is being developed for the Avionics Laboratory at Wright-Patterson Air Force Base, Ohio. The tube is, in effect, a real-time motion-picture machine.
Side-looking radar, unlike con,·entional radar, scans the ground line by line as th e plane passes overh ead. This scanning method produces a strip map with a resolution almost as good as in aerial photography [Electronics, Mar. 22, 1963, p. 22).
'Vhat the radar sees can be captured by a movie camera. This is fin e for later analysis , but it isn't a real-time display. The radar strip map can also be synthesized in real time by a scan converter and a cathode-ray tube, but this arrangement is bulky, and space in a military aircraft is at a premium.
Erasable film. The new display tu be, being developed by the Raytheon Co., is called a travelingimage storage tube. It looks like the blade end of an oar. Inside the evacuated tube is a belt driven by a slow-speed vacuum drive. The belt passes the viewing glass of the tube at a speed set by the aircraft's speed and altitude and by the pulse-repetition frequency of the side-looking radar.
The side of the belt that the radar operator sees is coated with a photosensitive material (Scotophox). When this material is swept by an electron beam containing the radar video information, a moving picture of the radar video is displayed. After the belt moves past the viewer, infrared light erases the electron-excited image.
The tube will display five shades of gray and will be readable even in broad daylight.

After slurry is poured into mold, it will rise like yeasty bread dough.
Ceramic that foams
A potting compound that cures at 150° F and then protects electronic circuitry from temperatures up to 2500° F? It's true. A ceramic foam that will do just that has been developed at the National Aeronautics and Space Administration's Goddard Space Flight Center in Greenbelt, Md.
Ceramic foams have been used before to protect circuits. But almost invariably they require high curing temperatures and must first be foamed, then shaped to fit around the circuit. Another alternative is filling the package with tiny ceramic or glass beads.
Because of its low curing temperature, Goddard's ceramic composition can be poured directly into the package. It is applied as a slurry, then foams in place at about the same rate as yeasty bread dough. Goddard developed the foam to protect satellite electronics from the heat of nuclear power sources.

Mixing and curing. Inorganic ingredients are used for the slurry. Typical proportions are: orthophosphoric acid , 31 grams ; aluminum hydroxide, 30 gm; bentonite, 1 gm; aluminum meta-phosphate, 6.5 gm; silicon dioxide, 1.2 gm; and metal powder, 0.15 gm.
The dry ingredients are mixed, then blended slowly with the acid. Vigorous stirring produces a chemical reaction that creates water of hydration, changing the mixture into a slurry.
The slurry is then poured around the circuit in a mold lubricated with silicone fluid . It takes about 30 minutes for the compound to become fully foam ed.
If held at a temperature of 85° C, the compound cures in about eight hours. Raising the temperature to 150° C after two hours will speed the curing.
Varying density. Density of the foam can be varied in three ways:
· By varying the amount of slurry poured into a covered mold. The cover constrains the foam. The more slurry used, the smaller the cell structure will be, raising the density of the foam.
· By varying the size of the metal powder. Large particles cause large bubbles to form, lowering the density. Cell structure, however, is irregular.
· By varying the amount of metal powder.
Porosity can be varied from 5% to 90%, and density from 19 to 140 pounds per cubic foot.
Metal particles can vary in size from 150 mesh to smaller than 325 mesh; 200-mesh power is used in the formula cited previously. Metals such as aluminum, zinc and magnesium can be used. The silicon dioxide has a particle size of 20 microns-its function is to improve the viscosity of the green ceramic.
In color, too. To identify potted modules, the color of the foam can be varied by adding pigments, such

Electronics I July 27, 1964


Electronics Review

as chromium oxide for green and iron oxide for beige.
After curing, the ceramic can be cemented, cut with a hacksaw, shaped with a wood rasp, or ground on an abrasive wheel.
A patent disclosure has been filed by Alfred G. Eubanks and Ronald E. Hunkier of Goddard's materials research and development section.
Industrial electronics
It's a strange studio for a sculptor. No clay. No curlings on the floor. No pedestal. No chisel. No armature to support the figure. Ju st a 50-foot-high tank, a library of punched tapes, and a tape-reader.
The sculptor's assistant selects a roll of punched tape labeled "Venus de Milo," places it onto a tape-reader and pushes a button. Within a few hours, a replica of a famous lady will emerge, 6'8" high, with her measurements (5539-51 in the vital dimensions) accurate to ten-thousandths of an inch.
No such studio exists yet. But it could well be a result of the collaboration of a famous sculptor, an inventor and some generous contributors.
Hero-size problems. The sculp-

tor, Robert Berks, discussed some problems of his art one day with Jacob Rabinow, president of Rabinow Electronics, Inc., a subsidiary of the Control Data Corp. He described the process that always results in distorted reproductions of heroic-size statutes. He mentioned the Ford Foundation's concern about damage to art works, and the foundation's offer of $250,000-to be matched by equal funds from other sources-to create a museum of numerical-control tapes of statuary masterpieces.
On July 21, Rabinow received his 115th patent-a method of milling copies of big statues accurately and quickly.
Underwater art. The key element
is a machine tool inside a liquidfilled tank. The tool floats in the liquid, its blade touching a shell of bronze two inches thick filled with a light, rigid plastic. The liquid makes the hollow cutting-arm weightless, and eliminates the effects of temperature and vibration during milling.
The machine tool, as it mills the bronze, could be directed by a scribe tracing over the contour of a foot-high model of a statue. Unlike the mechanical scribe of this pantagraph, which uses levers to enlarge dimensions and introduces mechanical errors, the Rabinow unit could use a noncontacting tracer system to gather data for the

Sculpting statues under water with numerically controlled machine tools is described by Jacob Rabinow to sculptor Robert Berks. Frogmen in the sketch are a result of artistic license. Bust of President Kennedy on table was made by Berks.

punched tape and later to guide the machine tool. Such a tracer system is already being used by the auto industry [Electronics, June 1, 1964, p. 64 and May 4, 1964, p. 102].
From the punched tape, masterpieces could be mass-produced in their ·original size.
The electronics of the numerically controlled system would be placed inside the tank, or connected by cable from a position outside the tank.
Shocking shrimp
For years, shrimp fishermen have b een dragging chains in front of their trawling nets to shake shrimps out of the mud and sand so the nets can capture them. For years , fish ermen have figured they could get more shrimps out of the ocean bottom if they could shock them awake. An electric shock causes a muscular reaction that makes shrimps jump.
An electronic generator that does the job by radiating highpower pulses into the water has now been developed for commercial use. It has been tested by the Department of Commerce's commercial fisheries gear research station in Panama City, Fla. One fishing fleet operating in the Gulf of Mexico, and another on the At· !antic coast have begun using it. Another fleet is still testing it.
Commercial system. The com-
mercial system was developed by the Sea Technology Corp. of Sarasota, Fla. An output circuit, operating with a silicon controlled rectifier, radiates two pulses per second into the water through an electrode array. The array is stretched in front of the otter doors of the shrimping rig.
Pulse widths are less than one millisecond. Peak amplitude is 100 volts and nominal peak power is 140 kilowatts.
Power for 12 hours of trawling is provided by nickel-cadmium batteries made by Gould-Nation al, Inc. A semiconductor inverter changes the direct current to alternating current. Induction is used to magnetically couple the power to

Electronics f July 27, 1964

Electronics Review

Government research vessel, t he George M. Bowers, was site of sea t ests. At rig ht is a shrimping rig, wit h t he pul se generator mounted on one of t he otter doors.

th e pulse generator. This eliminates the necessity of water-tight connections for cables and makes it easy to replace the batteries. The power supply fits into the pulsegenerator housing.
The littlest Biax
You've heard of the Flute, the Rope, the Twistor? No, these aren't dances. They're magnetic memory configurations. Now there's a new memory shape that could be called the Clarinet, or Licorice Stick, because that's what it resembles.
The memory consists of a Permalloy wire with pairs of tiny holes drilled at right angles to each other. Each pair of orthogonal holes constitutes a memory core, only a few thousandths of an inch long. Many such cores can be formed in a single wire by using a laser drill.
Microenergy memories. Prototypes have been made at the Radio Corp. of America's Aerospace Systems division in Burlington, Mass. Experimenters were looking for a memory so small and requiring such low driving power that it would be compatible with computers made entirely of integrated circuits. They think they have found the answer.
The units are a variation of the Biax configuration developed by

the Aeronutronics division of the Philco Corp. [Electronics, June 2g, lg64, p . 61]. Regular Biax memories are assembled from individual, molded-ferrite cores with a nominal size of 0.05 by 0.05 by 0.08 inch. They are among the fastest memories made because the polarity of only the tiny amount of ferrite between the two orthogonal holes is switched, and the change in magnetic orientation is only goo instead of the usual 180° domain reversal.
The RCA experimental units operate in the same way but because the magnetic volume between the orthogonal holes is much smaller they would require much lower switching power. Typical dimensions of the wire units would be 0.0001-inch diameter holes 0.005 inch apart, with the hole pairs 0.015 inch apart in the Permalloy wire. Each of these "cores" is joined by magnetic material to the next core. The cores are effectively isolated because the distance between pairs of holes is much greater than the distance between holes in a pair.
Laser drill. The key to the process for making the cores is a laser drill. Burton Clay, project engineer, explained why:
· Such small cores cannot be molded, with the holes, from ferrite. Nor can regular mechanical drills be made small enough. The tiny holes could be drilled by an electron beam in a vacuum chamber, but this would be a slower

process during which the material would heat up and lose its magnetic orientation.
· Lasers can drill microscopic holes in metal in a microsecond. There is almost no heat, so the wire keeps its magnetic orientation. Permalloy is oriented when the wire is made.
To make the cores, the laser is set up on an optical bench and aimed at the wire. One hole is . drilled. The wire is moved slightly forward, rotated goo and the second hole is drilled. The wire is then advanced the 0.015-inch spacing between cores and the process is repeated.
Clay thinks that refin ements of the production method would provide an automatic method of producing core-type memories.
Thin films of glass
The Corning Glass Works can now make a thin-film version of its glass capacitors on the same production lines where it manufactures thin-film resistors. The production line at Raleigh, N. C., does not use vacuum processing, but makes passive microcircuit networks that resemble a cross between vacuum-depo~ited thin films and screened circuits.
Corning expects the new capacitors to meet military specifications . Their rating is 50 volts, from 100 to 5,000 picofarads. Capacitance is about 80,000 pf per square inch, and the dielectric con stant is about 600. Tolerances of 5% , 10% or 25% can be held. Cost per capacitor is about the same as for discrete mica capacitors.
Compatible process. The capacitors are made by a p rocess that is compatible with the high-temperature pyrolitic deposition that Corning uses to make tin-oxide resis tors.
Layers of niobate-glass dielectric and gold electrodes are applied to the substrate. The capacitor is then fired ; this bonds it to the substrate. Firing changes the glass to a crystalline substance similar to Corning's Pyroceram. The resistors are then deposited at 600° C. Copper

Electronics I July 27, 1964


Electronics Review

Thin-film circuit contains four resistors and four glass capacitors.
conductor paths can be applied directly over the capacitors.
The capacitors will be shown for the first time at the \Vestern Electronic Show and Convention on Aug. 25.
Thin-film first
By mid-1965, the National Cash Register Co. plans to start deliveries of a new version of its NCR 315 computer, called the 315 RMC (rod memory computer). Unless another company beats it out, NCR will be first with a commercial computer whose main memory is made entirely of thin-film storage elements.
The memory is about half the size of the standard NCR 315 ferrite-core memory, eight times as fast and is part of a redesigned central processor unit. This unit could also be used to replace the central processors in existing NCR 315 and 315-100 computers, enabling them to execute about 100,000 instructions a second.
Some thin-film memories are now being used in commercial computers, as auxiliaries. The Univac division of the Sperry-Rand Corp. started using a thin-film control memory in the Univac 1107 in 1961. Three Univac military and aerospace computers use thin-film main memories.
Thin-film cylinders. Most thinfilm memories take the shape of a Hat plate. NCR uses a cylinder [Electronics, June 29, 1964, p. 65].

The basic memory element is a 0.010-inch diameter berylliumcopper wire, electroplated with a nickel-iron magnetic film, 4,000 angstroms thick and wrapped with a spiral copper ribbon. To assemble a memory module, the rods are inserted through a stack of 40 solenoid planes, in 16 rows of 66 rods each. The rods are provided with terminations for coincident-current operation.
The solenoids are spaced on 1/sinch centers in all three dimensions, for a packing density of 5.2 bits per cubic inch. In the laboratory, NCR has reached a packing density of 7,000 bits per cubic inch by spacing the rods 50-thousandths of an inch between centers. Ultimate interest is in possible use of the rods for mass memory, to compete with drums, disks and tapes.
Each group of windings for 66 solenoids is made from a single wire by an automatic machine that winds a 10-twin coil at each solenoid position. \Vh en current is sent through these coils, the adjacent cylindrical thin film is magnetized on the rod through which current has also been sent. The cylindrical shape of the rod is said to allow for tight coupling between windings and magnetic material, so that large switching fields can be provided with reasonable currents and small inductances.
Average access time is 267 nanoseconds per digit; the read-restore or clear-write cycle time is 800 nsec.
The 315 RMC has a basic 60,000digit memory (four bits per digit) made up of eight memory modules; the computer memory can be ex-
Memory module consists of plated wires in a stack of solenoid planes.

panded to 240,000 digits in increments of 60,000.
A 315 RMC with 60,000 alphanumeric character storage capacity will rent for $6,000 a month; a standard 315 with comparable memory size rents for about $5,000 monthly.
Also announced was the 321 communications controller, which links as many as 100 remote inputoutput machines to any 315 computer for on-line operation.
Out, damned spot
No more blemishes on those french-fried potatoes; no more embarrassing spots still on your best necktie or vest just back from the cleaners. This is the prospect offered by an unusual photosensitive device developed by Sylvania Electric Products, Inc., a subsidiary of the General Telephone and Electronics Corp. Photocells will pick out dark spots on opaque objects, or find internal flaws in transparent or translucent materials such as glass or plastic, before they get to you. A typical application for the device is monitoring conveyortransported objects in the food, textile and agricultural industries.
The new Sylvania photocell detects imperfections, which appear as dark spots, by responding to a reduction in light caused by dark areas. An ordinary photocell has limited sensitivity to small dark spots in random positions.
Cells in series. The dark-spot detector contains two strips of cadmium sulfide that form a number of small cells connected in series. Cell resistance increases when a blemish masks the light the cell would otherwise see. Because of the series hookup, the increase in resistance adds directly to the terminal resistance, raising sensitivity. A standard photocell comprises a number of small cells connected in parallel; the masking of a small area has little effect on the terminal resistance.
With a one-to-one optical sys-


Electronics I July 27, 1964


power supplies offer maximum flexibility
for any application at any ambient to 71°C

NOW 0-60, 0-40, 0-20 VDC IN ~ and ~ RACK MODELS









'Modular-Subrack LH



60°C 71°C


'- Model I LH 121

Voltage Range


30°c 0-2.4A

50°c 0-2.2A

60°c O-l.8A

71 · c 0-1.5A

Price (2)

LH 122







LH 124



0-1. IA




LH 125





O- l.9A


LH 127







I LH 128



{I) Current rating applies over entire voltage range. DC OUTPUT Voltage regulated for line and load

0-2. IA


O-l .5A



(2) Prices are for non-m etered models. for metered models and front panel controls,

add suffix {FM) to model number and add $25.00 to the price . for non-metered

chassis mounting models, add suffix (5) to model number and subtract $5.00 from

the non-metered price.

· AC INPUT-105-135 VAC, 45-480 cps


· REGULATION-Line or Load-.015% or I MV


· SIZE: LH 121, 124, 127 57]'/'x43{/'x 15112"

· RIPPLE-less than 250 microvolts rms and I millivolt P-P

LH 122, 125, 128 5;J.{611 x 8%" x 15%"


· RACK ADAPTERS Model RA- I for ruggedized mounting-Price $60.00 Model RA-2 for conventional mounting-Price $25.00

iAl l

L A M B D A E LE c TR 0 NI cs c 0 RP··.

Electronics Review

tern, the dark-spot detector can current that results represents a in industrial applications such as

spot a blemish Ya 2 of an inch in heavy loss of power.

induction heating, a-m broadcast-

diameter in a 112-inch field. Lens Right to the plate. In the Mach- ing, and in high-energy physics for

systems can extend the field with- lett design, a magnetic field chan- plasma studies. Low-power ver-

out loss of sensitivity. The photo- nels the trajectory of the electrons sions of the ML-8549 tube are al-
cell has detected Yi 6 -inch-diameter so that most of them miss the grid ready being developed.
spots at conveyor-belt speeds of and find their way to the plate. As

150 feet a minute with 12-foot- a result, the ratio of plate to grid

candle average illumination on the current is about 100 to 1, compared

face of the cell. Bridge circuits will with the usual 3 or 4 to 1.


compensate for thermally caused The first tube incorporating the

variations in cell resistance and offset a-c variations in the field

new design is Machlett's ML-8549, a nearly four-foot-high, water-

SAC speedup

light source.

cooled giant that puts out a whop- The famous underground war room ping 60 megawatts of pulse power, in Omaha, Neb., the nerve center

Superpower triodes
A new design approach to highpower vacuum tube triodes has produced a significant increase in their power output and efficiency. Five of these superpower tubes can do a job that formerly needed almost triple that number.
The new technique, termed a breakthrough in power tube design by Machlett Laboratories, Inc., a subsidiary of the Raytheon Co., hurdles one of the major stumbling blocks to increasing the output of power triodes-the problem of electron interception by the grid.
In conventional tubes, one third to one fourth of the electrons emitted by the cathode are intercepted as they make their way to the plate. The relatively high grid

with pulse widths up to 10 milliseconds. Pulsed-plate efficiency exceeds 90%. Another dividend of the new design is the unusually long duty factor (ratio of time on to time off) of 0.06. The usual duty factor for a tracking radar is between 0.0015 and 0.003.
The Machlett tube was developed to serve as a modulator in the new high-power tube-testing complex at the Rome Air Development Center, Griffiss Air Force Base, N. Y. The partially completed test center, designed to prove out future generations of r-f power devices for the Air Force, needed a hardtube modulator capable of switching 5,400 amperes at a variable pulse repetition rate of from 1 to 1,000 cps and a duty factor of 0.06. Fourteen conventional tubes, operated in parallel could deliver the power but they would provide only a 0.01 duty factor. Machlett filled the bill with only five parallel tubes.
Other jobs. The ML-8549 can be used as a switch tube in pulse modulators for radar or similar applications. As a pulsed r-f amplifier operating at frequencies up to 30 Mc, it can deliver 10 megawatts with a driving power of only 33 kw, also at long pulse durations and high duty factors. The tube also can operate as a class C amplifier or oscillator with a c-w output in excess of 2 Mw with a drive of approximately 10 kw.
Machlett engineers feel that the tubes will have an important future

of the Strategic Air Command, has been remodeled. Existing equipment is being replaced by th e new 465L command and control system.
High-speed sending and receiving equipment, fast computers to store and process data from all over the world and a novel multicolor wall display system are being delivered under a prime contract with the Data and Information Systems division of the International Telephone and Telegraph Corp.
World-wide input. Basically, the 465L is a gigantic two-way communications system that funnels information to SAC headquarters at Offutt Air Force Base in Omaha and transmits operational instructions from there to the Air Force. Information is fed into the system by field stations called r~mote communications centrals. A message composer at a central converts a standard-form message into computer data. The data goes by way of switching computers to the central computer at Offutt or to a second computer at March Air Force Base in Riverside, Calif.
Messages travel to the data processing central at speeds varying from 750 to 3,000 words a minute. Errors are checked, inaccuracies are brought to the attention of an operator, priorities are assigned and the quickest route is chosen.
The special stored-program computer at Offutt has a word length of 48 data bits and two parity bits. It also has four high-speed core storages, each capable of holding 16,-

384 48-word bits. In addition, drum

memories and magnetic tape stor-

Mammoth tube stands

age are used for masses of infor-

nearly four feet high.

mation that back up the fast-




Offner adaptability in ink rectilinear recordings
Only OFFNER offers the advantages of ink rectilinear recording with t he flexibil ity of fast input coupler exchange. Servo loop at the stylus point forces locked-in accuracy. The OFFNER input couplers change the function of the amplifier system and provide all necessary bridge balancing, calibration and "computing" facilities .·· thus obviating the need for expensive special-purpose amplifiers.


Number of Channels Sensitivity Frequency Response Phase Delay Linearity
Recording Amplitude


1-8 standard; to 24 special With preamp 1µv/mm to 5v/mm
Without preamp 1mv/mm to 5v/mm
DC to 150 cps
2.5 ms ± 0.05 ms, 0-120 cps

Input Impedance
Warm-up Time Nominal Cost/Channel

With preamp 2 megohms without preamp 1 megohm
With preamp $1,250 Without preamp $850

0.1% (full scale) for DC: or AC within maximum
amplitude envelope
(shorted input) With preamp 1µv/ hr at max. gain
Without preamp <0.05mm/hr
Full chart channel width from DC-40 cps with progressive
reduction to 5mm at 150 cps

B e c k m a n ® I NSTRUMENTS, IN C,
OFFNER DIVISION Schiller Park, Illinois
International Subsidiaries: Geneva. Switzerland; Munich, Germany; Glenrothes, Scotlan d

Electronics I July 27, 1964

Circle 33 on reader service card 33

Electronics Review

reaction core storage. Beyond this, disk files handle an additional 13 million words. The central processor has an access time of 2.5 microseconds and can execute 400,000 operations a second.
Color display. Information from the system is available by various types of printout; but for the SAC commander and his staff, masses of data must be quickly assimilated through use of large projection displays. Desired information can be reproduced on a 70-mm positive film in less than 15 seconds. Digital signals received from the data processor are converted into analog voltages which position a crt electron beam. An optical system projects the crt alphanumerics onto the film. Three images, correctly registered, carry all or parts of the same message. The projection light is split into the three primary colors by dichroic mirrors.
When each film image is present and illuminated, the colors combine to make white light, and the data appears normally. Absence of all but one film image produces single-color light for red, green or blue, as desired. When the identical image appears on two units of the film, resulting colors are cyan, magenta or yellow. In all , seven different colors are available to identify static, new or emergency information.
Six screens, each 16 feet square, are being installed at SAC headquarters. Maps or other transparencies can also be projected as a base for computer-derived information overlays.
More power
Police officers at the annual convention of the Associated Public Safety Communications Officers, in Norfolk, Va., will see on Aug. 5 the first public display of a line of transistorized two-way radios that can put out almost 60 watts of r-f power at ultra-high frequencies. This is almost double the power of existing commercial solid-s tate twoway radios operating at uhf.
The f-m sets are now in production at the General Electric Co.'s

Communications Products department, Lynchburg, Va.
GE thinks the development will increase the use of the uhf band (around 450 megacycles) and thus relieve the overcrowding of lower frequency bands. The higher power will permit uhf sets to be used in areas where reception is difficult.
Very high frequency. For customers who want to stay down at very high frequency, GE also has new vhf mobile units that put out 100 watts, and base stations with up to 330 watts. The sets use silicon transistors.
Other features in the sets are a new type of voltage regulation and a tuning search system.
The first protects frequency stability and provides stable squelch operation to insure that all calls are received. Even when the voltage from a vehicle battery surges with overcharge or drops off with heavy loads, receiver sensitivity and transmitter drive are unaffected.
The tuning circuit is used in sets that receive two frequencies . The circuit permits only the audio signal of the first station received to be heard by the operator.
The new GE line will be pitted competitively against the Motorola Co.'s all-transistor Motrac and Motran radios, already in use. The Radio Corp. of America's most comparable line is called SuperCarfone.
Space electronics
Which way is down?
A classic problem in satellite control is finding "down." This must be done accurately when an antenna has to point precisely at earth. A classic solution is to find the earth's horizon and determine the vertical from that.
The technique doesn't always work well. During Col. John Glenn's orbital flight, the horizon sensor was confused by a tropical storm and gave a vertical reading that was 10° off.
In an effort to eliminate such

errors, the National Aeronautics and Space Administrations plans a project called Scanner. It will use a satellite in its research for better ways of sensing the horizon and in studying the best optical frequencies for horizon sensors-infrared, ultraviolet or visible light.
New radiometer. Part of the project is an improved infrared radiometer being developed at Langley Research Center, Hampton, Va. It will have a 0.025° field of view, instead of the 0.25° field of present sensors. This will enable it to peer more closely at the horizon.
Two of these radiometers would be mounted back-to-back on a spinstabilized satellite with vertical orientation. One would sense wavelengths of 14 to 16 microns, and the other wavelengths of 20 to 35 microns or longer.
Electronics abroad
No cheating
A starting gate for swimmers is part of an electronic timer that was designed in Britain.
The starting circuit simultaneously operates a speaker at each starting position and vibrates the platform on which the swimmer stands. This overcomes two defects of the traditional starting gun. Deaf swimmers can't hear the gunshot, and competitors furthest from the sound hear it about 0.06 seconds after the gun is fired. The time lag gives the swimmers nearest the signal gun a head start.
To prevent cheating or false starts, the swimmers grasp bars. If they let go of the bar before the starting signal, an audible alarm is triggered and a disqualification rope drops into the pool. At the end of the race, as each swimmer finishes, he touches a rubber pad that then hits a metal plate, shutting off a timer.
The electronic timing and starting system is accurate to one millisecond. The timer is a one-megacycle crystal oscillator that feeds eight counting units by means of divider circuits.


Electronics I July 27, 1964

Voltage-To-Fre CHOOSE FROM
Vidar offers the widest selection of standard voltageto-frequency converters currently available. There are standard Vidar converters to han~le all these inputs : high and low-level de voltage, ac voltage, and resistance. Here are details.


The Vidar 241 is a high signal level version of the Vidar 240 offering input ranges from 10 to 1000 vdc, and choice of 0-100 kc, 0-10 kc, or 0-1 kc full scale outputs. Priced at $515, the unit is available in rackmount only.
The Vidar 211 is intended for multiple-channel applications where high level signals are available and unipolar operation possible. It offers an input range of 0-10 v and choice of 1-100 kc, 0-10 kc, or 0-1 kc output.
Electronics I July 27, 1964

For more information, or a demonstration, please call

your Vidar sales engineer (listed in eem) or write to

us at 77 Ortega Avenue, Mountain View, California.

Telephone (415) 961-1000.



Circle 35 on reader service card 35


It is no more like power or control cable than a Ferrari is like the old family sedan. Not knowing this can cause you a lot of grief: project delays, costly replacements, malfunctions.
THE THIN BLACK LINE On your schematics, instrumentation cable is a black line from launching pad to blockhouse or from one part of a computor to another. In the broadest sense, it connects data or signal sources with display or recording or control devices. Its function is to carry those signals unfailingly and with the required reliability. In this day and age, it's no easy job.
WHAT CAN GO WRONG The improperly designed cable can simply fail. This has happened and at important sites. An untried saturant, lacquer or compound ingredient used in the cable may destroy the electrical integrity of this primary insulation. This sort of deterioration need not be sudden; only experts know which impregnants will migrate in a week or a month or more.
Or a relative lack of art in manufacture may create problems for the future. Under certain circumstances in use, variations in insulation thickness, conductor placement, or conductor unbalance in the cable lay-up may cause spurious or ambiguous signals to arrive at the display, recording or control panel. Your sharp, precise pulses become displaced in time, are a little too fuzzy, or are joined by other unwanted signals from another line.
DESIGN IS HALF THE STORY Configuration of conductors within the cable is important, for physical as well as for electrical reasons. For example, positioning of coaxial components within the cable is critical in order to assure maintenance of minimum standards of concentricity between the inner and outer conductors when the cables may be subjected to bending operations during installation work.
Selection of insulating, filler and
36 Circle 36 on reader service card

jacketing materials requires expert knowledge and judgment. Some materials, as mentioned above, tend to migrate. Others harden or soften with cold or beat. Some change their electrical characteristics in time. These are not fundamentally new problems in cable design, but in instrumentation cable the standards are far more severe thart ever before.
MANUFACTUREIS THE OTHER HALF Even a properly designed cable may well become unacceptable sooner or later if it is not manufactured to new standards of precision. This requires stranding machines that reduce circular eccentricity to remarkably low figures and help assure insulation uniformity, insulating machines of considerable precision, and highly precise cabling equipment. It also requires, as is so often the case in precision manufacture, an indefinable skill on the part of machine operators.
ASK THE EXPERTS To protect the functioning of your system, there's only one way to make sure the thin black Jines on your schematics become cables with the requisite dependability: have them designed by experts, in consultation with you, and constructed by experts.
Rome-Alcoa is, frankly, one of the very few companies that qualify. We've been designing and constructing these cables since their first conception. If you're going to need instrumentation cable soon, call us, the sooner the better.
We now have a 24-page booklet titled "Instrumentation Cables, Cable Assemblies and Hook-up Wires." In it, we describe instrumentation cable constructions, production, military specifications and our qualifications. For your copy, write Rome Cable Division of Alcoa, Dept. 27-74 Rome, N. Y.
Electronics J July 27, 1964



an affiliate of Hewlett-Packard

*Trade Mark Pat. pend.

9 429

· New,exclusiveAUTOGRIP' hold-down for any size paper to ll"xl7" .
· 100 microvolts/ inch sensitivity at one megohm input resistance
·AC input ranges to 5 millivolts/inch
· 120 db common mode rejection at line frequency
· Multi-contact flat mandrel potentiometers for unprecedented reliability
· Time sweeps for either axis with automatic reset and adjustable sweep length
These improvements, coupled with proven Moseley quality and precision, make the Model 7000A the most advanced X-Y recorder available today. Available, too, is the companion model 7030A, same as 7000A but accepts paper to 81/:( x 11" , without ac inputs. Model 7000A, $2575; Model 7030A, $1795- Call your Moseley/ Hewlett-Packard field engineer or write: F. L. MOSELEY CO., 433 N. Fair Oaks Ave., Pasadena, Calif. 91102-
Circle 37 on reader service card

ype 230-A
1C> to 5C>


The BRC Power Amplifier Type 230-A is the ideal RF amplifier for low-level applications exhibiting a typical noise figure of 6 to 8 db. Three tuned, cascaded stages of grounded-grid amplification provide up to 30 db gain and a maximum power output of 5 watts. Typical applications include:
RECEIVER PRE-SELECTOR -The Type 230-A, when used as a pre-selector with conventional communications receivers, will readily provide fractional microvolt sensitivities.
TUNED SELECTIVE FILTER- BRC 230-A provides a convenient means for the selective amplification of RF signals in the 10 to 500 Mc. range with excellent rejection of undesired frequencies.
HARMONIC AMPLIFIER - The new power amplifier may be used to amplify desired harmonics in the output of signal generators and frequency synthesizers thereby extending their useful range.
FREQUENCY COUNTER PRE-AMPLIFIER-Type 230-A as a pre-amplifier
for conventional frequency counters, such as the @ 524/525, will
provide a 15 to 30 times improvement in input sensitivity. Remote, offthe-air frequency measurements of FM broadcast and communication transmitters may be readily performed.
RF MILLIVOLTMETER PRE-AMPLIFIER- When used as a pre-amplifier for
RF millivoltmeters, such as the @ 411, the 230-A will provide 15 to
30 times improvement in sensitivity.
A Division of Hewlett-Packard Company
Tel. 627-6400 (Area Code 201) TWX: 201·627-3912 Cable Address: Boonraco
38 Circle 38 on reader service card

RF RANGE: 10 to 500 Mc.
BAND RANGES: 10·18.5 Mc. 65·125 Mc. 18.5-35 Mc. 125-250 Mc. 35·65 Mc. 250-500 Mc.
RF GAIN: 30 db (10·125 Mc.) 27 db (125-250 Mc.) 24 db (250·500 Mc.)
RF BANDWIDTH: >700 Kc.*(10-150 Mc.) >1.4 Mc.*(150-500 Mc.)
*Frequency interval between points 3db down from max. response
RF OUTPUT: RANGE: Up to 15 volts*
*Across external 50 ohm load IMPEDANCE: 50 ohms. CALIBRATION:
0.2 to 3 volts f .s.; increments of approx. 5%.
1.0 to 10 volts f.s.; Increments of approx. 5%.
2.0 to 30 volts f .s.; Increments of approx. 5%.
ACCURACY: ±1.0 db of f.s. (10-250 Mc.). ±1.5 db of f.s. (250·500 Mc.).
LEAKAGE: Effective shielding Is greater than 40 db.
RF INPUT: LEVEL: ..,:o.316 volts· (10-125 Mc.) ~0.446 volts* (125-250 Mc.) <0.630 volts· (250-500 Mc.)
*For 10 volt output Into 50 ohms IMPEDANCE: 50 ohms
AM RANGE: Reproduces modulation of driv· Ing source 0·100% up to 5 volt max. carrier output
AM DISTORTION: <10% added to dlstor· !Ion of driving source
FM RANGE: Reproduces modulation of driving source except as llm· lted by the RF bandwidth
FM DISTORTION: Negligible distortion added to distortion of driving source for deviations and mod· ulatlon frequencies <150 Kc.
INCIDENTAL AM: <10% added to modu· latlon of driving source at 150 Kc. deviation
MOUNTING: Cabinet for bench use; by removal of extruded strips suit· able for 19" rack mounting
POWER REQUIREMENTS: 105-125/210-250 volts, 5D·60 cps, 15D watts
Price: $1200.00 F.O.B. Rockaway, N. J.
Electronics I July 27, 1964

Need Capacitors in
Here are a few we've made recently:

5400 mfd., 24 v., in a spe. cial mount. Four Mallory XTV wet slug capacitors in c ustom· designed geometry for an advanced missile program.

1000 mfd., 40 v., in l" cube. Four Mallory wet slug tantalum capacitors packaged for a top space program.

High capacitance, hermetically-sealed unit. Wet slug tantalum capacitors pack· aged for military and in· dustrial filter circuits.

-55° to +125·c hermeti· cally-sealed unit. Three Mallory HTA high -reliabil· ity aluminum electrolytics
for industri al applications.

Double-case hermetically-sealed unit. Special pack· aged tantalum foil capacitor for a space vehicle.

Packages have been designed for Apollo, Gemini, Pershing, TFX and other missile, space and aircraft programs. Whatever your packaging requirements,_ Mallory engineers can design and produce the capacity, reliability and geometry you need ... quickly and economically. They have a full line of tantalum and aluminum electrolytic capacitors and years of experience to apply to your problem. Please write giving details such as capacity, working voltage, dimensions and environmental conditions. Or, request a consultation. Mallory Capacitor Company, Indianapolis, Indiana 46206-a division of P . R. Mallory & Co. Inc.

See us at WESCON-Booths 169-171, Hollywood Park
Electronlcs I July 27, 1964

Circle 39 on reader service card 39

Some people call our inspectors fuss-budgets
(but Speer customers think they're great)

The man up there in the picture is a member of Speer Carbon's Quality Control and Inspection team. He's checking a resistor lead for solderability-one of many tests that are S.O.P. for Speer fixed carbon resistors.
He's also one big reason why Speer customers are happy customers. They know they can rely on Speer electronic components for uniformity and performance time and time again.
Actually, all of our inspectors are fuss-budgets. They just won't take anything for· granted and we're glad. That's why Speer has one quality-assurance employee for every eight employees in production and one qualityassurance engineer for every seventy-five employees in production. And that holds for every manufacturing step ... from raw materials to the finished product.

Mil specs? Speer participates in industry committees that cooperate with military departments in writing them. What's more, our tests don't stop there. This year, 141,912,000 unit life test hours are scheduled for Speer resistors and 40,000,000 for Jeffers coils.

But just to keep the record straight, our inspectors

don't deserve all the credit for Speer quality. The folks

up and down the line, in all departments, have the same

kind of pride in Jeffers' and Speer's performance that

our quality-assurance employees have. And we suspect that Speer's multi-million

S·PEErn...._ /) ,a dollar research and devel?P-
ment program has somethmg -
__, to do with it, too.

~ (.fa/xJtf_ .


Dept. 487, St. Marys, Pennsylvania 15857 Speer Carbon Co. is a Division of Air Reduction Company, Inc.


40 Circle 40 on reader service card

Electronics I July 27, 1964


100 MS. -60 SEC.


llll I llllllIllI


50 MS.
extended range

smaller sizes

: ; 11111111111111111111111111111
300 HRS.

, ,

, ,

, ,

, ,

, ,

... , ,


- now offered in Leach standard electronic time delay relays

Recent Leach developments in miniature magnetic cores, new applications in time base generators, and the complete redesign of Leach-patented unijunction circuits now make possible many additional maximum-performance features in standard time delays. NON- DESTRUCT MEMORY is an example. In the event of interruption of input power, t he non-destruct memory will maintain the timing count in the unit. Upon reapplication of power, the unit will continue timing as though no interruption had occurred. (Available in four of nine standard models.) HIGH ACCURACY OVER A BROAD TEMPERATURE RANGE : ±33 from -20°c to +11°c, ±53 from -ss·c to +ss·c, ±103 from -55°C to +125°C. INHERENT RELIABILITY guaranteed by design simplicity and solid state silicon components. All units can be built to meet Minuteman reliability specs.
Electronics J July 27, 1964

MA NY OTH ER FEATURES, including minimum power drain, fast automatic recycle and voltage regulation. Units are available with solid state or relay output, fixed or adjustable timing, and with delay on operate or release.

CHOICE OF 6 CONFIGURATIONS : Standard MS, Double Crystal Can (2), Crystal Can (2), and Half-size Crystal Can, with a wide variety of mounting and terminal configurations.

CUSTOM DESIGNS WITH SPECIAL CAPABILITIES can be produced to meet your most stringent requirements. Extended timers with up to 3 years delay. Accuracy to ±.023. Multiple output programmed events.

FOR PROMPT DELIVERY of standard units, or regarding custom orders, see your Leach representative, or write, wire
or phone:

CONTROLS DIVISION 717 North Co ney Avenu e, Azusa, California · Phone: (213) 334-8211

Circle 41 on reade r service card 41


EL SEGUNDO, CALIF.-From the bottom of the sea to the farthest reaches of outer space ... IR's components have demonstrated the success of fifteen years of research and development to advance the U.S. military effort.
Silicon rectifiers resulting from the programs have contributed to many highly varied military projects. Among them have been IR's superpower oil-cooled Rectifier Columns, which are a part of the Ballistic Missile Early Warning System IBMEWS), and HAYSTACK HILL-the largest research radar antenna ever built-designed around IR's superpower rectifier systems.

supplied to function as 3-phase AC motor speed controls; and TIROS, NIMBUS, and Space Project 823 Satellites for which International Rectifier

Other contributions by IR to the national military effort have .been the development for the U. S. Naval Ordnance Laboratory of a de-sensitized silicon controlled rectifier which would respond to activation and yet be relatively insensitive to all radio frequencies; and Project Mercury, for which Dallons Labs, IR's Medical Electronics Division, subcontracted physiological data monitoring equipment by which Astronauts Glenn and Carpenter sent signals picked up at 14 tracking stations around the world.
These projects and hundreds more of paramount importance to the military defense effort of our nation have given International Rectifier a unique repository of experience in fulfilling research and development contracts and in developing new ideas for government agencies concerned with our country's defense.
To put this experience to work on your projects, contact Larry Dudley, Director of Government liaison at International Rectifier Corporation, El Segundo, California, Telephone ORegon 8-6281.


Other notable military projects which have incorporated IR components are Polaris-equipped nuclear-powered submarines, which contain IR's 70 and 150 amp rated silicon controlled rectifiers,

produced solar cells which provided on-board power. Eight of the TIROS Weather Eye satellites contained IR's P/N type cells, and a new TIROS series will carry IR's N/P type, radiation resistant cells. All satellites launched have been highly successful, and JR continues to supply all cells for the entire project.
In terms of aerospace performance, JR solar cells and solar panels have logged millions of miles of space flight, providing an inexhaustable supply of electrical power under the most radical environmental conditions. Their reliability is clearly demonstrated by the fact that, after thousands of hours in orbit on a continuous duty basis, space vehicles incorporating JR solar cells are still transmitting data powered by their undiminished solar generators.




42 Circle 42 on reader service card

Electronics I July 27, 1964

Washington Newsletter

July 27, 1964

Pentagon rejects ComSat proposal

Secretary of Defense Robert S. McNamara has decided to proceed with plans for an all-military communications satellite system, rather than lease capacity in the Communications Satellite Corporation's commercial system. The Defense Department wanted tighter United States control over the satellite system than the State Department thought politically wise.
McNamara's decision may not be final. There are some reports that ComSat may design its satellites so that military communications still could be handled if the Pentagon should change its mind. After international agreements for the commercial system are signed, the question of Pentagon participation in the commercial system may be reopened.
Representatives of 18 countries met in Washington on July 21 to hammer out international participation in the venture.
A design for the commercial system won't be selected much before the fall of 1965. The military system is scheduled for 1966. Officials say there would be plenty of time for the commercial system to accommodate military use if the Pentagon should change its mind.

Job corps studies The job corps in President Johnson's "war on poverty" looks like a

potential market for companies involved with electronic teaching

teaching machines . machines.


In teaching new skills to workers, the corps should seek new tech-

niques for mass education, these companies reason. For months, Sargent

Shriver's job-corps staff has been discussing advanced teaching tech-

niques with representatives of the International Business Machines

Corp., Westinghouse Electric Corp. and others. The discussions have

touched upon the possible use of computer-based teaching systems.

The System Development Corp., a nonprofit research company that

works only for government clients, is also working with Shriver's staff on

the need for a computer system to handle information and internal

control for the job corps. The clients think such a system is needed to

keep track of the 200,000 trainees the corps is expected to enlist in the

next couple of years. H not computerized, the paperwork could swamp

the whole project, they say.

Congress is expected to act soon-before the Democratic National

Convention--on legislation to create the job corps.

Nike-X radar ready for tests

The heart of the Nike-X antimissile system-the Multifunction Array Radar-is now operating in a test version at White Sands Missile Range, N.M.
But a decision on whether to produce and deploy the Nike-X won't come until the end of this year and possibly later. Although impressed by the system, Defense Secretary Robert S. McNamara wants answers to detailed technical, strategic and economic problems before coming_to a decision.
Nike-X installations located around 20 cities containing 30% of the nation's populations would cost $15 billion to $17 billion to install and $1 billion to $2 billion a year to operate. McNamara believes that such

Washington Newsletter

a system should be accompanied by a fallout shelter program. Aside from the cost, another major question is what reaction ·the installation of the system would provoke from the Soviet Union.
The multifunction array, which combines the functions of three radars into one concrete-and-steel package, detects missiles at long ranges, tracks them, and discriminates between live warheads and decoys. Later versions, more sophisticated than the prototype at White Sands will be installed at Kwajelein Island in the Pacific Ocean.

Panel may assay automation's effects

Congress will create a national commission on technology, automation and economic progress before adjourning this year, according to Administration leaders. The bill has already been reported out by the House Labor Committee; the Senat«;l Labor Committee will approve it soon. No serious opposition is expected.
The bill would authorize the President to establish a 14-member commission of experts outside the government. The commission would predict the impact of technological and economic changes, including shifts in defense spending, on production and employment for the next 10 years. The Commission would also define needs toward which new technologies might be applied, and recommend ways in which the government might ease the industries' adjustment to these changes.
The commission would report to Congress and the President by
Jan. I, 1966.

Pentagon plans more cost cuts

The Pentagon plans to intensify its cost-reduction drive. With great fanfare, Defense Secretary McNamara announced that savings in fiscal 1964 reached $2.5 billion, a billion dollars above the original target. Furthermore, he promised savings at an annual rate of $4.6 billion by fiscal 1968, an increase of $600 million above the previous goal for that year. 'We haven't begun to scratch the surface," McNamara declared.
Much of the saving is credited to a shift to competitive contracting. In the first half of fiscal 1964, 38.6% of prime contracts were awarded on the basis of price competition, 6% more than 1961. McNamara estimates that each dollar shifted into competitive procurement results in a 25-cent saving.
In addition, cost-plus contracts have dropped to 12.1% of the total from a high of 38% in mid-1960. Each dollar shifted from cost-plus to other types of contracts results in a saving of IO cents, according to McNamara.
Pentagon officials give this breakdown of the $2.5 billion saving during the past year: $1.4 billion by "buying only what is needed" and by such cost-cutting techniques as value engineering; $450 million from the shift from cost-plus and noncompetitive contracting; $450 million by the closing of military bases and other reductions in operating expenditures.
One byproduct of the cost-cutting drive has been a reduction in engineer employment in defense industries. Defense officials say the trend leads to the dismissal of engineers who had been held in reserve by contractors. Extra engineers were not a great expense in a cost-plus environment and they enabled contractors to be in a better position to fight for contracts.
Electronlcs I July 27, 1964

How Sigma Instruments, Inc., cut its reject rate to less than 1% !

PROBLEM: Absolute cleanlines s of relay contacts is vital to the reliability of miniature remote controlled switches. Sigma Instruments, Inc. , Braintree , Mass. , was previously cleaning contacts with a chlorinated spray, which distributed contaminants over a large area without completely removing them. In-plant rejects were as high as 553.
SOLUTION: Relay contacts are now cleaned in an ultrasonic bath of FREON® fluorocarbon solvent coupled with vapor rinsing. Ultrasonic action , combined with the extremely low surface tension and high density of FREON, removes contaminants from the tiniest openings. Result: Sigma reports that

FREON solvents give them outstanding cleaning quality and that their reject rate has dropped to less than 13.
Sigma also points out that FREON dries quickly and leaves no residue . Its very low toxicity and nonflammability permit operation without expensive ventilating equipment. What's more, the new system is economical to use because FREON can be recovered in readily available equipment-for reuse over and over again.
Wherever you have a cleaning problem, FREON solvents can improve operations and cut costs. First, send the coupon for information on cleaning.

Electronics I Juiy 27, 1964


Better Things fo r Better living ·· , through Chem;stry


E. I. du Po nt de N emou r s & Co. ( In c.) FREON Pro du c t s Div ision E- 1 N ·2 4 3 0 F, Wilm i n gto n , D elawa r e 19898
Name_ _ _ __ __ _ _Title _ _ _ __

Company--------------Address _ _ _ _ _ _ _ _ _ _ _ _ _ __

Plea se send n ew b ook l et o n FR EO N solvents tor precision cleaning. I am inte rested in clea ni ng_ _ _ _ _ _ _ _ __
O I would like Du Po nt t o send a cleaning specialist.


Circle 45 on reader service card


Tektronix oscilloscope displays both time·-ba$8S s_eparately or alternately

NEW TYPE 547and 1A1 UNIT


DC-to-50 MC 50 MV/CM
DC·T0-28 MC, 5 MY/CM


2 CPS-to-15 MC
500 µv/CM

· With automatic display switching, the Type 547 provides twp independent oscilloscope systems in one cabinet, time-sharing a single-beam crt.

/\vww V I!\\ 1(\\ I I


·- --- - -- - - _ _.:::::=::--:---...=:
Single-exposure photog rapn .
2 signals - different sweeps
Upper trace is Channel 1/A sweep, 1 µsec/cm. Lower trace is Channel 2/B sweep, 10 µ sec/cm.
Using same or different sweep rates (and sensitivities) to alternately display different signals provides equivalent dual-scope op erati on, in many instances.
Triggering internally (normal) permits viewing stable displays of waveforms unrelated in frequency.
Triggering internally (plug-in, Chann el 1) permits viewing frequency or phase differen ces with respect to Channel 1.

Single-exposure photograph.
same signal - different sweeps
Upper trace is Channel 1/A sweep, 0.1 µ sec/ cm. Lower trace is Channel 1/B sweep, 1 µsec/cm.
Using different sweep rates to alternately display the same signal permits close analysis of waveform aberrations in different time domains.

e 547 also uses

Some Type 547 / 1A1 Unit Features
New CRT (with internal graticu le and controllable illumination) provides brigl1t "noparallax" displays of sma ll spot size and uniform focus over the ful l 6-cm by 10- cm viewing area.
Calibrated Sweep Delay extends con tinuously from 0.1 micr'osecond to 50 seconds .
2 ,Independent Sweep Systems provide 24 ca librated time-base rates from 5 sec/cm to 0.1 µsec /c m. Thre e magnified positions of 2X, 5X, and 10X, are common to both swee ps-with the 10X magnifier increasing the maximum ca li brated sweep rat es to 10 nsec/cm,

Single Sweep Operation enab les one shot displays for photography of either normal or delayed sweeps, including alt ernate presentations.
2 Independent Triggering Systems sim plify set-up procedures, provide stable di sp lays over the ful l passband and to beyond 50 Mc, and include bright line auto matic modes for convenie nce,
Type 547 Oscilloscope ··· ······ $1875 (without plug-in unit)
Type 1A1 Dual-Trace Unit , ·· , ·· $ 600
Rack-Mount Model Type RM54 7 ··· $1975
U.S. Sales Prices f.o.b. Beaverton. Oregon

For a demonstration, call your Tektronix Field Engineer

Single-exposure photograph.
2 signals - portions of each magnified
Trace 1 is Channel 2/B sweep, 10 µsec/cm. Trace 2 (brightened portion of Trace 1) is
Channel 2/ A sweep, 0.5 µ sec /cm. Trace 3 is Channel 1/B sweep, 10 µsec/cm. Trace 4 (brightened portion of Trace 3) is
Channel 1/A sweep, 0.5 µ sec/cm .
Using sweep delay technique-plus automatic alternate switching of the time bases-permits displaying both signals with a selected brightened portion and the brightened porti ons expanded to a full 10 ce ntim eters.
B sweep triggering internally from Chan nel 1 (plug· in) assures a stable tim e-related di splay without using external trigg er probe.


Inc. I P.O. BOX 500 · BEAVERTON. OREGON 97005 · Phone: !A rea Code 5031 Mltche/14 -0161 · Telex: 036-691 TWX: 503 -29 1-6805 · Cable: TEKTRONIX · OVERSEAS DISTRIBUTORS IN 25 COUNTRIES TEKTRONIX FIELD OFFICES in principal cilies in United States. Consult Telephone Directory

Tel<.lronix Australia Ply., Lid., Melbourne; Sydney · Tel<.tronix Canada Ltd., Montreal; Toronto

Tel<./ronix International A.G., lug, Switzerland · Tel<.lronix Lid., Guern sey, C. I. · Tel<.tronix U . K. Ltd., Harpenden, Hert s


Circle 46 on reader service card

I Clectronics Ju ly 27, 1964

If you ship from
5 to 50 pounds anywhere in the U. S.
you're missing a bet

...unless you check Air Express.

There are many reasons why. For example, you can actually ship a 20 pound package from New York to Chicago by Air Express for less than motor carrier ($6.20 vs. $6.82) ... and at a sizable saving in time.
Among air cargo services, Air Express is often cheapest and quickest too.
Another point. Air Express rates are figured door-to-door. You only

have one call, one waybill. And there's more. Air Express can
deliver by sunset tomorrow to any one of 21,000 U.S. cities. Pickup is made within 2 hours of your call. Your packages get top priority on every scheduled airline after air mail.
On the ground, 10,500 delivery trucks speed deliveries between you, the airports and your customers. Com-

pare this with any other service. Air Express is a joint venture of all
39 scheduled airlines and RE A Express. No wonder it gives you the best service in the air and on the ground.
Next time you ship from 5 to 50 pounds, try Air Express. Simply call your R E A Express agent.
Air Express outdelivers them all ··· anywhere in the U.S.A.

Electronics \ July 27, 1964

Air Express
Division of REA Express

Circle 47 on reader service card



The new TIDAX is a head-on approach to your problems in telemetry and general instrumentation.
This high-performance Recorder I Reproducer provides a full fourteen 1.5-mc tracks in one rack
- with fully automatic equalization at all speeds. Wideband FM (DC to 500 kc) is available without modification. Signal-to-noise ratio (RMS/RMS) is 25 db at all speeds. Tl DAX telemetry capabil ities include simultaneous post- and pre-detection recording in PCM, PCM/FM, PAM/FM, PACM and FM -type carrier systems. Mincorn's exclusive DC Top Plate is rugged, simple and rel iable-full dynamic braking, instant push-button speed control , tape change from I/2 " to l" in less than ten minutes. Write today for details and complete specifications.

3!Jl mincom Division
300 South Lew is Road , Cama rillo , California · 320 Shaw Road , South San Francisco, Ca liforn ia · S29 Pennsylvania Bui lding, 425 13th Street,
N. W ., Wash ingto n, D . C. · 135 West 50th St reet, New Yo rk, New Yo rk · Post Office Box 272, Fairborn, Oh io · 1230 O range Ave nue , W inte r
Park, Florida · 2121 Santa Anna Avenue, Dallas, Texas · Eltro n Enginee ring Sa les, Inc., 246 Walnut Street, Newtonville, Ma ssachusetts

48 Circle 48 on reader service card

Electronics I J uly 27, 1964

· . ..,.

n. · · · · · · · · · · · · · · · · · ·


11 ··················



with Integrated Circuits the big problem /testing
here are the BIG problem solvers
· 36 d-c tests · 14 active leads · Kelvin connections · "Do it yourself"
programming · .05% power regulation · Less than 1-mv long.
term drift · All logic types

Digital readout for quality control and incoming inspection testing. Optional digital comparator provides accurate, repeatable trip points. Can be quickly programmed for both high and low limits on each of the 36 tests. Recording output for a tape punch, typewriter, card punch or digital printer. Both automatic and manual handling equipment can be furnished for a variety of devices.

A fast go/no-go instrument designed for high-volume production and incoming testing. Short test times permit a complete 36-test sequence in i less than 2 seconds. Four programmable power supplies provided.

Similar to the 659A with space and connections for digital voltmeter. Includes two fixed power supplies and eight programmable power supplies.

Electronics I July 27, 1964



P.O. BOX G60Z7


Circle 49 on reader service card 49

··· with outstanding electrical and physical characteristics
to meet all your requirements for design and performance!

* CHOICE OF TEMPERATURE COEFFICIENTS + 105±25 ppm/ °C and 0 ± 25 ppm/ °C. (From
* + 105±25 ppm/ °C to-100 ± 25 ppm/ °C available.) CHOICE OF LEAD MATERIALS

Specify these features in any combination

* Solder Coated Copper, Dumet, Nickel A, etc. CHOICE OF LEAD CONFIGURATIONS

to meet your requirements

* Axial, Face Radial, Edge Radial THIN-LINE DESIGN

New space-saving feature


Quality features in all "VY" Capacitors

* DEMONSTRATED RELIABILITY * © Vitramon, Inc. 1964

See us at WESCON, Booth Nos. 324-325.


In United Kingdom contact:
Vitramon Laboratories Limited 45 Holloway Lane Harmondsworth, Middlesex England

50 Circle 50 on reader service card

Electronics I July 27, 1964


· -
·Accuracies to 0.01 %
· Conversion speeds to 30,000 per second

···· ··-·· ··-·· ····

Astrodata low cost Series 3000 Analog-to-Digital Converters meet the requirements of virtually all data acquisition systems with 1088 standard production models. From these you can select the full scale range ··· speed ··· accuracy ··· sample-and-hold ··. resolution . ·· output format best suited to your specific system.
Designed for easy integration into existing or new

data acquisition systems, standard features include individually buffered data output lines ··· adjustable output logic levels (clamped) ··· wiring installed for future addition of input amplifier or sample-and-hold circuits ··· front panel readout of data (including polarity) ··· and isothermal environment of converter network and reference voltage diode to assure maxi· mum accuracy over wide temperature range.

Series 3000 ADC's ideal for use with time-multiplexed input data

· ~--- ""'-..... __


Model 155-83 low cost, high·level ·input multiplexer

module has been developed for high speed analog

switching applications.

Inputs per card .... . .... .. . 6 one-wire or 4 two-wire

Input Voltage . . . . . . . . . . . . . . . . . . . . . ... ± 5 volts

Switching Time . . . ...... ......

. .. < 5 µsec

Crosstalk . . . . . . . . . . . . . . . . . . . .

. . ± 0 .01 %

Input Impedance . · .. ..... 1000 megohms/number of

switches in multiplexer group

Series 950 multiplexer assemblies consist of cards, shown at left, for single ended channels in multiples of 6 or differential channels in multiples of 4. Power supply and output buffer amplifier are included . Chan· nel identification data can be furnished in binary or BCD form . The multiplexer channels can be addressed directly by computers or advanced sequentially to meet the requirements of specific systems applications.

Contact your nearest Astrodata represen· tative today for a demonst ra t io n or write for technical literature giving complete specifications.

.A..&"rJB.OX>.&."r..A.. X::aTO.
240 E. Pala is Road · Anaheim, California

Electronics I July 27, 1964

Circle 51 on reader service card 51


a new semiconductor simplifies AC full-wave control circuits reduces

circuit size and cost . . . and is now available in 6 amp and 10 amp ratings!

The "TRIAC" is a new three-electrode AC semiconductor switch which is triggered into conduction in either direction by a gate signal (it's actually a power "integrated" circuit). Basically related to the SCR, the TRIAC simplifies control of full-wave AC power by reducing the number of power handling components, by generally eliminating need for transient voltage suppression, and by reducing the size and complexity of the gate control circuits. The illustrated cir· cuits show a simple full-wave AC static switch using the TRIAC, compared with the more complex circuit using

multiple SCR's necessary to perform the same function. If you're interested in applications such as stati c power
switching, temperature controls, lamp dimmin g, motor
speed controls, and many others, you should look into the
TRIAC, available in compact and rugged stud or press fit
housings. You'll also be interested in the new DIAC (diode AC switch) to trigger the TRIAC and SCR's. See your G-E Semiconductor Products District Sales Manager today, or write Rectifier Components Department, Section 16Gl25~ General Electric Company, Auburn, New York.

600W 120V 60CPS 100.0.

Breakover Voltage, VBR Load Current, It
Typical Gate Triggering
Requirements VG Is

TRIAC Specifications


±200 volts min.
6 amps rms AC max. at stud temperature= 75°C, full conduction (600 watts incandescent lamp load)

± 200 volts min .
10 amps rms AC max. at stud temperature= 75°C , full conduction (lKW incandescent lamp load)

± 3 volts, TJ=25°C

±3 volts, TJ=25°C

±50 milliamperes, TJ=25·C ±50 milliamperes, TJ =25°C

Available through your G-E Sem iconductor Distributor


Electronics I July 27, 1964

Electronics I July 27, 1964
Technical articles
Heat transfer makes low-frequency integrated circuits work: page 54 Harnessing thermal-electric interactions in silicon produces a new integrated circuit with a frequency response below 100 cycles per second . The new technique permits the design of linear circuitsoscillators, filters and time-delay networks-useful in many instrumentation applications .
Optoelectronics at work: page 58 Photons overcome a lot of the limitations of magnetic coupling in electronic networks. Some useful applications include small-signal linear amplifiers, high -voltage regulated supplies, modulators and demodulators, oscillators and signal generators, mixers and t ime-varying switches.
Bird's-eye view of the weather: page 81 New satellites will carry automatic picture-transmission systems to send to the ground a topside look at the atmosphere. Now a relatively simple receiving station makes it possible for many commercia l users who worry about the weather-airlines and utilities, for exampleto receive satellite pictures of overcasts and cloud formations.
Automatic circuit tester: page 76 A small computer does more than automate production testing ; it adds procedures that are impossible to carry out any other way. The result is better quality with faster and less expensive testing.


·Highlights of the Wescon program ·Understanding pnpn devices

August 10 · ComSat's first satellite · Driving light-emitting diodes


Low-frequency integrated circuits achieved with thermal transfer

They make it possible to build smaller oscillators,
filters and delay networks for below 100 cps

ByW.T. Matzen and R.A. Meadows
Texas Instruments, Inc., Dallas, Tex,

The inability to obtain inductances or large resist-
ances and capacitances in semiconductor integrated circuits has prevented the design of circuits requiring frequency response below 100 cycles per second. Now a technique has been developed that permits linear circu its, such as oscillators, filters and time-delay networks, to be designed for this range.
The technique, which uses thermal-electrical interactions in silicon, could be useful in many instrumentation applications of microelectronics, such as surgical implants in medical electronics and detection of low frequency transducer signals.
Basically, the method is to replace conventional resistors and capacitors with thermal transfer elements that can be fabricated in microcircuit size. Thermal propagation permits the functions of frequency selectivity and phase shift that, with electrical networks, would require large values of resis tance and capacitance. For example, the lower frequency range of conventional RC oscillators that can be fabricated in integrated-circuit form is limited by present technology to a few hundred cycles. Using the technique described here, stable oscillators at frequencies lower than 10 cycles per second and low-pass filters with frequencies less than 1 cps can be realized in a size compatible with the standard integrated-circuit flat package. These filter and oscillator circuits, which use thermal transfer elements and other applications of thermal phenomena, are expected to have a significant effect on future semiconductor-network technology.
Thermal transfer element
The transfer element shown on p. 55 consists of a J1eater transistor and sensor transistor built into a common silicon substrate by means of conven-

tiona] semiconductor network technology. A sinusoidal current in the heater transistor produces a variation in power dissipation at the collector-base junction, causing a change in the junction temperature. The temperature fluctuation propagates through the bar to the emitter-base junction of the sensor, producing a variation of current in the sensor transistor and an output current. For a sinewave input under small-signal conditions, all these quantities vary sinusoidally.
The transfer function of the thermal element is defined as

F = i?ut



The frequency response of this function may be related to physical parameters using the expression

F (w) = Ai PTBs = Ai '1' {w) 4> (w)



'l'(w) =TP-sn


is the thermal impedance of the heater transistor,

<I>(w) = ~:


is the propagation factor of the temperature wave from the heater to the sensor. A1 is a constant, dependent upon heater and sensor circuits. P 11 is the sinusoidal input power to the heater and Tn and Ts are the sinusoidal temperature swings at the heater and sensor, respectively.
Heat transfer analogy
The heat How into the bar, the heater temperature and the sensor temperature are related through


Electronics IJuly 27, 1964


1 r

----------------------ii, ___iour

Thermal transfer element consists of heater and sensor
transistors in a common silicon substrate.

"The bar used for the termal filter and oscillator
is mounted in a circuit board used for testing packaged semiconductor networks. The bar contains several transistors, and leads are brought out to contacts for five of these. Counting from the open end, the first transistor is the sensor and the fourth is the heater. Numbers 2, 3 and 5 are connected as diodes for monitoring steady-state temperature. The opposite end of the bar is soldered to a copper slug mounted to the circuit board.

~ ot

.. lC






+ :r~~~I 1I






The heat-transfer analogy consists of a semi-infinite bar (A) and an RC transmission line, where heat flow is analogous to current and temperature to voltage. The configuration (8) of the transfer element has a thermal path to a heat sink; this limits the steady-state temperature rise. The response for the RC equivalent circuit is similar to that of a distributed low-pass filter. The useful component of heat comes from the flow of a-c energy (shown in color) from the heater to the sensor.



Electronics I July 27, 1964


the classical heat-How equation with appropriate boundary conditions. A simple configuration, shown on p. 55, may be used to establish these relationships. The semi-infinite bar has a heat source at one end. Semi-infinite denotes a bar placed at the origin of a set of x, y and z axes, with infinite length in the positive x direction.
The assumptions are that heat is applied uniformly across the end surface of the bar and that the top, bottom and sides are perfectly insulated. The solution to the heat equation is identical in form to that of an RC tran smission line where heat flow is analogous to current and temperature to voltage. The analogy is shown on p. 55. The thermal bar is driven by a constant heat flow, P, which is independent of bar temperahue. Analogously, a constant current, I, drives the tran smission line. This establishes an input temperature

T, = P%


where T1 corresponds to Ei, the input voltage, and '110 , the characteristic thermal impedance, corresponds to the characteristic impedance Z. A traveling wave of temperature is established of the form


Based on these analogous relationships, the wellknown transmission-line equation s may be used to determine the transfer characteristics of a more complex struchue.
The configuration used for the th erm al transfer element is shown on p. 55. A themial path to a heat sink is provided to limit the steady-state temperatu re rise resulting from th e d-c power dissipation of the heater transistor. This configuration provides efficient a-c coupling between heater and sensor with good dis sipation for the d-c power.

Transmission-line analogy

The transmission-line analogy for the th ermal transfer element is an RC equivalent circuit with a response similar to that of a distributed low-pass filter. Measured amplitude and phase response for a th ermal element is shown at the right. F or frequencies approaching zero, the amplitude response approaches the value

T s(O)
F(O ) =A , Prr (O) = A1 '1' (0)


where '11(0) is the d-c thermal impedance from the heat source to th e heat sink.
The corn er frequency-the frequency at which the magnitude of the response decreases by three decibels-is determined by w(O) and the heater-tosensor spacin g. F or the geometry considered, th e corner frequency is about 1 cps. This could b e reduced somewhat by increasing the spacing L1 and L:! of the thermal b ar.
Thermal feedback amplifier
The thermal transfer element can be connected as a feedback loop around an amplifier. For this case the transfer characteristic is

A ' = - -1- =+- A-F, .A. .


in which A is the open loop current gain of the amplifier and F is the thermal transfer function . The calculated transfer function A' is plotted for several values of A (p. 57). For low frequencies, feedback is negative and the amplifier gain is low. The p eak in the response curve occurs at the frequency for which th e thermal element has a phase shift of 180° and the amplifier b ecomes regenerative. F eedback is decreased at high frequencies, and the response approaches that of the open-loop amplifier.

Low-frequency oscillator

A low-frequency oscillator was realized using the feedback amplifi er as a direct-coupled transistor circuit. As shown by equation 8, oscillation occurs at the frequ ency for which the th ermal tran sfer function has a phase lag of 180°, provided that IFAl > 1.0. For example assum e that at 180 degrees A is 200 and F is 0.005. Since F is negative for a phase shift of 180 degrees the denominator of equation eight becomes zero which is the condition for oscillation. The frequency of 180° phase shift (f180) may be related to the physical constants of the bar, using the tran smission line analogy. The thermal impedance presented to the source is the parallel combination of the input imp edances of a short-circuit line and an open-circuit line.
Since the spacings Li and L2 exceed one-quarter of a wavelength at f1so, it may b e shown th at each input impedance approximates th e th ermal characteristic impedance, '1'0 · As in th e case of the RC



o .01d' ,



0. 02~·


"C -10

~ -20



~ -30



.... -40 >



-50 -60






10 46100



30 60


90 120


150 ~

"' 180 <t .......J
210 en
240 :<rt 270 a..



At the sensor junction, thermal transfer element generates 8 .4 millivolts per watt of heater power at a frequency of 50 cycles. This voltage increases at lower frequencies. The bar is mounted in air, but others have been mounted on insulators of high thermal resistance.


Electronics I July 27, 1964

line, the characteristic impedance has a phase lag of 45°. Similarly, the resultant input impedance of the bar has a phase lag of 45°.
From equation 2, the transfer function will have a phase angle of 180° when the propagation factor

Thermal constants for silicon at 300°K

k -Thermal conductivity= 0.21 cal/sec cm· C

c - Specific heat

= 0.181 cal/gm· C

p - Density

= 2.33 im/cm3

<I> has a phase lag of 135°-the thermal impedance '1t lags by 45° as in the case of the analogous RC

circuit. This corresponds to the relationship


,R., L.- = -3411'

(9) ; 30






is the phase constant of the thermal wave through the bar. The physical constants of equation 10 are given above for silicon. From equations 9 and 10, the frequency of 180° phase shift is


~ 20

~"' 15
~-' 10


-"' 5.0




4J: fi so =



371" ]









The calculated frequency for 180° phase shift at 300°K is 40 cps, compared with a measured value of 46 cps.
Temperature effects

The peak in the response curve of the thermal feedback amplifier occurs at the frequency for which the thermal element has a phase shift of 180 degrees. One curve represents a measured response for one value of the open·loop gain. This response is in good agreement with calculations.

Shown to the right, f180 for the thermal element varies approximately inversely with the absolute ambient temperahue, TA· This is as expected since, from equation 11, f180 varies directly with the thermal conductivity, k, which is inversely proportional to TA· However, the measured oscillation frequency varies only 1% over an ambient temperature range of 50°C. Also, the substrate temperature is held practically constant for large changes in ambient temperature. This is because, at d-c, the amplifier and thermal feedback element comprise a negative feedback system that tends to maintain the substrates at constant temperature regardless of ambient temperature.
The average power dissipation of the source transistor decreases as ambient temperature in-

~>- ~i..150


lo.I Q.


a::-' >- I&.(.)
u30 .___ _,___ __._ _.L.__

_ . __


0.0029 0.0030 0.0031 0.0032 0.0033 0.0034 0.0035 0.0036


1 T4(°K)


creases, such that the substrate temperature increase equals the ambient temperature increase divided by the loop gain.
Although these experimental circuits use external components, they could be completely integrated into a common substrate using conventional semiconductor network technology.

15 20 25 30 35 40 45 AMBIENT TEMPERATURE °C
Frequency for a phase shift of 180° varies inversely with the absolute ambient temperature (A). The substrate temperature is essentially constant for large changes of ambient temperatures (B).

The authors

Walter T. Matzen is manager of the Molecular Functions Branch of Texas Instruments, Inc. He obtained his doctorate in electrical engineering from Texas A&M in 1954.

Robert A. Meadows, also of Texas Instruments, Inc., is investigating the dielectric properties of field-effect transistors. He is completing work on a master's degree in physics at Southern Methodist University.

Electronics I July 27, 1964


Solid state
Optoelectronics at work

Photon-coupled devices provide electrical isolation in applications ranging from oscillators to signal generators, modulators to multiplexers.
By Irwin Wunderman,
hp Associates, Palo Alto, Calif.

Conventional devices such as transistors and vacuum tubes use electrons for coupling signals thru the device. Because of the electron's charge, such structures do not have a high degree of isolation between the input and output circuits. To achieve this isolation function , a transformer is often used to isolate various parts of a network. Magnetic coupling has the disadvantage of being limited in bandwidth, impractical at low frequencies, useless at d-c, and not unilateral.
The disadvantages of magnetic coupling, and many of the problems associated with electron coupling in general, such as internal feedback and extraneous pickup can be overcome by using photons-a beam of light-as the coupling medium.

The cover

Photons are used, instead of electrons, for coupling circuits in a new family of solid-state components. The result: input-output isolation far beyond that of conventional devices.

The isolation afforded by the light beam is far superior to that of electron coupling because, when light is used as a signal carrier, the input and output circuits are electrically separate. Coupling between circuits at widely different potentials and over a frequency range from d-c to device cutoff is now possible.
A family of solid-state components has been developed to exploit the advantages of optical coupling. These consist basically of an injectionluminescent diode as a light source, a light pipe as an optical transmission medium, and a silicon photodetector.
When the diode is driven by an input signal, it emits a beam of infrared light, providing a photon stream proportional to the signal current. The stream travels through the light pipe to the detector. The detector's output current or voltage is then proportional to the diode's input.
The device is called an optic amplifier or a photon-coupled amplifier.
Properties of the amplifier
One version of the photon-coupled amplifier, the hpa 4302, consists of a gallium arsenide (GaAs) injection-luminescent diode irradiating a high-beta silicon phototransistor. The over-all current gain of the structure is close to unity with the base lead open. Under these conditions, the bandwidth is limited to several hundred kilocycles by the beta cutoff frequency of the phototransistor. Gain and bandwidth may be exchanged to some degree by connecting external conductance between emitter and base leads.
Where isolated coupling is required over greater


Electronics I July 27, 1964



The basic configuration of the photon -coupled amplifier has three elements-the injection-luminescent diode input, the light pipe and the silicon phototransistor detector which provides the output signal.

bandwidths, the hpa 4301 photon-coupled isolators can be used. These have a silicon PIN photodiode instead of a phototransistor. The frequ ency response is greater by two to three orders of magnih1de, with a correspondingly lower current gain In both these structures the emission from the GaAs source is coupled to the photodiode photodetector by means of a coherent-image bundle of optic fibers. The hpa 4104 consists of the source and an optic bundle, and can be used with a detached detector. Similarly the hpa 4202 phototransistor and the 4201 PIN photodiode are separate components, each in a package with a fiber-optic window.
The use of a coherent-image optic bundle enables the active semiconductor area to be projected to the exterior area of the package, thereby minimizing the need for external optics. A generalized comparison of photon-coupled and electron-coupled devices is shown on page 60.
Basic device operation
The photon-coupled amplifier shown above is an hpa type 4302. The input is a gallium arsenide (GaAs) injection-luminescent diode that emits light (photons) approximately proportional to the number of electrons flowing in the diode. This proportionality exists because a large fraction of the minority carriers. which are injected under forward bias, recombine radiatively giving up their energy to form photons. However, only a portioi:i of the photons so generated emanate from the semiconductor; the remainder are reflected from the surfaces and subsequently reabsorbed. The ratio of externally-emitted photons to the number of elec-

trons flowing in the diode is called the external quantum emission efficiency-typically 0.1 % to 0.3%. It is the device designer's objective to maximize this efficiency and to transmit the photons to the detector.
From the electronic viewpoint, the input of the photon-coupled amplifier appears as a conventional diode. Gallium arsenide has an energy bandgap of 1.4 electron volts and at a given current, the voltage is a few tenths of a volt higher than for a silicon diode. The emitted photons have an energy corresponding to the bandgap (1.4 eV, or = 9000 A). They propagate down the light pipe, and about 50% of th em arc usefully absorbed in the silicon phototransistor. This photocurrent is then amplified by the current gain of the phototransistor, a factor of several hundred. Output collector-to-emitter signal current is, therefore, comparable to the GaAs diode input signal current.
The configuration can be regarded as a high-gain transistor with two inputs; one a conventional base input, and the other a forward-biased diode electrically isolated from the transistor itself. Since the latter is spatialJy removed from and electrically independent of the output, a potential difference between th e input and output does not affect the operation of the device.
Pulse response is limited by the cutoff frequency of the phototransistor. The light source responds to an electrical input in nanoseconds. The time of photon propagation along the light pipe is of the order of 0.1 nanosecond. Although some of the photons impinging upon the detector are reflected back to th e source, this is independent of the output signal. Accordingly, the device exhibits completely

Electronics I July 27, 1964


4 120

~ 100


z wa:





Ca:l 40
"~ '
0u. 20

A 0.4 0.8 1.2 1.6 V1 FOWARD VOLTAGE


-10 -8 -6 -4 -2



100 200






400 500

"w>aaw::' ...:-

E 7


6 5


4 (.)


.0.... 3

w(__.,,) 2
0 1




B- 0 2 4 6 8 10 12 14 16 18 V2 EMITTER TO COLLECTOR VOLTS

~ 7

\;;; 6 w g§ 5

B 4


::? 3

w(__.,,) 2


. .c0



0 2 4 6 8 10 12 14 16 18


Volt-ampere characteristics of the photon-coupled amplifier include (A) the forward and reverse characteristics of the input diode, (B), those of the output phototransistor and (C), the current transfer characteristics for the entire structure.

unilateral photon signal transfer and is, therefore, electrically unilateral except for the slight parasitic output-input capacitance and very high leakage resistance.
Simple device model
The electrical properties are those of a GaAs diode at the input and a silicon phototransistor at th e output. The conventional volt-ampere characteristics for each of th ese components and the en tire configuration are illustrated above. The

forward transfer properties of the photo-coupled pair arc similar to a transistor. The cans surrounding each component are not electrically connected to the semiconductors and can b e used as electrostatic shields.
The basic circuit model for the structure is shown on page 61. Almost any equivalent circuit for diodes or phototransistors can be used in each portion of the device. For an input current level above two or three milliamperes, the photocurrent in the detector is approximately proportional to 11.

Characteristic properties of photon-coupled systems

Electrical isolation
Unilateral signal transfer
Minimal auxiliary components
Visual compatibility with man
Dual operability
Gain bandwidth product
Technological difficulties

Advantages of photon coupling
Input and output circuits are electrically separate and isolated. Resistance between light source and detector can exceed 1016 ohms. The capacitance may be as low as .0001 picofarad.
Signals are transferred unilaterally. Electrical conditions at the output of an optic amplifier are not reflected to the input. This permits independent design and operation of cascaded networks.
Logical circuit functions can be achieved with minimal auxiliary components. Because input and output are separate, an optic amplifier can be interconnected with itself and its neighbors in a great variety of useful configurations.
If visible light is used, the electrical state of the system can be made directly apparent to man. This simplifies checkout, servicing, and reading out information.
It is possible to perform either optical or electrical operations on the signal such as light fibers or conducting wires for signal transmission and optical focusing for electrical impedance transforming.
Present liabilities of photon coupling
Gain-bandwidth products that are now available are moderately low, typically 10' to 107 cps. Bandwidths range from 105 to 109 cps. Low gains are primarily due to the poor efficiency with which the light source converts input electrons into useful photons.
Linearity over large ranges is poor. This should improve with increased light-source efficiency.
As with other new devices, many theoretical and technological difficulties exist. These include: incomplete understanding of injection luminescence mechanisms, problems of channeling photons from the region of generation to the photodetector, limited availability of specific energy light source materials, difficulty of attaining room temperature injection luminescent lasers.
I Electronics July 27, 1964

At lower current levels the efficiency of the GaAs source falls off because of undesirable recombination which competes with the photogenerating process. This is analogous to the low-level b eta fall-off in a transistor. In th e simple equivalent circuits, a single effective output resistance and capacitance is used to characterize the emitter-tocollector properties.
Equivalent circuit
A detailed equivalent circuit is shown b elow. Approximate parameter valu es are d efined in th e table to the right of the circuit.
Th e input con sists of a spreadin g res istance, ri, in series with the junction resistance r,., shunted by th e junction capacitance. At zero forward bias, the transition capacitance is about 100 picofarads. With appreciable forward current fl owing, the diffu sion capacitance (associated with stored charge) increases in proportion to current, and predominates. Th e parasitic resistance and capacitance to th e input shield are included res pectively as rs1 and C.1. The conductance and capacitance b etween the GaAs input diode and the silicon output photodetector d epend s upon the length of the light pipe (and ex ternal shielding). For the type 4301, where the length of the pipe is such that the corona voltage exceed s 10 kilovolts, the leakage resistance is more than 1015 ohms and the capacitance, Cec, is less than 0.01 pf. No other solid-s tate device can provide a comparable degree of isolation.
The symbol il>E is used to denote a photon flux of il>E photons per second emanating from the diode surface, of which i!>p reach the photodetector.
The equivalent circuit of the output section is th at of a conventional transistor. Impedance parameters are shown, enabling association of the phys-
+ ical res istance and capacitance mechanisms with
the circuit model. A current generator (I1, ip) is used to represent the effect of the (d-c plus a-c) photon flu x coupled from the input source. The

usual transistor collector-current generator, Ir, the collector junction resistance, re, and capacitance, Cr, are present. Th e res istance in series with the emitter lead is r2 while the emitter junction is characterized by th e parallel combination of rc2 and C,.~. At moderate current levels, the phototransistor current-gain , bandwidth product is approximately given by:
f, = l / 2?rr.-zC.2
For small values of external load resistance R1, (and th e base lead floating), the over-all cutoff frequ ency of the photon-coupled amplifier is:
f c = (1 - a) J,
For larger valu es of R1,, the 3-db bandwith is RC-limited and reduced to:
f c = (1 - a ) 1211" R L C,.
The base resistance is divided into two parts, the relatively large series resistance between collector and emitter being due to the sheet resistance of the photosensitive p ortion of th e base layer. Both discrete base resistors represent a lumped approximation for th e actu al continuous resistance distributed b etween them.
Input current is the primary independent variable for the photon-coupled amplifier. Typical dep endence of variables upon this parameter is shown on p age 62. At low currents, the efficiency of the GaAs source is a monotonic function of the current. The a-c gain exceeds the d-c gain by a factor of two. The over-all current-transfer, cutoff

= = Approximate parameter values for equivalent circuit
conditions: I, 30 ma, V, 10 volts

Parameter Electroluminescent diode Series resistance Junction resistance
+ Transition diffu -
sion capacitance Forward voltage knee

c. v.

Nominal Value
2 ohms I ohm 3000 pF
1.2 volts

Parasitic coupling
0~e~~ ic,d resistance
Sem iconductor capaci· tance to shield
Inpu t-output resistance
I nput-outpu t capac itance

r,1 & r,2 C.i & C,2
c ··

>Hl' oh ms 1 pF 10" ohms 0.01 pF



A single effective output resistance and capacitance characterize the emitter-to-collector properties of the simple equivalent circuit. A detailed equivalent circuit (below) for the electroluminescent diode and output phototransistor includes the parasitic impedances.

Phototraneis tor Collector capacitance Collector resistance Cu rrent transfer ratio Emitter junction resistance Emitter junction capacitance Emitter "contact" re s is t a nc e Base sheet resistance Base con tact resistance
Over·all curre nt t ransfer ratio

c .2
t J--J -IIat-

Device ratings Maximum input-output voltage 10,000 volts peak Device dissipation at 25° C 100 m w for each device. Case-temperature-dissipation dera ting 2.5 mw/ °C I nstantaneous peak input current ( 11 peak ) 500 ma

5 pF 10' ohms 0.997 3 ohms
500 pF
50 ohm s
300 ohms 50 ohms

Electronics I July 27, 1964



.Iz.-, 5




en 0z 1.0

a: 0.5


::::; 0.2



~ Q..





g ~


0.2 1.0
~ 0.02
O.Q1 0.005

:-; 0.05 z <i <.!) 0.02
(.) <(



....C. l


z <i 100

aa:: 50 =>

ga: 20

;e;n; z




~ 5



;;; ~ 500
g 200


~ 100


0 z




"a..:,' 20
:::; ::E 10
.~ .. 5


1.0 2

5 10 20


..... 2
c=>J 1.5
> ~ 1.0 ~
.~ ....
a: 0.5
-0.1 20 -10 0

Parameters vary with the input current which is the primary independent variable for the photon-coupled amplifier (A). Some important parameters are temperature-dependent (B).

10 20 30 40 50 60 70 TEMPERATURE °C

frequency (with the base floating and a short-circuit load) is essentially the same as the beta cutoff frequency of the transistor itself. The temperature dependence of the important parameters is shown above.
The HPA type 4104 GaAs light source and 4202 phototransistor have equivalent circuits and device ratings corresponding to their respective halves in the photon-coupled amplifier. The optically sensitive regions are 0.020-inch diameter circles on the surface of the light pipe. The model 4201 PIN photodiode has an equivalent circuit similar to that shown on page 61 (exclusive of all parameters to

the right of re) and Cc is about one picofarad. The photodiode has a response time of about 0.1 ns with a 50-ohm load and a quantum yield of 50%. Response to a step of light is characterized by 70% to 80% of the total response in 0.1-0.2 ns whereas the remaining portion of the response requires about 100 ns. To achieve these speeds a minimum reverse-bias voltage of 20 volts is needed across the diode to extend the depletion region from the p to the n material.
The frequency response of the GaAs, PIN photodiode optic isolator is limited by the injectionluminescence diode to about 100 Mc.

Applications for optic couplers

Photon coupling is used in the simple isolated amplifier and the small -signal linear amplifier

There are many potential applications for photoncoupled amplifiers.1 Those which follow concentrate on use of the GaAs phototransistor, photoncoupled amplifier. Unless otherwise noted, the figures and discussion refer to type 4302 devices. The majority of th ese circuits have been built, or bread-

board ramifications have been examined.
Simple isolated amplifiers
The photon-coupled amplifier illustrated on page 63 can transfer and amplify signals without an electrical connection between the input and output


Electronics / July 27, 1964

I let INt


I -z..._






0 2 4 6 8 10 TIME (/'SEC!

The simple isolated line coupler (A) has the basic circuit shown in (B) and exhibits the typical pulse response (C). Its isolation properties extends from d-c to the cutoff frequency of the device.

z 10



5~------------------------. . . .



z Ci


~ 0.5


<~.!> 0.2

0 >

0.1 ~-::--~--~--~---,--~-~___,..--~

5x103 104 2x10 4 5x104 105 2x105


The small-signal linear amplifier has a common mode rejection of 230 decibels. Power gain occurs at the transistor input stage, in the optoelectric conversion at the GaAs diode and at the phototransistor detector.

circuits. The isolation property extends from d-c to the device cutoff frequency. It can be used over this frequency range to couple circuits that have no common connection and are at widely different potentials. The independent diode or transistor can itself be employed to replace its conventional counterpart in a circuit. Examples of applications are:
1. Remote sampling of current waveforms in existing diode circuits by replacing the in-circuit diode with the GaAs electroluminescent diode.
2. In transistor circuits, the functions of triggering, shifting of d-c signal level, or coupling where direct electrical connection is undesirable, by replacing a given transistor with the optic amplifier phototransistor.
3. In place of pulse transformers, particularly if d-c restoration of the signal is important.
4. Elimination of ground loops in large systems by avoiding multiple conductive paths between portions of the circuit. Large induced circulating currents and IR drops are prevented by utilizing optical coupling paths.
5. Isolating the separate black boxes in a large system to prevent a malfunction in one box from affecting the others.
If necessary additional amplification can, of course, be added to further increase the signal level.
Small-signal linear amplifiers
There are many applications which require direct-coupled linear amplifiers having Boating inputs. This function is generally fulfilled by conventional amplifiers or transformer-coupled systems

using a modulated carrier frequency. The commonmode signal rejection that can be achieved by these systems is usually limited to about 160 decibels. The amplifier illustrated above has a common mode rejection of 230 db in addition to being less vulnerable to extraneous pickup. Optic amplifiers are used to couple the signal from a differential Boating input transistor stage to the output. Power gain occurs at the transistor input stage, in the optoelectric conversion at the GaAs diodes, and at the phototransistor detectors. The composite gain and frequency response is shown.
Field-effect transistor preamplifiers can be used instead of, or in addition to, the input transistors to achieve high input impedance. As shown, the output phototransistors are electrically reversebiased while being optically forward-biased. The resultant equivalent input noise properties are thereby improved.
Potential applications of the differential amplifiers include: 1) isolated current probes, or other instrument probes; 2) bridge output amplifiers, differential to single-ended couplers; 3) thermocouple, or other transducer amplifiers; and 4) signal ground loop isolators, Boating-input null amplifiers.
High-voltage regulated supplies
In many systems, error feedback signals must be generated to maintain the system's equilibrium. For example, a voltage in the circuit is compared with a voltage standard or reference. One common use of this method is in a high-voltage regulated power supply which has reverse-biased semiconductor diodes as a reference. The limited range of reference standards, however, often prohibits a direct differential comparison.
A simple solution is provided through the use of the optic amplifier shown above.

Electronics I July 27, 1964


--- I /\11 AUXILIARY

-/1 I
/ -'--~







_ _ _ __,,






The high-voltage regulated power supply uses a photon· coupled amplifier for feedback control.

_::t-M--1- i
IINTE~~ ':"
A relatively small grid-to-cathode signal for modulating the beam intensity is direct-coupled by Optoelectronics.


~ -v




The crystal-controlled oscillator has an isolated output. The d·c bias current level is simultaneously monitored and can be used for automatic temperature compensation and amplitude control. The regenerative flip-flop in the oscillator uses the isolation coupling element down to d·c.

Under stable conditions, the GaAs diode is slightly forward-biased. A change in the regulated output potential alters the forward current. This change is coupled to the phototransistor which acts as a two-terminal controlled current source and compensates for the initial variation. From the voltampere characteristics shown on p. 60 it can be seen that the optic amplifier is very sensitive to input voltage changes. In more sophisticated systems, the feedback loop again can be increased and the thermal characteristics of the gallium arsenide diode can be directly incorporated in the design of the reference. An additional optic amplifier may also be used to sample the load current and control readout, overload protector or vernier controller.
Z-axis, cathode-ray tube modulator
Cathode-ray tubes require acceleration potentials in the kilovolt range. It is usually convenient to apply signals to the deflection plates at close to ground potential. The grid and cathode are then

several thousand volts negative with respect to ground. It is difficu lt to direct-couple to another circuit a relatively small grid-to-cathode signal for modulating the beam intensity. Generally this is accomplished by having a dual high-voltage supply (one for the grid and one for the cathode) and superimposing the control signal at a point where one supply returns to the ground. The additional capacitive loading of the high-voltage transformer and rectifier limits the bandwidth over which the intensity can be modulated. In addition, small differential variations between the two high-voltage supplies appear as large variations in intensity. The optic amplifier does not suffer from these diffi-
culties. The simplicity of the coupling circuit
shown above is apparent.
Oscillators and signal generators
Load variations degrade performance in many circuits. A crystal-controlled oscillator can have excellent frequency stability if load variations are


Electronics / July 27, 1964




Photon-coupled amplifier provides narrow bandwidth for a phase-sensitive detection circuit and thus reduces noise.






~ <D 10-2


....z.........Z ..-..... ~

!~10- 3

....,,a:: .....




· J »

10-5 e~~~:i__--.1.._..L_u...J 10-6 10-4 10-2 10° 102 104 106 Io/ Ib
The simple coaxial-line modulator, insert, uses series and shunt phototransistors to form a photon·controlled attenuator. The insertion attenuation is for a two·element optic attenuator.

minimized. Isolation resistors may be used to reduce the effect of load changes.
However, the use of an isolation resistor decreases the available power output and the signalto-noise ratio. Thus the spectral purity of the desired signal is decreased.
The photon-coupled amplifier or isolator can be used to achieve this isolation function since it possesses no output-to-input feedback. It appears (see p. 64) only as a passive element, a diode, in the regenerative loop. Load changes at the output will have no effect upon the performance of the oscillator itself. It is noteworthy that the oscillator d-c bias-current level is simultaneously monitored and can be used for automatic temperature compensation and amplitude control.
Photon-coupled oscillators can be designed with features other than isolated outputs. Many oscillators are possible using the optic section within the regenerative loop. The property of electrical isolation down to d-c permits a greater degree of

topological design freedom-in much the same way as the transformer proves useful in the design of a-c oscillators. Broadband regenerative circuits such as flip-flops and Schmitt triggers now can use an isolation coupling element that is analogous to the transformer, but extends to d-c. A great variety of new switching circuits using these components is possible.
Synchronous demodulators and detectors
If a reference waveform of a signal source is available, optic amplifiers may be used for phasesensitive detection as shown at the left. A variable-frequency reference signal (sine wave, square wave, or pulse) is applied to a test network. In addition to driving the test network, the signal source supplies a replica of this excitation waveform, e1n, to the GaAs diode. The phototransistor rectifies the output of the test network, thereby providing a d-c signal proportional to e0 · By increasing C and R, the effective pass band of the detector can be made as narrow as desired without the attendant problem of h·acking the signalsource frequency with a narrowband, or comb filter. The noise power of the system is, of course, reduced in proportion to the bandwidth. Phase as well as amplitude information can be resolved by maximizing Ed at each frequency by controlling the phase shifter.
Modulators, mixers, and time-varying switches
A simple coaxial-line modulator is shown at the left. The series and shunt phototransistors form a photon-controlled atte1rnator. This simple configuration has potential uses for: 1) general-purpose electronic potentiometers; 2) fast, automatic gain or level controls; 3) low-level, d-c to a-c choppers (or d-c level switch); 4) intentionally injecting spurious or random signals into systems for malfunction-susceptibility evaluation or noise measurement; and 5) mixing two, or more signals.
Other optically-con trolled attenuator and amplifi er combinations are possible. These operate independently of the potentials between the control and output ports. Their frequency response extends to d-c, and they do not introduce large extraneous signal transients in switching appli cations. The GaAs diodes might be acting simultaneously as envelope detectors, or mixers themselves, for veryhigh-frequency input signals.
It is also possible to form other modulator configurations using optic amplifiers. Many inputs can be used to feed a single line, or conversely, a single line may fan out to numerous signal paths as established by controlled phototransistors.
Optical switching applications can also be performed since the input and output halves of the optic amplifier can be provided separately. When the ends of hpa. types 4104 and 4202 are brought together, an optic amplifier is formed. They provide a coupling element that can be connected or disconnected by physical motion. Such optical switches have no contact bounce, produce minimal

I Electronics July 27, 1964







Six versions of the symmetrical Eccles-Jordan fl ip-flop circu it have photon coupling: between the collector-to-collector and the series-base element (A) ; between the collector-to-collector and the shunt-base element (B) ; between the series collector and the shunt-base element (C) ; between the series emitter and the shunt-base element (D) ; between the collector clamps and the shunt-base element (E), and between the shunt collector and the collector-base element (F).


Electronics IJuly 27, 1964

on-off transients, mm1mize electrical changes during switching, and can provide varying degrees of coupling.
High speed relay
The conventional electromagentic relay has survived as a high-usage component because of the flexibility afforded by its input-output isolation. Most of th e applications of low-power relays for signal control can use the new solid-state optical devices with a resulting improvement in speed and reliability. It is possible to form relay-logic trees, turn-on-and-off circuits and provide interlocks. A comparison of the basic properties of these two systems is shown in the table b elow.
Multiplexers, commutators, and signal samplers
Modern information-handling systems involve signal commutation. In th ese systems , it is convenient for the time-sequencing controls to remain electrically separate from the information signals. The speed and isolation capabilities of photoncoupled devices make them well suited for such applications. Shown b elow is a simple multiplex amplifier in which each input is successively sampled. Information on the "n" parallel input channels is fed serially to the single-channel ampli-

fier. If n ecessary, at a later point in the singlechannel link, an additional decommutator can synchronously separate the "n" amplified signals. The single channel may itself involve a telemetry link, a pulse-coding system , or an isolated amplifier as shown earlier. One of the inputs can be shorted and another conn ected to a reference potential to provide an "n" channel amplifier with chopper stabilization of zero drift and gain.
If the phototran sistor is designed for multiplexing applications, p erformance limitations such as differential phototransistor offset potentials , and speed of response are comparable to transformerdriven tran sistor switches. The optical device permits a periodic drive signals, and introduces smaller transients th an do magnetic systems. Signal gains are less than with conventional transistors and the devices typically require greater drive power.
The work leading t o the photoncoupler was jointly sponsored by the Air Force Avionics Laboratory Research and Technology Division and the Hewlett-Packard Co.
1. I. Wunderm a n , Photo-Coupled Circuits, Air Force Avionics Laboratory, Technica l Documentary Report No . RTD -TRD-63-4260, Jan. 1964.


Comparison of electromagnetic relay and optic relay





Optical devices improve the speed and reliability of the double-pole, single-throw relay.

INP lii ----1,._..,,
INP UT ----1,._..,,

Parameter 1\1 ax imum speed of res ponse ]n p u t - 011 tpu t resis ta nce Co n tact res iRt a nee " On " Leakage res istance ar ross contacts Lea.katre capacitance t hro u.e:h co ntac ts Input-ou tp u t ca pa 1·ita n cc 0 11t µu t contact <'11 rrc n t lim it M aximum open f'o n tac t voltage M aximum input-ou t put v oltag:e Actu a ti ng powPr S torC'rl cnC'rl!:-.·
M irron li ll' ·i ··
Rp11 r ious ra.<liaLed fi elds
L ife

Electromagnetic relay Optic relay

1 cps to 10' cps

]()< cps to 1()8 cps

109 to 101:; ohm s

101:; ohms t o a:i


N omina.lly 100 ohms

109 to 1012 ohms

10· to 1()9 ohms

1 pf

5 pf

2 pf

.01 pf

many ampe res

100 ma

IOOV to 2000V

20V to 50V

JQ3V to l(}IV

Virtually unli m ited

10mw to 1 W
Large inductive trn.ns.ie n ts
~usccp ti ble t o ,·ihratio n, shock; a. nd con tac t bounce
Di fficu lt t o sltield out ra diated mag netic fi elds Lirni led to Ill'· to 10· cycles

lmw to lOOmw Predomina ntly r esistive in put, no tra ns ien ts All solid state (no moving parts)
O ptical shielding from external environm ent is s im ple Solid state, no known w ear-ou t mecha nism

The author

Information on then-parallel input channels is fed serially to the single-channel multiplex amplifier. The time-sequencing controls are electrically separated from the information signals.

Earlier this year Irwin Wundeman was awarded a doctorate in electrical engineering by Stanford University. Since 1952, he has been working on solid -state devices. Wunderman has been with the Hewlett-Packard Co. for eight years; the last three have been spent in optoelectronic research of hp Associates, an affiliate of the company.

Electronics \ July 27, 1964


Stray signals can't throw this desensitized switch

It discriminates between r-f energy and a d-c pulse by using an extra zener junction

By John M. Gault and Richard J. Sanford

Spurious radio-frequency interference can trigger a semiconductor switch with disastrous results. For example, a circuit used with an explosive load such as a warhead detonator could be set off by a spurious r-f signal. The switch must b e designed to reject unwanted r-f energy and accept the desired d-c pulse that triggers it.
The switch shown (page 69) meets these requirements. It is triggered by a small d-c signal. Any stray r-f signal, induced between the gate and cathode, will not energize the load. The device can be used instead of pnpn switches in applications where signal interference might be a source of trouble. Diagram B (page 69) shows a lumped component equivalent of the desensitized switch.

Tentative specifications of desensitized switch

Range of protection: Anode: ± 100 volts, de to 29 Mc Gate: 100 kc to 29 Mc
Gate firing signal:
+ 0.5 ma at 10 volts (maximum)

Current handling ability:
0.5 amps de 10 amps for 5 milliseconds

Temperature range:

Operating - 65 ° C Storage -65° Cto


+ 80°
15 ° C


lnterlead capacitance: Approximately 60 pf between any two leads
Case: T0-5 can
Weight: approximately 1 gram

The firing level
The operation of the desensitized pnpn switch is best understood by examining the structure of au ordinary pnpn switch, on p. 69, bottom. Construction begins with a single crystal of pure silicon. Four alternating layers of p and n material form th e three interacting pn junctions. In the diagram, from bottom to top, these junctions consist of th e emitter or cathode, the collector, and th e conjugate emitter or anode. The two lower junctions form, in effect, a high-gain npn transistor. ThC' upper two junctions form a low-gain pnp transistor. Both transistors use th e same collector. The normal alpha, or d-c common-base forward current, of each transistor increases with collector current at low currents. Since the tranEjistors are connected for positive feedback, the device switches on when the collector current rises to such a value that the sum of the alphas exceed unity. A forward bias of about one-half volt must be placed across the emitter junction to raise the collector current to a value that will £re the switch. And so any d-c or r-f signal, which can raise the emitter to about one half a volt can fire the switch. 1· 2· 3 · 4
Switching ability
Any pnpn switch has some inherent protection against r-f signals introduced at its gate lead. The capacitance of the emitter junction combines with the resistance around the gate contact to form a simple RC Biter. This will attenuate a radio frequency signal.
In principle, an RC attenuator can give any amount of r-f protection desired. But practically, there is a trade-off between the desirable switching characteristics and good r-f Biter characteristics. Good Biter characteristics interfere with switching


Electronics J July 27, 1964

ability, and at the upper limit of filtering, the switch may not work at all. The capacitance, C, is limited by the cathode area and by the maximum allowable doping level of the p-type base region. These, in turn are limited by the requirement that the device be a good switch. The resistance, R, is somewhat limited by the manufacturing technique used in making the junction. If R is made high, this will limit the current needed to fire the switch. Further, there is a stray capacitance shunting this resistance, and if the resistance is made too large, the shunt capacitance dominates the impedance and the filter becomes a capacitor divider. Finally, an RC attenuator always introduces an undesirable time delay in switching action.
It is desirable to supplement RC protection by a method that discriminates between r-f energy and the d-c pulse. The most obvious difference between these signals is that the r-f changes its polarity continually, whereas the d-c pulse does not. If a switch is to be fired by a positive d-c signal, but not by a negative one or by r-f, the negative halfcycles of the r-f can be used to produce an inhibiting or desensitizing signal to prevent the switch from firing.
The RC filter
The desensitized pnpn switch consists of a normal four-layer switch structure with the following modifications: A resistor is diffused around the periphery of the switch and connected in series with the gate. This resistance combines with an abnormally large emitter capacitance to form an RC filter which attenuates r-f signals introduced between the gate and cathode leads. Between the resistor and the gate lead is a diffused zener junction which breaks down at eight volts. This extra junction rectifies r-f signals applied between gate and cathode, and places a reverse bias on the emitter junction. This must be overcome before the r-f signal can fire the switch. In normal d-c operation the gate voltage is raised slightly above the zener breakdown voltage sending sufficient current through the emitter to fire the switch.
The zener junction in this device is unusual in two respects. It has a small capacitance to keep it from being bypassed by the r-f. The junction is also carefully isolated from the rest of the switch structure. The electrons injected into the p-region of the zener junction during the negative half-cycle cannot diffuse to the collector and fire the switch. The small capacitance is obtained by limiting the area of the zener junction. Zener isolation is achieved by diffusing the collector junction to a greater depth under the zener than under the emitter. This longer path greatly decreases the probability that an injected electron will reach the collector before being recombined.
Prototype switches were fabricated by lapping a









Radio-frequency signals are attenuated by a resistor diffused around the periphery of the switch (A). The lumped component equivalent of the desensitized switch is shown in (8). The load in circuit (C) will not be energized if an r-f signal is induced between gate and cathode.









An ordinary pnpn switch can be fired by any d-c or r-f signal.

Electronics I July 27, 1964


Desensitized silicon pnpn switch, prior to encapsulation.

Desensitized switch ...



t 120

a: i.:


0........ 80


0 >


"a-: 40


20 2N1882






100 MC

Median gate sensitivity of desensitized switch is compared to that of a conventional 2N1882 device.

group of 50 ohm-cm n-type slices of silicon to a thickness of about 0.008 inch. The slices were etched to remove lapping damage, and one surface of each slice was polished to a mirror finish. The slices were cleaned and oxidized for 16 hours in an ambient of wet oxygen at l,170°C. The oxide was removed from small areas on the polished surface of the wafers with Kodak metal etch resist and a special mask; then oxide was removed from the entire unpolished surface of the wafers. The slices were diffused in boron for 140 hours at l,150°C, creating junctions at a depth of about 0.0018 inch.
This diffusion produced the conjugate emitter (anode) junctfon and the thick p-type region needed to isolate the zener. The slices were reoxidized for two hours at l ,170°C. The oxide was removed from the collector and resistor areas and the slices were then reoxidized for 16 hours at l,l70°C. A portion of this oxide was removed for the cathode and zener junction diffusion which consisted of phos-

phorous diffusion for one half hour at l,130°C in an ambient of phosphorous pentoxide and oxygen. The slices were cleaned in hydrofluoric acid and oxidized for one hour at l,170°C. After the oxide was removed from the cathode, zener gate, and anode surfaces, the surfaces were plated with nickel and gold. The slices of silicon were diced into units with a scribe-and-break process. Then, 0.002 inch diameter gold wires were bonded by thermal compression to the zener gate areas. The dice were soldered to T0-5 headers, etched, varnished and tested. The photo above shows a desensitized switch in this stage of fabrication. Caps were then welded on the headers to create a hermetic seal.
Gate sensitivity
Two lots of switches have been produced satisfactorily. Of the 17 switches in the final lot, all are less vulnerable to either gate or anode r-f signals than are conventional pnpn switches. The nine best

The authors
- John M. Gault, physicist, heads microcircuit development for the International Rectifier Corp., El Segundo, Calif. His work on the desensitized switch was in cooperation with the Naval Ordnance Laboratory. He has aided in the development of various tantalum capacitors, selenium rectifiers and silicon integrated devices for industry. Gault was
born in Cameroon, West Africa, in 1924.

Richard J. Sanford is a physicist in the advanced engineering division of the Naval Ordnance Laboratory at White Oak, Md. He has investigated the hazards of electromagnetic radiation to solid state components and has two patent applications pending in that field. Off the job, he is an enthusiastic spelunker and pistol shooter.
Electronics I July 27, 1964

... and its performance





t2o ~
~ ~:...J 15t-

<cz!c> 10t-


!:i 5




20· 30· 40·

s..oL ·






C> C[
g0.75 z


Response of gate r-f sensitivity (upper line) and d-c response (lower line) with temperature

Voltage drop in conducting switch. Graph uses a semi-logarithmic plot.

switches were selected as representative of desensitized switches of the future. Their median gate r-f sensitivity is compared to the sensitivity of a typical conventional pnpn switch, in the graph on page 70. The sensitivity of the new switch decreases rapidly at frequencies above 100 kc, while the conventional switch remains sensitive to much higher frequencies.
The gate r-f sensitivity decreases with increasing temperature, although the d-c sensitivity increases with temperature. This is shown in the graph above left. When r-f is applied between anode and cathode, the switches are not fired by 100-volt signals at frequencies up to 29 Mc.
The forward voltage drop in the switch in its on, or conducting, state is shown above. A semi-logarithmic plot has been used. The current is an exponential function of voltage between 10 and 500 megacycles.
Other properties of the switch are shown in the table on page 68.
These prototype devices prove that pnpn switches desensitized to r-f energy can be fabricated. But further work is needed to go from a handful of prototypes to production. During further development, the tentative specifications can be changed, if necessary, to meet specific needs of military systems.
Cans and chips
The prototype units are housed in T0-5 transistor cans, which have rather poor power dissipation. Identical device chips could be mounted in small stud-mounted cans. This would increase the current-handling ability without changing the other

electrical characteristics. Slightly smaller chips could be mounted in T0-18 or microtransistor cans; they would be compatible with the larger cans if higher power dissipation were needed. Thus, the mass production of only one type of silicon chip could result in a series of densensitized switches covering a wide range of sizes and power capabilities.
The desensitized pnpn switch can be used in any location where radio frequency interference might be troublesome. The switch has a capacitance value of 60 picofarad between any two leads, presents very little resistance to a d-c signal, and can be used to isolate a section of a d-c circuit from unwanted radiation sources. At higher frequencies , a small conventional Riter, or ferrite or carbonyl-iron attenuator can supplement an r-f blocking job without increasing the d-c resistance significantly.6
1. Lowry, et al. Controlled Rectifier Manual, General Electric Co., Auburn, N .Y ., 1960.
2. Sanford, R.J., RF Sensitivity of Controlled Rectifiers, Naval Ordnance Laboratory Technical Report 63-56, Apr. 1963.
3. Sanford, R.J., Can RFl-Control Prevent Weapons Failures?, Electronics, Nov. 8, 1963.
4. Sanford, R.J ., RF Sensitivity of Controlled Rectifiers, Second Hero Congress 1963 on Hazards of Electromagnetic Radiation to Ordnance, Apr. 30, May 1-2, 1963.
5. Gault, J.M., Final Report, U.S. Naval Ordnance Laboratory Contract No. N60921 -7050, PNPN Tiede Semiconductor Switch, International Rectifier Corp., El Segundo, Calif., 1963.
6. Wood, et al., Development of Broadband Electromagnetic Absorbers for Electro-Explosive Devices, Second Hero Congress 1963 on Hazards of Electromagnetic Radiation to Ordnance, Apr. 30, May 1-2, 1963.
7 . Sanford, R.J ., RF Desensitized Switch, Naval Ordnance Laboratory Technical Report 64-43 (to be published).

Electronics I July 27, 1964


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.


A 1

01 1N270






_ _ _ _,___n Eo

03 2N876

B 1

02 1N270

04 1N337



Register setting is held until circuit is reset by application of En. Waveforms depict input, ou~put and reset voltages (right).

0 -j----- t


_,:-12 I



Ee ~---tr---1---

----r 1



Eo 0 _1 ____ _1

-12 I







:0 I

lI r

Displaying the contents
of a computer register
By James J. Collins
Kollsman Instrument Corp., Elmhurst, N.Y.
An indicator circuit was needed that would sample the contents of registers fa small special-purpose computers, then display the information by visual means. A silicon controlled rectifier, used as a combination register and lamp driver, provides the solution.
The computer register to be sampled is connected to input A, and input B is supplied with a IO-microsecond, 12-volt positive pulse. The state of the register is indicated by the lamp.
If the signal applied by the register at A is at its low level (- 12 volts), D 1 will conduct. However, D2 will not operate because the trigger voltage applied at B will make its cathode more positive than its anode. The negative voltage at the junction of the diodes will maintain the rectifier in the nonconducting state and the lamp will not light.
If the signal applied by the register at A is positive (actually at ground potential), the positive trigger pulse introduced at B results in a coincident positive voltage (an AND circuit gate voltage) being applied to the base of the silicon controlled rectifier. This causes the silicon controlled rectifier to conduct. The voltage placed across the incandescent lamp turns it on.
The level of the voltage triggering the scr is determined by R1 and R2, which act as a voltage divider.

Because the output of this circuit also was used
to drive a digital-to-analog converter, resistor R1
was placed in parallel with the lamp as a precaution against its failure.
The circuit is reset by reverse-biasing the anode of the silicon controlled rectifier. The output lead, normally clamped to ground, is switched to -12 volts for 50 microseconds. Since the scr cathode is at - 11 volts, this provides enough reverse bias for reliable resetting.
In the waveform diagram shown, the register is negatively set when sampled at time ti and positively set when sampled at t2. Resetting occurs at t3·
Added transistor decreases
multivibrator reset time
By Steven A. Bell
Bennett Respiration Products, Santa Monica, Calif.
Adding a low-cost conventional transistor to a freerunning multivibrator circuit allows rapid resetting of the multivibrator and eliminates the need for a more expensive device, such as a unijunction transistor. In the circuit shown, the addition of Q:i reduces by a factor of about 30 the time required to recharge capacitor C1·
Transistor Q2 is saturated by the negative supply voltage applied through R3 to its base. With Q2 conducting and C1 charged as indicated on the circuit diagram, the negative side of C 1 is clamped to ground through diode D1 and Q2· Transistor Qa


Electronics j July 27, 1964


Rz fK


C3 0.001
R4 100K

+ 1N625


02 2N404

Addition of Q. and D, to a conventional .astable
multivibrator circuit allows rapid recharging of c,

DISCHARGE f . - t -
a, BASE~~

114-5 m SEC I ~ t~0.6R5Ct





o - - - , r - 03EMITTER
VOLTAGE _ _ _ _ _ _ _ _ \I_ _ _
n- -- 10
0 COLLECTOR O- - - - - 1


~ r-IOOµ,SEC +100-------~---


A Voltage waveforms

Resistor R. determines frequency

100 BO 60 40 20

IOK 20K 30K 40K 50K R5 (0HMS)

is off because its emitter-to-base junction is slightly
back-biased by the forward conduction voltage
across D 1· Transistor Qi is also off because of the positive voltage placed at its base by the charged
Ci. Capacitor C2 has been charged by the supply
voltage. No current flows through R1. Capacitor C1 starts to discharge. The discharge
path consists of R5, R2, and D 1· When the negativegoing voltage at the base of Q1 drops to about -0.4
volt, Q1 begins to conduct. Since the voltage across C2 cannot change rapidly, a small initial flow of
current through Q1 produces a small voltage drop across R1 and back-biases the emitter-to-base junction of Q2. Transistor Q2 turns off rapidly.
A current path now exists from ground through
the emitter-to-base junction of Qi, Ci, the emitterto-base junction of Q~, and R2 to the negative supply. Thi~ current- initially 10 milliamperes -
causes Qi to turn on rapidly and Q3 to conduct
heavily. Transistor Q2 is held off until C2 discharges
through R3 and Q1. During this period, C1 charges through R2, and the emitter-to-base junctions of
Qa and Qi. When C2 has discharged sufficiently, Q2 starts
to conduct, Qi and Q3 turn off, C2 charges through Ri and Q2, and the cycle is repeated.
If Q3 and Di were not used in this circuit, the time required to recharge Ci to a voltage approaching the supply voltage would be approximately 1.5 R2Ci or 150 milliseconds. Transistor Qa multiplies the charging current by the beta of the tran-
sistor (about 30) and reduces the time by the same

Using a value of 50,000 ohms for R5, the circuit provides timing pulses which vary in frequency from 90 to 20 cycles per minute (or periods from 0.67 to 3 seconds). Capacitor Ci recharges in less than five milliseconds.
Nomograph shows phase-shift angle
By M. Grelot
Vitry, Seine, France
The nomograph shown below gives the phase shift, cf>, obtained at any specified frequency, f, in a resistance-capacitance phase-shifting circuit. If the values of resistance, R, and capacitance, C, are

.1. 'f'


d I ~ 20 l O 40 60 90 100 120 140


I 1



/ h160



Ill 4' 10tGRtCS I

c J I 111111!1 I 'I l!llJI [\; I lllllllj 1)1'4 tl lllj l 11111111 1 11111111 c H ARAOSI



10 \

10- /

10 - 1

10- '

10- $

. ------------\/"X\~------------------.

' 111111 IO'

g / \ I 1111111 1 1 ~ I 11 I 111 '\: 1 11 111 11 1111 111111111

10 1


10 4

10 J





11 I

1 1 1 1 111 1!

1 1 1 111~e

1 1 1 111111 R1011ws1

10 I

!O J

10 4


Nomograph simplifies phase-shift calculations.

Electronics I July 27, 1964


i/J ( 10 15 20 30 40 60 90 lOO 120 140





- 1 - 1- - l l i - - l + - - . 1 - + - I...,.- + l - l -1-+-I-11--ll-+-I+-I+I-+-I-+-I-+l---r1-+l-r1-+-I- - . . - + - 1- - - . - - . - _ , , . - - , - - -


Ic I I' 1·1·111111 I I ·1·1·111111 I 1·1·1·111111 I 1·1·1·111111 I I II I' 111111 I I I'I'111111 c (FARAOS,








a--------------------~---------- ti

I f 111111'1'1 1 I I 111111'1'1'1 I 111111·1·1·1 I 111111·1·1·1 I 111111 11'1'1 I 111111'1'1'1


10 1

10 6

10 5

10 4

t0 3



10 2

111 I I I I I II

I I I II 11!
10 4


When three of the four quantities R, C, f, and <P are known, the fourth may be determined from the nomograph

unknown, suitable combinations may be selected for a given frequency of operation and desired
phase shift. If R, C, and f are known, the nomograph is used
as follows: · Draw a straight line between R and C. This line {d-e on the figure) determines point M on dashed line a-b. · Draw another straight line (shown as g-h) through
point M to the line for values of cp. Read the value of cp at which the line g-h intersects with the line

of values of cp.
= = In the example given, R 10,000 ohms, C 0.001
microfarads and f = 0.1 Mc. By using the nomograph, cp is determined to be 162° (see illustration).
When it is desired to choose values of R and C for a given phase angle and at a specified frequency, use the following procedure:
· Draw line g-h between cp and f, determining
point M. · Select any convenient values of R and C determined by a straight line drawn through point M.

Positive-pulse generator
By Richard J. Bouchard
Sanders Associates, Inc., Nashua, N.H.

In an automatic test set, a positive-pulse indication was required when a stepping switch passed through each of certain positions in its cycle. Generation of the positive pulse was needed when the switch stepped into positions 1, 3, 4, 5, 8 and

SWITCH ...R..O..-T-A-.T..I.O. N
---n so so 70 8
-10 v


-10 v


Rz 2K




v L - 3 T O - I O

h Vbe --' v------\!J"-- GROUND













Rotation of the stepping switch, left, provides input pulses to the positive-pulse generator. The circuit center, generates positive pu lses when the input pulse is applied or removed. The voltage waveforms are shown at the right; the output pulses occur when the transistor base voltage goes negative.


Electronics I July 27, 1964

10, shown on the wiring diagram. A simple circuit provides the solution by pro-
ducing a positive output pulse at both the leading
and the trailing edges of the input pulse. If the input is at ground, transistor Q is off
and the output is -10 volts. ·when the input signal is negative, R1 and L provide a d-c path
which clamps the base of Q to ground and the out-
put returns to -10 volts. During the rise or the fall of the input waveform, the circuit resonates, producing a sinusoidal-type waveform at the base of Q. The negative portion of this waveform drives
Q into saturation and the output switches to

ground. The result is a positive 10-volt output pulse, when the input pulse is either applied or removed.
With a step-function input, the voltage developed across the inductor of an unloaded RLC circuit will be an underdamped oscillation when
L/C < 4 (R1)~. Only one negative oscillation occurs
because the low input impedance of Q, as it is driven into saturation, shunts the tuned network.
With the component values shown, a 10-volt pulse is produced at the output for every application or removal of an input greater than three volts. The output pulse is slightly delayed.

47 µ, F


Ct O.t I

+ (

l --


10 K



tN7 52A


(5. 6V)


01 2N 2224


C3 IO.f





12 pF




t N9t4



R5 .


910 tw


R& to

+te v

C4 I O.I

Output is continuously variable from zero to 3.5 volts wit h input from zero to -4 volts.

R14 470

02 2N2224

C5 r o .f·

R15 tOK







Buffer amplifier
supplies bipolar output
By Freeman E. Sm ith
Raytheon Co., Wayland, Mass.
T his c ircuit (above) corrects alignment inaccuracies between electrostatic deflection plates and the rectangular face of a cathode-ray tube. It can also be used if paraphase outputs are desired. By putting two of these circuits on one printed circuit card, the same information can be fed into both circuits and one polarity of output can be taken from one circuit and the other polarity from the other circuit. The result is identical signals that are 180° out of phase with each other.
If no inversion is required the circuit may be

used as a buffer or as an inverter and buffer if an inversion is required. It provides an output which is continuously variable over a range corresponding to the maximum positive to negative input signal excursion with a zero volt baseline. Normal operation is with a negative input signal but the circuit will work with a positive input as long as
the amplitude is not large enough to saturate Q1·
With input signals from zero to -4 volts, the output goes from zero to ±3.5 volts.
Inverter amplifier Q1 has a gain of approximately one. Therefore, signals identical but 180° out of phase are seen at its collector and emitter. Resistor R8 varies the current in the collector resistor of Q1 such that test point TPI can be set at the same voltage as TP2 (typically +0.6 volt.) Under these conditions, R12 can be varied without changing the baseline of the output signal since the d-c voltage level across R11 , R12 and Rm is constant.
The circuit is stable from 10° to 50°C.

Elect ronics I July 27, 1964



Automatic circuit tester

A digital computer saves time and money in production-line checkout of digital logic modules

By Kenneth Wakeen~'
Digital Equipment Corp., Maynard, Mass.

The job of production testing has become much too sophisticated for patch-panel and wired-chassis techniques, except on a limited basis. Combining transistors, diodes, and resistors and capacitors into operational circuits which are then tested as integral packages has multiplied the problems of control. The small computer is the logical tool of the system designer for production testing. The computer test system concept does more than automate production testing; it adds procedures impossible to carry out previously to present test capabilities.

tested automatically at savings of about $2,400 per day. A more realistic cost comparison considers capital investment and overhead. Manual test setups consist of a good oscilloscope, voltmeter, power supplies and pulse generators. The cost for this hardware is generally from $4,000 to $10,000. In addition, a separate switching box must be designed and built for each type of module tes ted.


The figure at the right shows some typical cir-

cuits being tested by computer control. The flip-

flop and inverter are tes ted for logic functions ,

saturation voltages, fan-in, fan-out, rise time, fall

time, delay time, and sensitivity to signal and

noise. The circuits arc complex and manual testing


is costly and slow.

The table below compares costs and speeds of

testing the inverter manually and automatically.





Manual test


10 minutes

Operator rate and



Cost/ module

62.5 cents

Rate/ operator


Automatic test 10 seconds
$7.00/hour 1.4 cents 3,200/day

Assuming only 50% utilization time on the automatic tes ter, the savings per day total $980. Flipflops, which arc more complicated and require one-half to one hour in manual testing, can be
· Now with Nexus Research Laboratory, Inc., Canton , Mass.




tlOV M


Typical logic circuits to be tested


Electronics I July 27, 1964

Production-line testing of digital logic circuits, showing tray of adapters, one for each type of module to be tested . A PDP-5 is used in the testing system described.

Each box costs about $2,000. A typical manual-test facility consisting of 24
stations represents an investment of from $48,000 to $80,000. The total output of such a test area with 24 operators is only 600 modules per day. By comparison, an automatic test facility will cost from $70,000 to $100,000 ($30,000 of this is for a PDP-5 computer) and its total output is 3,200 modules per day with only one operator.
Automatic test system
The automatic module test system consists of three groups of equipment (see photo above):
·The central controller is a PDP-5 digital computer. It commands the testing functions, evaluates the readings, and controls the output devices.
·A test console which contains all of the necessary power supplies and analog metering.
·Input-output devices, consisting of a paper tape reader, a teleprinter, and a paper tape punch.
When the Digital Equipment Corp. built a system for its own use, the PDP-5 computer had not yet been developed, so the system was based on the PDP-4. With the advent of the PDP-5, it became possible to design a lower-priced testing system, and it is this system that is described here. Both the PDP-4 and PDP-5 emphasize flexibility in input-output functions. This flexibility permits the computers to service many types of peripheral

equipment, and to accept and feed out data at rates varying from one signal every several seconds to 125,000 a second in a PDP-4, or 166,000 a second in the PDP-5. These figures relate to computer cycle time, which is the time required to read information from memory and rewrite information back into memory. For the PDP-4, cycle time is eight microseconds; for the PDP-5, six microseconds.
The basic test operation consists of typing th e module number on the teleprinter keyboard, plugging in the module to be tested, and plugging in an adapter. The system then starts the test sequence. If the test is successful, the tester prints out an OK about six seconds later. If the module fails the test, the tester stops the system and types out complete information on the failure.
In the printout (at left on p. 78) type 1104 fourstage inverters were tested. The first entry, typed by the operator, caused the appropriate test parameters to be brought from computer core memory and started the tes ting. The next five entries typed out by the computer indicated five modules successfully tested. The sixth module failed the load test, and the tester typed out the name of the test, the measurement limits (1,400 to 1,600 ohms), the actual reading (710 ohms), the input pin (H), the output pin (L), and the word, reject. The second reject to occur was due to a slow transistor tied to

Electronics I July 27, 1964


1104 OK

1104 OK

1104 OK

1104 OK

1104 OK 1104



71 1104 OK 11 04 OK 1104 OK 1104 OK

""~ ECT

1104 OK

1104 OK

1104 OK





100 NS


108 s· V REJECT

1104 OK

1104 OK

1104 OK

1104 OK

& Production test printout, showing two rejects



1475 w z
1490 s v

1505 M R

1475 H L



w z

-3. 4

s v





70 w z

90 s v

90 M R

80 H L




100 NS



w z


Data-sheet printout, with complete logging ..

of test resu lts for one inverter modu le



s v



"' Measurement circuit for testing components and circu its







1----.... 9-BIT BUFFER
1---,...---1M REGISTER AND










Electronics \ July 27, 1964

pin V, shown near the bottom of the printout. The data printed out simplifies repair of a
circuit. In the first case, the load resistor tied to pin L was replaced. In the second case, the transistor tied to pin V was replaced with one having acceptable rise and fall times.
Automatic failure analysis
Printout of test results on go, no-go testing makes repairs to modules easy; manual testing relies on the operator to read a meter, lights or oscilloscope. He must make 60 to 100 decisions to evaluate defective components, based on the combinations of test results.
Manual systems, of course, have no data-logging capability other than operator, pencil and paper. Other semiautomatic data-logging systems must be built, with a specific data-logging function in mind. With a computer, data logging is simple. The computer already is equipped to communicate with typewriters or card punches. The printout (at right on p. 78) shows the complete data presented by the computer for a tested 1104 module.
The headings can be changed easily to fit any situation. For example, the heading "LWR LEV TEST" can be made to read "VOFF" by modifying the information in the computer memory. Both headings refer to the collector voltage for a turnedoff pnp transistor, but one may be preferred to the other in certain circumstances. In all cases, the test limits and actual test results are shown as well as the input pins, output pins and the test result.
To provide flexibility of programing of test conditions and test limits, the computer program can be modified by typing the new numbers into the proper locations in the memory. For example, voltage limits are stored numbers in the memory and the actual readings are compared to these stored numbers for go, no-go decisions. If it were necessary to change 3.7 volts to 3.5 volts, the operator would find the memory location of the 3.7 and type in the number 3.5.
For power supply flexibility, computers allow complete freedom as to the sequencing and delay between applied voltages (a feature often necessary to avoid destructive testing). The changes require only the modification of the stored program by typing the sequence of supplies required and the proper delays between applied voltages.
Frequently, certain inaccuracies which cannot be easily accounted for in any other test method can be modified by the computer. For example, in the measurement of the delay time of a Hip-flop, the reading of the digital scope did not include the 100-nanosecond pulse width of the generator. This constant of 100 nsec was added to the readings received by taking advantage of the computer's add function.
Computer communications for testing
Computer applications to testing result from the use of programable stimuli such as power supplies (digital-to-analog devices), and in analog-to-digital

converters. In the simplified sample circuit for measuring any device where a stimulus and a measurement are required (see figure at bottom of p. 78), a computer controls a programable power supply, and a measuring device, in this case an a-d converter.
Readings from the a-d converter are fed back to the computer for storage and comparison. In this kind of test set-up, it is possible to test, under controlled conditions, such devices as diodes, transistors, resistors, relays, and circuit packages and modules containing these components. Measurements of resistance, current, and voltage are made so that components can be tested rapidly and economically.
In the output process, information to be transferred is taken from the computer memory on command and put into an accumulator-a temporary storage register in the computer. This information appears in binary form. The computer transfers this information into a buffer register, also in binary form and in the same order it appeared in the accumulator. By selecting a particular output command, any one of a group of registers is loaded with the binary information from the accumulator. When this operation is completed, the power supply produces an analog equivalent of the digital volt· age. A typical technique for programing a powe1 supply is shown in the figure below.
The output of the power supply depends on the amount of resistance in the programing string. Relays 1 through 9 are opened as needed by a nine-bit storage register.
Inputs from the accumulator are fed to eight capacitor-diode gates that control eight Hip-flops. When these gate inputs are at zero volts and a command pulse also appears at the eight gates, a pulse is fed through the enabled gates, setting certain of the flip-flops to one state. Each flip-Hop in turn operates a relay driver. A clear pulse is provided to set all the Hip-Hops to the zero state.
The binary-weighted output of the programable



















Technique for programing a power supply, with a binary-weighted resistor string controlled by normally-closed relay contacts. Output voltage is KR,., where K equals IV/(100 ohms).


Electronics I July 27, 1964


power supply can be any value from 0 to 51.1 volts in 0.1-volt steps. The individual bit values are:

Bit number




















For a reading of 0 volts, all bits of the register

contain zeros. With ones in all bits, the voltage

reading would be 51.1. To program 25.8 volts, the

binary number would be 010 000 001; that is, 0.2

plus 25.6. To program 1.1 volts, the binary number

would be 110 100 000; that is, 0.1 plus 0.2 plus 0.8.

The routine used by the computer to load the

register is a simple two-instruction process:

Instruction LAC 1000
JOT 6754

Meaning Load the accumulator with the number in memory location 1000. Clear and load the ones from the accumulator into the buffer register.

To carry out these instructions, the computer transfers the binary number from memory location 1000 to the buffer register. To produce the 25.8 volts cited above from the programable power supply,

Computer routine

Inst. No. 1
2 3
4 5
6 7

Instruction LAC 5000

Load the accumulator with the contents of memory location 5000 (2.58 v binary)


Store 010 000 001 in programmable power supply buffer (PPS now goes to 2.58 v)


Convert a-d. A-D converter
reads V""' and converts it to binary 010 011 000. (l.52 volts)


Transfer the a-d converter binary output to the accumulator

DAC 5001

Store the contents of the accumulator in memory location 5001 for further reference

Jm s Compare Compare a-d reading with min-
imum and maximum stored limits


End of test routine

The author

Kenneth Wakeen is chief engineer at the Nexus Research Laboratory. He designed the automatic circuit tester while he was manager of production engineering at the Digital Equipment Corp. He is married, has five children, and his hobbies are oil painting and golf.

the number in location 1000 would be 010 000 001. After the programed voltage, Vp, is generated
the analog voltage, VL, must be measured. To do this, the computer issues a read command which causes the a-d converter, by successive approximations, to convert the reading to a binary number. For example if Vr, = 1.52 volts , the binary number generated by the a-d converter is 010 011 000,
+ + assuming a value of 0.01 volt for the least sig-
nificant bit; that is, 1.28 0.16 0.08 = 1.52. This information is now ready for the computer.
A third command, "enter data from a-d," is issu ed and the 010 Oll 000 (1.52 volts) is transferred to the accumulator of the computer, destroying the previous information in the accumulator.
A typical routine used to program a voltage and measure is shown at left below.
Circuit testing
By expanding the number of buffer registers and with proper programing, the tests for a large number of modules or components can be stored simultaneously in the computer core memory. Information is loaded into the memory from paper tape. The memory contains instructions for testing the 1104, as well as 20 to 30 other module types . To select the testing sequence for ll04, simply type in "1104." The computer then compares this number to a stored table, which lists all modules that can be tested. If the number is mistyped or does not exist in the memory table, the computer types back a "no," indicating error in selection.
On correct selection, the operator need only load the test socket with the module to be tested, push the test button, and the test procedure is carried out automatically. The module goes through a loadresistance test, VCE (collector-to-emitter terminal voltage) test, lower-level test (off-voltage), and rise and fall time tests, by expanding the concept of in-out transfer.
The programable power supply is programed at 2.8 volts, and the computer controls the sw'itching. This voltage is applied in sequence to each of the
bases of the 1104 inverter pins H , M, S and vV, as
shown on page 78 at top left. The voltage is measured by sequentially connecting the a-d converter through similar switching to pins L, R, V and Z. The a-d converter measurements are then fed into the computer and compared against stored limits.
The computer can now take action based on test results, and print a readout. Similar techniques are used to measure lower levels and load resistance with differen_t input voltages and test limits.
A-c rise and fall measurements are made by programing a digital-readout sampling oscilloscope and a pulse and sync generator. The digitized reading from the sampling oscilloscope is similarly fed into the computer memory for evaluation. This system depends on the analog readings that have been digitized rather than on a go, no-go type of comparator. Digitized readings allow for data-logging and easy modification of test limits and test conditions.


Electronics/ July 27, 1964

Space electronics
Birds-eye view of the weather

Nimbus I will send pictures automatically. Here's how to assemble a low-cost station to receive them

By Charles M. Hunter and Edward Rich Jr.
National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt. Md.

A topside view of the weather, taken from above by a meteorological satellite, will soon be beamed to anybody who cares to operate a relatively simple ground station.
Starting next month, when the Nimbus meteorological satellite is shot into orbit [p. 99], government agencies hope to keep at leas t one cameraequipped weather-eye in the sky at all times.
Nimbus I is scheduled to pass over the same area at the same time every day. One of its camera systems, called APT for Automatic Picture Transmission, will photograph a million-square-mile
Ground coverage as seen by Nimbus's APT camera. Near-polar orbit will bring Nimbus over a single place at the same time every day.

area every 208 seconds and transmit the pictures to any suitable receiving station.
Ground stations no longer have to cost $32,000, the price of a ready-made system. They're now within the reach of anybody-for example schools, airlines, television stations, farms and ship companies-for less than $6,000, on a do-it-yourself basis.
Information will be disseminated regularly as to when and where the satellite will pass over any given area. This data will enable a ground station to point its antenna toward the satellite. Then a facsimile recorder will provide a picture of warm fronts and cold fronts within 500 miles of the station. It will also show vortexes indicative of storm centers, and cumulus clouds that result from agitation in the atmosphere.
Nimbus I will be followed by another Nimbus satellite, and then-around next winter-by a group of Tiros Operational Satellites, launched by the National Aeronautics and Space Administration and financed by the Weather Bureau. Of the first five operational vehicles, two will have a pair of APT systems apiece and the other three will each carry two Advanced Vidicon Camera Systems (AVCS). AVCS pictures, of higher resolution than APT's, will cover 250,000 square miles of earth. They will be stored on tape, and later read out over a central facility, permitting the assembling of a worldwide collection of weather photos.
The master plan calls for keeping two satellites orbiting the earth at all times, one equipped with APT and the other with AVCS. Ultimately, NASA hopes to come up with a single camera system that does both jobs-transmitting photos every 208 seconds and storing others on tape.
Picture coverage ranges from approximately 800 nautical miles on a side for the camera system on

Electronics I July 27, 1964


· ······························
























· · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

.... ·· ··



-24.5V POWER


APT camera system on board the satellite transmits pictures to the ground every 208 seconds.

How the camera works
One reason why an APT ground receiver can be built with readily available equipment is that most of the work is done "upstairs."
The APT camera system is not only the photographer, but also the darkroom. What it sees, it transmits as signals that the ground receiver can easily handle.
The heart of the camera is a one-inch, 800·1ine storage vidicon. It looks atthe earth through an f/1.8108 °, wide·angle lens with a focal length of 5.7 millimeters, and a shutter.
The vidicon provides long-term image-storing capability. A polystyrene layer with high resistivity stores images for months in the form of distributed electrostatic charges.
The camera operates in automatic, repetitive cycles of picture-taking and readout. The vidicon has a programed electrical sequence of "prepare," "expose" and "develop" before a picture readout.
Taking the picture
"Prepare" consists of bringing the gun side of the polystyrene to a uniform potential and erasing any residual charge from the preceding picture. During "expose" the shutter is operated, projecting the image onto the photoconductor. The "develop" operation consists of switching grid potentials so that the charge pattern is transferred from the vidicon's photoconductor to the polystyrene layer. This charge pattern is discharged by the electron beam during the readout process converting the image to a video signal. The entire prepare·expose·develop (PED) cycle takes eight seconds.

Readout takes place immediately after the PED cycle. The readout is four lines a second; for the 800-line vidicon this results in a 200-second readout time for each picture. This, with the eight-second PED cycle, results in a span of 208 seconds per picture.
A beam-pulsing technique, rather than continuous scan, is used during readout to provide the optimum dwell time for the electron beam on the target. It has been determined that 25·microsecond pulses at 4,800 pulses per second yield the best results.
Out comes the video
The video information is contained in the peak-to-peak value of the 25-microsecond pulse-approximately one millivolt peak-to-peak for a black picture. The white level approaches zero volts. The video signal is coupled to a low noise nuvistor preamplifier used as a cathode follower. This in turn drives a 24-kilocycle bandwidth video amplifier providing a one-volt peak-to-peak output of sampled video information, which is fed to the video detector. The input of the video detector is clamped to a negative supply voltage by a transistor switch during the interval between sampling pulses. This clamps out any random noise that might possibly be present in the video chain.
The video detector attenuates all frequencies above 1,600 cps at the rate of 24 decibels per octave (referenced to one-volt sinewave input). The smoothed output of the detector then contains the video variations, but without the 25·microsecond pulses.
Modulating the signal
:The output of the detector is passed through a video


Electronics I July 27, 1964

Helix antenna with eight turns is used at many APT receiving stations. A set of four cross·polarized yagi antennas would do the job for less money.
Picture taken with APT camera on Tiros VIII shows the West Coast of the United States.
switch to a balanced modulator to amplitude-modulate a 2.400-cps subcarrier. The subcarrier is derived from a master clock with a stability of one part per million which is more than adequate for standard facsimile receivers. This results in a double sideband modulated subcarrier with sidebands of 1,600 cps above and below the subcar· rier frequency. The modulated subcarrier, in turn , frequency-modulates the 136.950-megacycle carrier of the transmitter. Facsimile transmission
To start and synchronize the ground station's recording device-a helix and writing-blade facsimile machine-the camera system transmits a three-second, 300-cps start tone and five seconds of phasing pulses (a 12.5-millisecond, black-level pulse at the beginning of each line for 20 lines). This transmission occurs during the eightsecond PED cycle and prepares the facsimile machine to receive video information and synchronizes it with the vidicon scanning beam. Then the picture is scanned, line by line, from the vidicon storage layer, and immediately transmitted to the ground.
Picture quality is measured in shades of gray detectable by the eye. In the present system it is possible to distinguish six or seven shades. This figure of merit depends on the noise and linearity of the systems. Minimum peak signal -to-rms noise ratios of 26 db have been consistently measured. This is calculated as 20 log,. peak-to-peak signal/rms noise.
The APT camera system' was developed by the Radio Corp. of America under the direction of NASA's Goddard Space Flight Center.

Tiros VIII (380 nautical miles altitude) to approximately 1,450 nautical miles on a side for a satellite at an altitude of 750 nautical miles. The Tiros VIII satellite was launched Dec. 21.2
Transmitting the pictures
Both Tiros and Nimbus use a commercial telemetry transmitter manufactured by United ElectroDynamics, Inc. At 136.95 Mc, it produces a fivewatt frequency-modulated carrier. Deviation of the transmitter is IO Kc and, allowing for a 30-Kc predetection bandwidth, the power requirement is five watts. Transmitter frequency stability over the
temperature range is better than 0.01 %. At the time
and temperahue of readout, the short-term drift is negligibl e.
For practical considerations, the Nimbus antenna is described here. When it is used as a basis for ground-station design under the worst conditions, the signal-to-noise margin is still adequate.
The antenna is a quadraloop mounted on the base of the spacecraft. It has the appearance of a dielectric-loaded, short-circuited transmission line, and has a radiation pattern similar to a standard dipole's. However, the pattern is distorted by both the spacecraft strncture and the solar paddles; thus, for design purposes, the gain must b e considered as one. Polarization is essentially linear, with a beam width of 122°. The satellite transmits signals of linear polarization with some right-hand components present because of atmospheric shift at low elevation angles. Normally, reception below 10° above the horizon is not practical and should not be considered in path-loss calculations. Initial Nimbus orbits are planned to be about 500 miles in altitude. This provides a slant range of approximately 2100 miles, and its associated path loss of 146.2 db. Slant-range is the line-of-sight distance from the spacecraft to the ground station, measured along the path radio waves travel.
Building a ground station
The APT ground station consists of an antenna, preamplifl.er, receiver and readout device. The requirements are easily satisfl.ed.
The antenna system can vary widely in cost and complexity. The commercially available Nimbus ground stations use a single eight-turn helix with manual, remote control in both azimuth and elevation. This antenna has a gain of 10 db, referenced to an isotropic source, to a linearly polarized signal, and 12 db to one of circular polarization with righthand components. Beam-width is 36° over a bandwidth of several megacycles.
Many variations are possible. Only two basic requirements must be satisfl.ed: 10-db gain, and pointing capability to maintain carrier-to-noise level high enough to receive clear pictures.
Normally, orbital data and predictions are available and published shortly after a satellite is launched. With this information, a practical compromise is possible to greatly reduce the antenna system's cost. Rather than motorizing the antenna

I Electronics July 27, 1964



!+-- - - - -- +2


---.~.. HOLD PA
START 300 '\J


B SEC L . . - - - - - l --- PHASING



960 CPS

Paper-type facsimile machine could be used to receive satellite's readout. General circuitry techniques are shown .

Canadian station at Ottawa has antenna programmer (left) to point the antenna directly at the satellite. Antenna at right was built by Danish Meteorological Institute from available radar equipment and has a gain of about 15 db.

and using the more complex h elix, a set of four single cross-polarized yagi elements may be employed . Two of the elements are tun ed to the h ori zon 180° apart. Th e center pair cover the area in between. vVhen such an antenna is used and current fed in phase quadrature, an eight-element w ide-sp aced yagi has b een shown to provide 12 db gain over isotropic sources. Beam-width is a cone that varies between 35° and 38° at the 3-db points. Bandwidth is only slightly less than th e h elix. Yagi d esign is a textbook operation and not critical.
The major drawback to such a sys tem is adjustm ent in azimuth during every second orbi t. Th is can b e simplified by mounting the four elemen ts on a single boom and rotating the b oom with a light-duty antenna rotator. The antenna can be simply switch ed, in accordance with the satell ite's position, with a coaxial switch. F or a slight increase in noise because of exposure of all elements of the array to high sky temperatures, the antennas can b e fed in phase. Such an array, built with sh1 dent labor, would b e quite inexpensive.
A typical antenna that could b e used to receive the APT signals is a yagi with eight elements or more, with the first set mounted horizontally and the second set mounted vertically through a common b oom. The reflector should b e one-half wavelength , (A/2) with the radiator and the directors 5% and 10% shorter, respectively. Spacing b etw een th e refl ector and the radiator should be 0.2,\, and b et ween the remaining elements, 0.25,\.
The radiator should have 300-ohm folded dipoles, vertical and horizontal, connected to a b alun and then to 50-ohm coaxial cable. Each folded dipole i s fed in phase with a one-wavelength cable.


Electronics I July 27, 1964

Comparative costs
Antennas Scientific Atlanta, Inc., motorized-manual with TACO 8-turn helix . ..... ..·· . .···. $7,000

The unit chosen should have a sensitivity of - 96 dbm (or 6 µ.v) or better, a predetection bandwidth of at least 30 Kc, and a noise figure of less than 8 db. Most facsimile printers have an input of 600

Telrex Laboratories cross polarized, 12 db, manual . .. .. . .·.·····

ohms, thus an output at this impedance should be 500·1,000 provided to balance it.

Home-made cross polarized, rotatable, 4-bay parallel array ... . .. .. . ...... ·· . 200

This direct approach is probably the most practical. Numerous telemetry receivers are available, but


at substantially higher prices. Another possibility

Vitro Electronics Div., Vitro Corp. of

is the use of 144-Mc amateur-band receivers. Con-

America, Nems·Clarke telemetry receivers . $1,400·2,400 verter modifications, if any, are simple, because the

Defense Electronics, Inc., general purpose f·m . . . . . . . · · · · · · · · . 2,000

frequency is close and the bandwidth sufficiently wide for APT. Modifications might include placing

Radio Corp. of America Carphone Model 150 (modified) . · · · · · · · 300

a capacitor across the tuned circuits to reduce the frequency by 7 Mc to 137 Mc. Low-frequency re-

Nuvistor Converter and Hallicrafter f·m/a·m receiver . . . . . . . . . . . . · · · · · · · · 500

ceivers for f-m are not common, but the military surplus market offers many interesting possibili-

Commercial preamplifiers . . . . · · · · · · · · · 400·1,000 ties including the World War II SCR-609. Or old

Facsimile Westrex, div. of Litton Systems, Inc. photofacsimile without automatic film processing .. .····· , ···. $35,000
Alden Electronic and Impulse Recording Co.-paper . . . . . . . . . . . . . . . . . 5,000
Muirhead Instruments, Inc., D·900·S·paper 5,000

police radios could be used.
The facsimile recorder
Facsimile recorders of the helix and writingblade type (rotating helix and fixed writing blade with paper coming between) provide duplication of the transmitted video signal in varying shades of

Muirhead Instruments, Inc., D-700-S-photofacsimile . . . . . . . . . . . . . . . 15,000

gray on a white, electrolytic recording paper. Iron from the recorder's printer blade is deposited in

the wet electrolytic paper by a marking current that

Numerous antenna plans have been proposed, varies in accordance with the received signal. On

most of which would satisfy the requirements. some recorders, a heater bar completes the elec-

Some other antennas suggested are a spiral array trolytic process by drying the paper and increasing

(made by Telrex Laboratories), a modified discone the density of the recorded copy.

or a log-periodic type.

In general, facsimile equipment operation is as

The preamplifier

follows : the start tone, modulated at 300 cps, which is transmitted by the satellite (seep. 82) is detected

Available preamplifiers include types using to start the machine and enable phasing. The phas-

nuvistors, transistors and tunnel diodes, as well as ing pulses from the camera system cause the helix

conventional tubes. For best performance, the pre- drive motor to fall out of synchronism and slow

amp should be installed at the antenna. This might down until some type of comparator circuit (either

indicate a choice of either the transistor or tunnel- electronic or mechanical) senses the in-phase condi-

diode models to take advantage of the use of the tion and allows the drive motor to return to syn-

coaxial cable for supplying power. However, based chronism. Also, during phasing, an automatic gain-

on economics as well as sustained good perform- control circuit senses the received white level of

ance, the nuvistor type is the best compromise.

one volt rms and sets up the amplifier gain com-

All of the available preamps offer, for the narrow mensurate with the transmitted video signal. To

bandwidth, a gain of 20 db or more with a noise prevent a return of phasing pulses during picture

figure of about 4 db. For outdoor installation, a printout, once phasing has been completed, they

preamp in a weather-proof box should be used. are locked out until reinitiated by the incoming

Preferably the box should be prefilled with an inert start tone at the beginning of the next picture. On

gas to reduce condensation. Suggested preamplifiers certain types of facsimile machines , phasing, after

include Nems-Clarke models PE 204A or SSP 137 it has been accomplished on the first fram e, is

transistor types, a tube type by Tapetone, Inc., of locked out until the end of the picture sequence,

Boston, or a nuvistor type by the Ameco Equip- and the equipment is allowed to return to the

ment Corp., Mineola, N. Y., model PV-144 modified standby condition.

to 137 Mc.

These machines can easily be modified for re-

The receiver

phasing on every picture if desired. Accurate motor drive of the helix is obtained from a highly stable

Like the antenna, the receiver can vary greatly source, usually using a tuning-fork oscillator and

in cos t and complexity. The basic requirements are the necessary amplifiers and motor-drive circuitry.

simple and can be met quite easily by the receiving The picture is printed out by taking the double-

section of most mobile receivers. Equipment is sideband a-m signal from the receiver, demodula t-

plentiful for the 150 Mc f-m band, and modifica- ing and inverting the signal and passing it through

tions are minimal.

a full-wave rectifier to supply the d-c marking cur-

Electronics I July 27, 1964


rent ti1at is inversely linear to the input-signal amplitude (maximum signal with minimum marking current or minimum signal with maximum marking current). This is necessary as the input signal is maximum for white while the electrolytic paper requires a maximum signal for black.
The facsimile equipment for the APT system must operate at 240 rpm to be compatible with the
Paper facsimile recorder is Alden dual mode model 9225. Muirhead and Fairchild Camera machines also may be employed.
Canadians receive pictures by taking Polaroid photographs of an oscilloscope readout.

satellite equipment, utilize a 2,400-cps carrier frequency and operate on an a-m double-sideband signal.
Several manufacturers of facsimile equipment have machines compatible with the transmitted signal.
Commercial facsimile recorders
The Mufax D-900-S Chart Recorder is manufactured by Muirhead & Co., of Beckenham, England. Muirhead also has a plant in Mountainside,
N. J.
The machine was used in the research and development of the APT system, and is still used during checkout and qualification testing of each camera system. The D-900-S consists of three separate units : the power-supply chassis, electronics chassis and printer. Th e machine produces a 9-inch by 9-inch picture with a resolution of 90 lines per inch. A 600-ohm, balanced, 2-wire input is required at a level of zero to -25 db, referenced to 1 mw (600 ohms) with a recommended input of -10 dbm An input-level tolerance of ± 2 db is required. The machine is set for operation over a black-to-white ratio of 32 db. Th e tuning-fork frequency is 1,000 cps. The recommended recording medium is Mufax electrolytic paper. The machine is sold for about $5,000.
The Fairchild Camera & Instrument Co.'s Scana-Fax, modified for APT compatibility, is used in APT ground stations around the world. The Scana-Fax has a resolution of 100 lines per inch with an 8-inch by 8-inch picture. The machine is capable of 10 shades of gray, varying from black to white in conformity with the 1961 gray-scale chart, pattern 8, of the Institute of Radio Engineers. The machine operates on a black-to-white ratio of 32
Summary of system specifications
Frequency Modulated Receivers Frequency range 136·137 Mc Predetection bandwidth-30 kc (min) Sensitivity-minus 96 dbm or better Noise figure--better than 8 decibels Audio output impedance-600 ohms balanced.
Preamplifier-Gain-20 decibels Input and output impedance--50 ohms Noise figure-4.5 decibels maximum
Antenna-lmpedance--50 ohms Linear or circular right hand polarization gain-10 deci· bels (min)
Facsimile Input impedance, audio-600 ohms Dynamic range black to white--32 decibels Writing speed-240 rpm Subcarrier frequency-2400 cycles per second Modulation-amplitude, double sideband Modulation sense--selectable positive or negative reproduction Start-automatic or manual, actuated by 300-cycle start tone Stop--automatic, by cessation of carrier Phasing-automatic, accomplished from 12.5-millisecond pulses at 4 cycles per second for 5 seconds. Lockout of phasing is desired at the end of 5-second phasing signal. Automatic gain control-required for optimum operation. Sets up during phasing and should then be locked out at the end of the phasing signal. Input range---0 to minus 30 dbm.


Electronics I July 27, 1964












Photofacsimile, of the type made by Westrex, does a better job but costs more.


db referenced to I mw (600 ohms). Input impedance is 600 ohms with a recommended input level of -10 dbm.
The tuning-fork frequency is 960 cps. The equipment can use several manufacturer's electrolytic paper. Fairchild's type 36-A is designed for the machine. The machine is in one chassis and utilizes transistorized circuitry. The company declined to quote a price for a single unit.
The Alden Electronic & Impulse Recording Equipment Co. has a machine identified as the Alden Dual Mode Facsimile Recorder No. 9225. This machine is designed for APT operation at 240 rpm, as well as for operation as a standard 120rpm facsimile recorder for weather maps. The recorder consists of three basic elements: the recorder head, transistorized electronics unit and a Mobile Uni-Rack. Either of the two operation modes can be selected by means of a switch. The manufacturer states that the picture is 10.5 by 10.5 inches, input impedance is 600 ohms balanced with an input range of 0 to -30 dbm, and utilizes Alfax type A2 paper which produces sepia tones rather than shades of gray. The equipment costs about $5,000.
The Westrex Corp. has converted its standard photofacsimile model 3030 TP, for APT. The Westrex system is designed for automatic turn-on and automatic or manual phasing. Westrex is a division of Litton Industries, Inc. Phasing in this system, is also monitored on a built-in oscilloscope. The phasing pulses are gated into phasing-control circuitry during a five-second period. Gating is then disabled so that video peaks appearing in the video

composite do not cause false phasing. Synchronization is maintained over the duration of a frame through the use of a stable 2,400-cps tuning-fork oscillator. Video conversion is accomplished by modulating a R-1168 readout tube made by Sylvania Electric Products, Inc. The tube, in turn, scans the film by means of an oscillating mirror.
Circuitry is also included for gamma correction to compensate for nonlinearities in spectral response in optics and the readout tube and the particular film or paper being used. While this is a sophisticated system, it does provide a highquality, high-resolution reproduction.
Map matcher
A data-reduction kit, which helps the stationowner identify local terrain from the APT pictures, is sold by the Aracon Geophysics Co. of Concord, Mass., for $225. It includes a set of overlay maps, a large plotting board in the form of a circular slide rule, worksheets and instructions to help the user to match his pictures with familiar land masses and to match the published orbital information with the position of the satellite to aid in pointing the antenna. Aracon and the Weather Bureau can provide additional assistance in reading the pichues.
1. R.A. Stampfl and W.G. Stroud, Goddard Space Flight Center, The Automatic Picture Transmission (APT) TV Camera System for Meteorological Satellites, NASA Technical Note, NASA TN 0 ·1 915.
2. D.W. Holmes, National Weather Satellite Center, U.S. Weather Bureau, and C.M. Hunter, NASA Goddard Space Flight Center, WMO Bulletin, Vol. 13, No. 3, July 1964.

The authors

Charles M. Hunter is spacecraft manager for the Tiros Operational Satellite System at the Goddard Space Flight Center. He was technical officer for the APT system for two years. At 30 years of age, he is among the youngest of NASA's key technical personnel.

Edward Rich Jr. is a senior electronic development technician at Goddard. He worked for 10 years for the Signal Corps at Fort Monmouth, N.J. When he's not raising roses or collecting guns, he likes to bounce signals off the moon with his ham radio gear.

Electronics I July 27, 1964


Tropo goes commercial

AT&T prepares to use tropospheric system in U.S. with solid-state equipment for more reliable service
By Alexander A. McKenzie
Communications Editor

Solid-state transmitting and receiving equipment for a tropospheric transhorizon radio network will be delivered soon by Radio Engineering Laboratories, Inc., to the Long Lines department of the American Telephone and Telegraph Co. The network will be the first commercial overland telephone and telegraph system of its kind in the United States. Although the extent of the network has not been disclosed, the nature of tropo and the quality and amount of the equipment indicate an exacting demand for high transmission standards and high reliabilty on an overland relay route of considerable length.
Each radio terminal will employ quadruple diversity and will be equipped with four low-noise receivers using parametric amplifiers. These receivers will use threshold extension circuits of the f-m feedback type to enhance the signal-to-noise ratio during periods of extremely low signal strength. The four receivers will obtain optimum diversity reception by using post-detection or
Solid-state exciter, with the modulation amplifier unit pulled out. Plug-in baseband-amplifier printed circuit cards are being removed.

baseband combining circuits that take full advantage of f-m signal-to-noise discrimination after limiting and deemphasis. In such a combining system, the composite output is always at least equal to the input from the receiver picking up the strongest signal. The noise-power ratio of the intermodulation distortion has been specified at more than 55 decibels, indicating that high-speed transmission of data is contemplated.
Success in the far north
During the last 10 years or so, the art of radio communication using both very high and ultrahigh frequencies over nonoptical paths-those over which the transmitter cannot be seen from the receiver-has grown from nothing to a multimillion-dollar investment. Nonoptical radio-wave propagation was first employed for defense purposes in Arctic regions, where the better-known high-frequency communications techniques falter and sometimes fail for hours, owing to the effect of the aurora borealis. Such uses have already b een described for the Bitter Sweet, Dew Line and White Alice systems linking Greenland, the Canadian Arctic and Alaska with defense installations to the south.
Bitter Sweet differs from the other systems in that it employs the E-layer of the ionosphere (a layer from 50 to 400 miles above the earth) to reflect, or bend, signals over the nonoptical path. While this mechanism is important, providing reliable teleprinter and even voice signals over distances from 600 to 1,200 miles per hop, it is limited to the radio frequencies between about 25 and 60 megacycles. It is mentioned here chiefly to differentiate clearly between it and fhe more versatile mechanism of propagation known variously as transhorizon tropospheric propagation, tropospheric forward-scatter, or just tropo. Its name derives from the region of the atmosphere, between the earth and an altitude of about seven miles,


Electronics I July 27, 1964


NATO communications system, Ace High, extends in a semicircle from eastern Turkey to the northern tip of Norway. This tropospheric network is 8,300 miles long, and the dashed portion has been in service since 1958. The short extensions, shown by light lines, are short·hop microwave links.

called the troposphere. Using frequencies from 400 to 8,000 megacycles, systems generally employ hops from about 100 to 500 miles.
Bending radio beams
How does a tropo system work? One theory is that the atmosphere is stratified into layers of varying size and thickness. Each layer comprises a discrete body of air, varying from the adjacent air in temperature and moisture content. These invisible cloud layers have different indexes of refraction owing to the differences in their temperature and moisture content. Thus, the boundaries between layers are reflecting surfaces. Radio signals reaching the surfaces are reflected, and the angle of reflection is equal to the angle of incidence.
Other workers have postulated radio clouds, blobs or similar scatterers. These are thought to refract a small portion of the radio energy back to the receiving location in much the same manner that we are enabled to perceive a distant searchlight beam as it illuminates moisture and dust particles of the air on a dark night. The terms "forward scatter" and "tropo scatter" derive from this explanation of the transhorizon radio phenomenon.

A ray from the transmitter, shown in the figure on page 91, is reflected in multiple fashion at the common volume (shown in color), having reached the region by fallowing ordinary laws of radio propagation, bending slightly to follow the earth's surface. After scattering or refraction in the common volume, the signal is directed toward th e receiver, obeying normal laws of propagation.
The figure also indicates that the height of the scattering volume varies with p ath length. Assuming unobstructed paths with zero horizon angles, the common, or scattering volume for each would be: 100 miles 1,000 to 6,000 feet 200 miles 2,000 to 10,000 feet 400 miles 10,000 to 70,000 feet These elevations assume use of antennas with diameters of 30, 60 and 120 fee t for 100-, 200- and 400-mile paths, and assume beamwidths th at result at frequ encies in the order of 800 megacycles. It is expected that the new AT&T system will operate at 2,000 megacycles, but the figures shown are representative.
Unpredictable signal
Since the exact nature of the tropo signal cannot be predicted mathematically, system design is pred-

Electronics I July 27, 1964


long path. Echoes, resulting from fast fading, can cause selective fading that produces distortion in wide-band transmissions. However, the high-gain antennas required reduce the delay time between direct and delayed signals to a point at which useful bandwidths of several megacycles can be obtained.

Path loss

Two pairs of sites (color) for the same distance may produce considerably different angles. Since a small scattering angle is generally desired, sites with good elevation are chosen.
icated upon path-loss measurements and other empirical data derived from observations on many circuits. For communications engineers unaccustomed to dealing in transhorizon tropo figures , median signal levels from 40 to 100 decibels below free space come as a shock. The median signal (for example, about 80 db for 100 me at 300 miles and a little more for 1,000 me) is that value of a widely fluctuating signal that is exceeded just half the time.
The three types of fading that cause fluctuation of the signal are fast-sometimes as much as 20 fades a second on short paths-diurnal and seasonal. Long-term variations from summer day-the most favorable signal-to winter night-the poorest signal-may account for 10 to 15 db on a short path and about half as much on a 400-mile path . Transmission is better over water than land.
The short-term variations result from interference effects. Sometimes rays arrive in phase and reinforce each other to create a strong signal. At other times they arrive out of phase, tend to cancel out each other, and reduce the signal level. Like the long-term changes, these variations are greater and occur more frequently on a short path than on a

The median signal figures are comparisons with free-space transmissions and should not be confused with the path loss experienced between transmitter and receiver in a tropo system. For example, on a typical 200-mile path the signal loss may be 200 db. This loss comprises several components. The free-space portion, following the inverse-square law, increases 6 db each time distance or frequency is doubled. Assuming a zero horizon angle, the over-the-horizon component of loss increases nearly 18 db each time the distance between terminals is doubled. It varies with frequency, increasing about 3 db each time the frequency is doubled. Since lower scatter angles [figure above, left] result in smaller path losses, it is important to site stations as high above surrounding terrain as is practicable. There are practical limits to th e size of antenna to be used in overcoming other losses. Although gain increases with antenna diameter, it does not increase in the same ratio in tropo work as it does in conventional communications, because some rays reach a large antenna out of phase. The cost of increasingly powerful transmitters, assuming that they are even possible with current technology, sets an economic limit on the length of tropo paths. Until now, such paths have been used for military circuits, and domestically only for overwater hops.
Diversity reception
The phenomenon that limits the effectiveness of very large antennas-the fact that rays arriving by different paths are out of phase-works to advantage for diversity reception. The effectiveness of diversity also counterbalances the need for high power that would otherwise be necessary to insure continuous workable signal levels.

Tropo: history and mystery
Until well into-the 1940s, many radio engineers believed that communication on frequencies in excess of about 40 megacycles required an optical path between transmitter and receiver, or at least-to compensate for optical refractive effects-a path based upon the concept of an earth having four-thirds the radius of the real earth.
This belief negated the experience of Guglielmo Marconi, father of practical radio communications, who in 1932 reported talking over a distance of 168 miles using a radio frequency of about 500 megacycles. Amateurs and other experimenters during the 1930s showed that nonoptical communication was often possible on frequencies of about 60 and 144 megacycles, even with very low-power transmitters and insensitive receivers,

although diurnal and day-to-day variations in signal strength were relatively enormous.
One group, of which the author was a member, under the direction of G.W. Pickard, inventor and experimenter at Seabrook Beach, N.H., found that over the sea, signals could be exchanged at a d istance several times that to the horizon. Results of these observations were correlated by the late Ross A. Hull of the American Radio Relay League in West Hartford, Conn. With the help of Charles F. Brooks, director of the Blue Hill, Mass., and Mount Washington, N.H., Observatories, he showed a correlation between meteorological air masses and sig· nal strength.
Later, with the advent of higher transmitter power-in the order of 50 kilowatts-moderate-gain antennas and frequency-modulation techniques, it was discovered that signals could be detected in the frequency range between 40 and 50 megacycles, at a distance beyond 300 miles.


! Electronics July 27, 1964

When two antennas are separated by more than 100 wavelengths, variations of signal level are similar but occur at different times. The signal-to-noise ratios in the output of one receiver tend to be low when those in the output of the other are large. The present practical limit is reached in signal improvement with four receivers. The outputs of the four receivers are combined in such a manner that the output of the combiner represents at least the input to the unit receiving the best signal. Generally, each signal received in a quadruplediversity system contributes to the final output signal to produce a total signal-noise ratio more favorable than that of the strongest signal alone.
Diversity can also be accomplished using two transmitters, each operating on a frequency that differs from the other by about 0.5% as shown in the diagram on page 92. These two signals are intercepted by only one high-gain receiving antenna, to which two receivers are connected.
Controlling reliability
The percentage of time in which a tropo circuit transmits perfect signals is a function of two kinds of reliability-that of the radio path and that of the equipment. Equipment reliability is of two kinds-its adequacy to perform within the working limits of the system, and its ability to function perfectly without breakdown.
Unlike high-frequency radio circuits, which can be blacked out by severe disturbances of the ionosphere through sun-spot activity or nuclear explosions, tropo propagation is inherently reliable. Some signal comes through at all times, no matter how weak. With statistical techniques in handling known data from existing tropo paths, it has been possible to design systems having desired reliabilities.
For example, a path over which a required signal is available 50% of the time for all hours of the year might have a path loss of 200 db. If the circuit must be 99.9% reliable, another 20-db gain may have to be added to the system, and the path loss is then expressed as 220 db. If it is desired to provide protection for the worst hour, the statistical distribution might show that another 3 db is re-

' \


\ //

\ /.

Scatter angle varies with path length so the scatter volume (color) occurs at different elevations in the troposphere. One characteristic of a short path is more rapid fading, owing to meterological effects.






u. -

0 rJ>


I- ......

Z w>-


<>:: -' UJ< 0.. ::>

'c-o": u..

Improvement of quadruple diversity over dual-diversity reception are indicated by outage time in percent of hours. Outages in minutes per month range from 43.2 and 475.2 minutes to 0.04 and 3.6 minutes respectively for the extremes shown on the chart.

Often these signals were strong, providing excellent
reception of music for several hours. At other times signals were weak and fading, entirely unsatisfactory for music reception and unreliable for communications.
Further exploitation of this mode of propagation was cut short by World War II, although there seems to be evidence that the inventor of f -m, Edwin H. Armstrong, was quietly collecting information that might have a bearing on what were then known as propagation anomalies. But Armstrong died in 1954 without making any formal contribution.
During the war, communications and radar people were bothered by occasional long-distance reception of signals that was unexpected by those who lacked knowledge of anomalous propagation. Considerable study, some of it at Radiation Laboratory, Massachusetts Institute of Technology, brought forth the theory of ducts-waveguides formed in the atmosphere by meteorlogical conditions

-to explain the radar and communications anomalies. Postwar publication of earlier data, and careful study
at the information available around 1950, made it clear that a new theory was needed to explain why signals propagated through some mechanism of the troposphere were so persistent as to rule out meteorological ducts as the sole cause. Nor could the median signal, received far beyond the horizon, he explained away merely by postulating an earth with a longer radius.
Because these phenomena were not thoroughly understood in the radio engineering community, a new schedule of television frequencies was assigned, in which it was assumed that television signals would hold to the quasi-optical nature ascribed to them by man. The resulting interference between stations on the same channel brought about a four-year freeze in the assignment of new stations, and prompted engineering measures of great economic significance.

Electronics I July 27, 1964






Communications systems with no diversity (A), dual space diversity (8), quadruple space diversity (C), and quadruple space-frequency diyersity (D). Polarization is employed in (C) and (D).

quired, for a total of 223 db. To attain the percentage reliability desired, trans-
mitting and receiving equipment must be designed to provide the gain or suitable signal-noise ratio that will guarantee proper functioning of the system. The engineering tradeoffs must be studied carefully. Assuming it is possible to use a 100-kilowatt transmitter instead of a 50-kw, the resulting gain is only 3 db. By contrast, relatively minor changes in receiver design may produce larger improvement. For example, typical receiver noise figures , with normal converters range from 7 to 8.5 db. Using a tunnel-diode amplifier, the figure is reduced to 3.5 to 4, while a parametric amplifi er cuts the noise figure further, to 2 to 2.5 db.
Another important aspect of reliability involves the nature of the hardware and its maintainability. If components are chosen carefully, and if longlife transistors and varactors are used to keep down power consumption, equipment life becomes very long as contrasted with some electron-tube equipment in which lifetime has definite limits. Modular construction, plug-in replacement units and drawer construction make for quick repair of failing equipment, and also obviate the need for highly skilled maintenance personnel except at supply depots. Reliability is also enhanced by visual trouble signals, such as lights, and by a provision for quickly plugging in meters that show whether the circuit is functioning in the proper range of adjustment also enhance reliability.
Solid-state exciter
Radio Engineering Laboratories' 2600-series equipment will be used in the AT&T system.
For the 2-gigacycle, 132-channel system (300channel ultimate capacity), noise and intermodulation distortion is kept low by using special solid-state techniques. Power amplification at the solid-state exciter output uses one traveling-wave tube to drive the klystron final power amplifiers.

Modulation, which is a critical function, is accomplished with a variable reactance-type modulator stabilized by a crystal-reference automatic frequency control circuit. The block diagram is shown opposite. The modulator consists of a Hartley oscillator with a tank capacitor made up of two series-connected, voltage-variable capacitor diodes. Modulation signals are applied to the center of the diodes, causing the frequency to vary around a rest value of 23.33 megacycles. The modulator and the tripler that follow are contained in a temperature-controlled oven, [picture] to minimize the effect of variations in loading and temperature on frequency stability.
The desired 70-megacycle component is amplified in the intermediate-frequency driver amplifier while the subcarrier sidebands are suppressed in a five-pole, :Bat-bandpass filter designed to minimize intermodulation distortion.
Although the reactance modulator is superior for wide frequency deviation and low f-m noise, it requires frequency stabilization. A small fraction of the i-f driver output is amplified and applied to a sampling switch that has very low forwardinsertion loss-in the order of 0.1 decibel with isolation of '70 decibels between ports. Samples of the f-m signal and of the output from a 70-megacycle controlled reference oscillator are alternately applied to the demodulator by means of bias from the sampling oscillator.
The output amplitude is proportional to the frequency difference between the reference oscillator and the average frequency of the outgoing f-m signal. This error signal goes through a lowpass filter, is amplified in the error amplifier and rectified in the synchronous chopper demodulator. The resulting voltage, related in amplitude and polarity to the frequency difference, is filtered and applied to the reactance modulator with a polarity that causes its frequency to change in such direction as to reduce the error.
Receiver preamplifier
In the receiver, a parametric amplifier of the negative resistance reflection type provides 20 decibels of amplification with a noise figure of 2.5 decibels [block diagram outline opposite]. The varactor is contained in the idler cavity, which forms a parallel circuit. The pump or local oscillator frequency at 13,900 megacycles is lightly coupled to the cavity by a pump filter. An adjustablewaveguide short circuit is used for idler tuning. A coaxial inductive stub on one side of the varactor can be tuned to series resonance for the signal circuit. The low-pass filter at the other side of the varactor eliminates the pump frequency. This is followed by a broad-band coaxial transformer that raises the impedance of the signal source from 50 to 62 ohms over the entire frequency range of operation.
To obtain an amplifier input voltage standingwave ratio (vswr) of no more than 1.2 to 1, waveguide circulators of inherently low insertion loss


Electronics I July 27, 1964

and low vswr are used. A wave guide T-junction circulator at the input gives 24 decibels isolation. A second circulator with 24 decibels isolation couples the input signal into the parametric amplifier, and the amplified signal into the ouput isolator. Temperature is controlled within ±5 degrees at 60 C.
The pump klystron is stabilized for frequency change, repeller modulation and power output, and does not require elaborate sensing and feedback controls. The klystron tuning is fixed, requiring no adjustment of pump frequency. Adjustment of the repeller voltage over a limited range achieves peak power output. Pump level is normally set for a nominal gain of 20 decibels.
The varactor is a silicon diffused epitaxial mesa type in a miniature pill mounting.
Post-detection combining
To take full advantage of diversity reception, it is necessary to combine signals from four receivers in such manner that the resultant signal is never poorer than that of the best receiver and usually some increment comes from several receivers. Equipment with maximal-ratio post-detection diversity combining is being supplied for the long lines system. This combining technique is also used in the Ace High 40-span tropo system of the North Atlantic Treaty Organization.
As shown in the block diagram page 94, the combining element is a highly degenerate cathode follower or solid-state equivalent circuit whose output is connected, for alternating current and direct current, to other receiver combining elements. The internal impedance, and thus the noise contribution of each receiver to the combined output, is controll ed from direct voltage generated by sampling the thermal noise above the baseband. The noise amplifier comprises several stages of feedback amplification, an output rectifier and stabilized automatic gain control, to provide an appropriate control characteristic. The control automatically removes from the combined output a receiver that has failed, and operates an alarm.
Post-detection combining has certain advantages over predetection combining. It operates after the f-m signal has passed through the limiting and demodulating processes, and is practically immune to selective fading. This immunity results from the fact that the noise sample extracted above the baseband for combiner control is taken at several times the baseband frequency and from a relatively narrow noiseband. Selective fading, or radio-frequency phase reversals within the signal ing band, will therefore produce negligible effects.

Up-converter in tropo transmitter employs a traveling -wave power-output tube but is otherwise solid state. Limit-type meters are a part of· equipment reliability plan.

R-F SIGNAL INPUT 1,700 - 2,400 MC







Parametric amplifier (varactor in color), used in the receiver's front end, improves signal -noise ratio over that of conventional amplifiers.







Low-noise, wide-deviation reactance modulator (color) requires frequency stabilization that is obtained by comparing average frequency output with a quartz standard (color) and correcting with an error voltage.

Threshold extension

In an f-m receiver, the output signal-to-noise ratio varies linearly with radio-frequency signal as long as the signal is above threshold level. For r-f signals below threshold, the signal-noise ratio falls off more rapidly than the signal. Threshold represents the signal power that produces signal-

Reactance modulator is kept at a controlled temperature to reduce variations in frequency.

Electronics I July 27, 1964
























Baseband combiner, (color), used with each receiver, insures that the best contribution to the composite signal is obtained from each source. This method is in contrast to a simple switch that selects only the receiver with the strongest signal.



















70 MC I-F










Basic f·m feedback threshold extension, depending upon narrowing (color blocks) pass band (A} , showing how the principle is applied to a receiver (B) and the actual receiver in block form (C).

voltage peaks equal to noise-voltage peaks at the first nonlinear element-usually the amplitude limiter-of the receiver. The ratio of r-f signal power to noise power, or the carrier-to-noise at threshold. is 9 to 10 decibels.
Threshold level is a function of the receiver noise figure and radio bandwidth before limiting. Thus, to lower the threshold, it is necessary to lower the noise figure, or bandwidth, or both. Decreasing bandwidth for this purpose lowers the signal level to which the receiver output signal-noise remains linear. While system reliability is improved by increasing the tolerance of the receiver to input-signal level, the use of threshold extension is not a substitute for higher transmitter power.
Phase-lock techniques, used extensively in narrow-band communications and telemetry systems, arc not suitable for wideband systems. The f-m feedback technique reduces the frequency deviation by a degenerative process before transmission through a narrow-band filter, lowering thershold without excessive distortion.
As shown in (A) of the basic diagram left, frequency deviation is reduced by a process of degenerative feedback around a typical loop. Outof-phase deviation is obtained from a demodulator and voltage-controlled oscillator in combination.
The simplified block diagram (B) illustrates organization of a receiver for application of threshold extension when a signal falls below the normal threshold region.
The solid-state device of the type supplied in the AT&T equipment is shown at (C). The incoming signal frequency, at an intermediate frequency of 70 megacycles, is preprocessed in a bandpass filter. Degeneration of the f-m signal occurs in the frequency converter, owing to the out-of-phase local oscillator modulation from the voltage-controlled oscillator and multiplier.
The bandpass filter determines the threshold of the extension demodulator. The demodulator shown recovers modulation for baseband output and loop feedback. The feedback loop is completed by the indicated phase converter, voltage-controlled oscillator and frequency multiplier. The oscillator is stabilized by an automatic-frequency-control circuit that is referred to a local oscillator. The frequency meter provides a reference.
Demodulated output is amplitude-equalized and passed to a transfer circuit where either the threshold extension demodulator output or wideband demodulator output is selected. Transfer is automatic and normally takes place a few decibels above normal threshold. To compensate for the additional time required for the signal to travel through the threshold extension demodulator as compared with the wideband demodulator, a delay equalizer is inserted in the wideband path before the transfer function.
The author thanks Radio Eng ineering Laboratories, Inc., for technical information on the 2600 Series equipment which is the basis of AT&T's new trope system.


Electronics I July 27, 1964

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Electronics I July 27, 1964

Probing the News

Space electronics
Homemade ground stations to receive weather pictures from Nimbus satellite

From Vandalia, Ohio, to Bandung, Indonesia, they'll aim their antennas at the sky starting about Aug. 5

By Joel A. Strasser
Space Electronics Editor

Question: What does a high-school freshman in Ohio have in common with the Australian government's Weapons Research Establishment and Radio Suisse in Bern, Switzerland?
Answer: They're all building ground stations to receive weather reports from satellites in orbit.
The Nimbus I weather satellite, scheduled to be shot into orbit

about Aug. 5 by the National Aeronautics and Space Administration, will pass overhead at about noon every day at points around the world. It will be far easier to find than its predecessor, Tiros VIII, and easier to tune in on. Tiros VIII is in an orbit that is inclined to the equator and observers have to get advance orbital information from NASA to know when the satellite

will pass overhead. The Weather Bureau wants the
results of Nimbus's automatic picture transmission (APT) to be available throughout the world, especially to ship lines, television and radio stations, farms, airlines, and other organizations that need fast, accurate weather data. NASA has authorized two of its scientists to write an article (p. 81) on how to build a ground station for receiving APT weather pictures.
Homemade components. In Vandalia, Ohio, 14-year-old Mike Valentine has gathered technical information from NASA, the Wea th er Bureau and Electronics m a g a z i n e, as well as some parts from the Alden E le ctronic & Impulse Recording Equipment Co.
Using a home-made radio-frequency preamplifier and a Heathkit f-m tuner, Mike intends to receive facsimile weather pictures with a helix antenna made from 54 feet of 3/s-inch aluminum tubing and as-

Window screen and bedspring are two ingredients of this homemade, eight-turn helix antenna for APT station built by graduate students at the University of Wisconsin. Ron Stewart adjusts azimuth and elevation while Dennis Thomson checks coordinates.

Ottawa station uses a scope for display, instead of a facsimile machine. R.S. Rettie of Canada's National Research Council, adjusts receiver while C.I. Taggart of the Meteorological Branch of the Department of Transport watches the signal on oscilloscope.
Canada's answer to the pointing problem. Each element of this stationary array covers a section of the sky in such a way that maximum gain occurs at about 22° above the horizon and at every 30° in azimuth. Eight "horns" (the structures that look like two right triangles placed together) feed preamps. RCA Victor Co. of Montreal will use this design.
Test readout is taken from a Fairchild-Stratos commercial station by Charles M. Hunter, Spacecraft Manager of NASA's Tiros Operational Satellite program. Hunter and Edward Rich Jr. describe on page 81 how to assemble a low-cost ground station.

sorted pieces of aluminum conduit. For a facsimile readout, he has been experimenting with a light beam from a neon bulb and an advancing rotating cylinder that his father helped him rig up.
Rooftop station down under. In Melbourne, Australia, the government weapons agency has combined commercial equipment with a homemade antenna, tripod and preamplifier to form a station suitable for picking up f-m signals from Nimbus I. The agency modified an Eddystone 770R vhf receiver to NASA specifications, assembled the entire station on a rooftop, and said it achieved satisfactory reception.
The antenna is a cross-yagi mounted on a tripod that is manually steered with a handwheel and permits movement in azimuth and elevation. Screw jacks are attached to each leg of th e tripod for leveling, and built-in spirit level are provided to check the angle of the azimuth axis. The antenna may be locked in any position . It has a forward gain of 10 decibels and voltage standing-wave ratio of no more than 1.5.
Another "home-brew" station has been set up in Salisbury, southern Australia. That country's Bureau of Meterology plans additional stations at Perth, Darwin and probably Cairns. These, in turn, will be linked to facsimile lines to provide cloud pictures.
Future stations will have crystal controlled receivers and remotely controlled antennas developed by the Weapons Research Establishment. J.W. Lillywhite, Australia's director of meteorology, concedes that the station is "in no way revolutionary," but he says it represents "an economical solution" to the problem of receiving pictures from Nimbus.
In Bern, Switzerland, Radio Suisse has assembled a station consisting of a helix antenna with a gain of 8 db, a Tapetone, Inc., converter (model 100), a conventional high-frequency receiver, a facsimile demodulator and a Muirhead D-900-S facsimile recorder. The station cost less than $25,000 contrasted to the $32,000 cost of a commercial receiving station.
Spring and Screen. Some stations are much more makeshift. At the

University of Wisconsin three graduate students have constructed o'ne using a combination of surplus and homemade equipment. The collegians have built an eight-turn antenna using 0.5-inch copper tubing to form the helix, and copper window screen for the ground plane.
To support th e helix, an 18-foot, 2-by-2-inch piece of wood was attached to the ground plane, with wooden dowling separating the helix from the support. A surplus military antenna-an SCR-658 400Mc antenna attached to a tripod and nicknamed a "bedspring"supports the helical antenna at the base. The station uses an old 108Mc minitrack receiver that was used in th e Vanguard satellite program with a 137-Mc converter on the front end, made by the Arneco Equipment Corp.; an f-m detector and a Magnecord tape recorder. The students plan to use a facsimile recorder or an oscilloscope-andPolaroid-camera combination for the readout.
Other homemade stations are operating in Hong Kong, West Germany, Brazil, Anaheim, Calif. and elsewhere.
Britain's Meteorological Office has taken readouts from the Tiros VIII satellite, using the tracking station of the Royal Radar Establishment. The British plan to build a small station at Bracknell.
Clever Canadians. Canada has built a station at Ottawa that displays cloud-cover pictures on a high-resolution cathode-ray tube. The weather pictures on the scope are then photographed with a Polaroid camera. This is an alternative to the facsimile machine. The Canadians have also built a programer to point the antenna directly at the satellite to receive the strongest signals.
They have used all-solid-state circuitry with an oscillator phaselocked to the 2,400-cps subcarrier in the satellites' transmission system (p. 82). The oscillator's output is converted to 4 cps to obtain the sweep frequency for the scope display. The scope can then be used to reproduce the satellites' signal. The antenna programer has indicator circles for azimuth and elevation, with holes every two degrees. Based on orbital data, a pin is in-


Electronics : July 27, 1964

serted into a hole corresponding to the satellite's location at every minute. A motor-driven pointer, which advances from pin to pin, so that it is always aimed at the satellite, guides the antenna. The Ottawa station uses a crossed-yagi antenna with 10-db gain.
Canada's requirements for APT data differ from those of the United States. The highest possible resolution is needed to get good pictures of ice conditions in Canada's coastal waters, in addition to weather information. So the received signal is recorded on magnetic tape to permit repeated playback into the display to obtain the best possible picture.
East and West. At the Bandung Institute of Technology's electrical engineering department, Indonesian engineers are working on a simple ground station to meet the needs of the island republic's weather forecasters while staying within a limited budget.
They have built a quadruple helical antenna with a 14 to 15 db gain and have converted a Collins Radio Co. VHF-101 receiver to receive the satellites' f-m signals. They are converting a Telephoto machine for recording the facsimile readout from the satellites.
Engineers at the Danish Meteorological Institute have built a station near Copenhagen that has been receiving pictures from Tiros VIII since Dec. 24. The Danes built a steerable yagi antenna with a gain of 9 db, and have access to another yagi antenna that was put together from available radar equipment. The latter has four yagis, is both manually steerable and autosteerable, and has a gain of about 15 db.
The U.S. 'Veather Bureau's instrument division is experimenting with a low-cost antenna programer that can be used with commercially available stations.
The programer automatically controls antenna slewing hy using predetermined orbital data that is stored by manually positioning switches on a control panel.
The 'Veather Bureau uses a spiral array antenna for its experimental station.
About 50 of the antennas that will follow Nimbus's flight will be of commercial manufactme. Their prices range up to $40,000.


State of the unions

They haven't benefited from layoffs of engineers. But a new kind of organization seems to be evolving.

At the Boeing Co.'s sprawling plant in Seattle, nearly one-fourth of the engineers have been laid off as a result of cutbacks in military spending. Employment of engineers has nosedived from 10,500 to 7,800. Yet membership in the Seattle Professional Engineering Employees Association, the bargaining agent for Boeing's engineers has increased from 2,300 to 2,700 during that time. About 25% of Boeing's engineers are electronic or electrical.
The seeming paradox has attracted attention from students of labor relations. Some have wondered whether the change in the engineer employment situation in the United States-from one of prosperity to one of shrinking opportunities [Electronics, May 18, 1964, p. 105]-might start a boom

in engineer unions. The answer at this time appears
to be "No." A survey by Electronics magazine indicates that the Boeing situation is unusual. Union members among electronics engineers seem to be concentrated on the East and West Coasts. The magazine's reporters could find few members in the Midwest, South or New England.
I. Is it a bellwether?
Because of its apparent success, a lot of people are studying the SPEEA. Some of its more militant opponents have called its pact with Boeing a "sweetheart contract." because it gives the company the exclusive right to decide which, and how many, employees may be dismissed.
Traditionally, unions have fought

Electronics I July 27, 1964


for a voice in determining the basis of layoffs. Today, with engineering layoffs on the rise, the agitation about layoffs is even stronger in those few areas where union membership is concentrated.
Boeing uses a "totem" system to which the SPEEA agreed. Under it, company supervisors determine an engineer's value by rating such traits as competence, diligence and potential on a l -to-5 scale. The higher an engineer scores, the less likely he is to be laid off.
Usually, union philosophy is to insist on seniority in layoffs. The longer a man works for a company, the less likely he is to be dismissed by the company.
Youth hit hardest. Although seniority was not the chief consideration in the recent layoffs, they still seem to have hit h ardest

at the young, inexperienced engineers who comprise the smallest segment of SPEEA membership. That may be one reason for the association's growth through adversity, according to James R. Randall, chairman of the executive committee. Another reason is the union's first aggressive organizing effort, instituted by John Jolly, who recently completed a term as president.
Some experts believe that engineers will eventually go to some form of union. In 1963, Prof. George W. Zinke, director of the Center for Labor Relations at the University of Colorado, did a study en titled "Union s of Professionals : Prototype for Coming Decades?"
Referring to SPEEA and similar associations, he wrote: "The presently organized unions of profes-

Engineering union elections, 1962-1964

General Electric Corp. Drexel Hill, Pa.

Association of Engineers & Engineering Assistants

Westinghouse Electric Corp. Westinghouse

Newark, N.J.



Radio Corp. of America Burlington, Mass.

Association of Scientists and Professiona I Engineering Personnel

Westinghouse Electric Corp. Lima Westinghouse

Lima, Ohio

Salaried Employees


Westinghouse Electric Corp. Westinghouse

Cheektowaga, N.Y.



Western Electric Co. 24 major locations
General Dynamics Corp. Astronautics Division San Diego, Calif. General Dynamics Corp. Pomona, Calif.
Leeds & Northrup Co. Philadelphia, Pa.
Sperry Gyroscope Co.
Great Neck, N.Y.

Council of Western Electric Professional Employees
Engineers and Architects Association
Engineers and Architects Association
Professional Engineers & Scientists Association
International Union of Electrical Workers, AFL·CIO

Date Nov. 1963
Nov. 1963
Fall, 1963

union decertified, 100- 77 (technicians voted to retain union, 60- 12)
union installed for manufacturing engineers (11- 10)
union representation rejected (288-53)

Sept. union discontinued 1963 (181- 118)

Sept. 1963
Aug. 1963 July 1963

union retained (of 271 eligible to vote, 175 for, 33 against, 11 for Federation of Westinghouse Independent Salaried Unions)
union representation rejected (4,375-2,582)
union decertified (2, 149-1,388)

June union decertified 1963 (565-542)

March 1963

unions swapped (PESA replaced
Leeds & Northrup Employees' Union, 80-50)

May 1962

union representation discontinued (1,669- 1,069) (technicians vote
to retain, 345-198)

sional personnel are . . . indeed prototypes of unionization in the coming decades. They meet the problem of unionization versus professionalism by choosing new union tactics and strategies compatible with professionalism."
Because the SPEEA has chosen som~ new tactics , some people have called it a company union. Paul Staples, labor editor of the Seattle Times, disagrees. He concedes, "It's had a difficult time becoming effective because it has not had the power. But it is gaining strength and know-how and it is showing increasing muscle."
Prof. J. B. Gillingham of the Uni-
versity of Washington, an economist and labor relations expert, considers the SPEEA to be "rather
sa1.bvley" . led and reasonably aggres-
Is it a union? Ever since its inception in 1944 to counter an organizing attempt by the International Federation of Technical Engineers, AFL, the SPEEA has stressed its role as a professional organization, deemphasizing the union approach. Only once-in 1953-did it even threaten to call a strike; it later decided that such action was not necessary.
A strike threat is not likely ir;i the near future. Randall says the association believes that a strike for economic reasons would be unsound. Any possible strike would be on philosophical, rather than economic, grounds, he explains. A present difference with the company involves the definition of "professional." This is the kind of difference that conceivably could lead to a strike, Randall says.
Robert J. Sartell, an area representative, says the SPEEA "is not like a union, but an organization of engineers working to accomplish collectively what they are unable to accomplish individually."
E. E. Wachter, chairman of the Council of Engineers and Scientists Organization, confesses: "Our members know we're a union, but we don't use the word because they'd rather not h~ar it." The council is a loose amalgamation of engineering unions in Southern California.
The association's reluctance to engage in a test of strength may have a more practical basis. Gil-


Electronics I July 27, 1964

lingham, the Washington University labor exp ert, notes that the SPEEA represents only one-third of the engineers in its bargaining unit. "The union couldn't b e militant," he says, " or else it would be bluffing. It doesn't have enough membership."
11. The strike weapon
The SPEEA's attitude toward strikes contrasts with that of another, stronger union-the Association of Scientists and Professional Engineering P ersonnel chapter in
Camden, N. J. Late in June, the chapter took a
strike vote of its 1,200 membersamong 1,500 engineers-at the Camden and Moorestown, N. J. plants of the Radio Corp. of America. The problem was layoffs.
The union contended-and an arbitrator agreed-that RCA had violated layoff procedures that were spelled out in the union contract. The union charged that the company proposed to dismi ss too many high-seniority men.
The outcome of the vote has not been disclosed because the dispute was settled peacefully. But union officials have hinted that the engineers voted to strike, as they did in 1960 when five RCA plants in the Camden area were struck for six days.
Jobs dwindle. The Camden chapter's membership reflects a downtrend in union membership that follows a decline in engineering employment. Just one year ago, the chapter had 1,700 members representing 2,000 RCA engineers.
Unfortunately for the unions, they have made their greatest gains at defense-oriented plants that are the most susceptihle to cutbacks in orders and layoffs of workers. This is especially true of electronics engineers.
In the present era of employment cutbacks, unions are especially concerned with job security. This issue appeals most to veteran engineers, who have the most to lose. Yet companies are hiring greater and greater percentages of new graduates. Last year, the bigges t decline in the engineering profession was in the hiring of experienced electrical and electronics engineers. This dropped 28% from the previous year, while the hiring of new graduates increased 0.9%. This re-
Electronics I July 27, 1964

how to match a PAV to tough GSE specs
from its all solid state circuitry to its MIL·type hermetically sealed meter and plug·inamplifiers, every design feature of the Model VM ·235 Phase Angle Voltmeter has been selected for rigorous service in Aerospace Ground Equipment.
Your North Atlantic man can quickly demonstrate how this rugged , miniaturized version of North Atlantic's famous PAV provides direct, accurate reading of phase angle, nulls, total, fundamental, quadrature and in-phase voltages-even under the roughest of military field conditions.
The VM -235's ability to meet tough system specs is demonstrated da ily in operational and support equipment for USAF and Navy aircraft and missile programs. Its capabilities for complex measurements are shown in the abridged speci ficat ions below:
Voltage Range..... .....................................,..1 mv to 300 v f.s., 12 ranges Voltage Accuracy....................................... .............................. ..±2% f.s. Phase Accuracy............................dial: ±1°; meter: ±3% of F.S. degrees Signal Frequency..................... _..................................................400 cps Input Impedance....................................................................l megohm Reference lnput..................................................................26 v or 115 v Meter scale.......................------ -------- ----------------·· --·····3-0-3, 10-0-10 linear Phase Angle Dial.............................................2 scales, 90° (elec.) apart Nulling Sensitivity....................................2 microvolts (phase sensitive) Harmonic Rejection....................................................55db (with filters) Dimensions___ ________ ____________ ____ _..........................8 11,." h. x SW' w. x 6%" d.
North Atlantic's field engineering representative in you·r area has full data on the VM-235, as well as modified versions for specific systems requiremel1ts. For his name, call or write today, or request Bulletin VM-235.
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sulted in an over-all decline of 19.5% in new hiring.
111. Why they're weak
Even at 33% representation, the SPEEA is relatively powerful among engineering organizations. Nationally, only 27,000 engin eers -or 4.5%-belong to unions .
One of the biggest concentrations of union members among electronics engineers is in New York and New Jersey, where four companies have 4,000 members . The companies are the American Bosch Arma Corp. , the International Telephone and Telegraph Corp., the Radio Corp. of America and th e Ford Ins trument division of the Sperry Rand Corp.
Arma's engineers comprise one of the few units affiliated with an indus trial union. In 1956 th e Engineers Association of Arma became Local 418 of the International Union of E lectrical Workers.
Dreams of grandeur. One reason for th e weakness of many engineering unions is that their potential members like to think of themselves as man agement. "They don't want to act like a union ," Gillingham explains.
Some engineers oppose unions on principle. A spokesman for a large defense plant in Dallas says: "Walk through our parking lots and see the Goldwater-for-President stickers on bumpers, and you 'll understand why unions have little su ccess in Texas."
Ch ristos T. Christy, president of the Engineers and Scientists Guild at the Lockheed Aircraft Corp. in Burbank, Calif. , complains: "Approach an engineer to join and he says, 'I don't want to contribute to (James R. ) H offa.'" Hoffa, president of the Teamsters Union, has been accused of illegal activities.
Apathy. Many engineers are apathetic, some in the belief that they're as well off without a union as with one. J. G. Tarr, a form er executive secretary of th e Southern California Professional Engineering Association, which represents engineers at the Douglas Aircraft Corp., explains:
" Companies aren't organized so you can strike effectively. There are enough supervisors to continue 80% of the work for at least a month. Production wouldn't be stopped, and the company feels
Electronics I July 27, 1964

that it can pick up after a walkout by heavy overtime. Besides, we have no money to wage a six-month strike." Tarr's union represents 24% of Douglas' 4,775 engineers.
In August, engineers at the General Dynamics Corp. rejected the San Diego Chapter of the Engineers and Architects Association as their bargaining agent. Wachter, head of the council of which the association is a member, recalls what happened:
''The company exerted real pressure. The president spoke b efore every engineering group in the plant. The union wasn't equipped to do anything like that."
Along Route 128 near Boston, electronics plants have mushroomed in the past 15 years. But engineering unions are conspicuous by their absence.
"We have not given up," says an unsuccessful organizer for the American F ederation of Technical Engineers, "but we see no immediate possibility of organizing there. The companies . . . are satisfying the demands of engineers on an individual basis; this is what is holding the line at present."
Mobile members. Unions' effectiveness is also hampered by their members' mobility. Arthur Carstens, administrator of labor programs at the University of California, Los Angeles, explains:
"Unions barely get their hands on people in their jurisdiction and the people are gone elsewhere." He suggests a return to the old craft-union organization. "Unions must organize withou t a special relationship to any company."
Whatever the reasons, engineering unions have b een doing poorly at the polls. In 16 elections since 1960 involving electronics engineers, unions have been b eaten 12 times. Only at two divisions of the ' Vestinghouse Electric Corp. did engineers vote for a union. At two other plants, engineers voted to retain unions as their bargaining agents. But unions were rejected by engineers at seven plants, and ousted at five others where the unions had been representing engineers at the bargaining table.
Westinghouse engineers rejected unions at 24 plants. Other union defeats included votes at two General Dynamics plants and one of the Aerojet General Corp.
Electronics I July 27, 1964


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Surgeon looks up from microscope to check cofor-tv monitor.
Medical electronics
Microsurgery on color tv
Fiber·optics bundle allows a color camera to peer through microscope and televise an ear operation

By Laurence D. Shergalis
Regional Editor

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Operating-room amphitheaters, the
scene of so many climaxes in television dramas, are rapidly fading out of the medical scene.
Surgeons are far ahead of the script writers. They have been televising operations, in living color, to medical audiences for at least 15 years. Everybody gets a closeup of new techniqu es.
The latest refinement in ~he use of television in medicine is a method of watching microsurgery -operations on organs so small that the surgeon looks through a microscope as he performs the operation.
At the June convention of the American Medical Association in San Francisco, physicians in the San Francisco Civic Center watched surgeons at the San Francisco General Hospital performing a stapendectomy-an ear operation. This consists of removing the stapes, a small stirrup-shaped bone, and replacing it with a wire-and-plastic substitute to restore hearing.
The surgeon looked through a

microscope into the patient's ear, to operate on an area only five to seven millimeters in diameter. The audience watched as the color-tv picture was projected on a screen 9 by 12 feet. An audio hookup allowed them to ask the surgeon questions.
Fiber-optics. Between the color-
tv camera and the microscope was a device that prevented the camera from int ~rfe::ing with the operation. The device was a bundle of 675,000 optical fibers , formed into a fivefo ot-long cable, optically coupling the camera with the microscope.
Small tv cameras can be coupled directly to microscopes, but color cameras are bulky. The fiber-optics arrangement keeps the camera out of the way so the surgeon can manipulate the microscope freely.
This was the second time such an operation had been televised live and in color. The first was in New Orleans in November, 1963.
Smith Kline & French Laboratories, of Philadelphia, worked for a year to develop the system used

Electronics I July 27, 1964

in both operations. Black dots. A few black dots still
speckle the tv picture. These are caused by broken fibers in the bundle. But they don't detract from picture quality and are considered unavoidable. Enginee rs are working on ways to eliminate the dots, perhaps b y undulatin g th e cable so th e dots move abou t while th e picture remains stationary.
To avoid picture di stortion , the ends of the fib ers mu st remain in the same relationship to each other. But th e cable itself can be bent fr ee ly .
One end picks up the scene by means of a partial mirror in a Zeiss binocular microscope. The microscope was modified For Carl Zeiss, Inc., by th e Urban En gineering Co. of Hollywood, Calif.
Splitting the beam. At th e camera, th e bundle goes directly into th e beam splitter, whi ch separates th e image into red, green and blue fo r transmission. Th e camera is a s tandard Radio Corp. of America model from which the relay lens and objective lens are removed.
Rotating couplings are placed at both ends so the ends of th e bundle can be moved without moving the image. This allows the surgeon to move the microscope.
Illumination for the camera and the surgeon is provided by another fib er-optics bundle, which pipes light from a bright source to a lens under the microscope.
The bundle is not needed to televise regular operations . The camera can be kept out of th e surgeon's way merely by placing a mirror over the operating table and aiming the camera at the mirror.
Doctors prefer color. Smith-Kline went to so much trouble to get
Fiber-optics bundle, connecting camera and microscope, is contained in this cable. Before an operation, a test pattern is used to line up optical system.
Electronics I July 27, 1964

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Both the Model 70 with single set point and Model 77 with dual set points for detecting high and low limits are normally supplied with non-latching outputs for DC inputs with ranges of 100 µ.a, 1 ma, 10 ma, or 100 ma. The Model 70 can also be supplied with latching or pulse outputs.


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PERLMUTH ELECTRONICS' 5057 W. Wastungton Blvd. Los Angeles . Cali f . (213) 931 ·1041
8068 Engineers Ad. San Diego, Ca lif. (714) 278-6230
2B59 E. Thomas Rd. Phoenix , Ar iz. (602) 264-4934
Ho. California ta Nevada
HELD & MOLLARD, INC.· 1125 Marsha ll Street Redwood City, Ca li f. (415) 365-1700
Washin1ton, Ore1on It No. Idaho
EICHER & COMPANY 5 W. Ha rrison
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PETERSON COMPANY 4949 Colorado Denver, Colo. (303) 333 .5434
521 W. 4th North Salt lake City, Utah (801) 355-7464
w. New MlllCO, Sia:
THIS Countiu

ELECTRONIC ENTERPRISES 1900 Washington St. , N. E. Albuquerque , N. M. (505) 256-1585
(Except Six West Co.)
BUTLER & LAND 5538 Dyer Street Dallas, Texas (214) 361-6631
1845 Line Avenue Shreveport , la. (318) 422-0697
1034 Constance Street New Orleans, la. (504) 524 -0688
RIDDLE & HUBBELl 302 S. Cheyenne Tulsa , Okla. (91B) 585-5624
Neb., Iowa, Kansas , Missouri and So. Illinois
IMPALA, INC. 7540 Lowell Street Overland Park, Kansas (913) 648-6901
247 South Pine crest Wichita, Kans . (316) 682-3593
1011 Clifton, N. E. Cedar Rapids, la. (319) 362·2125
P.O. Box 6164 Lambert Field, Mo. (314) 522-1600

No. Illinois, N.W. lndlana and Central Wisconsin
A & M INSTRUMENT" 4801 North Ridgeway Ch icago , Illinois (312) 539-4460
w. Minnesota, Dakotas,
N. Wisconsin
PINKNEY & ASSOCIATES 1925 Nicollet Ave. Minneapolis, Minn. (61 2) 338-0523
INSTRUMENTATION SERVICES, INC. · 917 Plymouth Avenue Minneapoli s 11 , Minn. (612) 521 ·6267
Michi1an &. Indiana (E:1cept Counties lake, La Porte &. Porter)
THE SATULLO COMPANY' 4515 North Woodward
r3°m 5~;~:i:tbch.

618 Cincinnati· Batavia Rd . Cinci nnat i, 0 . (513) 752-6683

E:astern Wisconsin

TAYLOR ELECTRIC' 4080 Northport-
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SREPCO DIVISION' 314 Leo St. Dayton , 0 . (513) 224-0871
511 New E:n1land St1t11
ALVIN S. MANCIB COMPANY' 365 Walden St. Cambridge, Mass. (617) 864-2494
Randolph & Coe Roads P. 0 . Box 467 Middletown, Conn . (203) 347-5629
Metropolitan New York, Loni Island, &. N. New JtrHJ
A & M INSTRUMENT COMPANY' 48-01 31st Ave . long Island City, N. Y. (212) 726-4343
E:. Pennsylvania, Delaware &. Southern New JtrHJ
ROBERT K. NYE ASSOCIATES P. 0 . Bo· 611 s . 24 Woods ide Rd. Berwyn, Pa. (215) 644-8479
ELECTRIC METER SERVICE ' 1014 Vine St. Philadelphia 7, Pa. (215) 922-3422

Mlt')'land, No. Virs lnia
THOMAS H. CLOSS 21 W. Pennsylvan ia Ave. Towson , Md. (201 ) 825·4455
North & South Carolina
SYSTEMS SERVICE CORPORATION P. 0 . Box 17525 3748 Monroe Ave. Charlotte 7, N. C. (704) 377·3407
6s9. 0w.Murphy Avenue
P. 0 . Box 10857 Atlanta, Ga. (404) 753-412B
Alabama {Florida Cauntlu west at Jackson, Calhoun & Culf)
THE JAMES SPADER COMPANY 512 North 18th St. Birmingham, Ala . (205) 252-7419
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Electronics\ July 27, 1964

living color because that's what doctors prefer. Without color it is difficult to tell diseased from healthy tissue, or to identify body fluids.
The company isn't even using videotape. Its engineers explain that taped operations wouldn't have the spontaneous quality and drama of live operations.
Although the company's business is ethical medicinal specialties, it has long promoted educational tv in medicine. As a service to medical organizations, it keeps a tv crew on the road full-time to televise operations for seminars and conventions of physicians.
Smith-Kline is a pioneer in the field. It began working on medical color tv around 1949, using the field-sequential camera designed by Peter Goldmark, president of CBS Laboratories of the Columbia

Broadcasting System. This type of camera, still used by the Ciba Corp., a pharmaceutical company, has a rotating color wheel in front of the lens and picture tube.
In 1956, Smith-Kline switched to the standard NTSC 525-line system-the standard broadcast color tv system-because it is compatible with available black-and-white tv receivers. In 1962, Smith-Kline participated in the first live color tv program from Europe using the Telstar I satellite.
In schools, too. Color tv is also
being used educationally in medical schools and hospitals. The University of Michigan has permanently installed an NTSC system. Walter Reed Hospital in Washington also has an NTSC system. A field-sequential system has been used at the University of Pennsylvania in Philadelphia.

Audience of physicians sees inner ear magnified on 9· by 12·foot screen. Black dots are caused by broken fibers in the fiber-optics bundle.

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Ser tester aids in standardization

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The new tester incorporates special features for testing most existing four-layer devices and unijunction transistors. The MP-101 allows rapid, accurate testing with capabilities for failure analysis, parameter characterization, unit-to-unit parameter matching and vendorsample evaluation. According to the
Model MP-101 scr tester also tests unijunctions and other four-layer devices.

manufacturer, this represents the first inexpensive test instrument that combines simplicity of operation with accurate measurement of the parameters of most nonlinear switching devices.
Designed for use both in the laboratory and for incoming inspection, the MP-101 incorporates an internal high-voltage current-limited power supply for the determination of forward and reverse breakdown voltages up to 500 volts, and of device leakage down to one microampere. A second test function provides for measuring gate characteristics by a continuously variable gate voltage and current supply. A high-impedance voltmeter and a series microammeter are used to monitor gate-firing voltage and current under various conditions of gate bias. Test functions are also provided for measuring holding current and forward "on" voltage with a forward current variability of from zero to one ampere. An added feature is the ability to determine the hun-off gain of gate turn-off scr's.
A special test fixture allows rapid testing of both stud-mounted packages and units with wire leads. In

Special fixture allows testing of both stud-mounted units and devices with wire leads.
addition, the binding posts permit the use of special-purpose test fixtures outside of the unit.
An important feature in the design of the instrument is the fact that all internal circuits conform wherever possible to MIL-S38103A. This is the latest military test standard for semiconductors used in high-reliability components. Instrument accuracy is 3% of full scale for all measurements. The price is $589.
Sensory Systems, Costa Mesa, Calif. Circle 301 reader service card

Integrated circuits
in a family of six
Six new DCTL (direct-coupled transistor logic) integrated circuits have been developed for mediumspeed, low-power digital computers. The new microcircuit family, which can comprise the entire logic section of a military or commercial computer, includes the MHM4001 gate, 4101 double gate, 4201 adder, 4301 half-adder, 4501 register (illustrated), and 4401 buffer. The circuits are fabricated on a

single silicon die by epitaxial deposition and planar diffusion. Worstcase fan-out for each of the first

five devices is four; for the buffer, 30. Propagation delay for the gate and double gate is 70 nsec; for the adder, half-adder and buffer, 140 nsec; and for the register, 210 nsec. Maximum power dissipation is 8, 6.8, 18, 14.5, 33.5 and 21 mw, respectively. All elements are designed for operating temperatures of -55° to 125°C. Storage temperatures of -65° to 200°C can be withstood. In 100-lot quantities, prices range from $11.30 for the gate to $30 for the register.
Honeywell Semiconductor Products Division, 1177 Blue Heron Blvd., Riviera Beach, Fla. [302]

Electronics I July 27, 1964


Maple Ayenue, Pine Brook, Moms County, New Jersey

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New Components and Hardware

Compact, fully shielded audio input transformer
An audio input transformer, compact and guaranteed to MIL-T-27B, has been developed. Type TF4RX17YY is encased in metal and hermetically sealed. It is shielded electrostatically and electromagnetically. Electrical parameters are: primary, 600 ohms; secondary, 600/ 150 ohms; frequency response, ±0.5 db from 300 cps to llO kc, within 1 db to 150 kc ; maximum level, +IO dbm ; distortion, 112% or less; size, 1% in. square by 11\ ; in. high max; weight, 200 grams max.
United Transformer Corp., 150 Varick St., New York 13 [311]
Co-ax cable connectors are easily installed

Grip cable attachment :mechanism will withstand surge cuneots to the limits of the cable sheath, thus making the connector particularly useful in hardened communication link applications. In phased array or precision delay applications, Quick-Grip permits rapid, precise trimming of cable length for phase or delay adjustment.
Communication Dynamics Corp. , 289 Nepperhan Ave., Yonkers 01, N.Y. [312]
High-megohm resistors
are stable to 125° C
Resistances from 108 to 1014 ohms, with virtually no aging drift, are offered by the Pyromeg series HR1250 Ultra High Meg resistors. Units have an unspiralled resistance element and are stable up to 125°C. By filling the interior with nitrogen and then hermetically sealing the resistor, the manufacturer has provided complete protection of the resistance element. Applications include photocell and electrometer circuits, radiation detection devices and measuring equipm en t. The resistor is l l/4 in. long and :tq2 in. diameter.
Pyrofil m Resistor Co., 3 Saddle Rd., Cedar Knolls, N.J. 17927. [313]

Quick-Grip connectors have been designed for all corrugated and smooth-sheath, air and foam-dielectric coaxial cables. The line covers r-f connectors for cables ranging in size from 0.062 to 31/s in. diameter in all standard terminations. Applications include phased-array feed networks, pulsed data transmission and community tv systems. Illustrated is a bulkhead mounted GR874, locking type connector for use on 112-in., 50-ohm, smooth-sheath, foam-dielectric 0able. Features of the line include extremely low vswr, and rapid, simple, low-cost installation on cable. The Quick-

Servo-mount pot
resists humidity
A single-turn servo-mount precision potentiometer of 7/s in. diameter is available in an all-plastic, moistureresistant housing. Model 3580 ex-

112 Circle 112 on reader service card

Electronics I July 27, 1964

ceeds steady-state requirements of MIL-STD-202B, Method 103. A special rotor design assures excellent wiper stability. The shaft is supported by precision ball-bearings for additional performance capability. Standard resistance range is 100 to 50,000 ohms; resistance tolerance, ±3% standard; resolution, 0.38 to 0.08%; linearity, ±0.50% standard; operating temperature range, -65° to +125°C; power rating, 1.0 w at 70°C; ganging, up to 24 cups; weight, 0.5 oz. Price is $20 in quantities of 100 pieces.
Bourns, Inc., Trimpot Division, 1200 Columbia Ave., Riverside, Calif. [314)

PCM D/A Converter
New 20 Channel 0-A Converter "Package".

Disk-type thermistor
is reliable and fast
A line of disk-type thermistors has been designed to provide high reliability in making close-tolerance temperature measurements at remote locations and in preventing thermal runaway by serving as a temperature compensator for transistorized circuit modules. These characteristics, plus high stability, fast response and high power sensitivity, make the units ideal for mounting or electrical packaging. The disk is 0.4 in. in diameter and 0.144 to 0.149 in. thick. Resistance values are 1,000 ohms ±1.5% at 77°F and 207 ohms ±1.5% at 150°F. Time constant in still air is 40 sec at 25°C. Dissipation constant in still air at 25°C is 8 mw per degree centigrade.
Victory Engineering Corp., 136 Springfield Ave., Springfield, N.J. [315)
Oil-enclosed resistor
in wirewound bobbin
A precision wirewound bobbin resistor which has its resistance element sealed in an oil-filled brass can is now being produced to special order. The SPR-106 is designed to fit applications that require ultra-precise matching, a low temper-
Electronics I July 27, 1964

· Self-Contained Calibtator · Integral Binary Display · Self-Contained Power Supply · High Linearity and Stability

The new modular DAC-2 from Defense Electronics, Inc. offers linearity of +.1% and overall accuracy of -+-.25% for digital-to-analog data conversion in PCM sub-systems ... pl us a self-contained calibrator and power supply.
The compact unit has 20 eight-bit, digital-analog converter channels, each with its own integral binary display. Storage of data samples in each channel is shown by eight incandescent lights.
A versatile and flexible d-a converter "package", DAC-2 permits calibration of any one or a selected group of channels without disturbing operation of remaining channels. Monitoring of percent of full-scale and output voltages by front-panel meters is also provided. Thumb wheel switches select the channels to be metered.
Input of each module is eight data lines and one tran sfer line and output furnishes sufficient current for driving analog displays, recorders and galvanometers. The unit will operate at word rates up to 100kc.
Ask for the DAC-2 Bulletin ... Watch DEi



Defense Electronics, Inc.
ROCKVILLE, MARYLAND PHONE(301) 946-2600 TWX301-949-6788

Circle 113 on reader service card 113

New Components

~···· ·





ature coefficient and excellent stability. According to the manufacturer, the oil-enclosed atmosphere in which th e resistance element is suspended provides the freedom from stress essential to precise performance. The SPR-106 has a power rating of 0.05 w and a resistance range of 100 ohms to 800,000 ohms. It can be provided in pairs match ed to 0.03% with a stability ratio of ±0.002%. Temperature coefficient is 0 ± 5 ppm/°C in an operating range of 70° to 90°C. Temperature coefficient matching to ±1 ppm/ °C js available. The unit has a body length of 0.625 in. and body diameter of 0.312 in. Leads are axial, 1% in. long.
Dale Electronics, Inc., P. 0. Box 488, Columbus, Nebr. [316]
Spiral cone antennas
cover broad band
Two conical log-spiral antennas are designed for use in rfi measurements in the 200-Mc to 10-Gc range, as specified in MIL-STD826. These light, 50-ohm antennas are of a broadband type with no tuning adjustments required, thereby saving measurement time. Their directional patterns assure good back-lobe suppression of signals originating behind the an-

Lapp pioneered the application of electrical porcelain and steatite to the radio/electronic field. We've solved thousands of knotty insulating problems with down-to-earth engineering ingenuity and production ability. · Tube supports, stand-off insulators, gas-filled condensers, entrance insulators, porcelain water coils, antenna strain and spreader insulators, tower insulators ... these are only a few of the many dependable insulators that bear the Lapp name. Hundreds and hundreds of special designs have been developed to meet tough specifications. · Send your next insulating problem to Lapp. We'll come up with an efficient answer quickly and economically. Lapp Insulator Co ., Inc. Radio Specialties Division, 220 Sumner Street, LeRoy, N. Y. 14482.
114 Circle 114 on reader service card

Electronics I July 27, 1964

tennas. Equal response to signals radiated in the horizontal and vertical planes is assured by the circular polarization of the antennas. Price for the 200- to 1,000-Mc antenna is $240; for the 1- to 10-Gc
unit, $250.
Stoddart Aircraft Radio Co., 6644 Santa Monica Blvd., Hollywood 38, Calif. [317)


Solid-state switches
are fast-operating
A line of high-speed solid-state switches has been developed for telemetry and multiplexing systems. They also act as chopper relays in d-c amplifiers and synchronous detectors. A self-contained driver is completely isolated from the switch elements, which open and close in 0.5 µ.sec. Switching frequencies from d-c to 500 kc may be used, and transient spikes are exceptionally small, typically less than 1 mv. Series 10 models have offset of less than 1 mv and can handle signal voltages of +40 v, while series 20 models have a lower offset of 100 µv at signal voltages
of ± 15 v. Both are 1h in. by 1h in.
by 1 in. Price (spst) for the series 10 is $49; for the series 20, $69.
Brower Laboratories, Inc., Turnpike Rd., Rt. 9, Westboro, Mass. 01581. [318)
Hermetically sealed
film resistors
Hermetic glass seals are the key to long-term stability and reliability, at moderate costs, for the type GEM precision film resistors according to the manufacturer. The resistors, which have evaporated metal-film elements, surpass characteristics C & E of MIL-R-55182. Three sizes are available-RNR 55,
60 and 65. They are rated at tn-,
1/s , and 1/4 w, respectively, at 125°C. Resistance values start at 50 ohms for all three sizes and range to 100,000 ohms for RNR55
Electronics I July 27, 1964

A new family of water-cooled xenon flashtubes by EG&G allows laser-pumping at average powers of 4K W(FX-62A), 8KW (FX-65A) and 20KW (FX-67A). These unique tubes have been designed with special electrodes efficiently cooled by a concentric water feed method to meet present day needs for fast repetition pulse rates and long life. Other applications include projection cameras and optical or visual illumination sources.

TOTAL EG&G has the industry's broadest line

FLASH TUBE of xenon flashtubes including linear,


helical, bifilar, annular, U-shaped and custom designs. Linear flashtubes,

rated up to 3,000 joules per inch of

arc length, are available.

Complementing its flashtube line EG&G also offers complete lines of trigger pulse transformers; chokes; cold cathode krytrons for trigger switching; ceramic-metal thyratrons for high energy switching; triggered spark gaps for crowbar protection; photodiodes, and instrumentation for nanosecond light detection; and equipment for driving flashtubes.
For detailed information on EG&G's water-cooled flashtubes write for data sheet FX-62A, FX-65A, FX-67A or contact EG&G Products Department, 176 Brookline Avenue, Boston, Mass. 02215. Phone: 617-267-9700. TWX: 617-262-9317.


Circle 115 on reader service card


New Components




These new General Electric
lamps have 25,000-hour
1· nsomn1· a

They're made for wide-awake designers. For men who want a longer-lasting, dependable lamp for Computer Systems · Displays · Read - outs · Aircraft Indicators · Switches · Etc.!
If you're noodling over one of the above (including Etc.!), you'll want to check out new, reliable #2187 and #387. The leads on the wire terminal version, incidentally, are cleaned and solderable-at no extra charge. Or for quick, easy installation, you may find #387's midget flanged base more to your liking.
Send for Bulletin number 3-4365. It's the best way to find out which of these newcomers you can use best. General Electric Company, Miniature Lamp Department M-420, Nela Park, Cleveland, Ohio 44112.




N o. Volts Power Amp s (average) Fi lam ent B ulb

B ase

387 2187


0 .30 0 .04 25,0 00




0 .30 0.04 25,000


C-2F C-2F

T-1 % Midg. Flanged
T-1 % Wire Terminal

. ~gress /s Ovr Most lmpo"'1nf Protlvd

116 Circle 116 on reader service card

sizes; to 499,000 ohms for RNR 60 sizes; and, to 1 megohm for RNR65 sizes. Standard tolerance is ± 1% ; special tolerances are available. Prices for standard units are approximately $1.80 each in medium quantity lots.
International Resistance Co., 401 N. Broad St ., Philadelphia 8, Pa . [319]
Resonant-reed relay follows audio orders
A 4-channel resonant-reed relay switches multiple circuits remotely by audio signal commands. The RD7 measures 1.23 by 0.67 b y 0.64 in. and is designed for printedcircuit mounting. Signals to the multichannel resonant-recd relay can be transmitted over copper wire or r-f loop. Upon receiving a predetermined a-c signal, the selected reed (or reeds) resonates. Contacts on the reeds then perform the switching functions. The reeds can be tuned to provide over 50 separate control frequenci es within a spectrum of 150 to 700 cps. The RD 7 is designed to operate in narrow bandwidths (±1.5% max). It is highly sensitive, requiring only 15 mw normal drive level. Output is lp4t or 2p2t.
Bramco Controls division, Ledex, Inc., College and South Sts., Piqua , Ohio. [320]
Electronics I July 27, 1964

New Instruments

Decade voltage source
with digital readout
Digital readout to 999 v in onevolt increments, and output accuracy of ± 0.5% even when used by unskilled personnel, are features of this a-c decade voltage source. Applications for the model 200 include recalibration of a-c meters, transformer testing, voltage comparison, nulling, and design of rectification circuits. Input, at 115 v, can be any frequency from 60 through 1,000 cps. Output is adjusted in three decades by front-panel rotary switches that provide in-line window display of the voltage setting in units, tens and hundreds of volts. Accuracy of output is determined only by the setting of the pointer of a built-in meter to a red index line. Then any desired voltage from 1 to 999 v may be dialed by setting the output indicators at the desired numbers. Output capability is 10 ma. Price is less than $400.
ldalee Electronics Corp., 891 Fulton St.. Valley Stream, N.Y. [351]

sories, with temperature-compensated and uncompensated thermistor mounts that have negative coefficient elements with operating resistances of 100 and 200 ohms. Full scale readings from 0.01 to 10 mw are covered in 7 steps, with a bridge accuracy to ±3% of full scale. With uncompensated thermistor mounts, the power range is limited to 0.1 mw at the low end with an accuracy of ±5% full scale. Two self-balancing bridges in the 686 render it essentially drift-free. Price is $395.
PRO Electronics, Inc.. 202 Tillary St., Brooklyn. 11201. [352]

Solid-state portable spectrum analyzer

Stable power meter
needs no accessories
A high-stability power meter, the PRD686, has been announced. According to the manufacturer, it can be used, without additional apces-

A solid-state spectrum analyzer, model TA-2, with four plug-in modules, covers 20 cps to 27.5 Mc. Rugged printed-circuit boards are utilized for maximum reliability in the 40-lb. unit. The swept-band TA-2 and its interchangeable modules provide graphic spectrum analysis from audio through r-f, for applications in the field and in plants where bulkier units cannot be used conveniently. Its silver cadmium batteries are good for at

Electronics I July 27, 1964

HERE'S WHY ··· HOLDING POWER - atlee clips are specially contoured to flex under tension. Their grip actually increases as shock and vibration increases. PROVEN RESULTS - no visible shifting or twisting - no lead·breaking resonance - holding power unchanged by heat or constant use.
COOLING EFFICIENCY - atlee clips, acting as heat sinks, approach within 10% of "infinity". PROVEN RESULTS- operation of transistor at maximum ratings without life shortage.
ELECTRICAL INSULATION-atlee clips are available with Dalcoat B coating, an enamel combining twice the dielectric stength of Teflon with equal heat conductivity of mica. PROVEN RESULTS- proper electri· cal insulation from chassis and proper thermal behavior.
SEND FOR TRANSISTOR APPLICATION TABLE -A comprehensive listing of atlee clips for specific transistor application.
atlee corporation
PAUWllW t · llOQ
Circle 117 onreadec-ser:vice .card .. .J.17

Need to say a lot in a little space?
(or make markings more durable...or more economical ... or at higher rates?)

New Instruments
least 4 hr. continuous operation and
recharge automatically when the unit is plugged into line at the end of the day. Terminals on the back permit use of 12- to 28-v d-c external batteries. With minimum space, installation, power setup and adjustment requirements, the TA-2 finds use in laboratories, production lines, and on ships, aircraft and similar conveyances, enabling graphic swept~band measurements where tedious point-by-point techniques were formerly required.
Singer Metrics division, The Singer Co., 915 Pembroke St., Bridgeport, Conn. [353]

We can show you how

We can show you how to identify
products so they will resist extreme amounts of handling, abrasion, many solvents and other atmospheric condi-
tions ... or how to sequentially number and identify components with savings of more than $50 per 1000 · .· or how to print trademark, type number, value and date code on 90 units a minute . . . or how to produce an imprint that remains readable after 1000 hours at 200°C. · ·· or get 10 digits and 2 letters in a micro-circuit area of 0.090" - or 21 characters on a T0-5 case with interchangeable type number and date code ... or save 75 cents of every dollar you now spend on buying, applying, inventorying and discarding obsolete preprinted labels.

The answers are in proven Markem machines, type and specialty inks, which daily produce better product or package identification by reducing costs, smoothing production control and increasing customer acceptance. And while Markem machines, type and inks are helping to produce better products through more complete and lasting identification, they frequently pay for themselves in the savings they make possible. Tell us what you make, what it must say, and for how long. we'll give you a specific recommendation and cost estimate right away. Write Electrical Division, Markem Machine Co., 305 Congress St., Keene, New Hampshire

118 Circle 118 on reader service card

D-c standard source
and differential voltmeter
In a single unit only 7 in. high are combined a precision d-c standard source, a 0.01% differential voltmeter, a high-gain d-c amplifier, and a high-impedance d-c electronic voltmeter. Model 740A, as a calibrator source, puts out continually adjustable voltages up to 1,000. Voltages, indicated with 6place resolution on four Nixie readout tubes and a taut-band suspension-type meter, are accurate to 0.01 %, and stable within 0.003% per month. As a differential voltmeter, the instrument offers an input impedance that remains greater than 1,000 megohms, regardless of null conditions, in contrast with usual differential voltmeters whose impedance drops sharply under offnull conditions. It compares d-c voltages from zero to 1,000 v with absolute accuracy of 0.01%. As a d-c power amplifier, the unit will give up to 60 db gain, with stability better than 0.001%, output up to 25 w. As a d-c voltage amplifier, with voltage output directly pro-
Electronics I July 27, 1964

portional to meter deflection, it offers up to 120 db gain at isolated recorder terminals. The individually calibrated meter may be used as an electronic d-c voltmeter of 1% end-scale accuracy, with full scale ranges from 1 µ.v to 1,000 v. Its floated and guarded input is of more than 1,000 megohms impedance on ranges from 0.1 v up, 100 megohms on the 10-mv range, and 10 megohms on others.
Hewlett·Packard Co., 1501 Page Mill Road, Palo Alto, Calif. [354]
Signal analyzer aids low-frequency studies
A multiple-input, low-frequency signal analyzer has been developed. This real-time, phase-lock tracking vibration analyzer accommodates from 2 to 100 transducers, and has a frequency range of 0.5 cps to 10 kc. The instrument is designed for use in shake-table work, rotating machinery studies, acoustical analyses, friction studies, or in any application where signals under 10 kc are undergoing study. The unit speeds up vibration analysis by simultaneously measuringin real-time - power spectral density, cross power spectral density, random signal amplitude and transmis·sabi1ity; or, in periodic analysis applications, measuring amplitude, phase and transfer functions. Other features include allsolid-state design, a 60-db dynamic sensitivity range and infinite frequency resolution.
Interstate Electronics Corp., 707 E. Vermont Ave., Anaheim, Calif. [355)
Filter synthesizer uses passive networks
Filter synthesizer model lOK-lM allows for high- or low-pass filters to be designed by means of nomo-
Electronics IJuly 27, 1964

How to calibrate a sensitive Temperature Transducer
Do what the gentleman at Micro-Systems, Inc:" (in the picture) is doing. Lower it gently into the warm, luxuriously isothermal interior of a Hallikainen Constant Temperature Bath.
Why Hallikainen? Because Micro-Systems' customers insist on having their transducers calibrated to within 0.1 °F accuracy. Hallikainen Baths of the type shown above better this stringent spec ten times over. That's why Micro-Systems have taken delivery on 15 Hallikainen Baths over the past three years.
Whether you're calibrating thermometers, filled system temperature instruments, or Piezo-Resistive Temperature Transducers, one of the 27 different Constant Temperature Baths you'll find on tap at Hallikainen will answer your needs. They offer control ranges that begin at -100°F and end at 1300°F, proportional and proportional with reset temperature control modes, and exclusive JetStir Impeller agitation that banishes temperature gradients from your bath.
Why not dip your problems into the world of Hallikainen Constant Temperature Baths? We've prepared a packet of warm literature to help you get a feel for the subject.
"Division of Electro-Optical Systems, 170 N. Daisy Ave., Pasadena, California
Dept. E 1341 Seventh St./Berkeley, California 94710
Circle 119 on reader service card 119

·· ·and It's BURNPROOF

New Instruments
graphs and built by the use of decade inductors and capacitors. The unit consists of passive elliptical function filters of several types. The frequency range extends from below 10 kc to above 1 Mc and impedance from 100 to 1,000 ohms. Attenuation up to 40 db is available.
Allen Avionics, Inc., 255 E. 2nd St., Mineola, N.Y. 11502. (356]

increases worker effici ency
The first produc:· tion toolavailable to ease, speed and improve the wire tying operation-
p rod u c in g tighter knou and more
uniform harness.
Handle holds bobbin of cable lace, feeds as needed. Easily refilled. Eliminates handling long sections of tape, reduces splicing. Get your Production De· partment to investigate.

The specification of non-combustible mate· rials in electronic equipment has, until now, required the use of special, higher priced lacings for harness tying. Through extensive work in their R&D Department, Gudebrod is producing two new burnproof lacing tapesboth available at no additional cost!
The first of their kind, these new tapes· are made of Dacron* fibers and are flat braided for excellent handling and knotting qualities. In addition to meeting or exceeding all requirements for MIL-T-713A, the bumproofing exceeds ASTM-D626-55T.
Two types are being produced-Stur-D-Lace FLH, impregnated with a flame-proof fungistatic synthetic rubber finish, and Stur-D-LaceR impregnated with a flameproof fungistatic vinyl finish. Both are essentially stable at -HX>0 to 350°F. Neither will burn, but they will melt when a hot flame is applied. Each type is available in seven different strengths. Gudebrod Technical Product Bulletin .;/6 gives details.
The introduction of bumproof lacing tapes at standard prices represents another advancement in cable lacing practice by Gudebrod. The Gudebrod line of lacing tapes covers the entire range of wire harness tying requirements for both military and commercial equipment. Send for the Data Book on Gudebrod Tapes.
~ "Dacron" is Du Poot trade name for its polyester fiber.

120 Circle 120 on reader service card

Operations recorder
uses heat writing
New heat-writing models of Event/ Riter recorders are available. The heatwriting system provides a continuous, constant-width trace at all chart speeds. An electrically heated wire stylus and special heat-sensitive chart paper make up a convenient, trouble-free writing system. The instruments can be obtained with as many as 42 channels in both portable and flush-mounting styles. The pressure-priming ink system, which utilizes individual ink wells and as many as six different ink colors, is also available in all models.
Texas Instruments Inc., 3609 Buffalo Speedway, Houston, Texas. [357]
Solid-state squaring unit
generates test signals
A solid-state squaring device, model 520, is used to gen erate test signals. Input is 1 to 3 v p-p of almost any waveform including sine waves, square waves and pulses,
from d-c to 5 Mc. Output is 20-
nsec rise time squared waveform of the same frequency and similar symmetry as the input. Amplitude
Electroni cs I July 27, 1964


is adjustable from 0 to 2 v peak. Applications include wideband and pulse amplifier testing, as well as radio-frequency testing when the device is used as a harmonic generator. Price is $21.
Crane Electronics Corp., 1401 Fire· stone Road, Santa Barbara Airport, Goleta, Calif. [358)

Actual Size
l 31s" LONG

Accelerometer records
magnitude of shock
A shock-recording accelerometer has been developed with ranges from 0-15 to 0-1,000 g. Incorporating a new damped seismic system to improve transient response, the model A12 records both positive and negative acceleration with accuracy of + 10% of nominal range. Only 11h in. in diameter and 2% in. long, its useful response range is approximately half its natural frequency which ranges from 40 cps on the 15-g range to 350 cps on the 1,000-g range. The unit operates reliably over an ambient temperature range of -30°F to +200°F. Major applications include recording shocks on containers of delicate instruments and equipment, missiles, aircraft landing gear and recovery parachutes.
Pace Engineering Co., 13035 Saticoy St., N. Hollywood, Calif. [359)
Electronics I July 27, 1964

Ounce for ounce the RJlA controls more power than any other relay in the world. It will handle 2 KW average power into a 50 ohm load at VSWR 1: 1 at 2 to 32 megacycles. And since it was designed for high volume production it offers the utmost economy.
The high strength vacuum dielectric guarantees a tremendous internal overvoltage safety factor - more than double the rated peak test voltage. Resistance is low (.010 ohms) and remains low and stable for the life of the relay.
The RJlA is ideally suited for such applications as airborne, mobile, or marine communications systems for switching between antennas, antenna couplers or transmitters, or between transmitters and receivers. In sonar equipment they are being used as long life relays to switch 25 amp, 100 milliseconds pulses to transducers.
For higher power applications Jennings offers a complete line of vacuum transfer relays not much larger than the RJlA. These relays are available in peak test voltages up to 38 KV Peak and continuous current ratings up to 75 amps RMS.
Write for more detailed information on the RJ1A and Jennings complete //ne of vacuum transfer relays.
Circle 121 on reader service card 121

Around the world ...
e KYORITSU Measuring Instruments




32 power, control & signal
circuits in one Federal cable
This Federal multi-conductor cable will handle: · 16 signal circuits · 11 control circuits · 5 power circuits
... all within one shielded jacket! This is a standard Federal cable available from stock.
Royal Electric has designed and built multiconductor cables for a variety of applications ranging from office intercom systems to the vast BMEWS network.
For more information, contact your nearest Royal representative, or write Royal Electric Corporation, a subsidiary of International Telephone and Telegraph Corporation, Pawtucket, Rhode Island.

120, Nakane-cho, Meguro-ku, Tokyo, Japan Cable address: KYORITSUKEIKI TOKYO Telex: TK 2849
Circle 203 on reader service card

122 Circle 122 on reader service card

Circle 204 on reader service card

New Semiconductors

All-glass flat packs house Micrologic

are designed for low-level triggering, such as cross-point matrix switching, core driving, digital information switching, pulse generators and memory elements. They are offered in both the T0-46 "pancake" and T0-51 microminiature coplanar packages, 100% production-tested for a true hermetic seal. Six types are available, with 20 µa or 200 p;a gate sensitivity, in 15, 30
and 60 v.
Sylvania Electric Products, Inc., 100 Sylvan Rd., Woburn, Mass. 01801. [332]

Miorologic and Milliwatt Micrologic are now being offered in allglass flat packs. The 9361 "black glass" package, developed by Corning Glass, is 145 mils wide, 265 mils long, and 50 mils thick after sealing. The packages have 10 leads, whidh are ·spaced on standard 50-mil centers. Each lead is 15 mils wide and 4 mils thick and is fabricated from gold-clad' No. 52 alloy lead material. To insure flat pack reliability, according to the manufacturer, the tested monolithic chip is attached to the bottom of the glass case by eutectic bonding techniques. Temperattire stresses are avoided by hermetically .sealing the lid and case at an oven temperature of 360°C, which is well below the eutectic temperature required to bond the chip to the case. Price per unit for Micrologic flat packs ranges between $21.45 (PL 900, buffer) and $46.48 (PL 905, half-shift register with inverter) in quantities of 100 to 999. For Milliwatt Micrologic flat packs, price per unit ranges between $15.95 (PL911, four input gate) and $43.55 (PL913, register) in quantities of 100 to 999.
Philco Corp., Microelectronics Opera· tion, Lansdale Division, Lansdale, Pa. [331]
Silicon switches turn on
at 69 nsec, off at 1.2 µsec
A line of pnpn, bistable, silicon switches feature turn-on speed of 60 nsec and turn-off of 1.2 µsec at 250 ma. The three-terminal devices

Thermistors have positive coefficients

Two positive temperature-coeffi-

cient thermistors, types 802 and

834, switch or rapidly increase in

resistance when their temperatures

exceed a certain value. Five switch-

ing temperatures covering the

range from 65°C to 155°C are avail-

able. A common use is to protect

equipment from excessive tempera-

ture. When the design temperature

exceeds a preselected level, the

thermistor actuates a control cir-

cuit, which turns off the power and

protects the equipment from over-

heating. T4e thermistor can be used

to limit voltage and current or as a

regulation device in electronic con-

trols. It can also be used as small

self-regulating heater. Dissipation

constant for the 802 is 15 mw per

degree centigrade at 25°C ambient

with a maximum power dissipation

at this temperature of 2 w and an

insulation capability of 1,000 v.

The 834 has a dissipation constant

of 11 mw per degree centigrade

with a maximum power dissipation

at 25°C of l 1h w and an insulation

capability of 600 v.

Westinghouse Semiconductor Division

Youngwood, Pa. [333]


Electronics \ July 27, 1964

Circle 123 on reader service card 123

Thoroughly proved in telephone switching operations. Stromberg-Carlson comQo: nents bring a new high in quality and reliability to many''' industrial applic~tions.
RELAYS Types A, B, BB, C and
E. All standard spri ng combinations are available. Send for our Bulletin T-5000R3.

New Subassemblies and Systems

All-silicon i-f amplifiers
give video outputs
These all-silicon i-f amplifiers feature both video and high-power i-f outputs, and a new approach to gain control employing feedback. Provision for closed-loop age is built into the unit. Standard models are available with 30- to 120-Mc center frequencies and bandwidths to 20 Mc. A machined aluminum wrapper and a brass deck assembly are used in their construction. Materials and workmanship are of military grade throughout. The price for most standard units is $325.
RH G Electronics Laboratory, Inc., 94 Milbar Blvd., Farm ingdale, N.Y. [371]

are isolated. Gain accuracy can be calibrated to better than ±0.05%, with stability of ±0.02% for 8
hours. Linearity is specified as
-+-0.025%. Input resistance of 1 megohm does not vary as gain is changed; source impedance is 10,000 ohms max. Rated output full scale is -+-10 v or ± 10 ma whichever occurs first. D-c common mode rejection up to 160 db is ob tained with optimum rejection selected with a polarity reversal switch. Price in quantity is approximately $495.
Texas Inst ruments Inc., 3 609 Buffalo Speedway, Houston, Tex. [372]

Differential amplifier with low d-c drift

KEYS Broad selection of push-
button, cam and twist types. Send for Bulletin T-5002R2.
HANDSETS High-efficiency mod-
els ; standard or with switch assemblies . Send for Bulletin T-5017R.
Plus all other teleph one switchboard components. For t echnical data on the full Stromberg-Carlson line, write to Industrial Sales Department.
124 Circle 124 on reader service card

A new differential d-c amplifier designed for use in data acquisition systems is also suitable for test and measurement applications where bandwidth up to 1 kc is required. Features of model 855 are: selfcontained design requiring no external power supply, use of solidstate components with no mechanical chopper, common mode voltage up to 500 v, and gain settings from 1 to 1,000 in seven fixed steps. D-c drift is low; settling time is short; input, output and chassis

Data acquisition system
operates rapidly
A multi-channel data acquisition system for thermocouple strain, and millivolt inputs, features speed and reliability. It is equipped with a 30-point relay scanner, a fully differential wide-band preamp with programable ranges and selectable filter, a solid-state highspeed a-d converter, and a 15-persec line printer. Specifications include -+-0.06% system repeatability at 10 mv full scale, pinboard programming of gain and deletion, 140 db effective system common mode rejection at 60 cps and 1,000 megohms input impedance. Price of the 160-El Economy Systrac is $11,700.
Systron· Donner Corp., 888 Galindo St., Concord, Calif. [373]

! Electronics Ju ly 27, 1964

Preamplifiers cover
wide dynamic range
Two r-f preamplifiers have been developed for use with existing or new receivers. The SP-130 covers 300 to 600 Mc with a max noise figure of 6 db (4.5 db typical) from -54°C to +11 °c. The SP-140 covers 300 to 1,000 Mc with a max noise figure of 8 db (5 db typical) over the same temperature range. The all-silicon design insures uniform characteristics over the temperature range and permits a gain variation specification of ±2 db for the SP-130 and ±2.5 db for the SP-140. Features include wide dynamic range, rugged encapsulated packaging, conformance to MIL-E5400, Class II, and MIL-16400 environmental specifications and calculated mean-time-before-failure of over 250,000 hours. Total volume for each amplifier is 7.5 cu. in. including connectors, and weight is less than 4.5 oz.
Applied Technology Inc. , 3410 Hillview Ave., Stanford Industrial Park, Palo Alto, Calif. 94304 [374]

for ~"-.._
ChiJP /

Digital integrator
operates automatically
A solid-state electronic digital integrator, model CRS-11, is designed for use with a variety of analytical instrumentation such as gas chromatography, amino acid analysis and spectrophotometry. It features expanded dynamic range for fully unattended operation in a
Electronics I July 27, 1964

BREW 300 SERIES solid state dispersive delay lines are specifically designed for "chirp" radar systems. These units replace the complex circuitry of L-C filters and provide: maximum reliability through solid state media ; increase in radar range ; greater power utilization from output tube and maximum resolution of long duration pulses.
Designed to meet Mil requirements, these low cost light-weight filters provide compact high performance compression and expansion dis· persive delay lines.
This series is available in a variety of standard units or may be custom designed to system requirements. Standard lines are avail· able up to 5mc with band width to 2 me and compression ratios up to 500/ 1. Typical size for a 5 me filter is 2 \1,i" x 1" x 10".

For further information please contact:


Circle 125 on reader service card


New Subassemblies
wider range of applications. Input may come from any analyzer electrical output of 1 mv full scale or greater. Peak areas and retention times are visually displayed and printed in digital form. Proved soHd-state, plug-in circuitry insures trouble-free operation. The CRS-11 is readily adaptable to process as well as laboratory operation. Computer-compatible output is available.
lnfotronics Corp., 1401 S. Post Oak Road, Houston, Texas 77027. [375]

how much should high reliability transformers cost?

The extra costs of Raytheon high reliability transformers can be and often are surprisingly small. Of course, should you require complete, quantitative, ultra-high reliability, then the program must be priced accordingly.

As a supplier of magnetic components for Minuteman and Apollo, Raytheon is eminently qualified to meet your most exacting specifications for high reliability transformers. If your budget or time requirements do not allow for a complete high reliability program, we can tailor a program that meets your reliability needs within your monetary and scheduling limitations. We can also assist you in establishing your own reliability specifications.

Full facts

on Raytheon's High Reliability Program

for its wide range of transformers are contained

in a new eight-page brochure.

Write or call for your free copy,

Raytheon Company Magnetics Operation,

Foundry Avenue,


Waltham, Massachusetts 02154.

Telephone 899-8400


126 Circle 126 on reader service card

Helium-neon gas laser
generates high power
A continuous-wave helium-neon gas laser, rated conservatively at 100 mw minimum c-w power output, can withstand shocks up to 10 g. U,nHke most lasers of this type whose applications are confined to laboratory experimentation, the LG-10 can be incorporated into field systems in areas such as satellite tracking, long-range communications, target image surveying, high-speed photography, and the generation of radiation with ultrastable frequencies. Only 57 in. long and weighing less than 50 lb, the laser uses two plasma discharge tubes optically coupled through a prism to produce a single high-intensity laser beam directed from one tube into a second parallel one. This makes it possible to generate the high-power output from the relatively compact laser. Model LG-10 is designed for optimum output at 6328 angstroms, but can produce coherent light at 1.15 or 3.39 microns with minor modifications. Price is under $20,000.
Raytheon Co., 130 Second Ave., Waltham, Mass. 02154. [376]
Electronics I July 27, 1964

New Microwave

Spectrum analyzer draws only 40-w power
A portable microwave spectrum analyzer, weighing less than 35 lb., draws only 40 w of power as a direct result of its solid-state circuits and low-drain components. Model S-64 covers the frequency range of 10 Mc to 40 Ge. Employing a persistent 31/2-in. square crt, the analyzer can display log (40 db) , linear (26 db) or square law (13 db) as the dynamic range. Using triode cavity oscillators as 1-o's-as opposed to the less stable klystron oscillators-f-m is less than 800 cps at C band, better at lower frequencies. The dispersion, or frequency width of display, is continuously variable between 10 kc and 5 Mc on one switch position , 1 Mc to 60 Mc on the other. Resolution bandwidth (3 db) of the S-64 is 1 kc to 100 kc, also variable. Sweep rate may be adjusted from below 1 cps to 100 cps. Price is $4,g8o.
Pentrix Corp. , 860 Shepherd Ave., Brooklyn. 11208. [391]
Rotary step twists cover broad band
A series of broad-band rotary step twists providing coverage throughout the full waveguide bandwidth is available in frequency ranges

from 8.2 to 40 Cc. Each unit is designed with segmented sections resulting in flat residual vswr (under 1.25) through its rotation, across any band in the frequency range, with an insertion loss of less than 0.1 db. Model 195 rotary step twist is used to change polarization in an antenna range system without uncoupling the system. To change goo of polarization, it is necessary merely to loosen a thumbscrew, and rotate a knurled section go0 · The unit may also be used to scan a goo sector by attaching a goo elbow with a scanning device, loosening the thumbscrew, and manually rotating the scanner from 0° through goo. A detent is provided at 45° for reference. Price range is from $300 to $400.
Microwave Components and Systems Corp., 1001 S. Mountain Ave., Mon· rovia, Calif. [392]
Co-ax slotted section
spans 2.0to12·.4 Ge
Excellent electrical characteristics over the frequency range of 2.0 to 12.4 Ge are claimed for the N115A coaxial slotted section. The instmment is fitted with precision type N connectors and is designed for use with model Zll6A universal carriage and model B200A tunable probe or B203A untuned probe. It is accurately machined from a solid block of aluminum alloy and carefully assembled to form a precision transmission line. Adjustable legs facilitate alignment with other test apparatus. Special precision type N connectors and a 0.100 in. wide terminally tapered slot reduce residual vswr to 1.04 at 2 to 8 Ge, 1.06 at 8 to 10 Ge and 1.1 at 10 to 12.4 Ge. Impedance is 50 ohms. In·

Electronics I July 27, 1964


Filter eter:nent cannot be seen through grille · · · 1s deeply recessed for protection.
New "digital design" features sharp sculptured shadows for clean horizontal accents.
Fingertip accessibility to the filter. Filter may be easily removed without tools.
Brushed aluminum surface adds a high note of polished elegance.
Motors available with guaranteed life of 20,000 hours.
Over 100 models providing air deliveries from 150 to 1,000 CFM. P~nel sizes ~rom 51/·" high to lO:Y·" high by 19" wide. Half size and special widths also available.
Send For NEW
Illustrated Brochure




P.O. Box 228, Princeton, New Jersey

Phone 609-799-0100 · TWX 609-799-0245

The Originator and Leader in Packaged Cooling

Circle 127 on reader service card



A high·performance memory with a low - men responsible for many of the most

price tag.; .space·saving philosophies in advanced ideas in digital technology.

circuit design .·· dramatic acceleration in thin·film technology ... this is the picture today at NCR Electronics Division.

If you are stimulated by a creative atmos· phere ... if you can make original contri· butions in any of the areas listed on the

At NCR you have opportunity in the pres· opposite page .. . if you would like to

ent tense - opportunity to conceive,: combine a good living with the good

design and produce the digital systems ·, Southern California life ·.. investigate

that will bring business automation to NCR now.

120 countries. ·Here is your chance to work with the men who created the NCR


315 system, the ROD memory, photo· chromic micro-image, the CRAM magnetic·card concept tn random·access memories, the 420 Optical Journal Reader

The National Cash Register Company ELECTRONICS DIVISION
2815 TWe.leEpl hSoengeu:nAdoreaBlCvdo.a1eH2a1w3·t7h5o7r·n5e1,11Calif.


New Microwave
sertion length is 9H in. Price of model Nll5A is $200
FX R, 25·15 50th St., Woodside, N.Y. 11377. [393]
Solid-state sources
operate in X band
Two new X-band solid-state microwave signal sources are designed for use as local oscillators in radar equipment. The MS160 and MS170 are mechanically single-screw tunable in the 8.5 to 9.1 and the 9.0 to 9.6-Gc range respectively. Both are voltage tunable over a 1% bandwidth. The devices deliver 2 mw of output power minimum off a 25-v, 125-ma input with spurious harmonics at least 60 db down within the specified frequency bands. Frequency stability is 4 parts in 103· Price is $2,200 in 1-5 quantities.
Fairchild Semiconductor, 545 Whisman Road, Mountain View, Calif. [394]
Backward-wave oscillator
is small and rugged
A volume of 13.5 cu. in., weight of 1.5 lb. and power consumption of less than 15 w make the SE-304 backward-wave oscillator ideal for airborne and space application in wide-band microwave systems. The tube can withstand severe shock and vibration without isolation mounting and requires no cooling for ambient temperatures up to 85°C. The delay line used is a precisely wound bifilar helix, whose dual r-f outputs are conibined in a coaxial balun. A closely spaced hollow beam is employed for maximum efficiency. An oxide cathode is used, and under typical operations the current density is less than 200 ma/ cm2· A uniform focusing field is provided by a stabilized Alnico magnet and a precisionstacked field straightener. The straightener also reduces the tube's sensitivity to external transverse fields.
Stewart Engineering Co., subsidiary of Watkins·Johnson Co., Santa Cruz, Calif. [395]
Electronics I July 27, 1964

New Production Equipment
wire reportedly permits extremely clean, smooth stripping with no nicks or cuts in the wire strand. The device strips plastic insulations from Teflon to low-melting vinyl materials.
Western Electron ic Product s Co., 107 Los Mol inos, San Clemente, Calif. [422]

Shearing tool removes integrated circuits

A precision shear for removing integrated circuits from carriers has been announced. The new hand tool progressively shears each lead to an exact, prescribed length. This progressive shearing, preferable to straight stamping, minimizes stress on component leads and glass seals. The tool utilizes a two-piece, precision-ground die and matching shear punch for efficient shearing and long life. Incorporated in the design is an extractor mechanism which gently removes the network from the die.
Texa s Instruments Inc., P.O. Box 66027, Houston, Tex. 77006. [421]

Laser metalworker for lab or production

Thermal stripper
handles small wires
A thermal wire stripper is available for use on the smallest-size wires and in extremely restricted space. Model G-1 Tiny-Therm features a miniature stripping head (1/s in. by l/s in.) at the stripping tip. Recommended stripping range is from No. 40 to o. 20 Awg. The handle weighs less than 2 oz, and is made of cork for cool and comfortable operation. Overall length is 6 in. Use of No. 20 Nichrome filament

Laser metalworking system model MW101 is available. Designed for either laboratory or production-line use, the compact, mobile console can readily perform such functions as microwelding, microperforating, micromachining, and microdrilling and grooving. The system offers provision for using any one of several available laser heads to obtain various output energies and pulse repetition rates, up to 1,500 joules and 50 pulses per sec. Location of both the laser head and the illuminating light directly over the work area make it possible to perform operations on both opaque and translucent materials. The optical equipment consists of an adjustable-intensity light source that can be focused to a bright spot anywhere in the control-free area. Water filters are available to remove the heat from the illuminating system, thus providing protection for sensitive materials. The laser beam itself is focused through a lens system to an intensely powerful spot

Electronics I July 27, 1964

. AT NCR, -.-

Look into tltese new openings for

Position will entail analysis and advanced design of complex mechanisms and applied mechan ics problems. PhD preferred, with applicable experience. Should be equally skilled in mathematical analysis and.labora· tory measurements.
Position entails design of word-select memories and memory circuits. Requires BSEE, MSEE desired, and at least 3 years' experience in the above-mentioned fields.
This senlor'position will involve analysis and advanced design of on-line, real -time . systems. Requ ires BSEE, MSEE desired , with good knowledge of digita l computer technology.
Intermediate to seniorengineer with BS degree, MS desired; with 3-4 years' e.xperl· ence in advanced magneiic recording tech· niques. Requires detailed knowledge of media, circuitry and magnetic head design.

To design, specify and Implement a general· purpose system-simulator program for the purpose of evaluating the design and per· formance characteristics of computer processors, peripherals and systems. AB degree or equivalent experience in math, business or related fields. Minimum of 3 years' experience In programming medium to large·scale computers. Experience should include coding in machine language. Prefer rnan experienced in simulator or compiler program development.
Experienced graduate EE's with 3 to 5 years in logic design and transisto rized circuit design of digital equipment. Assignments will enta il logi c and circu it des ign of buffer storage un its and digital peri pheral equipnrent.
To arrange an interview, please send resume immediately, including training,
.experience and salary history,Jo Bill Holloway, Personnel Department,
or telephone collect.


The' National Cash Register Comp.my



2815 W. El Segundo Blvd., Hawthorne, Calif.

Telephone : Area Code 213·757·5111

an equal -opp01't 1mity em11l011111'


NOW ... high accuracy synchro /resolver testing

New Production Equipment
that can attain peak power intensities of well over a million watts per sq cm. Standard magnification of the viewing system is 72 X, but greater magnifications can be provided. There is provision for automatic water cooling of any laser head used. Safety devices automatically shut off the entire system should there be any failure in the provided water supply, thus protecting the valuable laser head. Another design feature is the integral compact power supply, suitable for servicing any head used.
Maser Optics, Inc., 89 Brighton Ave., Boston, Mass. 02134. [423]

There is a Gertsch synchro or resolver instrument to meet virtually all requirements. Whether testing simple components or complete systems, you get accuracies up to 2 seconds-of-arc - accuracies maintained without constant checking and recalibration. These versatile units employ the same time-proven design techniques as Gertsch RatioTrans,® assuring high input impedance, low output impedance, and very low phase shift. Minimum operator error. Angles are selected with positive detent knob requires no critical adjustments. Direct-reading digital display reduces readout error. Simplified circuitry - least susceptible to the effects of stray capacitance, pickup, loading. Fewer accessories needed, hence less error from associated equipment. Over 100 synchro;resolver test instruments are available from Gertsch - synchro standards, ·resolver standards, synchro bridges, resolver bridges. In addition to conventional, manually-operated units, all standards and bridges can be supplied as rotary solenoid, relay (programmable), and decade (.001° resolution) instruments.
Gertsch dividing heads (both manual and automatic), in combination with Gertsch phase angle voltmeters, provide complete checkout capabilities for AC rotating components.
Complete information on all Gertsch synchro/resolver test instruments is available. Write for bulletins on Synchro Bridges, Resolver Bridges, Synchro Standards, Resolver Standards, and/or Dividing Heads.
3211 s. La Cienega Blvd, Los Angeles, Calif.· Phone (213) 870·2761·.lWX213·836·0466
0.li8n end produ~tion of PANORAMIC · SENSITIVE RESEARCH · EMPIRE · GERTSCH ina~ mtntt ror mHIYrement
130 Circle 130 on reader service card

Probing test station
for integrated circuits
A new series of probing micromanipulators and test stations is designed for analytical testing of integrated circuits, thin-film circuits and individual semiconductor devices on laboratory or production scale. A true and accurate probe contact to areas as small as 0.0005 in. in diameter can be es tablished almost instantly by means of a single joystick handle, reducing testing tirpe to an absolute minimum. Probe pressures can be setscrew-adjusted over a continuous range of 2 to 200 grams, serving a wide variety of probing needs. Test station model D-400 incorporates 4 micromanipulators, integral sliding stage and a variable 20-80 power precision stereo-microscope. Other models feature from 2 to 8 individual test positions, while single manipulators are also available.
The Dumas Instrument Co., 2950 Baker St., Costa Mesa, Calif. [424]
Electronics : July 27, 1964

New Materials

on electrical discharge machines.

Wear rates are much less than for

brass, copper-tungsten and other

electrode materials. The new mate-

rials can be readily machined to

close tolerances.

Rametco, Inc., P.O. Box 665 Clermont

Fla. [ 41 2]



Glass spheres are used as low-loss filler

Manufacturing· Quality Resistors under Rigid
' Reliability Control

Fluoroplastic tubing
shrinks to half size
A new irradiated expanded fluoroplastic tubing is available with elastic memory for heat-shrinking to half its original diameter. Called Thermofit Kynar, the tubing was ?esigned primarily as a tough , flexible sleeve to relieve strain on soldered or welded electrical connections. It also provides excellent protection and insulation for delicate electronic components a~d heatingelement connections. The basic ingredient is Kynar, a vinylidene fluoride resin. After extrusion. tubing is exposed to controlled-electron-beam (gamma) radiation to form a cross-linked, three-dimensional gel nehvork. Irradiation strengthens the plastic material and permits it to retain its physical properties at high temperatures. The final step in production is expansion of the tubing to double its original diameter. In use, Thermofit Kynar shrinks at temperatures above 175°C with no danger of subsequent loosening or relaxation. It provides nearly 35% more transverse shrinkage at about half the curing temperature of other thermoplastic fluorocarbons.
Pennsalt Chemicals Corp., 3 Penn Cen· ter, Phi ladelphia 2. [411]
Refractory materials
for use as electrodes
Two new series of refractory metal composites have been tested and found to have superior cutting properties when used as electrodes

Micron-sized hollow glass spheres used as a filler have a low-density, low electrical loss and low dielectric constant. The material has numerous aerospace applications as a high-temperature, low-weight resin filler. Applications include molding compounds, radomes, heat barriers, foams and casting resins.
Custom Materials, Inc., Alpha Industrial Park, Chelmsford, Mass. (413]

Microwave absorber made of flexible foam

New microwave absorber, Ecco-

sorb HPY, is very lightweight poly-

ureth~ne foam, in pyramidal shape,

tapering to a sharp wedge tip. It is

produced in 2-ft by 2-ft blocks as a

series of materials varying in thick-

nesses to achieve different low-fre-

quency cutoffs in high perform-

ance. All thicknesses are perfectly

flexible and capable of being

mounted securely on surfaces of

extreme radii of curvature. The

recommended adhesive is Ecco-

bond 87H. Reflectivity levels are

maintained to at least 70 Ge and

probably higher. Prices range from

$19.50 to $50 per 2 ft-by-2 ft block

depending on thickness.

Emerson & Cuming, Inc., Canton Mass




Electronics I July 27, 1964

Circle 13 1 on reader service card 131

New Literature

-4/iite- ANOTHER


..., '"""WU«(J SOLID


DO YOU PREFER SPECS TO SPECULATION? Here's a challenge from Interstate!

If you don't believe data sheet claims, ask for a demonstration ... make us prove our product.

At Interstate, we skip the fancy foot-work and weasel-wording. Here are the
straight.specs on our Series 450 Phase-Lock Tracking Filter that captures signals
with S/N ratios to -38 DB. Compare its performance with that of any instrument
of its kind. Then buy the one that stacks up best.

APPLICATIONS: Seeks out, captures, and locks on to signals in doppler phase·
lock tracking I data signal recovery I frequency analysis I data frequency multipliers I telemetry data signal separation I instrumentation data systems.

Input Frequency Range: 100 cps to 120 kc Tracking Bandwidth: 2.5, 5, 10, 25, 50 or 100
cps (selectable) Input Signal Level: Approx. 1.0 V rms.(signal
plus noise) Input Impedance: 10,000 ohms approx. Output Signal Level: 1 V rms min. Output Impedance: 500 ohms Power Requirement: 105-125 or 210-250 V AC
50-400-75 watts or less (depending on options) Dimensions: 19-inch rack mounted 17Y. Inches
deep excluding connectors and handles 5Y." high Controls (standard): Sweep (time and rate). Set Frequency (coarse and fine). Bandwidth. Set/ Acquire. Memory Out/In. Calibrate/AGC Input Connectors: BNC Coaxial

Misc. Inputs: External Calibrate Freq . (0.1 V rms; 10,000 ohms); External Reference Freq. (0.1 V rms; 1000 ohms)
Internal Calibration Oscillator Freq: 10 kc (crystal osc).
Other Outputs (BNC Coax) : Main Phase Detector Monitor: 0.5 V; 0.5megohms Correlation Amp/ifier: -4 V@100%; 5000 ohms AGC Voltage : -8 V max.; less than 1 ohm. Out· put Impedance with min. 10k load Reference Oscillator: 250 kc; 0.1 rms ; 500 ohms VCO Frequency: 1 V rms; 500 ohms Phones: 2 V rms; 2000 ohms Correlation Relay: C-Type Contacts; AN Con· nector (mating connector supplied)
Front Panel Indicators: Frequency Meters: 0-120 kc, 0-24 kc Correlation Meter: 0-100% Set/Acquire Lights

For a copy of the full specificati ons, check the reader service card. Or ask about
an in-person demonstration at your plant.
~ 707 EAST VERMONT AVENUE, ANAHEIM, CALIFORNIA Telephone 714-772-2222, TWX 714-776·0280
A Subsidiary of Interstate Engineering Corporation Worldwide Representatives

132 Circle 132 on reader service card

Wire taper. Possis Machine Corp., 825 Rhode Island Ave. South, Minneapolis, Minn., 55426. Model PWT-1 semiautomatic, bench-mounted wire taper is described in bulletin 6312HT. Circle 451 on reader service card
Silicon modules. Digital Equipment Corp., 146 Main St., Maynard, Mass. A 56-page brochure describes a new fam ily of lower-cost, 10-Mc silicon circu it modules. [452]
Instrumentation. Electronic Associates, Inc., Long Branch, N.J. The first issue of an instrument-products newsletter called "Readout" is available. [453]
Potting and filling resin. lsochem Resins Co. , 221 Oak St., Providence 9, RI. A technical data bulletin fully describes lsochemrez 421, a low-cost, asphalt co-reacted potting and filling resin with excellent physical and chemical properties. [454]
Silicon diodes. National Transistor, 500 Broadway, Lawrence, Mass. Engineering bulletin C-101 describes a line of fourlayer silicon diodes. [455]
Couplers. Microwave Development Laboratories, Inc., 87 Crescent Rd., Needham Hts., Mass. 02194. Bulletin CS-1 describes a line of sidewall multihole directional couplers. [456]
Pin and socket connectors. AMP, Inc., Harrisburg, Pa. An illustrated M-series catalog contains complete information on a line of pin-and-socket connectors with crimp, snap-in contacts. [457]
Semiconductor metals. Sigmund Cohn Corp., 121 S. Columbus Ave., Mt. Vernon, N.Y., has available a 16-page bulletin entitled "Metals and Alloys for Semiconductor Applications." [458]
Miniature switch. Cherry Electrical Products Corp., 1650 Old Deerfield Road , Highland Park, Ill. 60036. A catalog sheet describes a light-force, long-lever miniature switch, type E23·55H. [459]
Decade counter. Janus Control Corp., Hunt St., Newton, Mass., offers a technical data sheet describing model Bl00-2 high-speed decade counter that incorporates a latching storage readout feature. [460]
High-temperature compound. General Compounds Co., 6105 W. Washington Blvd., Culver City, Calif. A 4-page brochure describes GC-76, a high-tempera· ture compound that eliminates locking and seizing of soldering tips. [461]
Isolated-output reference sources. Elcor, a division of Halliburton Co., 1225 W Broad St., Falls Church, Va . 22046. Bulletin 66-363 describes the A4R series of low-noise, isolated-output reference lsoplys. [462]
Electronics I July 27, 1964

Circulators. Raytheon Special Micro· wave Devices Operation, 130 Second Ave., Waltham, Mass. An 8·page brochure describes high-power, differential phase-shift circulators. [463]
Digital computer. Packard Bell Compu· ter, 2700 S. ·Fairview St., Santa Ana, Calif. 92704. A 4-page bulletin covers the PB440 digital computer with micro· programed processor. [464]
Diode technology. Hughes Semiconduc· tor Division, Newport Beach, Calif. A 6-page folder features a microglass diode, the first in a series of glass· ambient diffused·junction devices. [465]
Data systems. Epsco, Inc., Data Sys· tern Products Division, 411 Providence Highway, Westwood, Mass. A well-illustrated bulletin discusses the company's facilities for the manufacture of data system products. [466]
Analog-to.digital converters. NP Labo· ratories, P.O. Box 226, Roselle, N.J. Technical data sheet GAD-200 de· scribes a series of 10-bit and 12·bit a-d converters with conversion speeds of 1 µsec per bit. [467]
Sampling oscilloscope. General Applied Science Laboratories, Inc., Stewart & Merrick Aves., Westbury, L.1., N.Y. An 8-page catalog describes the Lumatron model 120A high -speed sampling oscil loscope. [468]
Digital solar aspect systems. Adcole Corp., 330 Bear Hill Road, Waltham, Mass., 02154, has available a 16-page brochure on digital solar aspect systems. [469]
Cavity wavemeters. DeMornay-Bonardi, division of Datapulse Inc., 780 So. Arroyo Parkway, Pasadena, Calif. Direct· reading and micrometer-head cavity wavemeters for 2.6 to 140 Ge are dis· cussed in a technical bulletin. [470]
Compact converters. Astrosystems Inc., 521 Homestead Ave., Mount Vernon, N.Y. A 4-page brochure covers compact and highly accurate synchro-and re· solver-to-digital converters. [471]
Incremental tape transport. Potter Instrument Co., Inc., 151 Sunnyside Blvd., Plainview, N.Y. A brochure describes an incremental tape transport that provides both writing and reading capability in a 300 character-per-second incremental feed mode using an IBM tape format. [472]
High-environmental tape recorders. Leach Corp., 1123 Wilshire Blvd., Los Angeles 17, Calif. Technical data brochure HETR-364 covers a broad product line of miniature, high-environmental tape recorders. [473]
Clutches and brakes. Vibrac Corp., Alpha Industrial Park, Route 129, Chelmsford , Mass. Catalog 20 covers a line of magnetic dry particle clutches and brakes for precision instruments and servo systems. [474]
Electronics I July 27, 1964




You'll find lots of it at Space/' · Craf:t, Inc. Want proof? In' the

last two years alone our

organization has made im-

portant contributions to all of

these important space vehicle

and spacec;raft programs: SATURN I, SATURN I·B, SATURN v, .TITAN III,


EOGO, OS01 l~fP, MARINER B, ARIEL, FR· l, SAN MARCOS, !\IMC, lNJUN, SERT, EXPLORER and the SATURN SA"l'ELLITES. Just one more point. In addition

to talent, Space Craft employs generous amounts of creativity, experi- /

ence, modern equipment and old-fashioned sweat on all of its pro-
grams. D Need help solving some of your knotder pro?Iems? D Your
communication w~ll bring us running.

Astrlonics Dlvision
Space- O::ra.:ft, ::Ez1.c.
Circle 205 on reader service card

This MICRO TV TUNER, using 3 transistors, provides you with excellent performance while keeping high quality stability, thanks to our latest technical advancement. Spurious radiation meets the requirements of FCC and is guaranteed for performance of more than 40,000 operations. We also offer you many other lines of components for your use. Please write us asking for catalogs availa· ble on the following products:
Main Products Polyvaricon, IF Transformers, Oscillator Coils, Antenna Coils, Variable Resistors, FM Tuners, TV Tuners, Micro-motors, Sockets.


Head Office Komae, Kitatama, Tokyo, Japan. New York Office 11 Broadway, New York 4, N.Y., U.S .A.

Circle 133 on reader service card


SPt-1·Nx l MICR, D~DRILLS- \'.
A complete stock of these Swiss-made micro-driUs, known the world over as the standard of quality for high-precision instrument work, is maintained by Louis Levin & Son, Inc. For complete information, write for Catalog 62.





Straight shank

0.15-1.0 mm

Spirec pivot, right hand

0.10-3.0 mm

Spirec pivot, left hand

0.10-1.0 mm

Flat pivot

0.04-1.0 mm

Spirec center

0.10-0.7 mm

Other sizes and styles available on special

wi l request.

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Exclusive Dealers: Russell·Holbrook &. Henderson, Inc.. New York and Los Angeles / Industrial Taal l Supply Co., San Jose I Marshall Tool l Supply Carp., Los Angeles/ Royal ·Tschantre, Baltimore/ Marton L. Frl1dm1n Co., Chicago/ Plus dealers in all important Industrial Centers ·

Circle 206 on reader service card


Save a transistor; save a circuit; save a computer; save a mission. Solid state Hypersensors react in time to prevent transistor burnout . . . in nanoseconds ... and they can be reset over and over again with application of

only 12 V. Standard units, T0-18 transistor size, rated 10 to

300 ma, available from stock. Subminiature, axial lead Hyper-

sensors made to order. For information, write or phone, 1100-1 E.Ash Ave., Fullerton, California, 92631. Phone: 871-1930 (714)




134 Circle 134 on reader service ca rd

Packed with more important data than ever before ... the 1964-65 issue of Electronics Buyers' Guide. Four great major sections : Product Listings; Product Advertising; Index of Electronics Manufacturers; Government, other Agencies and Technica l Services.
Week in, week out, EBG is the industry's standard catalog-directory ... a necessary working tool for the men who buy and the me~ who sell components, equipment, systems, materials and services.
Electronics Buyers· Guide
A McGraw-Hill Publication 330 West 42nd Street, New York, N.Y. 10036
Electronics 1· July 27, 1964

New Books
Engineering reference
Thesaurus of Engineering Terms Engineers' Joint Council 1964, 302 pp., $15.
Intended primarily as a vocabulary reference for indexing and retrieving engineering literature, this volume is the result of 18 months' efforts, involving ten review committees comprising 130 engineers and other scientists. There are 10,515 main terms and their crossreference relationships, totalling over 80,000 entries.
The value of the thesaurus should be considerable, mainly as a basis for a standardized system of indexing and retrieval of the rapidly expanding volume of technical information. The Engineers' Joint Council undertook its development as part of a broad plan to improve the efficiency of technical information How, with the ultimate objective of developing an engineering information center and communications network.
The volume's preface suggests its use by authors of technical articles as an aid in selecting more meaningful terms for titles, as keywords for indexing, for abstracts, and for concepts discussed in their articles. Such use of the preferred terms in article titling and indexing would indeed make information retrieval much easier than it is at present.
Under each entry, which may be a word or complex technical expression, the volume gives a note of its scope, a definition or a limitation of its meaning or usage, then lists related expressions and identifies each as either a broader-term reference that covers a class of concepts, or a narrower-term reference covering a subclass, or as preferred synonyms and related terms.
The thesaurus could thus be used to find a better word foi:. a term , or to locate the word under which relevant literature is likely to be found, or even to learn whether a specific term refers to a general class or a narrow subclass of concepts.
Although all fields of engineering are covered, electronics and its related fields , including engineering optics, computer technology and

applied physics appear to be indexed with sufficient accuracy to locate the narrow specialties encountered today.
A discussion of the way in which terms were selected and how they can be used for various indexing procedures is included, as is a general description of the council's action plan and its principal objectives.
George V. Novotny Advanced Technology Editor
Digital circuitry
Modern Digital Circuits Samuel Weber, editor McGraw-Hill, Inc., New York 1964, 355 pp., $9.50
In his introduction to this volume, the senior technical editor of Electronics discusses the versatility of digital-type circuits. Their use has gone far beyond computer applications; they are now performing in a variety of functions such as communications, instrumentation and industrial controls.
The book is arranged in nine chapters; six of these are concerned with basic digital functions : counting, storage, conversion, switching and so on. The final chapters discuss specific applications.
The value of this collection is its presentation of design ideas that work, the product of the experience of many knowledgeable engineers who have contributed to Electronics. Emphasis was placed on articles which discussed design considerations in selecting material for this volume. Thus, as a general rule, the reader is shown how to vary a circuit under discussion so that he may custom tailor it for his own particular application.
The 109 articles are indexed. The book also has a unique method of presenting errata and providing additional background information on the material included. This is done through a short section of letters from Electronics' readers pertinent to the circuit articles included in the collection.
Computer-circuit designers and other digital circuit design engineers will find this collection a useful, up-to-date tool.
Jerome Eimbinder Circuit Design Editor

Electronics I July 27, 1964

magnetic fleed Relays-

! Basic and special REED RELAYS and/or COILS for high reliability and sophisticated switching,
Operating Inputs: low as ImA. and !SmW. Standard Coil Voltages: 6, 12, 24, 32, 48V in stock
for 1mmed1ate delivery. Special Voltage or Resistance, multiple windings for
flip_flop, memory and crosspoint selection appli· cations - to customer specifications. New Type SP Coils: for high voltage vacuum-type reeds, H\'6" lg. Standard Coil Termin_ation: 3" flexible leads . Also available w_1th solid copper leads, printed circuit pins and rigid lugs - silver plated or tinned. Relay Contacts in Form A, B, C and latching,
Coto -Co1·1::::::~.~~::$ 65 Pav1l1on Ave. Providence. R. I. 02905 Circle 207 on reader service card


A compl e t e l i n e of m i crophone cart ri dges
and u n its for the OE marke t

*Velocity *Dynamic

*Uni-Directional *Crystal *Magnetic *Condenser *etc.

For catalog write to :

Circle 135 on reader service card





A new concept in solid-state DC amplifiers; no tubes, no transistors, no choppers. Typical gains 4000, ± 5 µv null stability; ten-year life. Price only $84.00; quantity ·discounts, immed iate delivery.
Request Technical Bulletin No . 19 ·. ··

aero mag

111390 TELEGRAPH ROAD DETROIT, MICHIGAN. 48239 TELEPHONE (313) 838·4242 TELETYPE 313·538·4!136
Circle 208 on reader service card

COMES FIRST _ _ _____


Type PMX

=(en=cas=ed=ty=pe=) 1'il

:,iii1ii NCC liliiliii
l!&< PM X· 1P 2~
















Type PSM (encased type)

Type SFL ~ ~'--==-~==

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Cable Address " NCC MATSUO " OSAKA

136 Circle 13 6 on reader service card

Electron · and laser-beam processing. Susu m u Nam ba and Pil Hyon Kim, In stitu te of Physical and Chemical Res earch, Ko magome Bunkyo-ku, Tokyo.
By drilling holes in various materials, the authors compared electronbeam and laser-beam equipment for welding and drilling in the manufacture of microelectronic circuits.
Advantages of lasers over electron beams were found to be: 1) simpler apparatus, because a vacuum is not needed; 2) reduced thermal loss by conduction; 3) shallower penetration allowing surface processing to be made in any desirable atmosphere.
Disadvantages were: 1) larger minimum spot obtainable than with the electron beam; 2) low power effi ciency when the laser beam was used on highly transmissive or highly reflective materials; 3) impossibility of continuous processing or continu ous output of high energy density; 4) difficulty of controlling the output intensity and beam direction of a laser.
In addition, drilling with a laser beam is easier than welding with it because of the high peak energy and the spiked pulse of the laser beam.
The electron-beam micromachining apparatus consists of an electron-beam chamber and a machining chamber, both evacuated to 10-5 millimeters of mercury. The beam is radiated from a tungsten hairpin filament of 0.2 mm diameter, and accelerated by 50 kilovolts. The intensity is controlled by the bias potential on a control grid. Two pairs of electrostatic deflectors adjust the spot position on the material that is on a movable carriage in the machining chamber.
The laser-beam micromachining apparatus consists of a 15-centimeter-long ruby rod 8 millimeters in diameter. The ends of the rod are coated with a dielectric multilayer film that is fully opaque at one end and about 40% transmitting at the other. The ruby rod is supported inside two helical xenon
Electronics IJuly 27, 1964

Unusual stability

flash tubes that are enclosed in an aluminum cylinder and cooled by compressed air. A capacitor, consisting of two 500-microfarad units, supplies the flash tubes with energy, and duration of their simultaneous flashes is controlled by varying the time constant of the discharge network. The trigger pulse that discharges the capacitor is suppressed whenever the reflector is used to view the material through the built-in microscope. The maximum input energy is 12,500 joules. The laser beam is focused on the material by a lens with a focal length of 30 millimeters. The material can be moved independently in the x, y and z directions.
Presented at the Si xth Electron Beam Symposium, April 27-28, Boston.

in miniature, surface-mounted platinum temperature sensors



I' !


Vlf transmission
Lf/vlf transm itter power requirements for global -range communication systems. H.F. Tolles and W. Koppl , The Martin Co., Denver.
Calculations of vertical field intensities at long ranges show the importance of choosing an optimum frequency for the particular application to global communication s. Space wave communications in a bent waveguide mode between earth surface and the D layer can be calculated for frequencies up to 100 kc without appreciable error. For distances in excess of 1,200 miles the first order mode will predominate, simplifying the resulting expression for field intensity.
It is concluded that the optimum long range r-f carrier is 19 kc when only propagation losses are considered. The ideal frequency lies b etween 30 and 100 kc when atmospheric noise level is added to propagation losses. The optimum long-range frequency is somewhat higher than 100 kc when the effect of short antenna efficiencies is included. Interference from external sources will force the frequency as high as possible, consistent with permissible first-order-mode boundary losses.
Presented at IEEE-University of Pennsylvania Globecom VI, June 2-4, Philadelphia.
Electronics I July 27, 1964

Performance is excellent for such small sensors in the REC line of miniature surface sensors. Range covered is from
-435° F. to + 1800° F. Repeatability after 10 consecutive
shocks from liquid nitrogen at -320° F. to silicon oil at 300° F. is within ::1:: 0.1° F.
The easily attached sensors can be cemented, spot welded or clamped to surfaces. Cylindrical models fit around standard small pipe sizes.
REC surface sensors have elements of highest purity platinum wire, fully annealed and mounted so that the resistance wire is well isolated from any strain in the surface. Outer cases are platinum, stainless steel, epoxy compounds, or ceramic, depending on the model. Some have inter· changeable bridge networks to provide a choice of temperature-voltage relationships.
For more details, write for Bulletin 9625, Platinum Resistance Surface Temperature Sensors.

A complete precision line

Rosemount Engineering Company designs and manufac· tures high quality precision equipment in these lines:

Air data sensors Total temperature Pitot-static tubes (de-iced)

Surface temperature sensors
Pressure sensors

Immersion temperature

Accessory equipment and

sensors (including cryogenic) aeronautical research

For more information please write for the REC catalog. Specific questions on any temperature or pressure prob· lems are welcomed.
4900 West 78th Street · Minneapolis 24, Minn.

Circle 137 on reader service card 137


The advertisements In thl1 1octlon Include all om . ployment opportunities - executive. management, technical, selling, offtce, skilled , manual, etc. Look In tho forward section of the magazine fe r additional Employment Opportunities advertising.
DISPLAYED: The advertllli!lll rate Is $~2.00 per inch tor all advertising aooearing on other than a contract basis. Contract rates quoted on request.
An advertising Inch Is measured 111 · vertlcallY on a column-3 column&-30 Inches t o a page.
Subject to Agency Commission. UNDISPLAYED: $2.70 per line. minimum 3 lint1.
To ftgure advanoe payment count 5 average word s a s a line. Box numbers-oount as 1 llne. Discount of 10% If full ll&YIDODt Is made In advance for 4 consecuthe insertions. Not subject to Agency Commission.

Every working day at the Western Center of Motorola's Military Electronics Division advances the state-of-the-art in our nation's aerospace telecommunications. One of many exciting breakthroughs achieved by Motorola engineers is the Unified S-Band System - which uses a single transmitter/receiver and carrier frequency for tracking, rendezvous, command, data transfer, telemetry, and voice link. Result: a reduction of one half in size, two thirds in weight, and three fourths in power required - a technological advancement which will play a key role in bringing NASA's Apollo program to successful fulfillment at the earliest possible date.
Motorola offers excellent opportunities to engineers and space scientists of demonstrated capability. Specific opportunities are:

Antennas & Propagation Solid State R. F. Microwave Techniques
Missile & Space Instrumentation
Operational Support Equipment
Integrated Circuitry

Reliability Analysis Parts Reliability Reliability Program Coordination Data Acquisition, Processing &
CW Transponders Radar and Radar Transponders

Guidance & Navigation
Command & Control Space Communications Signal Processing ECM, CCM &
Surveillance ·Tracking & Telemetry

Contact Phil Nienstedt, Manager of Recruitment, Department 657



MllltarJI IElectronlcs Division ·Western Center· P.O. Box 1417, Scottsdale, Arizona

New Opportunities at Texas Instruments in Massachusetts
Metals & Controls, Inc., nationally known manufacturer of precision electromechanical controls, now has challenging openings for two electronic design engineers. These men will develop new solid state controls for applications in the appliance, electric motor, electronic a nd aerospace industries. Both positions offer project-type responsibility ranging from customer applications to manufacturing problems. Applications should have a BS or MS in electrical engineering and 2-4 years' experience, preferably in the design of low frequency or power-type circu its. Salary commensurate with experience. Outstanding Tr benefits. For addit ional information call collect to Mr. C. Fl anagan, Mgr., Precision Controls Engineering, at 617-222-2800, or write, sending confidential letter or resume, to Mr. T . M. Fowler, Director of Salaried Employment. Inquiries will receive immediate attention .
34 Forest Street, Attleboro, Mass. A CORPORATE DIVISION OF
INCORPORATED An equal opportunity employer
A DDR ESS BO X NO. R EPLI FJS T O : Bo:J1 N o. Classified Adv. D iv. of this publication. Send to oJJtce nearest you. NFJW Y ORK, N. Y. l OOH : P . 0 . B ollJ 1! CTTTCA OO, Ill . 6 0 6 11 : 645 N. M ic hig an A ve. SAN FR ANCI SCO, Cal. 94 111 : !55 Cal'fornia Bt .
Electron lc and Electro/ Mechanlcal Technic ians , d e signer s, che ckerS', d raftsm en a n d d etailers-Work for leading fi r m of li cen sed p rofessional Engineers . Write to Un it ed E n~ gi neers, 150 Ca u s eway Street, Bost on 14, Mass.
Electronics I July 27, 1964





The advertising rate la $27.2.5 per inch for advertising ·appearing on other than a contract basic. Contract ra'tes quoted on request. AN ADVERTISING INCH is measured 1/e inch vertically on one column, 3 columns-30 inches-to a page. EQUIPMENT WANTED or l'OR SALE ADVERTISEMENTS acceptable only in Displayed Style.

UNDISPLAYED RATE $2.70 a line, minimum 3 lines. To figure advance payment count !S
overage words as a line.
BOX NUMBERS count as one line additional in undisplayed ads .
DISCOUNT of 10% if full payment is made in advance for four con· secutive insertions of undisplayed ads (not including proposals.)

Send NEW ADS or inquiries to 'Classified Adv. Div. of Electronics P. 0 . Box 12, N . Y., N. Y. 10036

for all employment advertising including Positions Vacant or Wanted and Selling Opportun ities Offered or Wanted.
A national medium for Surplus New or Used Equipment and other Business Opportunities
A dignified method for Specialized skills and services
Benefit yourself by using these sections
Most useful to the advertiser Most useful to the reader
For Rates and Information Write:
Class. Adv. Div., P. 0. Box 12, N. Y., N. Y. 10036
Electronics I July 27, 1964

1,000 Burroughs Beam Switchina Tubes Type 6700
Price $16 each. Save over $8 per tube.
Price for quantities under 100 to be negotiated . For information write
FS-4742, Electronics 265 California St., San Francisco. Ca lif.

2nd DAY
between Chica20Wlllwaukee and Eastern Terminals ·

between Chica20Milwaukee and West Coast.


A· 11 complete, decorative purpose $17 .:m. Working order, Inter-comm. $19.:m Ext. on dial $24.~0. talking circuit only. Write for complete list. All ehlpments FOB, Simpson, Pa.
TELEPHONE ENGINEERING CO. Oept. E-7274, Simpson. Pa.

Why Can't

You Remember?

An Investment!
Productive advertising 1s an INVESTMENT rather than an EXPENDITURE. "Searchlight" advertisers invariably report prompt and satisfactory results. BE CONVINCED - send us your advertisement TODAY.

A noted publisher in Chicago reports there is a simple technique for acquiring a powerful memory which can pay you real dividends in both business and social ad· vancement and works like magic to give you added poise, necessary self-confidence and greater popularity.
To acquaint the readers of this book with the easy-to-follow rules for develop· ing skill in remembering name s, places, figures, date s, business tran saction s, or even passages of literary content. the pub· lishers have printed full detail s of their interesting seH·training method in a new book, "Adwentures in Memory," which will be mailed free to anyone who requests it. No obligation. Simply send your request to: Memory Studies, Dept. 1868, Chicago, Ill. 60614. A postcard will do.

Address Classified Advertising Division
P. O. BOX 12, N. Y., N. Y. 10036


ConJu/ting Engineer!

S:ntem1 EnalneerlDa

Ot>erat!on1 Research · Denlopment

FieJd Stud.let · Dedan · Procurement

Power · Transportation · Communtcatloo1

Water Supply · Waate Treatment

393 Seventh Avenue

New Yorll 1. N . Y.


Electronics advertisers July 27, 1964

. ........._
· I·
·, I I o

·AMP Inc.


Garceau, Hargrave & McCullough Inc.

Acromag Incorporated


Tri -Art Associates

Air Express Div. of REA Express


Ketchum, Macleod & Grove Inc.

Astrodata Inc.


Bonfield Associates Inc.

Atlee Corporation


S. Gunnar Myrbeck & Company

Beckman Instruments Inc.,

Offner Division


Erwin Wasey, Ruthrauff & Ryan Inc.

· Boonton Radio Company,

A Div. of Hewlett Packard


George Homer Martin Associates

Brew and Co. Inc. Richard D.


Allied Advertising Agency Inc.

· Bussmann Mfg. Co.,

Div. of McGraw Edison Co.

108. 109

Henderson Advertising Company

Chatham Electronics, Div. of

Tung-Sol Electric Inc.


E.M. Freystadt Associates Inc.

Clare & Company, C.P.


Reineke, Meyer & Finn Adv.

Cohu Electronics Inc.

Kin Tel Division

3rd Cover

Erwin Wasey, Ruthrauff & Ryan Inc.

Control Data Corporation


Barnes Chase Advertising

Coto Coil


The Williams Company

· Defense Electronics Inc.


Compton Jones ·Associate s

Delco Radio


Campbell-Ewald Company

DuPont de Nemours &

Co. Inc. E.I.

24. 25, 45, 95

Batten, Barton, Durstine & Osborn Inc.

Edgerton, Germeshausen & Grier, Inc. 115 Reach, McClinton & Humphrey, Inc.
Electronic Engineering Co. of California 7 Compton Advertising Inc.

Fairchild Semiconductor


Johnson & Lewis Inc.

· Fenwal Electronics


Larcom Randall Adv. Inc.

Flying Tiger Line


Hixson & Jorgensen, Inc.

·General Electric Company,

Minature Lamp Division


Batten, Barton, Durstine & Osborn Inc.

· General Electric Company,

Rectifier Components Div.


Ross Roy Inc. Advertising

· General Electric Company,

Semiconductor Products Dept.


Ross Roy Inc.

Gertsch Products Inc.


Balsam Advertising Inc.

· Globe Industries Inc.


Odiorne Industrial Adv. Inc.

Gudebrod Bros. Silk Co. Inc.


Lee Ramsdell & Co. Inc.

Hallikainen Instruments Hal Lawrence Incorporated
·Hewlett Packard Company LC. Cole Company Inc.
· Hughes Aircraft Company Foote, Cone & Belding
Hull Corporation The Michener Company Adv.

119 1, 12, 13
20, 21 106

ITT-Royal Electric Company


West, Weir & Bartel Inc.

Inertia Switch Inc.


Harold Marshall Advertising Co.

International Electronic Industries


Buti-Roberts Advertising

InternationaI Rectifier Corp.


Communication Associates

Interstate Electronics


Jones, Maher, Roberts Adv.

· JFD Electronics Corporation


Michel Cather Inc.

Janney Cylinder Company


John B . Ferguson Jr.. Adv.

· Je~~~n~a~Jr~~ Mfg. Corp.


Kay Electric Company


Josephson, Cuffari & Co.

· Kyoritsu Electrical Instruments Works,



Nichiden Adv. Ltd .

· Lambda Electronics Corp.


Michel Cather Inc.

· Lapp Insulator Co., Inc.


Wolff Associates Inc.

Leach Corporation


Hixson & Jorgensen, Inc.

Lepel High Frequency Laboratories Inc. 122

Apex Graphic Company

Levin & Son, Inc., Louis


M .R. Crossman Company

Machlett Laboratories Inc., The


Fuller & Smith & Ross Inc.

Mallory & Company Inc. P.R.


The Aitkin·Kynett Co.

Markem Machine


Culver Adv. Inc.

· Matsuo Electric Co., Ltd.


Asahi Advertising Agency & Co.

· Mclean Engineering Laboratories


Healy Adv. Agency

Minnesota Mining & Mfg. Co.,

Mincom Division


Reach , McClinton & Co., Inc.

Mitsumi Electric Co., Ltd.


Dentsu Advertising Ltd.

· Moseley, F.L.


LC. Cole Company Inc.

National Cash Register Co. Allen, Dorsey & Hatfield Inc.
· North Atlantic Industries, Inc. Murray Heyer! Associates

128, 129 103

Primo Co., Ltd.


General Adv. Agency

Princeton Applied Research Corp.


Mort Barish Associates

Qualtronic Corporation


Gerald C. Smith Associates

Radiation Inc. G.M . Basford Company
Radio Corporation of America
Al Paul Lefton Co. ·Raytheon Company
Fuller & Smith & Ross Inc. Rome Cable, Div. of Alcoa
The Rumrill Co. Inc. · Rosemount Engineering Co.
Midland Associates, Inc.

22 4th Cover
126 36

· Sanborn Co., A Sub. of Hewlett Packard 2

Culver Advertising Inc.

Space Craft Inc.


Preiss and Brown Adv. Inc.

Speer Carbon Company


Hazard Advertising Company Inc.

Sprague Electric Co.

5, 6 , 10

The Harry P. Bridge Co.


Div. of General Dynamics


The Rumrill Company Inc.

·Tektronix Inc.


Hugh Dwi11ht Adv. Inc.

Texas Instruments Incorporated

Industrial Products Group


Robinson -Gerrard, Inc .

·Toyo Electronics Ind., Corp.


Dentsu Advertising

· United Transformer Corporation 2nd Cover

Bradley Rosen & Kaus Adv .. Inc.

Unitrode Corporation


Chirurg & Cairns Inc.

Vidar Corporation


Bonfield Associates, Inc.

· Vitramon, Inc.


Ted Sommers, Inc.

Winston Research Corporation Jordan Advertising Inc .

104, 105

Classified advertising

F. J . Eberle, Business Mgr.

Professional services


Employment opportunities



(Used or Surplus New)

For Sale


Classified advertising index

Lifschultz Fast Freight


Memory Studies


Metals & Controls Inc.


Motorola Military Electronics Division 138

·Radio Research Instrument Co.


· Universal Relay Corp.


Advertising sales staff

Gordon Jones: [212) 971-2210
Advertising sales manager

Atlanta, Ga. 30309: Gus H. Krimsier,
Michael H . Miller, 1375 Peachtree St. N.E., [404] TR 5-0523

Boston, Mass. 02116: William S. Hodgkinson,

co McGraw-Hill Building, Copley Square,



Chicago, Ill. 60611: Robert M. Denmead, Daniel E. Shea, Jr., 645 North Michigan
Avenue, [312] MO 4-5800

Cleveland, Ohio 44113: Paul T. Fegley, 55 Public Square, [216] SU 1-7000

Dallas, Texas 75201: Dick Poole, The Vaughn Building, 1712 Commerce Street,
[214] RI 7-9721

Denver, Colo. 80202: John W. Patten, David M . Watson, Tower Bldg .. 1700 Broadway, [303] AL 5-2981

Houston, Texas 77025: Kenneth George,
Prudential Bldg .· Halcombe Blvd., [713] RI 8-1280

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] 971-3616
Frank LeBeau [212] 971·3615 George F. Werner [212] 971 -3617 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: Edward E. Schirmer, 34 Dover Street

Frankfurt/Main: Matthee Herfurth, 85 Westendstrasse Phone: 77 26 65 and 77 30 59

Geneva: Michael R. Zeynel, 2 Place du Port 244275

Paris VIII: Denis Jacob, 17 Avenue Matignon ALMA-0452

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Nagoya: International Media
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R.S. Quint: [212] 971-2335 General manager Electronics Buyers' Guide
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· For more information on complete product line see advertisement in the latest Electronics Buyers' Guide

Executive, editorial, circulation and advertising offices: McGraw-Hill Building, 330 West 42nd Street, New Vork, N.V.· 10036. Telephone Area Code 212·971·3333. Teletype TWX
~d~O~!f:·~~~~4~~~e~~~I~. ~i~~i:'a~1~~1; /Jo~a1~1g~eM~cf:a~~eJr.~~~c:~~~i~fn~iSi:1i~;:: ~~=~\~" l,is:ee~eI;!~~1~lanr~eYi'~:. P6Tt~~~~~t~~ {~~eg~r~Or~i\~~~ gg~~TJi0C'.5~~~hr~:.· ~~~~~~::::;
Hugh J . Kelly, Harry L. Waddell , L. Keith Goodrich, Executive Vice Presidents: John L . McGraw, Treasurer; John J . Cooke, Vice President and Secretary. Title R registered U . S. Patent Office; @copyright 1964 by McGraw-Hill, Inc. All rights reserved, including the right to reproduce the contents of this publication, i n whole or In part.


Electronics I July 27, 1964





Visit our Booth 7077 at WESCON, Sports Arena, Los Ang eles, August 25-28.

and ALL ACCESSORIES including monitors, control units, fixed -focus and zoom lenses, pan/ tilt units, video cable, video switchers, synchronizing generators, cabling, tripods, vi di cons ...


W RI TE for te chnic al informati on and syst ems engineering. Representatives in all major cities.
Box 623 San Diego. California 92772 Phone (774) 277-6700

Circle 901 on reader service card


Make your choice RCA Ceramic -Metal Tubes for more RF Power in UHF Communications

Here are four members of the newest RCA family of ceramic -metal tubes ... tetrodes already designed into compact, high-power equipment for airborne, fixed station, and mobile communications applications.
The four-each packing more RF power than previously available in tubes of comparable size-are designed expressly for UHF power use. Designers have specified them for use in aircraft communications systems, SSB linear amplifiers, localizer gear in GCA equipment, high-power deflection amplifiers for radar, mobile ground communications equipment and amateur radio transmitters.
RCA -8072 is conduction cooled and can be an ideal choice where space is at a premium. RCA-8462 featu res "quick heat" warm-up capability of less than 100 milliseconds in push-to-talk equipment. RCA -8121 and -8122 are air-cooled versions of the 8072 and offer higher power in devices of comparable silze.
Special characteristics can be custom-designed to fill individual needs . For more information, see your RCA Representative. For technical data on specific types, write: Commercial Eng'fneering, Section G-19-Q-2, RCA Electronic Components and Devices, Harrison, N. J.


Typical CW Operation


Maximum Plate
Dissipati on

Plate (Volts)


Useful Power Output (Watts)



8072 Conduction 100*

700 175




8121 Forced-Air



50 470

275 235

8122 Forced-Air










(Q uick- Conduction 100*

700 175





*May be higher, depending on heat-sink d esign .


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