Pioneer Car Stereo System SX 636 Poptronics 1974 11

User Manual: Pioneer Car Stereo System SX-636

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Pickering 0A-3 Ste - o Headphones
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American Circuits& Systems 151110Fúnction Generator
Royce 1`-600.CB Mobile Tra:'n ;eiver
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:peed while a record is playing. !kith of
nese sophisticated units are even

;quipped with a
'trobe light directed
the strobe marks
r easy viewing.
Pioneer's engineers
tally think of

,.linkages to provide the necessary ton-eel-ní_ cycling motion, the PL-A45D uses a `separate precision gear moto just to InoVe
the tonearmin accordance with your
`instructions, Its,áther 4 -pole synchrortous motor is free to
' ''The tradition of mexcelled
drive only tie`
' - performance c 5
12 -inch aluminum. - , _`
Still, all of these features and refine alloy die-cast plattsr- 7`tnents alone do -not guarantee the perform without interrúption- -;ance specificatrors of Pioneer's new
or change of torque --turntables. Each tonearm an,d turntable
and speed. _
pletter combináticn is shock mounted in
-'ita"specialty desigted natural grain cabinet
Automatic operation? .
(with hinged dust cover). Precision machinmanual precision
_ -zing of all rotatikn21 parts of each unit, plus
=

everything.

Xutomatic features without.
Mutomatic drawbacks
If you prefer to let your tonearm and
urntable do all the work, consider Pioneer's_
Ill new PL-A45D. With it you can play your a
cords without ever touching the tonearm. '
nlike other single play automatics which (epend upon complicated mechanical

,°Superb S -Shaped toneartns'

_
;.
_

for better tracking

'
-

Ile that's right for you.
Belt
pole synch.

PL -51A

PL 71

4Direct
DC Servo

Direct
DC Servo

8116l?

811M6"

12"

xHbs. 3 oz.
$169.95

12Y4"

121/4"

3
-

lbs. 1 oz.
$249.95

lbs. 8 oz.
$299.95

The tonearm of every
Pioneer turntable system
is the "S-shaped"
design, for optimum
groove tracking- All are
-statically balanced and

-a

prográm of continuous quality control

-.in-sure

use adjustable counter weights with direct read out of tracking force. All
o
have adjustable"
anti -skate contrcl and
a
oil -damped cueing for
S-sháped tonearm.
the gentlest application
for ideal tracking
of stylus tip to record
groove. Lightweight plug - in cartridge"shells
insure positive electrical contact and".
optimum stylus position and angle for.lower_1
distortion and reduced record wear.

that each Pioneer turntable will meet

exceed its published specifications
-;or:
a time honored;,tradition with all Pioneer
,ccmpon-enis,

',all

±2%

2%
pre than 47d1 More than 55dB More than 60dB
(WRMS) 0.06% (WRMS) 0.05% (WRMS)
latic Bal. "S" Static Bal. "S" Static Bal. "S",,

"lectronic speed adjust lent for each speed

fPL-A45D

:Manual turñtabtes-choice of
the professionals

Engineers, experts and enthusiasts
agree: to get the best performance, you
-`need a manual turntable. And to get the best
-manual turntab e, you need a Pioneer.
Every Pioneer manual turntable offers a
level of precision and performance un _paralleled in itspe_ice range. And every
is atotai system
complete with dust
-cóver and b99e4-and designed for
';years ofproféssianal trouble-free sound

reproduttiorl.

st manual urntab e.
t a Pióñe
The manual turntable is rapidly
becoming the first choice of hi-fi erthusiasts
'everywhere. The reason why is quite simple.
Today's enthusiasts are more knowledgeable, more sophisticated and more involved
with their music. And only the manual
turntable can provide the involvement
and performance they demand.
At Pioneer, this trend comes as no
surprise. We have long recognized the
superiority of the manual turntable. And
long recognized a simple fact: a record
changer in no way improves performance.
Lt can detract from it.
As a result, we now offer the finest and
most complete line of manual turntables
available. Manual turntables that are
cesigned with the needs of today's hi-fi
enthusiast in mind. Turntables that are
engineered for precision response.
When you get right down to it, good
record playing equipment really has only
two requirements: uniform rotation of a
turntable, and accurate tracing of a record
groove by a tonearm and its cartridge.
Pioneer's engineers have long recognized that these requirements are best met
by single -play turntables and precision
engineered tonearms. Our five new belt drive and direct-drive turnable systems
mean you needn't settle for the higher wow

and flutter and the poorer signal=to-noise
ratios (rumble) of record changers. Whether
you've budgeted $100 or $300 for this vital
element of your high fidelity system, there's a Pioneer turntable that outperforms any
record changer in its price class:

Pioneer's direct -drive models, PL-51A
and PL -71 go even a step further in achieving noise -free, precision platter rotation.
The DC electronically controlled servomotors used in these models rotate at
exactly the required 331/2 or 45 rpm platter
speed. Their shafts are directly connected
tc the center of the turntable, with no intermediate pulleys or other speed reduction
devices. This means no extra friction -

producing bearing surfaces.
Because of the unique technology
embodied in these new, direct -drive motors,
it's possible to control their speed electronicalry. This is more precise than any
mechanical drive system. Both our PL-51A
and PL -71 offer individual pitch control for
both 331/3 and 45 rpm speeds. Their turntable platters are edge -fitted with stroboscopic marks, so you can adjust precise

Cónsider the performance advantages Belt -drive, featured in Pioneer's PL-10,
PL-12D and PL-A45D, means smoother,
more uniform platter rotation than can be
acnieved with typical idler-wheel/pulley
arrangements normally found in record-.
chargers. Even changers equipped with
synchronous motors transmit
vibration to the turntable platter. This is
picked up as low -frequency rumble by the
tonearm and cartridge. By driving the platter
with a precision -finished belt, vibration
is effectively absorbed before it can be
translated to audible rumble.
-

Belt -drive for
rumble -free rotation

Direct -drive motoi:
reduces friction

l
_4

Choose the Pioneer turnta
PL -12D
PL -10
Belt
Belt
Drive system
4
4 -pole synch.
ive motor
4 -pole synch:
Speed control
More than 47dB More than 47dB M
SI N -(Rumble)
01
Wow & Flutter
0.1% IWRMS)
0.1% (WRMS)
Tonearm Type Static Bal. "S" Static Bal. "S" Si
81]16"
Tonéarm Length
óF/Í6"
Is Turntable
Diameter
12"
12"
Turntable"

Model

Weight.
Pnce:

lbs. 3 oz.
$99.95

a lbs.

3 oz.
$119.95

rt
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ormance,
et a manual

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when you want something better
U.S. Pioneer Electronics Corp., 75 Oxford Drive, Moonachie, New Jersey 07074
West: 13300 S. EstreÍla, Los Angeles,90248/Midwest: 1500 Greenleaf, Elk Grove Village, Ill 60007/Canada: S.H. Parker Co
CIRCLE NO. 41 ON READERS SERVICE -CARD

Pickering cartridges feature low frequency
tracking and high frequency tracing ability*
Pickering offers you "The Best of Both
Worlds" in discrete 4 -channel and in
stereo cartridges. These cartridges have
been specifically designed and engineered
to peak specification and performance
characteristics. They possess traceAbility,
vital for both stereo and discrete playback.
For example, take the case of discrete
s
-

J
(B)

(C)

playback. You are looking at a model of a
discrete groove, magnified 3,000 times
(figure A). You can sée it is made Up of
complex groove undulations. This makes
the demands on the cartridge and its
stylus much greater than ever before. The
left side of the groove possesses all of the
information recorded on the left side of the
room, and the right side likewise. The
stereo signals for the front speakers are
represented by the broad sweeps (figure
B), and the special discrete high frequency tone carrier is represented by the
wiggles on the same groove walls (figure
C). This high frequency carrier centered
at 30,000 Hz, demands a superior stylus
assembly (and shape of the tip) which we
call our QuadrahedralT" another Pickering
exclusive which makes it possible for the
stylus to trace both the stereo and discrete signals in the groove.
So, the QuadrahedralT" stylus picks up

CIRCLE NO. 30 ON READERS SERVICE CARD

(A)

all 4 signals, which the computerized demodulator sorts for the amplifier, which in
turn transmits the sound to the proper

speaker.
So, whether you look forward to the
fabulous reality of discrete 4 -channel
sound in your home, or the finest stereo
to satisfy your listening taste
depend on
the traceAbility of Pickering cartridges to
make possible "The Best of Both Worlds".
the world of stereo and matrix, and
the world of discrete 4 -channel.

For further information write to
Pickering & Co., Inc., Dept. PE
Sunnyside Blvd., Plainview, New York 11803

PICKERING
"for those who can ihearl the difference"
TM-PICKERING TRADEMARK
POPULAR ELECTRONICS

NOVEMBER 1974 VOLUME 6, NUMBER 5

!oiu,,a.

ectronics

WORLDS LARGEST- SELLING ELECTRONICS MAGAZINE

FEATURE ARTICLES
HOW THE NEW FTC HI-FI RULES AFFECT YOU!
The buyer must still be wary of power claims.
WHAT'S NEW IN COLOR TV RECEIVERS FOR 1975

Leonard Feldman

Art Margolis

NEW DOLBY-ENCODED FM BROADCASTS
How new FCC rules affect FM reception

Edward Roberts

Allan C. Stover
Leslie Solomon

Roger Legge

John

Frye

Giancarlo Punis & Joseph O'Donnell

Jim White

Hollabaugh

Forrest M. Mims

BASIC DIGITAL LOGIC COURSE
Part 2: Concepts and circuits
CAREER OPPORTUNITIES FOR THE TECH REP
COMPUTER TERMINALS ARE COMING
Time savers for the home and small business
ENGLISH LANGUAGE SHORTWAVE BROADCASTS

& H.

November to February

THE SIMPLEST TEST GEAR

Test probes can solve many service problems

CONSTRUCTION STORIES
BUILD A LASER TV SYSTEM
Transmit and receive BIW pictures on

laser beam

BUILD A DIRECT -CONVERSION COMMUNICATION RECEIVER
Good performance at

fraction of the cost of

superhet

John

MEASURE LOW MILLIVOLTS WITH A MULTIMETIER

Range expander increases sensitivity by X10 or X100

Thomas R. Fox 54

BUILD A VERSATILE DIGITAL LED THERMOMETER

COLUMNS
HOBBY SCENE
STEREO SCENE

Editorial Staff

Ralph Hodges

Glenn Hauser

Len Buckwalter

Lou Garner

Blazing speakers
DX LISTENING
"Secret" shortwave stations

CB SCENE
CB to the rescue

SOLID STATE
Circuits using field-effect transistors

PRODUCT TEST REPORTS
59
60

PIONEER MODEL SX-636 AM/STEREO FM RECEIVER
ROYCE MODEL 1-600 MOBILE CB TRANSCEIVER
PICKERING MODEL OA -3 STEREO HEADPHONES
DRAKE MODEL SPR-4 COMMUNICATIONS RECEIVER
AMERICAN CIRCUITS & SYSTEMS MODEL MK1 FUNCTION GENERATOR

66
68

DEPARTMENTS
EDITORIAL

Art Salsberg

Run It Up The Flagpole

LETTERS
NEW PRODUCTS
NEW LITERATURE
NEWS HIGHLIGHTS
POPULAR ELECTRONICS, November 1974, Volume 6, Number 5 Published monthly at One Park Avenue, New York, NY 10016. One year subscription rate for U.S.. Possessions and Canada, $6.98; all other countries,
$8.98. Second class Postage paid at New York. NY and at additional
mailing offices. Authorized as second class mail by the Post Office Department, Ottawa, Canada and for payment of postage in cash. Subscription service and Forms 3579; P.O. Box 2774, Boulder, CO 80302.
POPULAR ELECTRONICS Including ELECTRONICS WORLD, Trade
Mark Registered. Indexed in the Reader's Guide to Periodical Literature.
COPYRIGHT C 1974 BY ZIFF-DAVIS PUBLISHING COMPANY. ALL
RIGHTS RESERVED.

NOVEMBER 1974

12
16
27

Ziff -Davis also publishes Boating, Car and Driver, Cycle, Flying, Modern Bride, Popular Photography, Skiing and Stereo Review.
Forms 3579 and all subscription correspondence should be addressed
to POPULAR ELECTRONICS, Circulation Dept., P. O. Box 2774, Boulder,
CO 80302. Please allow at least eight weeks for change of address. Include your old address, as well as new-enclosing, If possible, an address label from a recent Issue.
Editorial contributions must be accompanied by return posrage and
will be handled with reasonable care; however publisher assumes no
responsibility for return or safety of arl work, photographs, models, or
manuscripts.
3

Popular Electronics
EDGAR W. HOPPER
Publisher

ARTHUR P. SALSBERG

Editorial Director

LESLIE SOLOMON
Technical Editor

JOHN R. RIGGS
Managing Editor

ALEXANDER W. BURAWA

ANDRE DUZANT
Technical Illustrator

ELLEN S. FINKELSTEIN
Editorial Assistant

LEN BUCKWALTER
LOU GARNER
JULIAN D. HIRSCH
RALPH HODGES
WALTER G. JUNG
MILTON S. SNITZER
Contributing Editors
JOSEPH E. HALLORAN
Advertising Director

JOHN J. CORTON
Advertising Sales

LINDA BLUM
Advertising Service Manager

PEGI McENEANEY
Executive Assistant

STANLEY NEUFELD
Associate Publisher

FURMAN H. HEBB
Photo

ZIFF-DAVIS PUBLISHING COMPANY

Popular Electronics
Editorial and Executive Offices
One Park Avenue New York, New York 10016
212-725-3500
William Ziff, President
W. Bradford Briggs, Executive Vice President
Hershel B. Sarbin, Senior Vice President,
Secretary, and Treasurer
Philip Sine, Senior Vice President
Phillip T. Heffernan, Vice President, Marketing
Frank Pomerantz, Vice President, Creative Services
Arthur W. Butzow, Vice President, Production
Edward D. Muhlfeld, Vice President, Aviation
and Automotive Divisions
George Morrissey, Vice President
Sydney H. Rogers, Vice President
Sidney Holtz, Vice President
Lawrence Sporn, Vice President, Circulation
Edgar W. Hopper, Vice President, Electronics Div.

Midwestern Office
The Pettis Group, 4761 West Touhy Ave.,
Lincolnwood, Illinois 60644, 312 679-1100
GERALD E. WOLFE, GEORGE B. MANNION
Western Office
9025 Wilshire Boulevard, Beverly Hills, CA 90211
213 273-8050; BRadshaw 2-1161
Western Advertising Manager, BUD DEAN

Japan: James Yagi

F-DAYrd

AFFECT YOU!
BY LEONARD FELDMAN

EFFECTIVE November 4, 1974,
new rules governing the disclosure of the output power of audio amplifiers and receivers go into effect.
The new rules were promulgated by
the Federal Trade Commission after
several years of study. They follow a
long period of advertising abuse by

some segments of the electronic
home -entertainment industry.
Well-known "low-fi" productsclaiming output power capabilities of as
much as 100 watts "instantaneous
peak power (IPP)" have been measured by reputable laboratories and
have consistently produced no more
than a few watts of output power per
channel at best. Meaningless terms
such as IPP, peak power, peak music
power, and dynamic music power-if
they are to be used in the future at
all-will have to be given less typographical prominence in all advertising media.

Still Room for Ambiguities.

Will

the FTC rule end the confusion about
NOVEMBER

1974

1.0

ALL AMPL FIERS REFERENCED TO
8 -OHM LOADS

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0.2
A

30
40
50
POWER OUTPUT/CHANNEL (WATTS)

Fig. 1. When all three amplifiers are measured the
same way, "lower spec" amplifier A turns out
to be.the highest powered unit among the three.
39

power ratings in the minds of all consumers? Unfortunately, the answer is
a resounding "No!" While the rule
goes a long way towards enforcing
honesty in audio equipment advertising, adherence to its requirements will
not, in and of itself, make everyone's
power specifications read like
everyone else's. The consumer can
still be thoroughly confused when
reading specification sheets describing competitive amplifiers and receivers. Here is why confusion can arise:
Henceforth, manufacturers will be
required to state continuous output
power delivered by their products into
a specified impedance, at a specified
harmonic distortion, and over a
specified power bandwidth. The
power specified in this manner must
be delivered by the amplifier or receiver when all its channels are driven
simultaneously. For a stereo receiver
or amplifier, this means that both
channels must be going at the same
time, while in a 4 -channel setup, all
four amplifier channels must deliver
the rated power to all four loads at the
same time.
Let us consider the following sets of
competitive specifications, all of
which would comply with the "letter of
the law":
AMPLIFIER A: 50 W/channel output
power into 8 ohms at 0.3 percent harmonic distortion from 20 Hz to 20,000
Hz.

AMPLIFIER B: 60 W/channel into 4
ohms at 0.5 percent harmonic distortion from 60 Hz to 400 Hz.
AMPLIFIER C: 65 W/channel into 4
ohms at 1.0 percent harmonic distortion from 60 Hz to 4000 Hz.
Reading these three descriptions,
the uninitiated consumer might conclude that Amplifier C has the greatest
output power capability. He would be
wrong. Nearly all solid-state amplifiers
produce their greatest output power

levels when connected to 4 -ohm
speaker loads. Connected to more
popular 8 -ohm speaker system, AmplifierC might well produce less than 50
watts.
Notice, too, that the rated distortion
of Amplifier C is 1.0 percent. How
much less power would it be able to
deliver-even into its 4 -ohm specified
loads-if distortion were limited to 0.5
or 0.3 percent, as in the cases of Amplifiers B and A? For that matter, we
have no way of knowing from the figures given whether or not the distortion level will ever go down to the
0.3 -percent level. Perhaps 1.0 percent
is the best Amplifier C can do even at
low output power levels.
The new FTC rule merely requires
that the amplifier be able to deliver its
specified power at a harmonic distortion that does not exceed the published figure. Doing some hypothetical calculation based on typical
measurements observed with "real"
amplifiers, Fig. 1 plots power versus
distortion curves for our three fictitious amplifiers. The parameters were
changed so that each amplifier was
operated into 8 -ohm loads, and all
three were permitted to reach a distortion level of 1.0 percent, so that the
comparison would be fair.
As you can see, the results are just
the reverse of what is implied by an
uninformed reading of the specification listings given earlier. Amplifier A
produced 68 watts under these conditions, Amplifier B produced 50 watts,
while the amplifier with the highest
"published" power rating-Amplifier.
C-produced only 48 watts.
In the example, we were dealing
with only a single middle -of-the -band
audio frequency. However, the FTC
rule requires that the power bandwidth over which the rated power can
be developed at rated (or less) distortion must be specified as well. Refer-

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FREQUENCY

-Hz

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1

10K

Fig. 2. Again, amplifier A proves to be much
lower in distortion than amplifiers B and C, in
spite of its more conservative published spec.
40

ring again to the "published" specifications given above, each manufacturer has complied with this requirement. The maker of Amplifier C has
honestly stated that his amplifier will
deliver 65 watts at any frequency between 400 and 3000 Hz. But most of us
know that the real test of a good amplifier is its ability to deliver maximum
power at the frequency extremes. This
is particularly important at low bass
frequencies where musical energy
demands are usually greatest. The
thundering beat of a bass drum calls
for more power than is required when
reproducing the sounds of instruments and voices in the midrange register.
Reading the specifications of Amplifier C, we have no way of knowing
how much power the product can deliver (if any) at 40 Hz and lower frequencies, or at what level of distortion. The
curves in Fig. 2 show what the distortion of each of our fictitious amplifiers
might look like even if we were to
use 50 watts/channel as a reference
power level. Again, contrary to first
impressions, Amplifier A comes up
the winner as far as distortion is concerned.

Buyer Beware-Still. So, while the
new FTC rule may alleviate some of
the worst abuses of the industry, it
does not entirely correct them. In fact,
many consumers may falsely conclude that, with the FTC in the act, all
product specification sheets are
going to read the same-that they will
be comparing apples to apples.
You can be sure that manufacturers
who have reason to "gimmick" their
specifications will still find enough
ways to obscure the facts. The component manufacturers who have always sought to tell the true performance story of their products did not
have to wait for federal legislation to
adhere to truth -in -advertising doctrines. They have been specifying continuous power over the entire audio
range, from 20 Hz to 20,000 Hz, at low
distortion levels and with all impedances defined since long before the
FTC ever heard about watts, decibels,
and THD.
The Institute of High Fidelity (IHF)
hopes, before long,.lo publish more

complete measurement standards for
amplifiers. If adhered to, the new
standards would help to eliminate the
many ambiguities that still remain
prevalent, even in the face of the new
FTC requirements.
POPULAR ELECTRONICS

AmericanRadioHistory.Com

MANUFACTURERS of TV receivers unveiled many innovations
in their 1975 models. For example,
major moves have been made toward
providing brighter, sharper color pictures; tuning is getting closer to the
one -button concept; power -supply
designs indicate a trend toward compensation for anticipated voltage fluctuations caused by power shortages;
and serviceability has been improved

with modular designs and other
niceties. Here are details on what each
major color TV manufacturer is offering in their 1975 all -solid-state chassis
lines.

Admiral. The latest

in Admiral's line
of color TV receivers is the Touch
Tuning M25 chassis. Its main feature
is a tuning system programmed with
toothed cards. Six printed -circuit
cards are used to program uhf channel number readouts. A seventh is for

programming the remote control
channel selector- to go to the next
higher active channel, bypassing all
inactive channels. The cards are prepared for individual viewing situations
with the aid of longnose pliers.
Once the cards are prepared, they
are inserted into connectors in the
tuner. This permits the viewer to select
a channel from the keyboard or the
remote control transmitter. The channel appears on the screen, and a separate readout indicator displays the
channel number.
In the companion M30 chassis, a
special transformer provides voltage
regulation. The transformer is wound
in such a way that its secondary pro NOVEMBER 1974

BY ART MARGOLIS

duces fixed -amplitude square waves,
with the transformer operated at saturation. The transformer is tuned to
resonate at the line frequency with the
aid of a capacitor.
When the input voltage is nominally
117 volts ac, the clipped output voltage is a fixed -amplitude square wave.
Should the line voltage vary (within
±10 percent of nominal), any change
produces an inverse change in the
clipping action. The peak -to -peak
square wave applied to the rectifiers
then remains at about the same amplitude.
While the Admiral chassis does not
tilt (it is horizontal), it does slide out for
easy servicing.

General Electric. MB, MC, QB, and
YA are the designations given by General Electric to its 1975 chassis. The
stress is on reliability, quality, and performance. For 1975, GE is introducing

the third generation of its Quadline
color picture tube. In -line gun arrangements are featured in the
Porta -Color 13: and 15 -in. picture
tubes. The tubes have short necks and
90° deflection angles. The necks are
up to 2 in. shorter than comparable
tubes with triangular gun arrangements, which eliminates the bump on
the rear of the cabinet. Also, the in -line
arrangement reduces from 12 to 8 the

number of convergence adjustments
that must be made.
In addition to manual and preset
color, tint, and brightness controls,
there is a Custom Picture Control.
Coupled to the contrast, color, and
brightness circuits, it adjusts all three
parameters simultaneously to maintain a balanced ratio.
A One -Touch Color system incorporates tint lock, avc, and the preset
color tint and brightness. The tint lock
widens the demodulation angle by
cross -coupling B-Y and G-Y at the
output of the chroma demodulator IC.
The seven models in the YA series
have chassis that accommodate about
90 percent of all the electrical components. Off -the -module components
are overrated to increase reliability.
More than 95 percent of component
failures are claimed to be repairable
by module replacement, and all IC's
plug in for easier servicing. To further
endear itself to the serviceman, GE
has a lot of the service information
pasted on the inside of the cabinet and
printed on the circuit boards. This includes layouts, catalog part numbers,
detailed adjustment instructions, and
even the schematic.
In the larger chassis (like the MC
series), a high -voltage quadrupler that
develops 30 kV is used instead of the
usual tripler. Regulation of the 30 kV is
achieved with a three -winding saturable reactor circuit.

Heath Company. The latest kit marvel from Heath is its Model GR-2000
digital color TV receiver. The tuner
uses a varactor diode that eliminates
41

""T

Magnavox. The latest color

moving parts. An up/down counter
digital programming board has provisions for presetting up to 16 channels
in the vhf and/or uhf bands in any sequence, even' repeating channels if
desired. The tuning, activated by a
front-panel control or a button on the
optional remote control transmitter,
sweeps up or down through the 16
preset channels.
The number of the channel selected
can be placed anywhere on the screen
for a preset time of up to 90 seconds,
or it can be set permanently on. The
brightness of the display is adjustable.
And the numerals can be instantly recalled at any time by tapping the
volume -down button on either the receiver or the remote control transmitter. The numeral readout is digitally

Philco Model C1922FRW

ceiver displays the channel's number
in bright numerals on the upper left of
the screen for about 3 seconds.
Depressing the M (for mute) button
on the remote control transmitter
turns off the sound for 1 minute without disturbing the picture.
The latest in negative guard band
color picture tubes is used in the 13 through 19 -in. STAR chassis. These
tybes have a black matrix surrounding
color stripes (not dots). The electron
guns are arranged in -line (rather than
in the usual triad configuration),. reducing the number of convergence
adjustments that must be made. Finally, the picture tubes' necks are
shorter than usual. (The 25-in negative
guard band picture tube requires a
wide deflection angle that precludes
an in -line gun arrangement.)
The power supply employs a new
voltage -regulating transformer in a
special circuit whose output maintains relatively constant voltage during minor changes (a few percent) in

generated by a special character
generator IC on one of the receiver's
modular boards.
As icing on the readout cake, Heath
offers an optional 12/24 -hour digital
clock accessory that fits into the receiver. It generates the time in an
hours/minutes/seconds format. The
time is displayed on the screen, simultaneously with the channel number.
The receiver's plug-in IC amplifier/fixed-tuned LC filter -f strip eliminates the need for periodic sweep
alignment. Serviceability is aided by
such niceties as modular circuit
boards, built-in dot generator, slide out service drawer, and an illustrated
troubleshooting guide in one of the
manuals. A test meter also comes as a
basic part of the receiver kit.
i

Sony Model KV -1920

TV re-

ceiving system from Magnavox is
called the STAR (for Silent Tuning
At Random), which refers to its
varactor-diode tuner. The viewer can
call up any vhf or uhf channel by
punching buttons on a compact remote control transmitter. The receiver
instantly and silently tunes to the
selected channel. The tuning system
is not sequential; it goes directly to the
selected channel without having to
clunk through all the in-between
channels. A special circuit in the re-

THE NEW 1975 ALL -SOLID-STATE TV RECEIVER CHASSIS

Company

Tuner

Chassis

-F Strip

Channel

Muting

Indicator
Admiral

M25

Varactor

Transistor

Varactor;

GR-2000

Varactor

IC/Fixed-

On screen

tuned LC

(Time optional)

Selector dial

Yes

General

Electric
Heath
Magnavox

Star

Varactor

Panasonic

Quatrecolor

Detent

Boss

Varactor

QS -3000

Detent vhf

Philco
Quasar

Varactor uhf

Sony

Sylvania
L

Detent `

series

GT-matic

Zenith

Heath Model GR-2000 with on -screen
channel and optional time

Detent,

XL -100

RCA

Chroma-color

MOSFET

Digital (on
control panel)

Yes

On screen

Yes

Selector dial

Yes

Digital (on

control panel)
Selector dial

Varactor

Transistor

Digital

Yes

Varactor

Transistor

Selector dial

Yes

Note: All chassis are solid-state and modular and have negative guard band picture tubes, aft, audio
output jacks, automatic degaussing, and 300/75 -ohm antenna inputs. All have electronic remote
control except Zenith (see text).

POPULAR ELECTRONICS

AmericanRadioHistory.Com

óq

NEGATIVE vs POSITIVE GUARD BAND
COLOR PICTURE TUBES

In a standard color picture tube, 85
percent of the screen is covered with
phosphor dots, with nothing between
them but an aluminized coating that
covers the entire face of the tube? The
dots are 17 mils across, while the electron beams are 13 mils in diameter.
This means that the beams cannot
completelyexcite the dots. In fact, only
about half the area of each dot ever
becomes excited. The part not excited
is required as a "guard band" to prevent degradation of color purity resulting from the beams overlapping onto
adjacent dots.
Ambient light is reflected from the
aluminized coating and tends to wash
out the picture. So, a tinted face glass
must be used to reduce glare, Tinting
works, but it also kills about half of the
light from the dots. This system is referred to as "positive guard band" because the unexcited portions of the
dots protect purity.
In the "negative guard band" system, as employed in many of the latest
color picture tubes, the dots are sur=
rounded by an opaque black material.
The electron beams are allowed to become thicker than the diameter of the
dots by increasing the sizes of the
holes in the shadow mask. The entire
dot can now be excited,.whlle the black
material serves as the guard band. Tinting is not required because ambient
light is not reflected by the black surround. Hence, a full 85 percent of the
light produced by the excited dots
comes through the picture tube's face
plate.

the line voltage. The high -impedance
MOSFET -f module gives the -f strip
improved sensitivity and reduces any
tendency to overload.
The STAR's modular design caters
to serviceability. And the vertical
chassis has 20° and 45° tilt positions.
i

Panasonic. Quatrecolor is the name
of Panasonic's line. The new Quintrix
color picture tube employs a negative
guard band black matrix with an additional pre -focus lens to make the picture sharper and brighter by bunching
the electrons into a narrower beam.
The featured 0-lock oné-button color
system is like the preset control systems, except that the color and tint are
adjusted on a continuous basis, while
brightness and contrast adjustments
are made via preset potentiometers
with a fixed control.
The electronic remote control system permits up/down channel selecNOVEMBER 1974

tion. A "vacation" switch on most
models defeats the Speed -O -Vision
instant -on feature. The vhf dipole antenna is detachable to permit it to be
moved around the room to where it
exhibits the best signal -gathering performance.. This is a convenience if the
TV receiver is set into a permanent
location.

Philco. The solid-state modular color
TV receiver chassis from Philco is
called BOSS (for Best Of the Solid
States). It features a 37- to 47 -percent

power saving over last year's hybrid
receiver models, tilt -out front controls, and a built in Invis-A-Tenna with
its own reception selector.
Voltage regulation and suppression
are accomplished by Picture Guard
and Surge Guard in the Philco receivers. In the event of a sudden voltage
spike, due to lightning or voltage
transients on the power line, a filter
capacitor absorbs the temporary overload.
Hands-off tuning is accomplished
by a network of automatic circuits.
The viewer engages the Philco Master
Control button and selects a channel.
When the Philcomatic COLOR Control light comes on, he pulls his hand
away and the receiver automatically
tunes itself.
Quick On replaces Instant Play to
eliminate power wastage by not having the picture tube's filaments continuously powered. The audio still
comes on immediately, while the picture follows a few seconds later.

Quasar. The "works

in a

Choosing channels on Zenith's color
TV receiver line is accomplished
with non-detented slide control

drawer"

people are featuring more serviceability, line -voltage regulation, a picture
system responsive to ambient lighting, and more simplified and reliable
modules. A special twist -lock connector is used to simplify removal of the
power supply by the serviceman. This
connector eliminates multiple wire
leads that could have been potential
trouble spots.
Quasar's Insta-Matic system employs a patented demodulator IC that

RCA XL -100 Model GT-795

/¡

a light dependent resistor. The LDR is

works in conjunction with

mounted behind a honeycomb lens
located on the front panel of the receiver where it measures the ambient
light and allows more or less current
to flow into the video-chroma circuit.
This automatically raises or lowers the
brightness, contrast, and color to suit
the light level in the viewing location.
On the remote control panel is a

Panasonic Model CT-934
43

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RCA. Continuing its XL -100 color TV

Sylvania's vertical'ramp and drive waveform generator
PART OF
SIM SWITCH

LIGHT
SENSOR

MANUAL

PICTURE
CONTROL

APPLIED
VOLTAGE

NEW INTEGRATED CIRCUIT
(IC) PERMITS SIMULTANEOUS
CONTROL OF BOTH VIDEO AND
COLOR LEVELS WITH A SINGLE
VARIABLE VOLTAGE.
A

2. RESISTANCE

OF
THE LIGHT
DEPENDENT RESISTOR ILORI
VARIES INVERSELY WITH ROOM

LIGHTING.

WITH SUPER INSTA MATIC ON,
VOLTAGE FROM LOP VARIES
WITH ROOM' LIGHTING AND
CONTROLS IC GAIN FOR
AUTOMATIC PICTURE LEVEL.

VIDEO

REO
BLU

GREEN

COLOR

Quasar's automatic picture
level control changes
urith room lighting

11704
81711

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GE's MB chassis, uses saturable reactor (T1704) for high volts
44

the correct position.

NOR

41420

receiver system, RCA has shaped up
the 1975 line by installing an electronic digital display for the vhf and
uhf channel numbers. The display is
on the control panel, rather than onscreen.
There are no more tubes (except for
the latest negative guard band color
picture tube) in the RCA lineup. The
instant -on feature common in earlier
XL-100 models has been eliminated in
a move toward energy conservation.
Going all solid state and eliminating
instant -on, RCA claims an energy savings of 27.5 percent over its tube -type
receivers.
The concentration in the XL -100 line
is on the Acculine portable color TV
receivers. The deflection yoke is permanently bonded to the Acculine picture tube (which, incidentally, has an
inline electron gun arrangement) to
prevent it from shifting position.
Hence, the yoke is an integral part of
the picture tube.
Between the Acculine tube and the
bonded yoke, there are only four

dynamic convergence adjustments
instead of the usual 12 that must be
made for setting up the receiver. There
is also only one purity adjustment
-the purity magnet-instead of the
usual two. The second purity adjust-

REACT

T1700

t143V

volume -step IC/LED system. Volume is
muted or varied by the differences in
brightness produced by the LED's
glow. In the receiver is a Slumber Sentry circuit. It samples the vertical and
composite sync pulses. If the receiver
is left on after the station signs off, the
Slumber Sentry detects the loss of
sync pulses. Then it automatically
shuts off the receiver following a short
delay. [Panasonic recently purchased

regulation.

Sony. Sony this year offers the KV
color series, featuring its Trinitron system, which uses color stripes in a
negative guard band matrix, and an
in -line gun arrangement, and the TV
transportable lifestyles line. Sony incorporates 114° wide-angle deflection
picture tubes and Econoquick instant -on features for greater viewer
pleasure and convenience. One of the
major benefits of the Trinitron system
is the elimination of costly, timeconsuming set-up adjustments that
conventional three-gun color systems
require.
POPULAR ELECTRONICS

The KV series features one button
control for Automatic Fine Tuning,
Color and Hue for accurate and simple

color reception adjustment. Optional
accessories for the Sony line include
rechargeable battery packs, car battery cords, sun glare filters and auto
and home antennas.

Sylvania. The new Sylvania chassis,

Quasar's 100 -percent
solid-state chassis'
modular design system

called GT-matic II, is said to add
another dimension to no -button tuning. Parroting preset adjustments, the
viewer simply turns on the power and
selects the channel. Then, the receiver
automatically sets the proper volume,
brightness, contrast, color, tint, and
other major tuning requirements. Automatic vertical and horizontal holds
and Perma Tint supplement the preset

controls. A pushbutton varactor tuner,
muting, instant -on, remote control,
and 100 -percent solid-state chassis
round out the GT-matic II's features.
The automatic vertical and horizontal holds are controlled by a six section IC that produces a synchronized horizontal and vertical scan
system. Other automatic circuits work
on reducing airplane flutter, maintaining a constant voltage, etc.
The Perma Tint circuit acts as a
monitor to maintain color at preset
levels. It attempts to reduce flesh -tone
changes. Once the hidden controls
are adjusted as desired, the Perma

Tint control can be activated, increasing the demodulation angle between
R-Y and B-Y to provide a wider
range of phase angles for determining
the actual color of the flesh tone.
The red demodulator IC gates the
Perma Tint on only when there is a
positive component of R-Y present.
This limits the effect of the increased
angle to only those colors in the flesh tone range without affecting the
yellow -green, green, cyan, and blue
colors.
Serviceability in the GT-matic II
chassis is supported by plug-in devices and modular arrangement of the

features an all -solid-state vertical
chassis, voltage regulation, and one button preset controls.
The Space Command remote control transmitter still uses a mechanical, rather than an electronic, scheme.
A tiny hammer in the transmitter
strikes a rod that then vibrates at a
specific frequency. The sound thus
produced (it's beyond human hearing)
activates the specific control channel
in the remote control receiver.
Cr.

pc boards.

Zenith. For

1975, Zenith is introduc-

ing its Chromacolor

receiver line. It
'

' i.

Magnavox's remote -control system
features on -screen channel
number in seven -segment format.
MAUI
AMPLITUDE

CRT
FILAMENTS

NOVEMBER 1974

Admiral's power supply system
features fixed-amplitude
outputs that minimize, voltage reduction effects over a
uiide range of variations.
=

Zenith calls its modular construction "plug-in/pull-out" Dura -Modules.
Eight modules accommodate 75 percent of the circuitry in the receiver.
Tuning in the Zenith receivers is accomplished with 14 preset channels
and a slide -switch arrangement. The
presetting need not be sequential.

In Conclusion. So it is obvious that
the consumer has many new features
to look for when buying a 1975 TV receiver. Of course, he will have to expect to pay a little more for these innovations. But, in the long run, the initial
investment may be returned to him in
the form of fewer service charges and
an increase in the life of the set. O
45

THE FCC now allows FM stations
to use a combination of Dolby
B -Type noise reduction and reduced
pre -emphasis in their signal processing. Here's why the new proposal was
accepted and how it affects the performance of your FM tuner.

duction is almost completely counterbalanced by the effects of B -type
compression. In low -to -medium quality equipment, there is no noticeable difference, and the increase in
the highs noticed from medium -to high -quality equipment can be compensated for by a slight reduction of
high response of the amplifier using
the treble control(s).
Brilliance is a subjectively measured quantity, and to ascertain the effects of B -type encoding, several stations switched unannounced to the
new system. Many listeners wrote letters praising the increased quality of
the sound. Not one complaint was re-

For years, many responsible people
in the broadcasting field have pri-

vately or publicly suggested a reduction in pre -emphasis. This process
was introduced in the early days of
FM. It boosts the level of high frequency content by passing the
baseband signal through an RC
high-pass filter with a 75-ps time constant, a break frequency of 2.123 kHz,
and a 6-dB/octave slope. In this way,
the S/N (signal-to-noise) ratio of the
FM channel is increased. At the receiver, de -emphasis must be introduced to balance the spectral content
of the received signal as in the original
information. The de-emphasis network is a simple low-pass RC filter,
with a -6-dB/octave slope, a 75-ps
time constant and 2.123 -kHz break
frequency. The time constant was
chosen at a time when there was mar-

ginal high -frequency content, by

today's standards, in recorded sound.
low break frequency was required to
radically boost the highs to prevent
them from being lost in the high frequency noise that is characteristic
of FM.
Today, we have reached a point
where the recording media can give
much flatter frequency response.
Anyone who has compared an old and
a recent recording of a certain piece
will note a dramatic increase in high frequency content, or a more "brilliant" sound. This presents problems
to FM broadcasters, though. They are
constrained to a frequency deviation
of 75 kHz, and with increased high frequency content, they must either
lower the modulation index, or use
high -frequency limiting. Stations with
integrity wil not color the sound of the
modulating signal, and thus lose some
of their potential audience to less
scrupulous, but louder competitors
who shape the spectral content of the
baseband signal to achieve higher
levels of modulation while staying
within the law.
The proposal by Dr. Dolby will redress the inequities of the situation. If
the level of pre -emphasis were reduced, using a 25-ps time constant
and 6.36-kHz break frequency, stations could modulate their carriers
more fully, and their signal strengths
A

NEW
DOLBY ENCODED
F

BROADCASTS
would increase an average of 4 dB.
However, the sound from the millions
of FM tuners already in use, with their
75-ps de -emphasis networks, would
be exceedingly dull. Obviously, the
FCC could not allow such incompatibility to be introduced. If FM stations
simultaneously change the time constant of their pre -emphasis networks
to 25 psand incorporate Dolby B -Type
noise reduction, an interesting situation arises.
The reduction of high -frequency
brilliance caused by pre-emphasis re FM TUNER

OUTPUT

Z.IK
3900PF

75ps

20K

25p
FM CAL.
10K

ceived.
For those with conventional receivers and no noise reduction, there will
be a reduction of high -frequency distortion, and an increase in brilliance
and program level. Listeners equipped
with 25-ps de -emphasis and Dolby BType noise reduction, as produced
now by Dolby licensees as per Dolby's
advice, will receive four benefits: improved signal to noise ratio; full program dynamic range, even at high frequencies; better reception in weak signal areas; and reduced likelihood
of SCA interference.
Some tuners and receivers are already equipped to receive the 25-ps
Dolby encoded FM broadcasts. If a
75/25 switch is on the back of the unit
it should be set at 25 during reception
of all subsequent Dolby FM broadcasts. Otherwise, ordinary B -Type
noise reduction units can be easily
adapted to take advantage of the new
broadcast technique by installing the
FM Compensator shown in the diagram. Only one channel is illustrated;
two will be required for stereo reception. Anyone may build a compensator
for personal use or manufacture it for
resale without a license. The parts are
inexpensive and may be obtained
from any electronics supply house.
The unit does not require a power
supply.
The PLAY CAL controls on the noise
reduction unit should be turned to

FM
TO "FROM RECORDER"
INPUT ON NOISE-

REDUCTION UNIT
TAPE
RECORDER
OUTPUT
TAPE CAL.
IOK

FM compensator provides choice
of 75- or 25-ps time constant.

maximum, and TAPE CAL control on the
compensator used in their place. FM
CAL should be set so that the DOLBY
TONE broadcast by the desired station

gives .a DOLBY LEVEL reading on
the meters of the noise reduction
unit.

46
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NOVEMBER

1974

Good AM-SSB-CW

performance
at a fraction of
a superhet's
41,

cost

5
5

PRESECCCTOH

BUILD A

DIRECTCONVERSION

COMMUNICATION
BY JIM WHITE, W5LET

essential ingredient for the
neophyte in amateur radio is a
good receiver-one that is sensitive
enough to pick up signals that are
down near the noise level and selective enough to separate adjacent
signals and provide clear copy. Without such a receiver, one can only look
forward to "unanswered" CO's and
lots of frustration. However, a good
communications receiver can cost
anywhere from $250 to $500, and most
beginners don't have that kind of
money. Even a good used receiver can
cost $150. As an alternative, a direct conversion receiver should be tried. It
performs well over a range of 3.5 to 4.3
MHz on AM, SSB, and CW and is easily
constructed at a cost near $30.
Direct conversion is a much neglected type of design that can best
be described by comparing it to the
more common system, superheterodyning. In the superhet system (Fig. 1),
the first stage is an r -f amplifier. This is
followed by a mixer where the signal is
AN

RECEIVER
combined with the output of a local
oscillator. The frequency of the latter
is a certain amount above or below
that of the r -f and the difference is
called the intermediate frequency.
The output of the mixer contains a
high -frequency component and a
low -frequency component.
These two signals are produced by
superheterodyning; that is, combining two signals to produce one at a
frequency equal to the sum of the frequencies of the original signals, and
one at a frequency equal to their difference. At this point we filter out the
high -frequency component and amplify the lower in a stage that has high
gain and a narrow passband, which
affords selectivity. The output of the -f
amplifier is sent to a detector, which
may be of two types: for AM reception,
it is an envelope detector (a diode followed by a low-pass filter); for SSB
and CW, a product detector, which is
really a second mixer, fed by a
beat frequency oscillator (BFO), is
i

used. The difference component of
this heterodyning process is an audio signal, which is then amplified through one or more stages and
passed on to phones or a speaker.
As you can see, there are usually
four or more stages that must be

properly tuned in conjunction with
each other for proper signal recovery
in a superhet receiver. Most quality
communications receivers have two
or three -f stages, with separate mixers, local oscillators, and tuned amplifiers for each stage. These complications drive the cost of receivers out of
the reach of a large portion of newi

comers to the hobby.
The direct -conversion technique is
a much simpler process. The block
diagram of this system is shown in Fig.
1. The r -f amp supplies the mixer with
an amplified version of the signal received from the antenna. The mixer is
also fed an r -f signal of the same frequency as the incoming carrier from a
local oscillator whose frequency is ad POPULAR ELECTRONICS

justed by the main tuning dial. The
output of the mixer contains one
audio frequency signal and one r -f
signal at twice the frequency of the
original. The r -f signal is then filtered
out by a low-pass filter and we are left
with an audio signal. This is then amplified by one or more stages of high
gain and the output is connected to a
speaker or a pair of phones. That's all
there is to it. We have none of the
complexities of dual- or triple -conversion superhet receivers; .but do
have good sensitivity, and if we use a
high -quality, narrow audio filter, we
have selectivity that will rival that of a
superhet unit costing ten to twenty
times more. The simplicity of operation is reflected in the ease of construction.

cuits, which are the basis of the selectivity of the receiver's front end.
The other contributor of selectivity
in a direct conversion receiver is the
audio filter. This filter performs two
functions. It rejects the high -frequency component of the mixer output, passing the audio signal, and it
provides a large part of the receiver's
selectivity by virtue of its audio bandpass characteristics. In this circuit, L3,
C5, C7, and C8 comprise the low pass
filter. Coil L3 is a variable TV width
coil, and the capacitors are of the
Mylar type.
Transistors Q2 and Q3 are conventional audio amplifiers, and almost
any npn silicon transistor will work
well in this circuit. Variable resistor
R10 serves as a volume control in the
standard voltage divider mode and
/01 serves as a high -gain audio output
amplifier. Any one of the common
audio modules furnishing 0.5 to 1 watt
output can be utilized for this purpose.
If desired, a headphone jack can be
installed as in Fig. 2.
A power supply was not incorporated into the receiver. A suitable
source supplying 500 mA at 9 volts
should be used. If you intend to use
the receiver for portable operation, or
don't wish to construct a supply, six D
cells in series will work perfectly. An
inexpensive plastic holder can be obtained for handling them. It is important to take care in observing polarities while connecting the supply. To
protect the sensitive semiconductors,
diode D2 has been incorporated. If the
wrong polarity is applied to the re -

Circuit Operation. A comparison of
the block diagram (Fig. 1) and the
schematic diagram (Fig. 2) will point
out a few differences. For economy's
sake, an r -f amplifier has been omitted
from this receiver. However, the receiver is still sensitive enough to pick
up many signals that would be missed
with a cheap "communications -type"
superhet model. Signals from the antenna are coupled to the MOSFET
mixer, Q1, over the tuned LC circuit
composed of L1, Cl, and C2. Transistor Q4 is the local oscillator and its
output is coupled through a small
silver mica capacitor, C28, to the second gate of Ql. The antenna coil, L1,
and the oscillator coil, L2, are wound
on small toroidal cores, which is an
effective way of attaining high Q cir-

ANTENNA
LOW-LEVEL

SUM aDIFFERENCE

R -F

AMPLIFIED
R

-F

MIXER

AMPLIFIER

AMPLIFIED
(-DIFFERENCE

-F

I -F
AMPLIFIER

DETECTOR

!AMPLIFIED
AUDIO SIGNAL

AUDIO

AMPLIFIER

SPAR

(A)

ANTENNA

`\I/

LOW-LEVEL
-\AMPLIFIED

-F
R

-F

AMPLIFIER

MIXER

-F

SUN (R -E)
DIFFERENCE (A-F)

AMPLIFIED
AUDIO SIGNAL

AUDIO

AUU IO

FILTER

AMPLIFIER

AUDIO

SPKR

(B)

Several stages are tuned simultaneously in superhet (A).
Direct-conversion receiver (B) is much simpler to operate.
Fig". 1.

NOVEMBER 1974

ceiver, D2 is reverse biased and will
not conduct. If this diode was not installed, the transistors and the IC
would be destroyed in the event of accidental reversal of power supply polarity. However, when incorrect polarity is applied, the receiver simply will
not work, thanks to the protective action of D2.

Construction Details. The receiver
was assembled on a 7" x 9" x 2"
aluminum chassis. Two separate circuit boards were used, and laid out on
the chassis as seen in Fig. 3. The two
cutouts for the boards should be made
following this scheme, but layout is
not critical. The use of individual
boards for the r -f and audio stages
eases troubleshooting as well as construction.
Mount the components on the audio
board first. When you have done this,
position the board in its cutout and
secure it to the chassis. Connect the
positive lead of the power supply to
the center -tap of the transformer and
the negative lead to the chassis
ground. Then connect a speaker to the
secondary of transformer Ti. If you
have correctly assembled this board,
you will hear a hum or buzz from the
speaker when you touch the base lead
connection of Q3. The remaining
board can then be assembled and
mounted on the chassis. Try to keep
all leads as short as possible.
After the boards are in place, spray a
7" x 10" piece of 1/4" masonite with
aluminum paint. When it has dried,
mount the tuning dial on the panel,
and secure the panel to the chassis.
Mount the oscillator tuning capacitor,
C26, on a small bracket, and insert the
shaft of C26 into the dial drive
mechanism. After you have made sure
that the shaft is correctly lined up, fasten the bracket to the chassis. Using a
pair of pliers, turn the tuning
capacitor's shaft until the plates are
fully meshed. Then turn the dial to the
9 o'clock position and tighten the
setscrew on the shaft receptacle. You
can then log frequencies on the dial
using a crystal calibrator or an accurate VFO. The audio gain control, R10,
and the preselector capacitor, C2, are
mounted in 3/8" holes in the front of the
chassis. Drill the holes all the way
through the front panel. Three holes
must be drilled through the back of the
chassis, for the antenna and speaker
jacks, and the power supply leads. If
you choose to include a headphone
jack, it can be mounted either on the
front or the rear of the chassis.
49

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02
2N5665

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HEP-F2007

03
2143565

C13

.IyF

01
Sil

LI*
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200p1100pF
C26
100pF

1C25

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50pF

AIyF

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C21

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C20
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CA3020

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3
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100

C23

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SI

9 VOLTS
TM

PARTS LIST
.

C1 -200 -pi, 500-V sil"ver mica

capacitor
C2,C26-Variable 100-pF capacitor
C3-21-pF, 50-V disc ceramic capacitor
C4-20-µF, 15-V electrolytic capacitor
C5,C8-0.02-1.1F, 100-V Mylar capacitor
C6 -50-µF, 15-V electrolytic capacitor
C7-0.01-µF, 100-V electrolytic capacitor
C9, C10,C20-5-µF, 15-V electrolytic
capacitor

C11,C12,C13,C15,C22,C23-0.1-µF,
50-V disc ceramic capacitor
C14 -10-µF, 15-V electrolytic capacitor

C16,C17,C18-l00-µF,

15-V electrolytic

capacitor

C19 -1-µF, 15V electrolytic capacitor
C21,C29-0.01-µF disc capacitor
C24,C30-0.005-µF disc capacitor
C25-180-pF, 500-V silver mica capacitor
C27-50-pF, 500-V silver mica capacitor

C28-5-pF, 500-V silver mica capacitor
D1-IN914 diode
D2-Silicon power diode (100 PIV, 750
mA)

IC1-Integrated circuit (RCA CA3020)
J1-Chassis-mounting coax connector

J2-Phono jack

J3-Two-circuit phone jack (optional)

L1-34 turns No.

22 wire tapped 11 turns
from ground end
L2-34 turns No. 22 wire tapped 5 turns
from ground end
L3-TV width coil, 10-50 mH (Miller 6319
or equivalent)

QI-Dual-gate MOSFET, (Motorola
HEPF2007)

Q2,Q3-2N3565 transistor

Q4-JFET (Motorola MPFI02)
R1 -100,000 -ohm
R3 -560 -ohm

Fig. 2. Receiver employs-toroid-wound coils for L1 and L2. Q1 is

Other Frequencies. The receiver
can also be used on other frequency
bands. Only the LC combination at the
input of the mixer and the tuned circuit of the local oscillator need modification.
For forty -meter operation, remove
Cl. Remove L2 and replace it with 15
turns of No. 22 enamelled wire, wound
uniformly spaced on a T50-2 toroid,
and tapped 7 turns from the ground
end. Also, connect a 225-pF silver
mica, 500-V capacitor in parallel with
C25.

For twenty meters, remove Cl, and
wind a new oscillator coil, L2, on a
T50-2 toroid core. It should be 7V2
turns of No. 22 enamelled wire, evenly
spaced, and tapped 21/2 turns from the

ground end. Remove the 225-pF
capacitor across C25, if it was installed for 40 -meter operation.
50

For ten and fifteen meters, Li, the
antenna coil, must be replaced with 8
turns of No. 22 enamelled wire, wound
on a T50-2 toroid core. Then L2 must
be replaced with 5 turns of No. 22
enamelled wire, tapped 2 turns from
the ground end. In winding both coils,
spread the turns to space them evenly
around the forms.

Alignment. Making sure that you observe correct polarities, connect a
9 -volt power supply to the receiver.
Connect a speaker and antenna to
their respective jacks. Turn the audio
gain control until you feel it click, and
then advance it further until you hear
the "rushing" sound of atmospheric
noise. Rotate the preselector
capacitor, C2, slowly. At one point
there will be a noticeable increase in
sound from the speaker. Carefully ad-

R4-2200 -ohm

R5,R15,R17,R19-100-ohm
R6 -3300 -ohm
R7-33,000 -ohm
R8-390 -ohm

R9,R14-2700-ohm

All resistors
h -W, 10%

RI -39,000 -ohm
R12-3900 -ohm
R13-470 -ohm
R16 -470,000 -ohm
R 18 -4700 -ohm
R20-27,000 -ohm
R10 -10,000 -ohm potentiometer
Sl-Spst switch (part or RIO)
TI-Transformer: 200 -ohm CT primary;
3.2-ohm secondary (Calectro D1-729)
Note-Q1 ($1.65) and T50-2 toroids (3 for
1

are available from Circuit
Specialists, Box 3047, Scottsdale, AZ
$1)

85257.

a dual -gat.' MOSFET.
just C2 for this peak. There is only one
adjustment for receiver alignment,
setting the value of inductance of L3.
This prevents any r -f components
from local oscillator feedthrough or
the heterodyne process from entering
the audio stages of the receiver. The
procedure is very simple. Adjust L3
until the tuning slug is positioned
about half -way into the coil. This completes receiver alignment.

Operating the Receiver.

As you

tune across a band, keep the front end
of the receiver resonant by adjusting
the preselector capacitor. You will
notice one basic difference in receiver
operation between the direct conversion receiver and a superhet. On the
conventional receiver, there is a mode
switch which must be adjusted for the
type of signal you want to receive.
POPULAR ELECTRONICS

.
.

Fig. 3. Etching and drilling
guides for audio and r -f
pc boards are at left and
bottom left. Component layout
guides for r and audio
boards are shown immediately

below

and at bottom.

JCN ASSIS'

y
C4

01
GI

-R3- I--R2-

C 26

4- L2--

R19

-C271

CI7

-R20-

C26

C24

J2 Jb

C E
6

-CII

c21-+

..C19+

-C20-41+

-C30- sCI6

R14--

1-C13 -4a
r.

-C6--

---R11-41

..-RI2-,

Fit

=B,

RI3

-40

WIPER

CI6

4-C14-7}

CHA

NOTE

C7 MOUNTS ON LUGS OF L3

When this switch is in the SSB/CW
position, it activates the BFO and product detector. It is not possible to
properly demodulate such signals
when the switch is in the AM position,
which directs the signal to a simple

conversion receiver, no such switching is necessary and any signal (CW,
AM, SSB, or FM) is properly detected
just by adjusting the frequency of the

envelope detector. With the direct

dial.

NOVEMBER 1974

local oscillator, which is accomplished by turning the main tuning

Thus, the direct -conversion receiver
provides many advantages over the
superheterodyne model. It is less expensive, easier to build, and simpler to
operate. Why not try something
different-you'll be pleasantly surprised.
OO
51

:CONSTRUCTION
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Measure Low Millivolts
with a Multimeter
Range expander increases sensitivity by X10 or X100
BY JOHN F. HOLLABAUGH

HAVE you ever needed a simple
device that would let you expand the ranges of your multi meter so

that you could measure low-millivolt
ac and dc voltages? Perhaps you need
a small amplifier for checking out the
high-level inputs of an audio amplifier.
Well, the decade meter range expander described here will do both and
more.
The decade range expander can be
used to increase the usefulness of a
multimeter by adding ranges divided
by 10 and 100. It can also be used on
decibel scales, subtracting 20 or40dB
from the existing ranges in your VOM.
Use the expander as a sensitive signal
tracer to obtain quantitative measurements of the signal level at points
of interest, or to read voltage amplifier
stage gain directly in decibels on your

ofni

yy
,

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t,
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,

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Owing to simplicity of circuit,
pc or perforated board
construction is equally suitable.

POPULAR ELECTRONICS

AmericanRadioHistory.Com

PARTS LIST
B1;

132

-9-volt battery

C1-3-pF capacitor

C2, C4-1-12.F, 15 -volt .electrolytic
capacitor
C3-100-pF capacitor
-

IC1-709 operational amplifier
IC2-741 operational amplifier
J1, J2-Phono jack
R1 -3900 -ohm, 1/4 -watt resistor
R2-37 -ohm, '/-watt resistor
R3-1500 -ohm, '/a -watt resistor
R4, R 11-1-megoh m, '/4 -watt resistor
R5, R6 -10,000-ohm, 1/4 -watt resistor
R7-10,000 -ohm trimmer potentiometer
R8, R9 -25,000-ohm trimmer potentiome=

ter
RIO-100,000 -ohm potentiometer
R12-100,000 -ohm linear potentiometer
SI-Spdt toggle or slide switch
S2-Dpdt slide or toggle switch
S3-Spst toggle or slide switch
-position, double -throw-slide switch
S4
Misc.-Cliassis box, 9 -volt transistor bat-

-4

tery clips, shielded cable and audio
phono plugs (for test cables), IC sockets or Molex Soldercons'l, pc_board or
perforated phenolic board and solder
-clips, hookup wire, solder, hardware,
control knob, etc.

meter. You can even use the range
expander to measure the output voltage of a phono cartridge. Try that with
an ordinary multimeter.

About the Circuit.

The range expander makes use of two operational
amplifier IC's (IC1 and 1C2 in the
schematic), exploiting the particular
advantages of the types 709 and 741
op amps. A monolithic amplifier using
bipolar transistors appears to the
signal being processed as a series of
resistances and shunting capacitances. An RC system like this forms a
phase -shift network that at some frequency will cause the amplifier to oscillate.
Compensation is required to insure
low gain at the frequency at which oscillation occurs. The 741 op amp is
unconditionally compensated. (Gain
is reduced to unity at the point where
oscillation is possible.) The 709 op
amp is not internally compensated,
requiring external components to ob-

tain the necessary compensation.
However, it can be compensated for
frequencies up to MHz, while the 741
is restricted to a top -end frequency of
about kHz by its internal compensation.
The 741 op amp has provisions for
input offset nulling, which makes it
operate well as a dc amplifier. In the
range expander, the 741 (IC2) is used
as a dc amplifier with output nulling
1

NOVEMBER 1974

Two operational amplifiers (ICY and IC2) form heart

and a feedback network that minimizes drift. The 741 has input over voltage protection and output shortcircuit protection, while the 709 has
neither. To próvide input overvoltage
and output short-circuit protection for
the 709, R1 and R2 are used.
The 709 (IC1) in the range expander
is compensated for a 40 -dB gain up to
about 200 kHz by Cl C3, and R3. It has
a feedback network consisting of R4
and R5. Both ac and dc amplifiers (IC1
and IC2) have a common vernier control (R12) that can be used where
exact values of gain are not required.
The incoming signal (or voltage) is
applied viaJi while the mode of operation (ac or dc) is selected with S2.
Switch S1 permits selection of X10 or
X100 in the dc mode, while switch S3
applies power to either the IC1 or the
IC2 circuit. The final switch, S3, permits the range expander to be bypassed when in the DIR position. In this
position, it routes the incoming signal
at Ji directly to output jack J2. (Note:
When S3 is in the DIR position, S4 can
be switched to off to conserve battery
life.)
,

Construction. Assembling the range
expander is relatively easy, owing to
the simplicity of the circuit. The entire
circuit can be easily accommodated
inside a 4 in. by 23/4 in. by 2 in. metal
utility box, with the four switches and
vernier control R12 mounted on the

of expander.

top of the box for convenience.
You can use a printed circuit board
of your own design or perforated
phenolic board and solder clips for
mounting the IC1 and IC2 amplifier
circuits inside the box. JacksJl andJ2
can be mounted at one end of the box.
When the circuit has been fully assembled and all parts are mounted in
place, use dry -transfer letters to label
the control, switches, and jacks.

Calibration. With the range expander switched to DC (bothS2 and S4 must
be set to this position) and R12 set for
maximum sensitivity, connect a multimeter set to a low -voltage range acrossJ2. Adjust R7 fora zero indication
on the multimeter's scale.

Connect a variable -output power
supply or a potentiometer in parallel
with a 1.5 -volt battery to J1 and adjust
the supply or pot for a 0.1- to 0.5 -volt
indication on the multimeter's scale.
Adjust R8 for an indication of 10 times
the reading of the input voltage level.
(Use the multimeter to monitor both
the input and output voltage levels.)
Now, decrease the output voltage of
the power supply (or battery/pot
setup) again for a meter reading of 0.1
to 0.5 volt and switch S1 to the X100
position. Adjust R9 for a reading of 10
times the previous meter reading.
With the input disconnected, recheck
the null produced by adjustment of
R7. It necessary, readjust the null.
53

}
V

IG I TA L

THERMOMETE R
á

Build a

VERSATILE
DIGITAL LED
THERM6ZME TER
Low-cost, accurate device can be used as
indoor/outdoor thermometer
heater/cooler thermostat
temperature alarm
fishing thermometer
BY THOMAS R. FOX

digital thermometer described here was designed for
low cost and simplicity, as well as accuracy. If you check the semiconductor sales ads in this magazine and use
a conventional thermistor, you can
build the thermometer for about $15. If
you decide to use a precision thermistor, the cost will be about $20. Since
the thermometer operates from a
+5 -volt line, it can be used in a car,
THE

boat, or camper. With a line -powered
supply, it can be used in the
home.
It is possible to use two switchable
5 -volt

thermistors to check temperature
differentials-such as between the
outside and inside, or between two
rooms. If a long lead is used between
the thermistor and the electronic circuit, the project can be used as a fishing thermometer.

How It Works. The frequency of the
CMOS multivibrator (Fig. 1) depends
on the resistance of thermistor TDR1,
which is determined by the ambient
temperature. Thus, if the temperature
goes up, the frequency of the multivibrator goes up, and vice versa. Trimmer potentiometer R23 is used to adjust the linearity.
The two -transistor multivibrator (Q1
and Q2) automatically resets the two
POPULAR ELECTRONICS

TDRI

R23

+5V

IC640n

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Io!

14.6(

ICI
7490

IC2
7490

+5V

3
9

+5V

04
2N404

IC3
7447

I/4
IC6

a
13

121 11110

IC4
7447

1 bode

6
t

9115 14

R8-RI4

I21

9 15 14

R15-R21
10011

'con.

Ic 10

T1211I

131101 8

ANI
(UNITS)

(TENS

+:5V

DIS

D1S 2

Fig. 1. Two gates in, IC6 form inultivibratorr,
whose frequency is determined by resistance
of TDRI. Pulses (cóntrolied by IC5, Q1, and
Q2) are' couñted by _two -decade system IC1, IC2.

PARTS LIST

IC6-Quad NAND

C1 -0.027-µF

silver mica capacitor
C2-10-µF, 10-V tantalum capacitor
C3 -320-µF; 10-V electrolytic capacitar
C4-15-µF, 10-V electrolytic capacitor
DIS1, DIS2-LED display- (Monsanto
MAN-1 or similar)
ICI, IC2-7490 TTL decade counter
IC3, IC4-7447 TTL,decoder/7-segment

brator

decade counters (IC1 and IC2) and
IC5, which triggers the monostable
multivibrator. When IC5 operates, it
closes the CMOS AND gate and allows
the output of the temperature -dependent multivibrator to pass to the
counters. The length of time that IC5 is
on is determined by the value of C2
and the setting of R3.
be as-

sembled on perforated board, using
sockets for the IC's and transistors.
Everything is on one board except the
power supply and thermistor.
Choose an enclosure that will accommodate the board, the power
NOVEMBER 1974

Hl, J2-Banana jacks
Q1, Q2-2N388, HEP641 or similar
Q3, Q4-2N404, HEP739 or similar
R1 -2000 -ohm, 5%, 1/ -watt resistor
R2, R23-5000 -ohm miniature trimmer
,

potentiometer
R3 -50,000-ohm miniature trimmer pbten-

tiomer

driver

IC5-74121;TTL monostable multivi-

Construction. The circuit can

gate (RCA "CD4011

or similar)

R4, R7-1500 -ohm, 1 -watt resistor
R5 -50,000-ohm, 1/4 -watt resistor

supply, and the two readouts. Be sure
you have access to the three trimmer
potentiometers (R2, R3, and R23)
through suitable holes. If you use the
thermistor called for in the Parts List,
you can use an 1800 -ohm fixed resistor for R23. Other 1000 -ohm thermistors will require some adjustment of
R23. For stability, C1 should be silver
mica and C2 should be tantalum.
The on and off times of the display
are determined by the values of R5/C3
and R6/C4, respectively. These can be
varied to suit individual choice of
times.
If the temperature of more than one
area is to be measured, a simple

R6 -25,000 -ohm, V4-wátt resistor
R8-R21 -100 -ohm, 1/4-watt resistor
R22 -22,000-ohm, 5%'/ -watt resistor
TDRI-1000-ohm, negative coefficient
thermistor (USI 44004, available from
Yellow Springs Instruments, Box 279,
Vellowl Springs, OH 43587)
Yellow
Misc. =Suitable enclosure, flexible wire
for thermistor leads, rubber glue,
optional 9 -oz plastic jar and cover,
Optional switch for two thermistors,
mounting hardware and soc(Ce,

switching scheme can be arranged
between J1 and J2.
Carefully solder the flexible two wire cable to the thermistor and insulate the joints. If the thermistor is to be
used only indoors, coat it with some
rubber glue. If it is to be used outside,
it must be protected from the direct
rays of the sun and other weather
conditions. In this case, mount the
thermistor in a plastic jar (about 9 -oz
capacity), being sure to drill many
ventilation holes. The thermistor
(mounted through the cover) should
not come in contact with the jar. The
jar must be positioned so that it does
not get the direct rays of the sun.
55

Power Supplies. Three possible
power supplies are shown in Fig. 2.
Select the one that suits your needs.
Any 5 -volt supply that can deliver at
least 300 mA can be used. If the digital
thermometer is for fishing, use the
ac -powered circuit. In this case, omit
the transformer and diodes and use a
battery holder to mount four 1.35 -volt
mercury cells, with an spst switch to
control power.

THERMOSTAT CONTROL
MODIFICATION
You can convert the digital thermome-

ter described in this article into a multipurpose heating/cooling thermostatic
control with a 0° to 99° F temperature
range by adding to it the circuit shown
below. Relay Kl and any alarm or circuit
connected to it can be made to trip at any
temperature selected by switches S1
through S8.
The reference temperature selected
by the switches is the sum of the closed switch designations: For example, td set
thesystem up for 34° F, you would dose
S3, S5, and S6 (4° + 10° + 20° = 34°). If
the sensed temperature falls below 34°,

Calibration. Connect

the thermistor
to J1 and J2 and apply power to the
circuit. Allow it to warm up for at least
30 minutes. You will see a numerical
display that will "blink" as the multivibrator operates every few seconds.
Fill a glass with ice cubes and top it
off with cold wáter. Fill another glass
with water that is as close to 90 degrees as possible. (Use an accurate
mercury thermometer.) Set R23 to its
midpoint; and place the thermistor in
the ice water adjacent to an ice cube.
Without disturbing the glass or thermistor, adjust R3 until the display indicates 33. Place the thermistor in the
90° water. If the display shows greater
than 90, increase the value of R2 until
a reading of 90 is obtained. If the display indicates below 90, decrease the
value of R2.
Insert the thermistor back in the ice
water and touch up R3 if the reading is
less than 33. These adjustments will
have to be repeated several times to

+
2

FROM

ICI-12-0
-9p

crease the value of C3 to at least 2000-µF
and change the value of R5 to 100,000
ohms. Also surround thermistor TDR1.,
with 1/4 -in. (6.35 mm) of insulating material and protect it from drafts.

5V
CO

ly2

52.

+5V

_..._.

MEATER!

COOLER
CONTROLS
OR ALARM

KI
5V

2Nié8

IC2-I2

ío

-12

118-4,

g+.

-a

-o
12

14 116

ST
S8

C5-0.5-pF disc capacitor
C6-1000-pF, 10 -volt electrolytic capacitor
C7-3000,,pF, 20 -volt electrolytic capacitor
C8-10-pF, "I5 -volt electrolytic capacitor

+5V

DI,D2-l-ampere silicon diode (IN4001

or similar)
1C7,1C8-7485 magnitude comparator integrated circuit

+12V

state-of-the-art environmental control
system that eliminates troublesome
mechanical thermostats., For the most
reliable thermostatic operation, in-

14 116

ADD-ON PARTS LIST

+12V

sound an alarm or turn on the
heat. Conversely, if the reference temperature is 99° and the sensed temperature rises to 101°, K1 .can sound a different type of alarm or turn on the cooling
system.
The use of a 5 -Jolt, relay far K1 and
suitable connections for its contacts to
the heating/cooling controls produces a
K1 will

'IC9-7410 triple 3'input NAND integrated circuit

IC10-7400 quad

2 -input

NAND inte:

grated circuit

ICI1-7805 5 -volt regulator integrated circuit

-5

-volt relay with spdt contacts
Q5 -2N388 (or similar)'transisior
R24-100 -ohm, 'h -watt resistor
K1

S1-S8-Spst switch
P-ampere filament transformer

TI -12.6 volt,

4en

Fig. 2. Three typical power
sources for thermometer. Top
is for line power, other
two are for mobile operation.

+5V

get the readings as accurate as possible. If you encounter difficulty in attaining a linear display, adjust R23. In
general, a decrease of resistance in
R23 results in an increase in sensitivity
near the high end and a decrease in
sensitivity at the low end.
Once calibration is complete, the
digital thermometer should be within
degree between 0° and 90° F and
1

usable between -50° and 130° F. Al-

though this project was designed for
the 0-90 range, it could be used to take
readings of temperatures below zero
and above 100° F. A reading of 90 on a
bitter -cold winter day would mean that
the true temperature is -(100-90) or
-10°F. A display of 5 on a hot summer
day means the temperature is 100 + 5
or 105°

Q
POPULAR ELECTRONICS

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PART 2:
CONCEPTS AND CIRCUITS

PART

of our short course in

1 digital logic, we discussed the binary number system, binary arithmetic,
and the octal number system. In Part 2,
we are concerned with logic concepts
and circuits.

Boolean Logic. In 1847, George
Boole, a British mathematician, published his Mathematical Analysis of
Logic. This booklet did not equate
mathematics with logic, but it did demonstrate how any logic statement can
be analyzed with basic mathematical
relationships. Boole published a much
longer and refined version of his theory
of logic in 1854. To this day, all practical digital computers and countless
other electronic digital circuits are
based on the concepts pioneered by
Boole.
Boolean logic (or algebra) makes the
important assumption that

logic

statement is either true or false. Since
electronic circuits can easily be made
NOVEMBER 1974

to operate in either of two states, on or
off, it is convenient to equate "true"
with "on" and "false" with "off." Similarly, we can equate the binary 1 with
on and the binary 0 with off. With the
foregoing in mind, let us review
Boole's basic logic concepts.
The mathematical explanation of

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OW:

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logic put forth by Boole can be simplified into three basic logic functions:
AND, OR, and NOT. The AND function requires that one logic state or condition
and at least one other be true before
the entire statement is true. The OR
function requires that one logic state
or at least one other be true before the

/.rJ_/

AND
m-,

-Our.

Our

OuT

/tl

0#1.,

-0..--our

our.

1. Switches are
arranged to illustrate

Fig.

three basic digital
electronic functions.

NOT
57

entire statement is true. The NOT function simply reverses a stazement from
A
0UT.
true to false, or vice versa. Electronic
9
NOT circuits are commonly referred to
A
A BOUr
0 0 /
0
as "inverters" because their function is
0 / /
0
to invert the polarity of the signal.
/
/ 0 /
The above definitions can be tabu1
/ O
/
lated into a table such as shown in Fig.
Fig. 3. NAND and NOR
1. Such a table is useful in showing the

relationships among Boole's three
logic functions and their electronic

associated truth tables.

input

0(JT:

8
0

OUT:

/ 0
0

l 0

symbols with

and arithmetic counterparts. This type DeMorgan's Theorem. About the
of table is sometimes called a "truth same time Boole developed his logic
table" since it sets forth the various theories, Augustus DeMorgan was also
logic conditions for which each state- developing
some
fundamental
ment is true. Generally, truth tables are theories of logic. His most important
arranged in a more compact form simi- contribution, known as DeMorgan's
lar to those shown for the three basic Theorem, relates the AND, OR, and NOT
logic functions in Fig. 2.
functions as follows:
Truth tables can be created for any
A+B=Áx6.
logic function. Specification sheets for
A x B = Á + B.
digital logic circuits almost always in- The arithmetic symbols + and x mean
clude a truth table.
OR and AND, respectively. The bar, or
vinculum, over a letter indicates the
NOT function. Thus A means NOT A.
The importance of DeMorgan's
our.
our A
our
Theorem is that an AND circuit containing a NOT at each input corresponds to
A B OUT
A B OUT.
A OPT.
0 0 0
0 0 0
an OR circuit followed by a NOT. Simi0 /
/
0
0 1
0 /
/ 0
larly, an OR circuit with a NOT at each
/ 0 /
1
0 0
input corresponds to an AND circuit fol/ / /
/ / /
Fig. 2. AND, OR, and NOT symbols are lowed by a NOT. This does not equate
shown with truth. tables. the NAND and NOR functions, but it does
mean that NAND circuits can be used to
implement NOR functions, and vice

Logic Symbols. Boolean logic
statements can be implemented by
simply writing them on paper, using
alphabetic symbols to correspond to
"true" and "false" conditions. Electronic logic diagrams, however, are
much easier to design and interpret if a
sort of block diagram of the circuit is
presented. For this reason, standardized logic -block symbols have been
devised for the three basic logic functions. They are shown in Fig. 2.

versa.

Complex Logic Systems. Logic

B in the EXCLUSIVE OR circuit
shown in Fig. 4. Since only one input is
enabled (input A), AND circuit 1 does
not turn on. Hence, a 0 is present at the
cARRv output. OR circuit 1 does turn on,
since only one input need be present.
Since the NOT circuit inverts the 0 from
AND circuit 1 into a logic 1, AND circuit 1
has two input signals and is therefore
turned on. The result is a logic 1 at the
sum output. (The circuit has added 0 +
to obtain 1.)
The EXCLUSIVE OR circuit is often
called a "half -adder." Try verifying its
operation yourself by adding 1 + 1 in
binary.
1

Practical Logic Circuits. Figure

demonstrated how simple switching
circuits can be used to implement each
basic logic function. However, it is
usually not practical to employ
switches in real systems. Instead,
transistors, SCR's, tunnel diodes, or
other solid-state switches are employed.
The most commonly used switch in
digital electronics is the transistor.
Relatively simple circuits that combine
diodes, resistors, and transistors can
be used to implement the AND, OR, and
NOT functions. Thanks to integrated
circuit (IC) technology, several or even
dozens of individual logic circuits can
be placed on a single compact silicon
chip. Resistor -transistor logic (RTL)
was once the most popular type of digital IC, but it has been largely replaced
by the more noise -immune transistor transistor logic (TTL) type.
In recent years, field-effect transistor
(FET) technology has been adapted to
integrated logic circuits of amazing
complexity. By insulating the gate of a
FET with a layer of silicon dioxide, extremely high impedances are made
possible. The result is a logic circuit

systems that contain three or more
basic logic elements are termed "complex." One of the simplest of the complex logic systems is the EXCLUSIVE OR
(sometimes written xoR) function
shown diagramatically in Fig. 4. From
the truth table, note that this function is
identical to the OR function with one
important exception: A true condition
exists only when one or the other conthat requires microamperes or
dition, but not both, is true.
Compound Logic.Circuits. Two cirThe EXCLUSIVE OR function com- nanoamperes of operating current at
cuit combinations (the NOT -AND and the
pletes
the connection between relatively low voltages.
NOT -OR) are used so frequently that
Insulated -gate fabrication techniBoolean
logic, the binary number systhey are treated as basic logic elements
tem, and electronic switching circuits, ques are collectively known as MOS
and given their own logic symbols and
for it can be used to add two binary bits. (for metal oxide semiconductor) techtruth tables.
To see how this is accomplished, as- nology. Since MOS transistors are uniWhen the AND function is followed by
sume a logic 1 at input A and a logic 0 at polar (p- or n -type) and do not require
a NOT statement, the meaning of the
separate p and n sections like convenAND function is reversed to NOT -AND,
tional bipolar pnp and npn transistors,
commonly called a NAND function.
MOS IC's can have a much higher
Similarly, when the OR function is fol- A
CARRY
component density than most convenlowed by a NOT statement, the meaning e
tional IC's. The result is large-scale inof the OR statement is reversed to
tegration (LSI). So, the next time you
NOT -OR, commonly referred to as a NOR
read or hear the phrase "MOS LSI,"
sVM
function. The logic symbols and truth
you will know _thatit refers to a largetables for the NAND and NOR functions
scale integrated circuit employing
Fig. 4. Logic array for XOR circuit.
are shown in Fig. 3.
metal oxide semiconductors.
58

POPULAR ELECTRONICS

AmericanRadioHistory.Com

and AUX positions. Plugging a microphone into its jack automatically
disconnects the phono pickup and
applies a monophonic microphone
signal to the preamplifiers of both
channels. Another pushbutton switch
is for the high -cut filter. And for maximum convenience, there are two ac
outlets on the rear apron, one of which
is switched.
The Pioneer Model SX-636 AM/
stereo FM receiver comes complete
with a walnut -finished cabinet for a
fair-trade retail price of $349.95.
FM,

Product
Test Reports
PIONEER MODEL SX-636 AM/STEREO FM RECEIVER
(A Hirsch -Houck Labs Report)
25-wattslchannel receiver with superlative stereo FM tuner section

Laboratory Measurements.

The

audio amplifiers of the Model SX-636
receiver clipped at 29.7 watts/channel
with both channels driven simultaneously at 1000 Hz into 8 -ohm loads. Into
4 ohms, the power was 36.7 watts,
while into 16 ohms, it was 20.5
watts/channel. The 1000-Hz THD was
less than 0.1 percent from 0.1 to 30
watts, typically measuring less than
0.03 percent. The IM distortion was
also less than 0.1 percent from 25
watts all the way down to less than 5
mW output.
At the rated 25 -watt output level,
and at one-half and one -tenth of rated
power, the distortion was typically
0.025 percent or less over most of the
audio -frequency range. It never exceeded 0.055 percent, this at full
power and 20,000 Hz. At normal listening levels, the THD was about 0.01
percent. Our figures were a great deal
better than Pioneer's very conservative 0.5 -percent published figure.
A 10-watt reference output level was
obtained with an input of 75 mV (Aux),

USED

s
_

ROUGHLY in the middle of the
current line of stereo receivers
from Pioneer, the Model SX-636 features a tuner section that makes the
most effective use of integrated circuit

and FM (apparently quadrature) detection. The detected signal then goes
to a phase -locked loop IC for multiplex
demodulation. The entire AM tuner
consists of only one IC, plus a handful

technology that we have yet seen in a
hi-fi component. The result is a level of
performance, in a moderate -priced
receiver, that in some respects surpasses that of most separate
components-to say nothing of far
more expensive receivers.
The receiver's audio amplifiers are
rated at 25 watts/channel over the entire audio range, with less than 0.5
percent THD. They are operated from
balanced positive and negative power
supplies and are direct -coupled to the
speakers. The preamplifier section
features tone controls with 11 lightly
detented click -stop settings, and a
balance control with a detented center setting. The phono preamplifier,
whose gain allows the rated output to
be developed with only a 2.5 -mV input,
can handle signals greater than 100
mV in amplitude without distortion.
The FM tuner section employs a
fairly conventional front end containing a FET r -f amplifier followed by a
dual ceramic -f filter featuring linear
phase characteristics. All other FM
functions are performed by a single
large-scale integrated (LSI) circuit-a
proprietary development of Pioneer,
containing circuitry that provides -f
amplification, five stages of limiting,

of external components. Consequently, Pioneer has made an AM/FM
tuner with only three IC's and a relatively small number of discrete components, the performance of which
proved quite exceptional in our
laboratory tests.
The receiver has two pushbutton
switches labelled TAPE MONITOR that 1.25 mV (PHONo), and 3.6 mV (MIc). The
allow two tape decks to be used simul- respective hum and noise levels were
-81 dB, -75 dB, and -61 dB. The
taneously, with off -the -tape monitorPHONO inputs overloaded with a
ing from either deck and the ability to
100 -mV input, and the MIc input overcopy tapes from one deck to the other.
The FUNCTION Switch has a PHONO/MIC loaded with a 275 -mV input.
The bass tone controls had a sliding
position, in addition to the usual AM,

NOVEMBER 1974

+10
MONO

____STEREO

AUDIO OUTPUT AT TAPE OUTPUT JACKS

OdB='VOLT
I

PIONEER

¡J

IIIII

SX-636

FM TUNER SECTION

` 1

*TOTAL D STORTION, NOISE,
RE:100% MOD. AT 1000Hz

ó
50

..,.._

if -STEREO NOISE CURVE RISES ABOVE THE CURVE UNDER 209V BECAUSE WAVE
ANALYZER WAS USED TO EXCLUDE 191,Hz PILOT SIGNAL

100

HUM

_ _. _

illii"
NOISE
4K

IOK

30K

INPUT -MICROVOLTS (9V)

PIONEER SX-636

0.5

PIONEER

REFERENCE POWER (25 1
HALF POWER (-3dB1

LOW POWER

- ---

0.5

I-10dB1

SX-636

CHI TOTAL HARMONIC DISTORTION
60/0000(1, (4:111. DISTORTION

0.2

0.1

TN%

.....

_ 1...

100

200

500

101,

5YN,

21111(

turnover frequency that allowed appreciable correction at the lower frequencies with no effect on the midrange. The treble tone control's
characteristic was hinged at about
2000 to 3000 Hz. Loudness compensation boosted both the low and the high
frequencies. The high -cut filter had a
6-dB/octave slope, with the -3 -dB
point at 4700 Hz, while the RIAA
equalization was virtually perfect over
most of its range (less than ±0.25 dB
variation between 50 and 20,000 Hz).
There was a very slight bass roll -off
caused by the loading of the
10,000 -ohm input impedance of our
graphic level recorder on the tape recording outputs where we made the
RIAA measurement. The cartridge inductance had only a moderate effect
on the equalization, about as much as
we have found on most other good
amplifiers. The microphone response
was essentially flat, within ±0.5 dB
from 25 to 6000 Hz, falling off to -1.5
dB at 10,000 Hz.
The FM tuner had an IHF usable
sensitivity of 1.8 µV in mono and 10 µV
in stereo. The 50 -dB quieting sensitivity was 3µV in mono and 100 µV in
stereo. Ultimate queting was 70 dB in
mono and 55 dB in stereo, while ultimate distortion was about 0.11 percent in mono (very low) and about 0.5
percent in stereo.

.0101

0.2

MN:

FREQUENCY IN Hz (CYCLES PER SECOND)

O-.

PIONEER SX-636
FM STEREO

AVERAGE BOTH CHANNELS

40
CROSSTALK

-60

IDO

100

modulator, which operate with remarkable effectiveness. The AM
tuner's frequency response was down

1111111
,FREQUENCY RESPONSE

+'°

CONTINUOUS AND EQUIVALENT
SINE -WAVE POWER OUTPUT PER CHANNEL IN WATTS

500

200

,,--...-

IOK

2CR

FREQUENCY IN H.

The capture ratio was an impressive
0.7 dB, about the best we have ever

measured in a tuner. AM rejection was
51 dB. Image rejection was 75.5 dB,

alternate -channel selectivity was 63
dB, and muting threshold was 2.2
µV-the last low enough to exclude
noise but not any receivable signals.
Automatic mono/stereo switching occurred at 2.5 µV. The 19 -kHz pilot carrier leakage into the audio outputs
was 41 dB below full modulation.
The stereo FM frequency response
was within±0.25 dB from 30 to 13,500
Hz. It was down only 1.5 dB at 15,000
Hz. The channel separation was extraordinary, measuring between 50
and 53 dB over a frequency range of 30
to 2500 Hz. It reduced to 40 dB at
10,000 Hz and was still an extraordinary 31.5 dB at 15,000 Hz. Clearly, this
must be credited to the linear-phase -f
filters and the phase -locked loop dei

dB at 100 Hz and 5300 Hz.

User Comment.

As the above test
data shows, the Pioneer Model SX-636
receiver merits the use of superlatives
in describing some of its characteristics. In particular, the stereo FM separation taxed the abilities of our signal
generator. In this one respect, the
system's tuner performed in a manner
that has been matched only by a component tuner that sells for $2500!
Impressive as our measurements
may appear to be, they cannot adequately describe the performance of
this receiver. It is not enough to state
that the receiver surpassed every one
of its published specifications during
our tests, even though this in itself is a
rather unusual event in our experience. The real proof is in the using.
The operation of the receiver is totally
smooth, with noise -free muting, very
accurate dial calibration, and not a
trace of switching transients or other
undesirable side effects. One can easily be lulled into taking these things for
granted, but it is surprising how many
audio components-in all price
ranges-are deficient in some of these
important respects.
CIRCLE NO. 65 ON READER SERVICE CARD

ROYCE MODEL 1-600 MOBILE CB TRANSCEIVER
Moderately priced unit features crisp speech quality
THE

moderately price Model

1-600 solid-state mobile CB
transceiver from Royce Electronics
features crystal -synthesized operation at full legal power on all 23 AM
channels. It has a meter that indicates
relative signal strength on receive and
relative output power on transmit. Additionally, the transceiver incorporates only the main essentials: adjustable squelch, a -f volume control, au60

tomatic noise limiting (anl), and
external -speaker jacks for receiver or
operation. Supplied with the transceiver are a detachable dynamic microphone and mobile mounting hardware. The rig is designed to be operated from 12- to 13.8 -volt dc, negative or positive -ground, electrical systems.
Retail price is $124.95.
PA

The Receiver. The receiver section
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of the transceiver employs double
conversion. The first -f is nominally at
10.6 MHz, while the second -f is at 455
kHz. The r -f stage ensures good sensitivity, which measured out at 0.3 µV
for 10 dB (S + N)/N. This is enhanced
by low -noise first and second mixers.
Six synthesizer crystals cut for frequencies between 37.600 MHz and
37.850 MHz provide heterodyning
signals for the first -conversion -f,
which occurs over a 40 -kHz -wide
spread from 10.595 MHz to 10.635
MHz according to the heterodyning
crystal frequency used in relation to
the CB channel frequencies. Four
synthesizer crystals between 10.140
MHz and 10.180 MHz provide the
heterodyning signals for the second
conversion to the 455 -kHz -f.
Selectivity is obtained at the second
-f amplifier with a ceramic band-pass
i

and actuates the S meter, which registered S9 with a 100-µV input signal.
The squelch, driven from the emitter
of the second mixer, was exceptionally smooth in operation. It eases
nicely in and out of operation without
"plopping." The squelch threshold
range was less than 0.5 µV to 1000 µV.
The a -f section consists of two cascaded stages, followed by a class -B
push-pull output stage that developed
a bit more than 4 watts with 11 percent
distortion at the start of limiting when
driven by a 1000 -Hz signal into an
8-ohm load in both the receive and the
PA modes. When the a -f system is
used for PA work or for modulating the
transmitter, an extra speech amplifier
is switched into the system.

filter which, together with the
receiver's a -f response, provided a
total response of 300 to 4200 Hz at the
6-dB points.

Adjacent -channel rejection was
found to be at least 45 dB. Two
455 -kHz -f stages are used in an uni

usual setup that has two direct coupled transistors in lieu of the usual
transformer coupling. This permits
high gain to be obtained with good
stability.
The diode detector furnishes an agc
voltage that maintained an a-f output
within 12 dB with a 20 -dB r -f input
change (1-10 µV) and 7 dB with a
60 -dB input change (10-10,000 µV). A
second diode provides a dc voltage in
accordance with the signal strength

The Transmitter. On transmit, one
of the four crystal signals, spotted between 10.595 MHz and 10.635 MHz, is
mixed with one of the six nominal
32.7 -MHz signals from the synthesizer
to generate the on -channel carrier. A
three -section bandpass filter at the

mixer's output minimizes spurious responses.
The rest of the transmitter consists
of an r -f amplifier, a driver, and the
power amplifier, with the two last
stages collector -modulated as usual.
A three -section antenna -matching
network, plus a TVI trap, are incorporated into the power amplifier's output. Antenna switching is accomplished electronically. And no relay is
used for send/receive transfer.
The output power of the carrier into
a 50 -ohm dummy load measured 3.5

watts when the transceiver was operated from a 13.8 volt source. Complete
modulation of the carrier was obtained with 9.5 percent distortion at
1000 Hz. However, the positive peaks
did not reach the point where peak
power would normally be four times
the carrier power. On the other hand,
further raising the speech level extended the positive peaks to nearer
the full amount, with clipping occurring on both positive and negative
peaks to just 100 percent without
crossing over or overmodulation.
Under these conditions with the EIA
standard test tone of 2500 Hz, the
adjacent -channel splatter was 35 dB
down. With normal voice operation, it
was at least 55 dB down.
The normal overall a-f response was
300 to 4200 Hz at the 6 -dB points. The
frequency tolerance was 450 Hz or
better on any channel.

Comment. The Model

1-600 Royce
CB transceiver is attractively styled,
a wood -grain -finished control
panel and a chrome -finished bezel.

with

The edgewise -mounted S/power
meter is somewhat easier to read than
usual. It is illuminated in white on receive and switches to red on transmit
where it varies in brilliance in step with
the percentage of modulation.
The receiver is a relatively quiet one
which, with an effective and and crisp
speech quality on both transmit and
receive, make this transceiver well
suited for Citizens Band communication.
CIRCLE NO. 66 ON READER SERVICE CARD

PICKERING MODEL OA -3 STEREO HEADPHONES
(A Hirsch -Houck Labs Report)
Comfortable open-air phones provide

"airy"

sound quality

phones are fitted with vinyl -covered
foam rings that rest lightly over the
ears. The lack of sound isolation
works in both directions. The program
being played through the phones can
be audible to others in the immediate

vicinity,

THE Pickering Model OA -3 "open-

air" stereo headphones provide

little or no isolation from room
sounds. Unlike conventional isolatingtype phones that have air-tight seals
betweeen the ear -cups and the
listener's head, the Model OA -3
NOVEMBER 1974

as well as letting outside
sounds in.
Open-air phones have a distinctly
different sound quality than coventional phones. The quality might be
described as "airy" or "light,"
perhaps because the normal room
ambience is not excluded from the
listener's ears (although it does not
directly interact with the musical
program as it does when listening
through loudspeakers). This type of
headphone is also exceptionally corn-

fortable to wear, owing to its very light
weight of only 8.5 ounces (about 0.86
kg) and the slight pressure it exerts on
the ears and head of the person listening with them.
It is generally recognized that good
row -bass response through headphones requires a tight phone -to -ear
seal. While this statement appears to
contradict accepted acoustical theory
in the open-air design, it is not really
so. The bass response of an open-air
phone may extend down to 60 Hz or
so, but subjectively appear to go to a
much lower frequency. Since there is
little music content in the lowest octave of hearing, one is not aware of any
lack of deep bass sound when listening with good open-air headphones.
61

Join `THE TROUBLESHOOTERS'.'
They get paid top salaries
for keeping today's
electronic world running

Suddenly the whole world is
going electronic! And behind the
microwave towers, push-button
phones, computers, mobile radio,
television equipment, guided
missiles, etc., stand
THE TROUBLESHOOTERS
the men needed to inspect,
install, and service these
modern miracles. They enjoy
their work, and get well paid
for it. Here's how you can
join their privileged ranks without having to quit your job
or go to college in order
to get the necessary -training.

r
62

.r'iro-'-- 'Ill
s

...mot_

,r1y

0'''

POPULAR ELECTRONICS

Just think how much in demand you would be if you
could prevent a TV station from going off the air by
repairing a transmitter ... keep a whole assembly line
moving by fixing automated production controls ... prevent a bank, an airline, or your government from making
serious mistakes by servicing a computer.
Today, whole industries depend on Electronics. When
breakdowns or emergencies occur, someone has got to
move in, take over, and keep things running. That calls
for one of a new breed of technicians The Trouble-

shooters.
Because they prevent expensive mistakes or delays,
and a title to match. At Xerox and
they get top pay
Philco, they're called Technical Representatives. At IBM
they're Customer Engineers. In radio or TV, they're the
Broadcast Engineers.
What do you need to break into the ranks of The
Troubleshooters? You might think you need a college
degree, but you don't. What you need is know-how-the
kind a good TV service technician has-only lots more.

...

Learn at Home
In Your Spare Time
As one of The Troubleshooters, you'll have to be ready
to tackle a wide variety of electronic problems. You may
you
not be able to dismantle what you're working on
must be able to take it apart "in your head." You'll have
to know enough Electronics to understand the engineering specs, read the wiring diagrams, and calculate how
the circuits should test at any given point.
Learning all this can be much simpler than you think.
In fact, you can master it without setting foot in a classroom ... and without giving up your job
For over 37 years, the Cleveland Institute of Electronics
has specialized in teaching Electronics at home. We've
developed special techniques that make learning easy,
even if you've had trouble studying before. Our AUTO PROGRAMMED® Lessons build your knowledge as
easily and solidly as you'd build a brick wall one brick
at a time. And our instruction is personal. Your teacher
not only grades your work, he analyzes it to make sure
you are thinking correctly. And he returns it the same
day it is received, while everything is fresh in your mind.

age components to let you perform 242 fascinating
electronics experiments. You learn the "how" as well as
the "why" of Electronics ... the Science of the Seventies.
Many leading companies use CIE courses to train their
own employees who are working on the latest electronic

equipment.

or Your Money Back!
Get an FCC License
Two-way mobile work and many other types of troubleshooting call for a Government FCC License, and our
training its designed to get it for you. But even if your
work doesn't require a license, it's a good idea to get one.
Your FCC License will be accepted anywhere as proof
of good electronics training.
A good way to prepare for your FCC exam is to take
a licensing course from CIE. Our training is so effective
that, in a recent survey of 787 CIE graduates, better than
9 out of 10 CIE grads passed the Government FCC
License examination. That's why we can offer this
famous Money -Back Warranty: when you complete any
CIE licensing course, you'll be able to pass your FCC
exam or be entitled to a full refund of all tuition paid. This
warranty is valid during the completion time allowed
or your
for your course. You get your FCC License
money back.
Mail Card for 2 Free Books
Want to know more? Then fill out and mail reply card
or coupon today. We'll send you our two FREE books on
opportunities in Electronics. For your convenience, we
will try to have a representative call. Act now, and get a
high -paying job that much sooner.

APPROVED UNDER G.I. BILL
All CIE career courses are approved for educational
benefits under the G.I. Bill. If you are a veteran or in
service now, check box for G.I. Bill information.

The Science of the Seventies
To keep up with the latest developments, our courses are
constantly being revised. CIE students receive lessons
in Field Effect Transistors, Digital Switching Units,
Microwave Systems, Lasers, Binary Coding and Computer Arithmetic.
In addition, CIE offers an exciting Electronics Technology with Laboratory course that includes 161 space-

C IE

Cleveland Institute
of Electronics, Inc.

1776 East 17th Street, Cleveland, Ohio 44114
Accredited Member National Home Study Council
I-

Cleveland Institute of Electronics, Inc.
1776 East 17th Street, Cleveland, Ohio 44114
Please send me your two FREE books:
1. Your school catalog, "Succeed in Electronics."
2. Your book on "How To Get A Commercial FCC License."

Learn By Doing...

am especially interested in:

Electronics
Technology
Electronic
Communications

Electronics Technology
with Laboratory Course
teaches you the funda-

-.
_a

mentals. Using space-age
components and testing
techniques youwill apply
the principles you learn
.. actually analyze and

Industrial
Electronics

Electronics
Engineering

FCC License

Name
(PLEASE PRINT)

Address
State

City

Zip

Veterans and Servicemen:

electronics equipment.

CIRCLE NO.

First Class

Electronics Technology with Laboratory

troubleshoot modern

NOVEMBER 1974

Broadcast
Engineering

Check here for G.I. Bill information.

ON READERS SERVICE CARD

PE -66

J
65

Í17

PICKERING OA -3 PHONES
FREQUENCY RESPONSE

f`:

5dB

VOLT APPLIED

FREQUENCY (Hz)

The published specifications of the
Model OA -3 phones indicate that they
are quite efficient, requiring only 0.1
volt across their nominal 15 -ohm impedance to produce a 100 -dB sound
pressure level (SPL) at 1000 Hz. The
maximum rated input power is 0.2
watt/channel, but the series resistors
built into all amplifier headphone output circuits will provide adequate protection even with a high-powered amplifier. The distortion is specified at 0.5
percent for a 110 -dB SPL output.
The Pickering Model OA -3 headphones are supplied with an adapter
plug to permit them to be used with
small transistor radios and cassette
decks. Retail price of the phones is
$39.95.

mounted so that it is virtually impossible to compare data on different coupler designs, especially at the higher
frequencies. However, one can obtain

reasonably valid picture of the
headphone's overall response even
though the specific peaks and dips on
the response curve may be as much a
property of the coupler as of the
phone (and would certainly be still different through the ears of any individual wearing the phones).
The measured frequency response
was relatively uniform from 100 Hz to
11,000 Hz, with a total variation of only
±5 dB over that range. The output fell
rather quickly at frequencies beyond
11,000 Hz and at a smooth 6 d B/octave
at low frequencies. The response was
measured with
volt applied to the
phones, producing an average 120 -dB
SPL over the measurement range,
which happens to agree exactly with
the published specifications.
Normally, one would expect distortion to be a function of frequency, but
the published specifications do not
specify the test frequency. We measured the distortion at several frea

Laboratory Measurements.

tested the frequency response of the
phones on a Koss -designed coupler,
which is a slightly modified version
of an accepted standard earphone
coupler. The measured frequency response of any headphone is closely
connected with the dimensions of the
coupler (or artificial ear) on which it is

quencies between 200 Hz and 1000 Hz,
where the output was both strong and
smooth, at a 110 -dB SPL. The distortion was typically between 1.2 and 1.6
percent and was principally second
harmonic. In view of the high SPL
used, this amount of distortion cannot
be considered serious, even if it does
slightly exceed the published rating.
The electrical impedance of the
phones was an almost constant 20
ohms across the audio range. It gently
rose to 25 ohms at 150 Hz and underwent a slight drop to a 16 -ohm
minimum at 20 Hz.

Comment. Since our first experience
with open-air phones several years
ago, we have enjoyed their special
qualities-which eliminate many of the
objections voiced about headphone
listening (heavy weight arid pressure
exerted, inability to hear desired outside sounds, such as the ring of a telephone, etc.). The Model OA -3 phones
embody all the virtues of a good
open-air headphone and have a
smooth response and the ability to
handle high volume levels without objectionable distortion.
The vinyl -coated ear cushions make
the Pickering phones a little less
"open" to outside noises than are
some other types that feature simple
foam pads. In fact, in aquiet room,one
might almost believe that the phones
are the isolating type.
The low impedance and high efficiency of the phones makes them exceptionally well suited for use with
small radio receivers and tape recorders.
CIRCLE NO. 67 ON READER SERVICE CARD

DRAKE MODEL SPR-4 COMMUNICATIONS RECEIVER
(A Hirsch -Houck Labs Report)
Versatile solid-state receiver for shortwave, amateur radio, CB
The receiver measures 121/4 in. deep
10n in. wide by 51/2 in. high (31.1 x
27.3x14 cm) and weighs 18 lb (8.2 kg).
Its built-in 5 -in. by 3 -in (12.7 x 7.6 -cm)
speaker is mounted on the left side of
the metal receiver cabinet. The price
of the Model SPR-4 receiver is $579.
Various crystal kits are available for
the amateur radio, marine, aeronautical, MARS, Citizens Radio, and other
special -interest bands. The external
optional speaker, 100 -kHz calibrator,
and noise blanker are priced at, respectively, $22, $20, and $65.
by

77,

THE Drake Model SPR-4 solid-

state communications receiver
covers any 23 bands (each 100 -kHz
wide) between 150 kHz and 30 MHz.
Thus, it offers the user reception of
international SW, amateur radio, and
CB radio transmissions, among
others.

Technical Details.

The receiver
employs a double -conversion superheterodyne design. Its first -f of 5645
i

kHz is obtained by the mixed product
of a crystal oscillator selected by the

band switch, while a stable permeability -tuned oscillator (PTO) takes
care of the 4955 -kHz to 5466 -kHz
range. Tfie'PTO alone is used for the
lowest -frequency band.
Following the first mixer, selectivity
is provided by a crystal filter, and the
signal goes without further amplification to the second mixer. Here, it is
converted by a crystal oscillator (with
switched crystals for USB and LSB reception) to 50 kHz. Then a four -pole
LC filter and a tunable -notch filter
provide additional selectivity. After
two stages of -f amplification, the
signal goes to a product detector for
i

POPULAR ELECTRONICS
AmericanRadioHistory.Com

SSB and CW or a separate diode detector for AM. The audio amplifier is
rated at 3 watts output into a 4 -ohm
speaker load.
The PTO's dial is calibrated at 1 -kHz
intervals from 0 to 500, with about 50
kHz of "overrun" at each end. The
dial's reference mark can be shifted to
calibrate the receiver precisely to any
known frequency. At the upper center
of the receiver's front panel is a small
opening for the frequency range dial,
which is marked to indicate each of
the 10 basic bands, together with the
appropriate settings of the RANGE
switch and the PRESELECTOR control
knob. Decals are supplied for the 13
blank spaces on the dial, to be added
when other crystals are installed.
The front -panel controls include
concentric a -f and r -f gain controls,
mode switch (with positions for AM
CW, LSB and USB), and an accessory
switch. The last activates an optional
100 -kHz crystal calibrator and -f noise
blanker when they are installed. Concentric with the accessory switch is a
knob that is used to tune the rejection
notch filter through the -f passband to
,

reduce interference from heterodynes.

On the rear apron of the receiver are
phono jacks for the antenna and muting connections and an audio in/out
jack that can be used either to supply a
signal to a tape recorder, ahead of the
volume control, or to amplify an external signal through the SPR-4's amplifier. There is also a 120/240 -volt line
selector and a switch that disables the
dial lights for low battery drain (only
2.5 watts at 12 volts).

and was typically a little better than
0.30 µV.
The agc is stated to hold the audio
level within 6 dB for an input signal
variation of 100 dB. We were able to
check it over only an 86 -dB signal
range, where it varied by only 3.2 dB.
The -t bandwidths at the -6 -dB points
were essentially as rated: 4.8 kHz on
AM, 2.4 kHz on SSB, and 0.4 kHz on
CW.
The dial calibration was within kHz
on all bands, even without "zeroing"
the dial on each range as recommended. When we set the zero at
either end of the tuning range, the dial
was about as accurate as it could be
i

Laboratory Measurements.

The

Model SPR-4 receiver has sensitivity
a 10 -dB (S + N)/N ratio of
0.25 pV on CW and SSB and 0.5 µV for
AM at 30 percent modulation. We
measured the sensitivity at the center
of each band (except the two lowest
where the input impedance is too high

ratings for

to match our signal generator). It
proved to be substantially better than
claimed and varied little from band to
band.
The CW sensitivity measured better
than 0.15 µV throughout and about 0.1
µV on most bands. The SSB sensitivity
was typically about 0.18 µV and
reached 0.22 µV on the highest and
lowest frequency bands tested. The
AM sensitivity was better than 0.35 µV

read-certainly within

200 Hz at all

points. And there was no discernible
drift over extended periods; the rating,
incidentally, is less than ±100 Hz.
The S meter is, of course, a relative
signal strength indicator. On the
7 -MHz band, an input of 1.8 µV gave an
S2 indication, while S9 was attained
with only 17µV of input signal
strength. This is by any standards a
most 'generous'. meter. Furthermore,
a reading of S9 + 20 dB required 38
µV, which is only about 6 dB greater
than the S9 input. To reach S9 + 40

Now available, our latest version of the amplifier that startit all; the faithful old "Universal Tiger'. We have put
him in a fancy new chassis and added our famous complementary differential input circuit, but this is still the rugged, low distortion, economical amplifier that thousands of
you out there love so well. With a power output of 75 Watt
into an 8.0 Ohm load, or 90 Watt into 4.0 Ohms the
"Tiger B" is the ideal BASIC amplifier for all types of applications; from HiFi systems to public address work, to
instrument amplifiers; you name it. With its tremendous
frequency response, -1.0 dB at 1.0 Hz and 100KHz and
super low distortion of .05% M at rated output, Tiger "B"
is ideal for almost any application using an audio amplifier.
ed

Nothing but the best components and first quality fibrecircuit boards are used in this kit. The chassis is bronze
anodized and the perforated metal cover is standard.
glass

For those who insist on "guilding the lilly" we have an
accessory kit to add an output meter, input level control,
overheat indicator lamp, front panel power switch, etc.

Circle our reader service number for your free copy of our
latest catalog.

# 275 Amplifier Kit (single channel)
# AC -275 Accessory Kit

NOVEMBER 1974

$64.50 PPd
$ 7.90 PPd

Ail

Southwest TechnicarProducts Corp:
219 W. Rhapsody,
San Antonio, Texas 78216

CIRCLE NO. 37 ON REA:%cRS SERVICE CARD

dB, we had to supply a 5500 µV input,
which is actually 50 dB over the S9
input and 43dBoverthe S9 + 20 input.

Comment. The Drake Model SPR-4
receiver, in spite of its deceptively
simple appearance, is a highly sophisticated unit. It is not to be confused
with the many low-priced "communication receivers" directed toward the
young SWL and novice ham. It may be

simple enough to be operated by beginners, but it is obviously meant
forthe advanced SWL, while also offering excellent flexibility for the intermediate and advanced operator.
The SWL in search of an elusive DX
station can set the dial to the station's
frequency with complete assurance
that he is tuned to what the dial says. In
addition, if his antenna and propagation conditions are right, he will surely

hear the station he is after-assuming,
of course, it is on the air.
If you plan to buy the Model SPR-4
receiver, we feel you should seriously

consider including the optional
crystal calibrator in your order. Without it, the receiver will probably be
tuned to within a kilohertz of the indicated frequency, but why settle for
that when it can be "on the nose?"
CIRCLE NO. 68 ON READER SERVICE CARD

AMERICAN CIRCUITS & SYSTEMS
MODEL MK1 FUNCTION GENERATOR
Sine, square, or triangle waveforms from

Hz to beyond 1.25 MHz

for the desired frequency.
Hence, if you wanted a 5000 -Hz output
frequency, you would set the RANGE
Switch to X1K and the FREQUENCY Control to 5. (The actual range of the MK1
is from less than 10 Hz to beyond 1.1
MHz.)
On the rear panel of the instrument
is a TTL output jack that provides a
TTL-compatible signal of the same
frequency as that at the OUTPUT binding posts on the front panel. The
logic -0 and logic -1 levels of this signal
11, is set

THANKS to low-cost integrated
circuits and new approaches in
design, a very important change is taking place in audio (and digital) signal
generators. Until fairly recently, audio

signal generators simply provided
sine and square waves that were variable in level and covered a frequency
range of about 20 Hz to 100,000 Hz.
The new "function" generators that
havebegun to make their appearance,
by contrast, provide sine, square, and
triangle (or ramp) waves over a range
of about 10 Hz to MHz and beyond.
One good example of a low-cost
function generator is the Model MK1
made by American Circuits & Systems,
Inc. The MK1 sells for $135 in kit form.
It is also available factory -wired,
tested, and adjusted for $195.
The Model MK1 function generator
features sine-, square-, and triangle wave outputs that are selectable by a
WAVEFORM switch. The waveforms,
available at a pair of color -coded binding posts on the front panel, are continuously variable from 0 to 20 volts
1

peak -to -peak via an AMPLITUDE con-

trol.

Another

control,

labelled

can be used to provide 0,
20, or 40 dB or attenuation.
Built into the instrument is a dc
OFFSET control that permits the ac
signal to be dc biased anywhere from
+10 to -10 volt into an open circuit
(±5 volts into 600 ohms).
ATTENUATE,

Selecting a frequency is a two-step
process: First, the RANGE switch must
be set to the desired position (X10,
X100, X1K, X10K, X100K). Then, the

control, calibrated in
equally spaced increments from 0.9 to

FREQUENCY

are

The only test instruments needed to
put the function generator into service
order are a multimeter (for the voltage
checks) and an oscilloscope (for dis-

tortion adjustments).

frequency

counter comes in handy, but is not
necessary, for calibration. (Three
methods of calibration are detailed in
the instructions.) Using the scope, the
sine -wave distortion can be set within
a few percent of optimum, while it can
be fully optimized with the aid of a
distortion meter.

and +5 volts, respectively.

(CMOS logic can be driven directly
from the OUTPUT binding posts.)
Also on the rear panel is a vco input
jack that virtually doubles the versatility of the function generator. With the
appropriate inputs applied to this jack,
the output can be swept through a
range of frequencies, be frequency
modulated with tone or voice, or be
frequency shift keyed.
Within the instrument itself are six
IC's, two of which are precision voltage regulators, with the remainder
being linear devices. The power supply employs circuit-protecting fusing
and operator -protected three -conductor line cord.

Kit Details.

We selected the Model

function generator kit for our test
report. Upon opening the cartgn in
which it arrived, we were gratjfied to
note that all components were of preMK1

mium quality. Most of the resistors,
even some in noncritical parts of the
circuit, were of 5 -percent tolerance,
while the trimmer potentiometers that
serve as hidden set-up controls were
of OEM quality. The large printed circuit board on which the majority of the
components are mounted is made
from G-10 epoxy fiberglass.
Assembly is simple and straightforward, guided by clear step-by-step
instructions and detailed drawings.

After Assembly.

Once the function
generator was ready to be put into service, we subjected it to a few tests.
Using a precision frequency counter,
we determined that its frequency
range was from 6 Hz to 1.254 MHz in
five overlapping bands. The FREQUENCY control's dial calibration was
well within the specified ±5 -percent
figure over almost the entire range.
The amplitude of the output signals
could be adjusted from 0 to slightly
more than 20 volts peak -to-peak, while
the dc offset was adjustable to its
specified ±10 -volt limits into an open
circujt. Triangle waveform linearity
was better than 1 percent between 10
Hz and 100 kHz and about 2.8 percent
maximum from 100 kHz to 1 MHz.
Without using a distortion meter, the
distortion in the sine-wave function
averaged an excellent 6 percent.
When a distortion meter was used, the
figure could be optimized at 2.4 percent. All other specifications were met

or exceeded.

Comment. The American Circuit

Systems Model MK1 function generator is an excellent buy, particularly
.in kit form. It offers a quality and versatility that should appeal to the audio or
digital experimenter and service technician.
CIRCLE NO. 69 ON READER SERVICE CARD
POPULAR ELECTRONICS

AmericanRadioHistory.Com

tEV Years experience

VJ AN

with

TrcCH,C ent `n
for assignmen

three
or

o co\\ege

oppore 9'oppor
$1.9,000

Ps a 0-000 o

$,ngook, or

engineer-

C`o\ management
anag
tegesJ pfl ers

yearcstatfree
to move

tunity iJ transe
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ing. Force Captain,

pX an

C,pb.

CA
OPPORTUNITIES
FOR THE
CH
BY ALLAN C. STOVER

'f you read an ad like the above
in the classified section of your
newspaper, you might think it was too
good to be true. Hdwever, it accurately
describes many technical representa-

tive and field engineering opportunities available in the electronics
field. On the whole, a tech rep job pays
well, offers excellent opportunities for
travel, and encompasses a number of
duties.
A tech rep is hired by an electronics
company which, in turn, sells his services where needed. The U.S. Government, private industry, and local and
foreign governments sometimes need

electronics technicians.for special
projects. So, they often sign a contract
for enough tech reps to get the job
done. The contract might call for .the
tech reps .to do anything from teaching a Job Corps class in New Jersey to
manning a lonely tropospheric scatter
site in Thailand.
On the job, a tech rep's work varies
from assignment to assignment. On
one assignment, he might be an advisor, telling a crew of workers what to
do. On his next assignment, his job
might be to teach a group of students
or working technicians the theory and
operation of new avionics equipment.
Then again, he might operate and
maintain á communications system.
Most tech reps are called upon to do a
bit of everything. In a typical month, he
might spend a few days each at teaching a class in electronics theory, and
practices, helping out on installing or

renovating electronics gear, and repairing a radio or radar system:
Tech reps have been known tó óperate, maintain, and repair computers,
avionics equipment, radar gear, communication's systems, test equipment,
navigational aids, and just about everything else that uses electronic circuitry. One tech rep might specialize,
his duties confined to repairing a
single complex transceiver model,
.while.another might be called upon to
repair a dozen or. so different models
and types of equipment. Some tech
reps specialize in teaching.
Án assignment might put a tech rep
in the heart of downtown Manila, right
in the midst of civilization. On the
other hand, assignment locations can
be lonely and far from the amenities of
civilization, such as in the heart of a
jungle or atop a mountain. Assignments can be almost permanent Or
highly mobile, depending on the contract. Some tech reps stay in -the same
location for years, while others must
pack up and _move to.'a 'new location
every few months.
Most tech reps enjoy their assignments, but few find "paradise." The
Manager .of International Recruiting
for Page Communications Engineers
says, "One word -of caution to those
who are tempted to cast all aside and
dash off to unknown places: To the
neophyte who expects to find all the
creature comforts he is -accustomed
to, my advice .is to look before he
leaps.' Instead of some pleasurable
-

NOVEMBER 1974
AmericanRadioHistory.Com

off -duty relaxation in exotic Bankok,
he might find himself repairing a radio
(t~ansmitter) on an;isolated mountaintop in Iran."

Electronics companies employ
thousands of tech reps, stationing
them in every corner of the world. You
can find tech reps in almost every
state of the Union, Germany, on the
island of Crete, in Taiwan, Ethiopia,,
a -id Iran, Vietnam and Korea, Spain,
Turkey,- the Philippines, New Guinea,
Jamaica, the. Arctic, and on some
Pacific islands, and aboard ships and
submarines.

RCA Service Co. Technical Services
Grp-eseutative works on radar unit.

)`"

jai

What and Where. ITT's Federal Elec-

formed operational and maintenance
services as the prime contractor on
the Air Force's Western Test Range,
where they manned range tracking
ships and stations, among other
things. They installed a computerized
reservations system in the British
Overseas Airways Corporation's offices in New York.

tric Corporation ships their tech reps
all over the world. Sometimes they include tech rep services as part of a
contract for new equipment. In December 1973, Federal Electric signed
$56 -million worth of new contracts
and renewals, which gives an idea of
the size of the corporation's operations. Here are a few of the hundreds
of jobs the Federal Electric tech reps
have handled:
They have installed a microwave
communications system in South
Vietnam. (The South Vietnam government issued a stamp in their
honor.) In Italy, Germany, France, Belgium, England, and the Netherlands,
they installed a tropospheric scatter

Tech reps from RCA Service Company have tackled hundreds of different jobs in as many different places all
over the world.
A satellite ground station was installed in the People's Republic of China.
They operated and maintained a tracking site in the Arctic, and they operated and maintained missile tracking
stations on islands in the Atlantic
Ocean for the Air Force's Eastern Test
Range.
The RCA teach reps gave technical
assistance and training to the Philippine, South Korean, Ethiopian, and
Spanish air forces.

system. For years, they have operated
and maintained DEWLine (Distant
Early Warning Line) sites ranging from
Iceland and Greenland to northern
Alaska in some of the bleakest and
frostiest locations inhabited by man.
The Federal Electric Corporation has
held this contract since 1956-almost
two decades.

Salaries and Extras. Most companies pay their tech reps well. Base
pay usually is on an average with a

Federal Electric tech reps per-

RCA Service Co. Government Services Technician
works on Meteorological Data Handling System
Center's computer control console at the
Goddard Space Flight Center.

- r -'

38R N
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..
.

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good technician, but "extras" can
push the total -package up to more
than what the average electronics engineer earns, from $10,500 to $19,000
per year. Overtime can run these figures even higher. The extras depend
on the company the tech rep works for
and the assignment on which he is
sent. Examples of extras include:
Per Diem: A daily allowance that is
designed to repay the tech rep for
most of his extra expenses. It covers
hotels, meals, cleaning bills, tips, and
other expenses. Per diem is usually a
flat rate; so, if a tech rep cuts corners,
he can pocket the money he saves.
The per diem rate runs from a few dollars up to and beyond $25 per day.
Some companies pay per diem for as
long as the tech rep remains on the
assignment, while others pay it for
three to six months only. Still other
companies pay per diem only when
the tech rep travels on business away
from his regular assignment. A few
companies pay the tech rep's actual
expenses instead of per diem.
Cost -of -Living Allowance (COLA): A
few companies pay COLA to cover the
difference in living costs between a
U.S. city and an overseas location. The
COLA in Tokyo, the world's most expensive city in which to live, can run
hundreds of dollars a month. One
company gives a flat 30 percent of
base pay no matter where they assign
a tech rep. Some U.S. Air Force contracts direct the local military disbursement officer to pay a COLA to
each rep. COLA can start at $7 per day
on some contracts.
Bonuses: Some companies pay a
flat bonus for overseas service. It can
be 10 percent of base pay or $125 per
month, depending on the company for
which the tech rep works. Some companies pay a bonus that depends on
the location of the assignment; a tech
rep who lives in a soggy tent in South
Vietnam gets a bigger bonus than one
who works in downtown Brussels.
This patchwork of pay and allowances makes it difficult to predict a
tech rep's pay package. But the average paycheck for tech reps, all extras
considered, runs from $12,000 to
$16,000 per year, with some reps receiving salaries above and other
below these figures.
The tech rep who works overseas
has an opportunity to take advantage
of one of the juiciest Internal Revenue
tax laws ever written. If he spends 510
days (about 17 months) out of 18
months outside the U.S., up to $20,000
POPULAR ELECTRONICS

AmericanRadioHistory.Com

of his yearly income during that period
is tax-free! If his company withholds
any taxes, the tech rep claims a re-

fund.
Other privileges sweeten the picture
even more. Most military contracts
with overseas assignments grant the
tech rep most of the privileges of a
captain. This means that he can live in
the Bachelor Officers Quarters, eat
and drink in the Officers Club, and
shop in the PX and commissary.
The company handles the tech rep's
transportation to his assignments. In
return for paying per diem while the
man is en route to his assignments,
the company requires him to spend at
least a year on assignment. Should the
tech rep decide to terminate his employment before the year is up, he
must pay back all the company spent
on getting him to his assignment.

Becoming

a Tech Rep. The qualifications for becoming a tech rep are
surprisingly light. Only a handful of
positions call for an engineering degree. Most require only technician level electronics training and three to
five years of specialized practical experience. If you worked on a new system in the armed forces, no matter
what your rank, you stand an excellent
chance of landing a tech rep job. Many
companies train some tech reps, but
most prefer to hire the man who already has the knowledge and practical
experience to go right to work.
If you live near an electronics company that hires men for tech rep positions, apply in person. Alternatively,

you can type up a resume and mail it
to the companies that hire tech reps
and field engineers. (Consult the want
ads in your newspaper for addresses.)
If your background fits in with a
company's needs, you will receive a
job application form in the mail or be
hired on the spot. (When making up
your resume, keep it down to two
pages. Just give the facts about education and experience and some personal data.)
The personal data in your resume
should include full name, age and date
of birth, marital status, state of health,
and dates of military service, if any.
Under education, list all schools you
attended in which you received training for the type of work you are applying for. Include resident, home -study,
and military courses taken, detailing
the titles óf the courses and types of
equipment you studied.
When giving details of your work
NOVEMBER 1974

experience, start with your present
position and work back in time. List
job titles, the dates you held the positions, and short descriptions of your
work duties. List the names and model
numbers of all the equipment with
which you are familiar. Also, mention
any achievements and awards you
have received or earned.

Who Needs Tech Reps? Scores of
large and small companies need qualified men to serve as tech reps. As a
rule of thumb, try the large companies
first. If you think you can qualify for

the work, you might try the following
three companies first:
Federal Electric Corp., 621 Industrial Ave., Paramus, NJ 07652. (Address correspondence to the attention
of Mr. Ridings, Director, Field Services.)
Page Communications Engineers,
Inc., Vienna, VA 22180. (Attn.: Manager, International Recuiting)
RCA Service Co., Camden, NJ
08101.
If these companies do not need your
talents, try Bendix, Philco-Ford, and

Kentron.

Walt Qsfrañdei'Aüdioiinalyst,
As {Seen Through Th ;_yes
His A-100X Spea ir..

His tortures drive drivers to drink.
Wnl,rt.n.,d.l NveGun.

This perfectionist believes
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assembly. "Unusually flat
toward the top of its price
range" says High Fidelity
of our A. 100X bookshelf
speaker. We say. a Six Year
Wan-anty on every speaker in the Audioanalyst
line. $94 to $249.
Everyone boasts clean highs. low
bass, a bet er driver. Fact. The
best drivers are pretty much
alike. Its what our Audio-

analysts do with them that's different. Is there
a percentage in this kind of obsession? A sound
one to be sure.To test our speakers. simply
write to us. All we ask is that you give them what
we give them.The works.

Meet the Audioanalyst Master of Torture.
Live! At the Boston High Fidelity Music
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AmericanRadioHistory.Com

MAC'S SERVICE SHOP

The Simplest
Test Gear
By John T. Frye, W9EGV
HEY, Mac, what are you doé
ing with the tattle lights?"
Barney asked his employer, who was

examining several small objects
spread out on the service bench.
"Taking them with me on vacation,"
Mac replied. "Some of the folks in
Florida we visit are sure to say, 'Mac,

our electric or electronic whatchamacallit isn't working. Wonder if
you'll look at it.' These lights will let me
find anything simple, which is all intend to tackle on vacation. Actually,
it's amazing what a fellow can do with
some simple, rugged, inexpensive test
lights and a little gray matter."
"For instance?"
"Well, take this Ne-O-Lite Test Light
put out by GC Electronics, a division of
Hydrometals, Inc., Rockford, Ill. It carries Audiotex catalogue No. 30-245 or
Calectro No. H3-452 and sells for just
under a buck. As you can see, it consists of a special two -inch -long, red,
high -impact plastic socket carrying a
neon bulb protected by a tough clear
plastic cone in one end. A current limiting resistor of-I'd guess-about
200,000 ohms is contained in the
socket, and red and black flexible,
sharp-pointed leads come out the bottom. The lamp glows with any voltage
from 90 to 550 volts, ac or dc. The
higher the voltage, the brighter the
glow.
"The neon lamp itself has almost infinite resistance until the contained
gas is ionized by over 90 volts. Until
then, there's no voltage drop across
the series resistor, so the full voltage
across the test leads is applied to the
lamp. Once the gas is ionized by a
voltage in excess of 90 V, current
through the lamp and series resistor is
a function of the voltage across the
leads, but it never exceeds 3 mA, even
with the full 550 volts applied.
"What can you do with it?"
"A zillion things. If one lead is attached to a spark plug of a running
motor, a bright flash will indicate a
good plug; a dim flash, a fouled plug;
and no flash, a dead plug. Hold on to
I

one test lead and probe the two sides
of a 120 -volt outlet receptacle with the
other. When you touch the 'hot' side of
the line, the lamp will glow. If a device
controlled by a wall switch will not
turn on and you don't know if the trcuble lies in the device or the switch, turn
the switch on and bridge the test lamp
across the switch terminals. If the
lamp glows, the switch is bad. Do the
same thing to locate a blown fuse.
With a device on the fused line
switched on, check across the fuse
with the lamp. If it glows, the fuse is
open. Alternately, you can check from
the grounded side of the line or the
cabinet of the fuse box to the output
sides of the fuses, one at a time. Failure of the lamp to glow with full 120-V
brilliance will indicate the bad fuse.
"This little sketch shows how the
test lamp can be used for a continuity
IRON

EXTENSION
CORO

TESTER

indicator. Plug an extension cord into
a wall receptacle and locate the hot
side of the cube tap on the end of the
cord. Plug one lamp lead into this side.
Now plug one prong of the cord of the
device you want to test for continuity
into the other, grounded, side of the
cube tap. Touch the free lamp test lead
to the free prong of the line cord of the
device. A glow of the lamp indicates
continuity.
"The test light will indicate the presence of leakage current. As you know,
one side of the 117 -volt line is
grounded. If there's current leakage
from the hot side of the line to the case
of a device, say a hedge -trimmer, electric drill, refrigerator, dishwasher, etc.,

person touching the device while in
contact with the ground or a grounded
device may receive a severe and
perhaps fatal shock. With a clip lead,
connect one side of the test lamp to a
good ground, such as a water faucet,
and touch the other lead to the case of
the device being tested while the device is operating. Reverse the plug of

the device in the wall socket and test
again. If the lamp glows in either case,
you know there'ssome leakage. It may
not exceed 0.5 mA through 1500 ohms
of noninductive resistance shunted by
0.15 µF, which represents the average
impedance of the human body and the
current is considered permissible for
most devices; but if the lamp glows at
full 120-V brilliance, you can be suspicious. In all the devices checked at
home, only the electric drill, some fifteen years old, lit the light dimly."
"What's this thing?" Barney asked,
picking up a small round plastic object
with three prongs on one end to fit a
standard 15-A, 120-V grounding receptacle.
"That's a GT-20 'Grounded Outlet'
Tester made by Alco Electronic Products, 1551 Osgood Street, North Andover, Mass. 01845. It sells, in single
lots, for $7.95 and reveals instantly if a
receptacle into which it is plugged has
current available and is properly and
safely wired. Note the three little round
windows in the end. Two of them,
labelled NEUTRAL and POWER, are
amber, and the bottom one, labelled
DANGER, POLARITY is red. When the
GT-20 is plugged into a grounding receptacle, one or more of the lights behind the windows light if power is
available at the socket. If the socket is
correctly wired, the two amber windows glow. Any other combination of
lights indicates a potentially dangerous receptacle that is improperly
wired or has a broken connection.
"What's inside the thing?"
"Not being like the little boy who cut
open his drum to find what made the
noise, didn't take it apart to see; but
I'd guess there are three neon lamps
I

with accompanying current -limiting
resistors, each wired between a pair of
prongs. Can you figure out which
lamp is wired between which prongs
to produce the conditions shown in
the little charts?"
"Child's play!" Barney scoffed.
"Will it work on 2 -hole outlets?"
"The Code requires that, in all new
construction, only grounding receptacles may be installed. If you replace
a defective receptacle in an existing
POPULAR ELECTRONICS

88
AmericanRadioHistory.Com

installation, the new one must be the
grounding type if you can effectively
ground it. If this is difficult or impossible, the receptacle may not be of the
grounding type. You don't want a receptacle with a dummy grounding
orifice that seems to promise but does
not actually provide grounding of a
device with a 3 -wire cord plugged into
it. You can use the GT-20 as a 2 -wire
tester by using an adapter plug with
the pigtail fastened to the outlet box
by placing it under ametal screw holding the receptacle plate in place. If
red light of the GT-20 glows when
adapter is plugged in, reverse
position of the two blades. If the

the
the
the
red

light still glows, a ground fault is indicated and repairs should be made.
The only fault the GT-20 will not reveal
is switching of the neutral and ground
wires, since both are normally at
ground potential; but this very rarely
occurs.

"How come you've got two neon
test lights?"
"I haven't. That one you're holding
looks like the H3-452, but it is really a
Calectro No H3-454. About the only
difference you can see is that the plastic is blue instead of red. It is called a
Lo -Volt Test Light and will light with 5
to 50 volts ac or dc. If you look closely;
however, you'll see the bulb in the end
is a filament type instead of neon. 'I've
found this filament will glow dimly
with 3 volts across the test leads while
it is drawing 18 mA. At 12 volts ,the
filament is a very bright yellow and
draws 45 mA. This goes to 11Q mA at
50 volts, and the filament is incandes
cent white. Filament resistance goes
from 80 ohms cold to 550 ohms at 50
volts, which explains the wide range of
lighting voltage.
"The Lo -Volt Tester is especially
useful in trouble -shooting auto electrical problems. Failure to light across
the battery terminals indicates a dead
battery. If the battery is OK, you can
trace the voltage from it right to an
accessory that fails to work. With the
accessory turned on, the lamp will
light across a defective switch or fuse.
It will also light across a high resistance connection, say a battery cable
connection or starter solenoid contacts, when the starter is actuated and
tries to draw heavy current through
the connection. By connecting ,the
lamp between an insulation -piercing
darning needle and ground, you can
pinpoint a break in a wire. The lamp
will indicate generator output. 'It can
be used with the 12 -volt battery to in-

dicate continuity, since it will glow
with any series resistance from 500
ohms down.
"The Lo -Volt Tester is also useful in
the home for checking out low -voltage
door-bell circuits, electric trains, and
slot cars. With a 9 -volt transistor battery, it can be used as a continuity indicator. With a little practice, you can
also use it to indicate the condition of
6- and 9 -volt batteries."
"Well," Barney said as Mac paused,
"that only leaves this little red bulb no
bigger than a match head."
"That's a brand new RLC-400 Battery Status Indicator just released by
Litronix, Inc., 19000 Homestead Road,
Cupertino, Calif. 95014. It sells for a
dollar at Litronix representatives all
over the country. A GaAsP LED and a
voltage -sensing IC are both packed
inside that itty-bitty T-1 lamp package
designed to warn of imminent battery
failure in cameras, tape recorders,
calcualtors, and similar batterypowered equipment. The LED lights
brightly at 3 V, glows dimly at 2.5 V,
and is completely dark at 2 V. It drawl
about 300 microamperes at 2.5 V, 8 mA
at 3 V, and 20 mA at 4 V. Five volts,
forward or reverse, is maximum.
"To use the RLC-400 with higher
voltage batteries presented a bit of a
problem. A series resistor subjected
the device to a high turn -on voltage
and separated on on -off points too
much. A zener took care of the first
problem, bLt the on -off points were
only a half-volt apart. finally worked
out the circuit shown to let me use the
I

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make the on -off span proportional to
that voltage. With the values shown, 3
V appears across the LED with 12 V
across points X and Y. There is 2.5 V
across the LED with 9 V at X-Y. Other
zeners and resistor values can ac-

commodate other battery voltages
and provide any desired span between
new and discard battery voltage. This
little lamp has a lot of exciting pos-

sibilities," he concluded.
"You know," Barney mused, "a
knowledgeable guy can do a lot with
comparatively simple equipment."

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CECLE NO.

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89

NOVEMBER 1974

AmericanRadioHistory.Com

Solid State

-1111AF/

By Lou Garner

USEFUL CIRCUITS FOR FIELD EFFECT TRANSISTORS
THOUGH more versatile than bipolar types, except in
some power applications, field effect transistors
-FET's-have never been overly popular with experimenters and hobbyists. True, FET's have been featured in
magazine construction articles from time to time, and
there have even been several.project booklets published
featuring FET circuits but, somehow, these devices have
never really "caught on."
There are probably several reasons for the FET's lack of
popularity. One may be the paucity of application data
compared to what is available on bipolar devices. Another
reason, perhaps equally important, may be the somewhat
confusing situation regarding types. FET's are manufactured in two general categories and six major subcategories, in addition to variations relating to electrical
specifications. The two broad categories are insulated
gate types, or IGFET's, and junction types, or JFET's. Since
many insulated gate FET's are manufactured using MOS
technology, these are often designated MOS-FET's, while
junction FET's frequently are identified simply as FET's
(without the J prefix). But there's more. IGFET's may be
manufactured for use in either depletion or enhancement
modes, each of which has its own technical advantages,
but which may require somewhat different application
techniques, depending on the circuit in which it is used.
Finally, both IGFET's and junction FET's are available as
either n -channel or p -channel devices. These are analogous to npn and pnp bipolar transistors, in that they may be
used in similar applications, but require opposite dc

polarities.
Poor availability may be another reason for the FET's
lack of popularity. The first low-cost experimenter's transistor, the famous Raytheon CK722, was a bipolar device.
FET's, on the other hand, were comparatively late arriving
on the scene and, by the time inexpensive FET's were
available, a mass of application literature and project articles had been published featuring bipolar devices, resulting in a much larger demand by users for these types. As a
result, suppliers offering general-purpose semiconductor
devices today may list scores of different bipolar transistors but maybe only from one to a half -dozen FET's. As of
the present writing, for example, there are only five different FET's listed in Sylvania's ECG line, two types in RCA's
SK line, eight in Motorola's HEP line, three in GC
Electronic's Calectro line, and one in Radio Shack's
Archer line. There are many other types of FET's in production of course, but the prospective user will not find these
in a general line on a self-service sales rack. Instead, he'll
have to buy them across the counter, specifying
manufacturer's name and type number, and perhaps even
seek out a broad line or industrial electronics distributor

stocking the units needed. In extreme cases, the user may
find it necessary to order specific devices from a large
mail-order or semiconductor specialty house.
The FET has been called the"semiconductor equivalent
of the vacuum tube." This analogy is pretty close to the
truth. The FET offers high input and output impedances. It
is a voltage, rather than a current, amplifier. It can be
self -biased via a source resistor and its characteristics
curves are quite similar to those of a pentode vacuum tube.
The basic FET has three terminals-gate (G), source (S)
and drain (D). These correspond, generally, to the base,
emitter and collector of a bipolar transistor, or to the grid,
cathode and plate of a vacuum tube, respectively.
The IGFET (or MOSFET) has an extremely high input
impedance. The junction FET also has a high input impedance, although not nearly as great as the IGFET; but, from
an experimenter's viewpoint, it is by far the easier device to
use in practical circuits. Except for those types with internal protection, the IGFET (MOSFET) requires special
treatment. It is particularly susceptible to damage from
static charges or transient voltages applied to its gate
electrode, even during the simple processes of handling
and installation. Some types, in fact, are supplied wrapped
in metal foil or with their leads shorted by a metal eyelet or
spring to prevent accidental damage. The short can be
removed safely only after the device is installed in its circuit.
Perhaps the best way to become familiar with the FET is
to try the device in a few practical projects. Several useful
and easily constructed junction FET circuits are illustrated
in Figs.
and 2. These were adapted from a FET applications bulletin published several years ago by Siliconix, Inc.
1

Fig. 1. Useful FET circuits: (A)
Crystal oscillator; (B) Tone control.
BASS
R2

vBOOST

MEG

R6
ATTEN

V-

300N

60-120yH

300

fi'

TAL
G

OUT
R2

2.2N

NOTE: ALL CAPACITORS ARE

(A)

IN pF

(B)
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(2201 Laurelwood Road, Santa Clara, CA 95054). In each
circuit, resistors are rated for 1/4 or I/2 watt, while the
capacitors may be ceramic, mica, plastic or tubular paper
types, except where a dc polarity is shown, in which case
an electrolytic should be used. Capacitor working voltages
should be chosen on the basis of the do supply voltage
used, of course, with 50 -volt, or better, units adequate for
all four circuits. Although p -channel devices are indicated,
comparable n -channel FET's may be substituted in each
design if dc polarities are reversed and if bias and supply
voltages are readjusted for optimum performance.
Suitable for use as the first stage of a transmitter,, as a
marker generator, and in similar applications, the FET
crystal -controlled oscillator shown in Fig. 1A requires rela-

tively few components. The original design specified a type
2N2608 for Q1, a -MHz crystal, and a 22 -volt dc power
supply. It may be assembled on a pert board, etched circuit
board, or even on a small chassis using point-to-point
wiring techniques.
In operation, the drain -gate feedback needed to start
and sustain oscillation is provided by stray interelectrode
and wiring capacities. Gate bias is established by source
resistor R2, shunted by bypass capacitor C2. Drain tuning
is provided by adjustable inductance L1, shunted by Cl.
The L and C values specified are for 1 -MHz operation but
these may be changed, of course, for other frequencies.
Featuring separate treble and bass controls, the tone control circuit illustrated in Fig. 1B may be used with virtually any audio amplifier-phonographs, tape recorders or
playbacks, or PA systems. Depending on application, it can
be assembled as a separate control or incorporated as part
of more complete amplifiers. Except for the treble control,
R4, standard components are used throughout the design.
As in the previous circuit, a 22 -volt dc power supply should
be used, and Q1 is specified as type 2N2843.
In operation, Q1 serves as a conventional commonsource amplifier, with gate bias provided by source resistor R8, bypassed by C5. Resistor R7 serves as the drain
load and C1 and C6 as the input and output coupling
capacitors, respectively. A variable frequency response
characteristic is achieved by a combination of attenuation
and negative feedback techniques. When bass control R2
is shifted toward its BOOST position, it serves as a shunt
across C2, increasing the amplitude of the bass portion of
the applied signal. When R2 is set toward its ATTEN position, its shunting effect across C2 is reduced and, at the
same time, a negative feedback signal coupled back from
the drain through R6 serves to reduce effective stage gain
at the lower frequencies. A similar technique is used for the
treble control. With treble control R4 in its maximum boost
position, C4 serves as a high -frequency shunt across the
bass control network. With R4 set forr maximum attenuation, high -frequency negative feedback from Q1 's drain is
applied through C4 to the gate electrode, effectively reducing stage gain.
You can use the phase shifter circuit shown in Fig. 2A in
test instruments, such as oscilloscopes, in demonstration
projects, and in musical synthesizers. It requires a 12 -volt
dc supply when 2N2609 FET's are used for Q1 and Q2.
In operation, Q1 and Q2 are used as cascaded split -load
amplifiers, with R3 and R6 serving as the drain loads and
R2 and R7 as the source loads, respectively. Networks
C1 -R4 and C2 -R5 provide a control over the signal phase
shifts, with each stage supplying a controllable shift from
0° to 180°.

2.2K

4.7K

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.OSyF

G
R4

250K

250

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10MEG

OUT
R2

2.2K

v+
(A)

NOVEMBER 1974

Fig. 2. Phase shifter (A) and
automatic gain control (B).

Never

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MS -416 is a valuable tool for circuit analysis:
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L
CIRCLE NO. 27 ON READERS SERVICE CARD

There are probably many uses you can devise for the
audio automatic gain control (agc) circuit illustrated in Fig.
2B. Use it to maintain a constant level in a tape recorder, to
prevent overmodulation in a transmitter, or as part of an
expander or compressor. According to Siliconix, the circuit will provide an effective agc range of 60 dB and has a
frequency response flat to within 1 dB from 1.0 Hz to better
than 10 kHz. Type U112 devices are specified for both Q1
and Q2, with a 12 -volt dc power supply.
In operation, Q1 serves as a variable resistance, Q2 both
as a gate bias control for Q1 and as a source -follower
amplifier. Series resistor R1 and Q1's source -drain resistance, shunted by R2, form a simple voltage divider. FET
Ql's source -drain resistance, in turn, is determined by its
gate bias, which is established by Q2's drain current and
the agc voltage applied to Q2's gate. As increasing agc
voltage is applied, Q2's drain current is reduced, increasing Q1 's negative gate bias and thus reducing Q1 's effective source -drain resistance, thus reducing the effective
level of the input signal applied through C2 to Q2's gate
and, therefore, the output signal developed across Q2's
source load, R4. As the agc voltage is reduced, the opposite action takes place, increasing the output signal level.
Although the parameters of the agc circuit are not critical, one simple adjustment is required for optimum performance. Wirth the circuit wiring completed and checked,
apply the dc supply voltage, a small input signal, and zero
agc voltage. Adjust drain load R5 for a maximum output
signal across source load R4.
If you've been intrigued by our discussion of the versatile
FET and would like to explore the subject in greater detail,
we can recommend any (or all) of the following books:
An Introduction fo Field Effect Transistors, by J. Watson,
published by Siliconix, Inc.
FET Circuits and abc's of FET's, both by Rufus P. Turner,
published by Howard W. Sams & Co., Inc.
Field Effect Transistor Projects, published by Motorola,
Inc., Semiconductor Products Division, and offered
through HEP distributors.

Reader's Circuit. Featuring

a popular IC op amp and a
pair of zener diodes, the portable scope calibrator circuit
given in Fig. 3 was submitted by reader Ted Reiter (1442
Brook Drive, Titusville, FL 32780). Layout and lead dress
are not critical and the project can be duplicated quite
easily in a single evening or on a weekend by the average
hobbyist.
In this circuit, IC1 serves as a simple relaxation oscillator, supplying an output signal which is clipped by zener
diodes D1 and D2 in conjunction with series resistor R4,

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Fig. 3. Reader's circuit for
portable scope calibrator.
R0

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R4
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GREENLEE TOOL CO

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CIRCLE NO. 19 ON READERS SERVICE CARD
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The "NEW LOOK"

1975

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developing a fixed -level square -wave
output signal with a peak -to-peak amplitude equal to the total zener voltage. Operating power is supplied by
batteries 81 and B2 controlled by a
dpst switch, S1.
Readily available standard components are used in the design. Ted
chose a type 741 op amp for ICI. The
terminal numbers shown are for the
"minidip" version used in his original
model. The resistors may be either 1/4
or 1/2 watt, while Cl is a low -voltage

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ceramic capacitor. Batteries 81 and
82 are conventional 9-volt transistor
units, with S1 a toggle, slide or rotary
switch. Ideally, the zener diodes
should be matched, with a total voltage of 10 volts. Unable to obtain a
perfect match, Ted assembled his
model using a 5.6 -volt zener for D1, a
4.5 volt device for D2, providing a
nominal 10.1 -volt output signal. The
actual output voltage, of course, will
depend on the zener diode voltage
tolerances.
If a particular application requires
an accurately known output voltage, a
simple test will establish this value.
Disconnect R4's upper lead (pin 6,
ICI). Reverse D2. Connect R4's free
lead to the positive terminal of a
15 -18 -volt dc source, negative to circuit ground. Finally, measure the dc
voltage across the series zeners using
an accurate voltmeter. Restore the
circuit to its original condition for
normal operation.

Device/Product News. We've received a number of inquiries from
readers asking what LED's have the
lowest current ratings. Actually, most
LED's will operate at currents much
lower than their maximum ratings,
and we've obtained satisfactory light
outputs with levels as low as 8 to 10
mA using commercial 50-mA (max)
devices. However, the results are not
consistent. One LED of a given type
may provide a good output at a 7-mA
level, while another of the same type
may require 10 mA, and still another 12
or 15 mA. At least one firm, however,
Data Display Products (5428 W. 104th
St., Los Angeles, CA 90045), offers
complete LED panel -light assemblies
designed to be used at a mere 5-mA
current level. Available colors are
green, yellow, amber and red, at voltages from 1.8 to 28 V. Single unit
prices range from $1.58 for a 1.8 -volt
device (requiring an external current
limiting resistor) to $1.76 for a 28 -volt
type (with built-in resistor). Each unit
is supplied with a mounting clip and
Neoprene washer.
You can add another name to the
roster of firms manufacturing dual
555 -type timer IC's: Silicon General,
Inc. (2712 McGaw Ave., Irvine, CA
92705). Packaged in 14 -pin DIPs, the
Silicon General version is identified as
the SG556/SG556C.
Perhaps a dual timer is not enough
for your application. If this is the case,
you might check the new quad timers
now available from Signetics (811 E.

Argues Ave., Sunnyvale, CA 94048).
Identified as Models 553 and 554, the
new units are supplied in a 16 -pin DIP.
The 553 and 554 are not exact duplicates of the industry standard, the
familiar 555, however. They have no
reset control line and a common control voltage pin is provided for all four
timers in the package. Basically similar in application, the 553 is rated to
sink 100 mA, the 554 to source an
equivalent current, compared to the
200 mA ratings of the 555/556 types.

Another interesting difference between the 553/554 devices and the
555/556 types is a simplification of
their timing equations, from T = 1.1 RC
to T = RC for the new units.
How many watts in a dollar? If this
seems like a silly question, comparable to a mixing of apples and oranges,
it is, however, the type of question that
a transmitter designer must ask himself. According to Motorola, its new
MRF621 uhf power transistor can deliver an output signal in the 406 -to 512 -MHz band for less than a dollar
per watt. Designed for 12.5-V dc operation, the new device can deliver 45 W
at 470 MHz with a minimum power
gain of 4.8 dB and collector efficiency of 55%. Featuring an internal MOS

capacitor chip for "controlled -Q"
operation, the MRF621 sells for
$39.00 each in unit quantities, even
less if you want to buy 25 or more at
a time.
RCA's Solid State Division (Box
3200, Somerville, N.J. 08876) has introduced a new linear IC and added
another COS/MOS device to its ex-

line.

panding

Designated

type

CA3127E, the new linear device con-

sists of

independent general-

purpose silicon npn transistors constructed on a common monolithic
substrate to provide close electrical
and thermal matching. Suitable for
low -power applications at frequencies
up to 500 MHz, the CA3127E, supplied
in a 16 -lead plastic DIP, can be used in
vhf amplifiers, mixers and oscillators,
in -f converters and amplifiers, and in
sense amplifiers, synthesizers, and
cascade amplifiers. RCA's latest
COS/MOS device, identified as the
CD4093AE, is a quad 2 -input NAND
gate consisting of four identical
Schmitt trigger circuits, each of which
functions as a two -input NAND gate.
The CD4093AE, packaged in a 14 -pin
i

plastic DIP, is suitable for use in
wave -shapers and pulse -shapers, monostable and astable multivibrators,
and NAND functional logic circuits.*
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LOWEST Prices Electronic Parts. Confidential Catalog
Free. KNAPP, 3174 8th Ave. S.W., Largo. Fla. 33540.

Control. Schematics, Speakerphone, Telelink Burglar
Alarm, Voice Scrambler. 53.00 each. ELECTRONIC:

ELECTRONIC PARTS. semiconductors. kits. FREE FLYER.
Large catalog $1.00 deposit. BIGELOW ELECTRONICS.
Bluffton, Ohio 45817.
RADIO-T.V. Tubes -36 cents each. Send for free catalog.
Cornell, 4213 University. San Diego. Calif. 92105.

each. Catalog of plans 50 cents. All of the construction
plans above. $19.95. TELETRONICS COMPANY OF
AMERICA. P.O. Box 3486, Los Angeles. California 90028.
USA.

Emotion/Lie Detector - Touch Tone Dial Ignition
Quadraphonic Adapter - Transistorized
items. Send
over
Burglar Alarm - Sound Meter
stamps)
complete catalog. Technical
coin
WE SELL CONSTRUCTION

PLANS. TELEPHONE:

LOOKING FOR A NEW CHALLENGE?
than bulk/ a TV cameral

vior--

ONLY SOLID STATE CAMERA AVAILABLE IN KIT FORM

OR FACTORY ASSEMBLED. COMPLETE KIT WITH V101.

TUBE ONLY 5166.00. POSTPAID DELIVERY ANY.
U.S.A.. CANADA .nd MEXICO. OPTIONAL
AUDIO SUBCARRIER $18.95. WRITE 5, PHONE NOW
FOR COMPLETE CATALOG OF KITS. PARTS end PLANS.
CON

WHERE IN

1301

0N402-987-3771.

_..

ATV Research

@ROADWAY

DAKOTA

City,

Mee.

61731

DIGITAL ELECTRONICS: Complete schematics. parts
Discrete Component Digital Clock,
lists, theories
Sound Sensitive Switch, $1.50. Increase technical
53.00
Complete Course in Digital
competence, hobby skills
Electronics is highly effective, $10.00. Free literature.
DYNASIGN, Box 60A7, Wayland, Mass. 01778.
MECHANICAL, ELECTRONIC devices catalog 10 cents.
Lowest Prices. Fertik's, 5249 "D",
Greatest Values

Philadelphia, Pa. 19120.
SOUND SYNTHESIZER KITS-Surf $12.95, Wind $12.95,
Wind Chimes $17.95, Electronic Songbird $6.95, Musical
Accessories, many more. Catalog free. PAIA Electronics,
Box J14359, Oklahoma City, OK 73114.
FREE CATALOG. Parts, circuit boards for POPULAR
ELECTRONICS projects. PAIA Electronics, Box C14359,
Oklahoma City, OK 73114.

NOVEMBER 1974

demo

record 5100

free catalog
-=

PAIA ELECTRONICB, INC.
BOX P14359, OKL.AMOMACFTV,OK-73114

INSTRUMENTED, FLYING

for

ROCKETS

AUTHENTIC.
casual or serious experimenters. Over 80 scale original.

multi -stage or ready -to -fly models. Solid -propellant
engines for safe, electric launch system liftoffs up to 2.500
feet. Measure altitude, temp. inversions, more. Real
telemetry, electronic tracking, aerial still and movie photography with super -miniaturized equipment. New, detailed
tech manual and full -color catalog. 25 cents from ESTES

TELEMATIC Test Jigs

Free Catalog

FORDHAM RADIO SUPPLY CO., INC.
Bronx, N.Y. 10451

2e 558 Morris Ave.

BURGLAR -FIRE alarm supplies and information. Free
catalog. Protecto Alarm Sales, Box 357-G, Birch Run,
Michigan 48415.

Answering Machine, Speakerphone, Carphone.
Phonevision, Auto Dialer, Touch Button Dialer, Central
Dial System. TELEVISION: $35.00 Color Converter, Video
Tape Recorder. 525.00 Camera. HOBBYIST: Electron
Microscope, 96 Hour Tape Music System, Ultrasonic Dishwasher, Radar-Oven. Plans 54.95 each. NEW ITEM: $75.
Electronic Pocket Calculator. $7.50. COURSES: Telephone
Engineering 539.50. Detective Electronics $22.50,
Integrated Circuit Engineering. $49.50. NEW SUPER
HOBBY CATALOG plus year's subscription to Electronic
New Letter AIRMAILED 51.00. Don Britton Enterprises,
6200 Wilshire Blvd.. Los Angeles, Calif. 90048.
JAPAN HONG KONG DIRECTORY. World products
information. 51.00 today. World Trade Inquiries, Hillyard.
Washington 99207.
FREE CATALOG. IC's, Puts, Transducers, Thermocouples,
Led's, Transistors, Circuit Boards, parts. Chaney's. Box
15431. Lakewood, Colo. 80215,
WAVEFORM GENERATOR KIT 8038 Function Generator
IC Producing Sine. Square, Triangular Waveforms, $10.95
PPD. 8038 IC. $6.75 each PPD. PHOTOLUME
CORPORATION, 116 East 28th Street. New York, NY 10016.

KITS

DISCOUNT PRICES
& K, SENCORE, LEADER and RCA
Test Equipment
RAYTHEON, ICC/MULLARD Tubes

27607.
METERS -Surplus, new, used, panel or portable. Send for
list. Hanchett. Box 5577, Riverside, CA 92507.

SYNTHESIZER

Mu Itilrequency Encoder Network (Speeds telephone
calling 100%!). 55.00 each. DODECAHEDRON Speaker
Enclosure 57.50. Photographic Pinhole Camera $2.00. ONE
YEAR SUBSCRIPTION: Telephone -Electronics Newsline
S3.00. COURSES: Telecommunications. Electronic
Protective Systems, F. E. T. Theory and Application, 524.95

modular

for
(no
cents
Writers Group. Box 5994. University Station, Raleigh. N.C.

HAS...

Biofeedback Conditioner, Horticulture Stimulator.

AMATEUR SCIENTISTS, Electronics Experimenters.
Construction plans -Complete.
Science Fair Students
including drawings, schematics, parts list with prices and
Lasers
Psychedelic shows
sources. Robot Man

INDUSTRIES Dept. 18B, Penrose, Colo. 81240.
ELECTRONIC Parts wholesale. Catalog 10 cents. Donlyn
Electronics, P.O. Box 15421, Phoenix, Arizona 85060.

INTERNATIONAL ELECTRONICS UNLIMITED
7400
t""

°B

7401

.19
.19
.19
.19

TTL
7474

LINEAR CIRCUITS
S

7475
7476

.43
.75
.47
1.11
.44

7402
7403
7483
.22
7486
7404
.22
2.75
7405
7489
.39
7406
7490
.76
.39
1.29
7407
7491
.25
.79
7408
7492
.25
.79
7409
7493
.89
.19
7494
7410
.79
.89
7413
7495
.39
.89
7415
7496
.39
74107
.49
7416
.39
.57
7417
74121
.99
.19
74123
7420
.35
.69
7423
74125
7425
.39
74126
.79
.29
1.23
7426
74141
1.15
.35
74145
7427
.22
74150 1.09
7430
.89
.29
74151
7432
.45
74153 1.29
7437
.39
74154 1.59
7438
.19
7440
74157 1,29
1.39
7441
1.09
74161
1.59
.99
74163
7442
7443
.99
74164 1.89
7444
1.10
74165 1.89
1.10
74166 1.65
7445
1.65
1.15
74173
7446
.99
1.15
74177
7447
1.15
7448
74180 1.09
3.65
7450
.24
74181
.89
.27
74182
7453
.39
74190 1.59
7454
.19
7460
74193 1.39
.39
1.39
7464
74194
.39
74195
.99
7465
.36
74198 2.19
7472
.43
7473
74199 2.19
DATA SUPPLIED ON REQUEST
WITH ORDER. ADD 8.50 PER DATA
FOR ITEMS PRICED UNDER S1,00

I-

4000 SERIES RCA-EQUIV.
CD4001
CD4009

CD4010
CD4011
CD4012
CD4013
CD4016

.55 CD4017

.85
.85
.55
.55
1.20
1.25

CD4019
CD4022
CD4023
CD4025
CD4027
CD4035

301
°

307
308
309K
311

319
324
339
340T
380
380.8
381
550

mDIP
Hi pert. op amp
mDIP
Op amp
mDIP
Micro-pwr op amp
TO-3
5V reg 1A
10DIP
Hi perf. V comp
DIP
Hi -speed dual comp
DIP
Quad op amp
DIP
Quad comp
Pos V reg (5V, 6V, 8V,
12V, 15V, 18V, 24V) TO -220
DIP
2w audio amp
mDIP
.6w audio amp
Lo noise dual preamp DIP
' DIP
Prec. V reg

555
560
565

Timer

709
723
741

Op amp

747
748
1458
3900
3905
8038

Dual 741
Freq adi 741
Dual Comp op amp
Quad amp

Phase
Phase

Volt

locked loop
locked loop

LOGIC PROBE KIT
S

Comp. op amp

Prec. timer
Function gen.

Internal 5V regulator
is complete with all necessary compocase, probe, complete instructions
$19,95
and logic chart

Kit

t1'96

next.

1.69
1.95
1.49
.89
1.79
.79
.99
2.75
2.65
.29
.69
.35
.79
.39
.69
.65
.65
5.95
.39
.39
.39

mDIP
DIP
DIP
mDIP
DIP
reDIP
mDIP
DIP
DIP
DIP

reDIP
rnDIP
mDIP

75451 Dual prl. driver
75452 Dual prl. driver
75453 Dual prl. driver
75491 Quad seq driver
75492 Hex dig. driver
DATA SUPPLIED

Ten nano/sec capability
Checks TTL & DTL logic
Dual slope memory

1'10
1.65
1.05

DIP
DIP

reg.

.32
.35

FOR ITEMS PRICED UNDER $1.00

CALCULATOR & CLOCK CHIPS w/data
S
5001 LSI 40 pin DIP 4 funct
5002 LSI Same as 5001 exc batt pwr
5005 LSI 28 pin DIP 4 functw/mem
MM 5311 28 pin BCD 6 dig raux
MM 5312 24 pin 1 pps BCD 4 dig mux
MM 5313 28 pin 1 pps BCD 6 dig mux
MM 5314 24 pin 6 dig mux

2.95

1101
1103

256 bit RAM MOS
1024 bit RAM MOS

5260
7489
8223

1024 bit RAM low power
64 bit RAM TTL
Programmable ROM

3.95
8.95
8.45
9.95
6.95
7.95
8.95
12.95

51.75
4.95
3.95
2.75
4,95

ON REQUEST
WITH ORDER. ADD S.50 PER DATA

MM 5316 40 pin alarm 6 dig

MEMORIES

.79
.89

DIP
DIP

POWER SUPPLY SPLITTER KIT
Ground reference for positive & negative
output from single supply any DC
source to 20V
Balanced output adjustment
1 amp -current capability with sink
Increase usefulness of your power supply
Complete with all components &
S4 95
instructions

° LED'S AND OPTO ISOLATORS
S .25 ea.
MV10B Red TO 18
.20
MV50
Axial leads
.33
MV5020 Jumbo visible red
.60
ME4
Infra red diH. dome
2.50
MAN1
Red 7 seg..270"
4.95
MAN2
Red alpha nulo .32"
.79
MANSA Red 7 seg..127"
MAN3M Red 7 seg..127" claw 1.15

MAN4
MANS

Red 7

MAN7

Red 7

MANS

set..190"

Green 7 seg..270"

seg..270"
Yellow 7 seg..270"

MAN66

60" high dir. view

DL707
MCD2
MCT2

Opto-iso diodes

Red 7 seg..3"

Opto'iso transistor

2.15
2.95
1.35
3.95
4.65
2.15
1.09
.69

ON ORDERS OVER $25.00 DEDUCT 10%

1.35
2.75
.55
.55
1.35
2.85

tested functional.
All items are new, unused surplus parts
Sadsfaction is guaranteed. Shipment will be made via first class
mail - postage (paid
in U.S., Canada and Mexico within three
$5.00. California
days from receipt of order. Minimum order

residents add sales tax.
14081.659-4773

INTERNATIONAL ELECTRONICS UNLIMITED
P.O. BOX 1708

MONTEREY, CALIF. 93940 USA
I

CIRCLE NO. 21 ON READERS SERVICE CARD

DIP SOLDER TAIL SOCKETS

DUAL IN-LINE SOLDERCONTA TAIL SOCKETS
8 PIN
14 PIN
16 PIN

....44
.. ..52
....54

18 PIN

22 PIN

24 PIN

.74
1.00
1.05

Also available - wire wrap sockets

28 PIN
36 PIN
40 PIN

...

1.30
1.55
. 1.75
1/2/3 levels write or call for
.

large volumn DISCOUNTS

TTL
7400

.18
.23
.23
.23
.25
.24
.50
.50
.25
.25
.23
.30
.89
.45
.45
.25
.23
.27
.32
.27

7401

7402
7403
7404
7405
7406
7407
7408
7409
7410
7411

7413
7416
7417
7418
7420
7421

7423
7425
7426
7427
7429
7430
7432
7437
7438
7439
7440

.31

.32
.40
.33
.26
.45
.50
.50
.23
1.10

7441
7442
7443

1.05
1.10
1.15
1.10
1.25
1.25
1.25

7444
7445
7446
7447
7448
7450

.25

7451

.27

7453 $ .27
7454
.40
7459
.25
7460
.25
7470
.45
7472
.41
7473
.47
7474
,47
7475
.90
7476
.47
7480
.50
7482 1.75
7483 1.15
7485 1.10
7486
.47
7488
4.00
7489 3.00
7490
.89
7491
7492
7493

7494
7495
7496
74100
74107
74121

74122
74123
74125
74126

.95
.95

1.50
.47
.55
,47
1.05

.60
.80
1.15

74145
74150

1.15

74151

L20
1.50
1.25

74155
74156

1.30

1.65

74163
74164
74165
74166
74170
74173
74174
74175
74176
74177
74180

2.50
2.50
2.50

74181

3.75
1.00
2.30
2.30
7.00
1.50

1.75

3.00
1.75
1.85

1.85
.85

.85
1.05

1.50

1.50
1.50
1.50
1.05
1.25
1.05

2.25
2.75
7.00

PROJECTS
8263 Sig. 7.00
8267
4.00
2513
14.00
2518
7.00
2424
7.00
2425
7.00
4024
2.25

.95

74154

74161

74182
74184
74185
74187
74190
74191
74192
74193
74194
74195
74196
74197
74198
74199
74200

1.15
,95
.95
.97

74141

74153

74157 $1.55
74160 1.65

1.30

20% Discount for 160 Pieces Combined

CMOS
04001 S .55
CD4002
.55
CD4009
1,40
.60
CO4010
.55
CD4011
.55
CD4012
1.50
CD4013
1.40
CD4016
.55
CD4023
.55
CO4025
1.25
CD4027
.60
CD4030
.45
74C00
.70
74C04
.65
74C20
2.60
74C173

8000 Series
8090
$ .35
8091-8098 .55
8223
5.00
8280
.75
8288
1.15
8880
1.35
Many Other
8000 Series
LEDS
MV 10
MV 50

5/1

MV 5024
MAN -1
MAN.3
MAN -4
MAN -7
DL 33

6/1
5/1
1.95
.95
1.95
1.50
1.95

- Above 7400 Series

041.9 E%$PECIAL$
Silicon Signal Switching Diode
TIS37 - TiS98 NP!J Transistor
7400 - 7401 - 7403 GATES
7404 - 7410 - 7420 GATES
LM301H/LM301N OP. AMP.
5 V 1 AMP
LM309K
LM311N/LM311N Comparators
2 Watt Audio AMP
LM380N
Quad AMP DIP
LM3900N
LM3905N
Precision Timer
LM741CH/LM741CN OP. AMP.
MM5314
24 Pin Digital Clock Chip
MM5316
40 Pin Alarm Clock Chip
MM5016H
512 Blt Dynamic Shift Reg.
MM1103
Bit Dynamic RAM
1024 X
2519
40 X 6 Static Shift Register
2529
240 X 2 Static Shift Register
1144148

øot
15/1.00
10/1.00
6/1.00
5/1.00
3/1.00
1.25
1.00
1.25
.55
.65

3/1.00
7.95
11.95
2.00
3.95
4.00
5.00

LINEAR
LM300

To 5
$ .85
.40
LM302H
Voltage Follower
.85
LM304H
Negative Voltage Regulator
1.10
LM305H
Positive Voltage Regulator
1.00
LM307H/N
Op Amp (Super 741)
.40
LM308H/N
Micro Power Op Amp
1.15
LM309K
5 Volt Regulator / Amp
1.70
LM31oH
Improved Volt. Follwer Op Amp
1.35
LM311H/N
Hi -performance Volt. Comp.
1.15
LM319H
Hi -Speed Dual Comp.
1.55
LM32OK-5V-15V To 3 Neg. Regulator
1.75
LM324N
Quad 741 Op Amp
1.90
LM339
Quad Comparator
2.35
Positive Volt Regulator
LM340K-5V-12V-15V-24
2.00
LM37ON
A 6 C - Squelch Amp.
1.55
LM373N
AM/FM S$B Strip
3.30
LM38ON
2 Watt Audio Power Amp
1.50
LM703H
RF/IF Amp
.45
LM5558V
Dual Op Amp
1.00
LM741 H/N
Comp. Op Amp
.40
LM747H/N
Dual Compen. Op Amp
.90
LM748N
Freq. Adj. 741
.40
LM1458N
Dual Comp. Op Amp
.65
LM3065N
T.V.-FM Sound System
.75
LM3900N
Quad Amp
.65
LM555N
Timer
1.00
LM565-LM566-LM567 Phase Looked Loops
2.50ea
LM 7522
Core Memory Sense Amp.
2.50
LM 7524
Core Memory Sense Amp.
1.50
LM 7535
Core Memory Sense Amp.
1.00
LM75451
Dual Peripheral Driver
.49
LM75452
Dual Peripheral Driver
.49
LM75453
Dual (LM3511
.65
Satisfaction Guaranteed. All Items 100% Tested
$5.00 Min. Order
1st Class Mail
No Extra Charge
California Residents
Add 6% Sales Tax
Wholesale Outlets
Write for Special Discounts
Write for FREE Catalog Data Sheets .20 i each
LM 301 H/N

Pos. V Reg
Improved Op Amp

JAAJ
Electronics
P.

0. Box 822 -Belmont, Ca. 94002
PHONE ORDERS WELCOME

(4151 592-8097

CIRCLE NO. 22 ON READERS SERVICE CARD
100

WE SELL MONEY MAKING CONSTRUCTION
MANUALS! -Reclaim refined GOLD and SILVEP for
EXCELLENT full time or part time money! -Color Catalog
25 cents -Airmailed 50 cents. Creative Products, Dept PE 1174, 8415 Lotland, Houston, Texas 77055.
BUGGED??? New locator finds them fast. Write, Clifton,
11500-L N.W. 7th Avenue, Miami, Florida 33168.
TELEPHONE "BUGGED"? Countermeasures Brochure
$1.00, Negeye, Drawer 547, Pennsboro, W. VA 26415.
HEAR POLICE/FIRE Dispatchers! Catalog shows exclusive

directories of "confidential" channels, reéeivers. Send 10
cent stamp. Communications, Box 56 -PE, Commack, N.Y.
11725.

YOU

WILL SAVE BIG MONEY! Surplus, Clearouts,
Bankruptcy, Inventory, Deals. Catalog $1 (redeemable).
ETCOA Electronics, Box 741, Montreal, H3C 2V2. U.S.
Inquiries.
CONVERT any television to sensitive. big -screen oscilloscope. Only minor changes required. No electronic
experience necessary. Illustrated plans. $2.00. Sanders,
Dept. A-33, Box 92102, Houston, Texas 77010.
CONSTRUCTION PLANS: Laser...52.00. Rocket Tracking

Transmitter...52.00.
Tracker... $2.00.

Space

Monitor -Missile

Free Catalog. Electro -Research, P.O. Box
20285, Ferndale, Michigan 48220.

CD IGNITIONS, VHF/UHF monitors, crystals, CB radios,
Southland, Box 3591-B, Baytown, Texas 77520.

SJ
ome th
CLEAR

th -,

1975 COM
HANDBO

ALPHA/THETA BRAINWAVE biofeedback instruments,
Analog instruments from $125; digital processing systems
from $225. BioScan, Box 14168-E, Houston, Texas 77021.
SURPRISE! Build inexpensively, the most Unusual Test

all -new

!CATIONS

111,LI

Here ís everyttlhá
you want to krái
need to know

about Citizen
Amateur Radi,o,/
Shortwave Li$ti~riri

CRYSTALS, Scanners, $3.88, include make and frequency.
G Enterprises, P.O. Box 461PC, Clearfield, UT 84105.

PRACTICAL Applications of Digital IC's. 100's of tips,
circuits. projects. on TTL. 443pp $19.95. Money Back
Guarantee, GEA, P.O. Box 285, Northfield, Ohio 44067.
FREE CATALOG. Kits, Components, audio equipment.
Electronic Supply Pecs, Box 175, Floral Park N.Y. 11001.

DON'T TURNEAA,/DIAL`n fact don't even buy
a dial or any, h(rig ele bin
you've checked
out the 197 / C
mu
tions Handbook.
Whatever y t ur
to s cialty
whether
you're an olci''i h bl tSt (getting started
this vital "hip
o g
e Will help you get
greater valuee dry to ,'etOjnent out of every
minute you 'pen
dth otl,(lequipment.
I

Instruments, Futuristic Gadgets using Numerical
Readouts! Catalogue Free! GBS, Box 100A, Green Bank,
West Virginia 24944.
ELECTRONIC ORGAN KITS, KEYBOARDS and many
components. Independent and divider tone generators. All
diode keying. I.C. circuitry. Supplement your Artisan
Organ, 35 cents for catalog. DEVTRONIX ORGAN
PRODUCTS, Dept. C., 5872 Amapola Dr., San Jose, Calif.
95129.

ELECTRONIC IGNITION: Capacitor, transistor, pointless.

Auburn sparkplugs. Information 10 cents. Anderson
Engineering, Epsom, N.H. 03234.
WHOLESALE Scanners. CB, Crystals, Directories,
SSB/AM, Catalog 25 cents. G -Enterprises, Box 461P,
Clearfield, Utah 84105.

ELECTROENCEPHALOPHONE: Brainwave monitor.
Professional biofeedback tntruments. J&J, 8102-E,
Bainbridge, WA 98110.
HOBBYISTS -For all your electronic parts requirements at
low prices, send for free flyer to: Dartek Electronics, Dept.
P, Box 2460, Dartmouth, Nova Scotia, Canada. U.S. Inquiries.
CALCULATOR OWNERS: Use Your +-x- calculator to
compute square roots, trigonometric functions, logarithms,
and more! Quickly, Accurately, Easily! Send today tor the
First and Best Calculator Manual ... now in use throughout the world ... still only $2.00 Postpaid with Unconditional Money-Back Guarantee! Mallmann Optics and
Electronics, Dept. 21A, 836 South 113, West Allis,

Wisconsin 53214.
FREE 1975 Electronics Catalog. McCord Electronics, Box
276-N, Sylvania, Ohio 43560.

BUBBLE ETCHER. Etches 6"x8" board in halt time. Acrylic

construction. Complete photo process instructions.
Requires inexpensive aquarium pump. $12.00. ETCHER,
Box 25066, Northgate Station, Seattle, WA 98125.
AUTORANGING DMM, deluxe VOM's, logic probes and
more. Lowest prices. Free catalog. Electro Industries. 4201
Irving Park, Chicago, Illinois 60641.
ARE YOU PREPARED? 10,000 cubic foot. pull ring ignited
emergency smoke grenades are now available! 3 for $7.50.
9 for $20.00. Postpaid. Pacific Aero Supply, Box 601,
Malibu, Calif. 90265.

DIGITAL/ANALOG PLANS for Home and Lab!!! Send for

ideas catalog featuring the
16 -page
EXPERIMENTER'S COMPUTER SYSTEM, practical plans,
tutorials, etc. M.P. Publishing Co., Box 378-P. Belmont,
Massachusetts 02178.
free

PYROTEChNICAL chemicals, casings, tools. supplies,
fuse. Price List 50 cents. Westech, Logan, Utah 84321.
VIDEO GAMES -attaches to your TV. Ping-Pong plans
$3.50. Information 25 cents. Duncan Electronics, 20650
Runnymede, Canoga Park, Calif. 91306.

COMMUN
is sclfef/'r¡l d

nation$y

\Io

ANDBOOK
on sale

jenlb21, 1974.

YOU CAN RESERVE
YOUR COPY NOW
AT THE SPECIAL
PRE -PUBLICATION
PRICE OF ONLY
$1.00 POSTPAID.
Regular newsstand price is $1.25,
mail order $1.60.
So to make sure you come through
"Loud and Clear" in 1975...

RESERVE YOUR COPY NOW AND SAVE
WITH THIS SPECIAL PRE -PUBLICATION
OFFER AVAILABLE TO READERS OF
POPULAR ELECTRONICS MAGAZINE ONLY.

PRE -PUBLICATION
RESERVATION FORM
Communications Handbook
PE -1174
Ziff -Davis Service Division
595 Broadway
New York, New York 10012
Enclosed is $1. Please reserve my copy of
the 1975 Communications Handbook at the
special pre -publication price to be mailed
to me on or before November 21, 1974.
Print Name
Address
City
State

Zip

PAYMENT MUST BE ENCLOSED WITH ORDER

POPULAR ELECTRONICS
AmericanRadioHistory.Com

AM -FM MULTIPLEX

WITH
ESCUTCHEON

sL.,,

ú0o -wane
MW( -DIAL

-speaker system, built-in
FM antenna. record player jacks on separate panel.
Another external panel consists of provisions for external FM and AM antenna, "satellite" speakers to
provide 4 -speaker ground, jacks for connecting a tape
recorder to radio tuner or phono of systems to record.
Lower inputs for connecting tape deck that will ploy
back thru the internal amplifier for systems. AC jack for
phono power connection. RED. CREEN and CLEAR indicators for Phono, AM. and FM respectively. Includes
red indicator on front panel for STEREO indicator.
Nos separate input to plug into mike, guitar and other
musical instruments as well as another jack for plugzing in a pair of stereo headphones.
Has controls on front panel. PHONO-

dei

...Al.-

IndletorI

F ature_:

WATT GUITAR AMP

With Tremolo

$7.95

20 -WATT

STEREO

AMP

SOLSTATE

Each

1.49
2.50

.19

3
3
3

15, 18. 24V ....2.95
LM -350 Dual Peripheral Driver DIP
.69
LM -370 ACC Squelch op amp. TO -5
1.50
1 25
LM -371
R -F, I.E. op e p
3 50
LM -373 AM -FM SSB I.A!D, TO.5
3.50
LM -374 AM -FM SS IVAD TO -5
LM -376 Pos. V. Reg.
.65
LM -377 Dual 2 -watt audio amp
2 69
1.69
LM -380 600mW LM -380, minl DIP
LM -381 Low noise dual pre amp DIP .. 1.69
.. 1.89
LM -382 Low noise dual pea amp DIP
59
LM -703 RF-IF amp, TO -S
LM -703M RF-IF, op amp, mini DIP
51
.36
LM -709 Operational amplifier (A)

4 -Channel Spkr. Systems!

Special
for $9.
for $3.
for $6.

SLA-1

Sale
MIRI s Type Watts
8.88
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s0
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AMPS
AUDIO POWERhi-fi systems, tape decal, FM Iv,Used extensive ly In stereo components, musical instru1/a db trae'
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All amplifiers, fiat within
with
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err0
hz tovy
lug
tie
output.
VC.
ed
ended -duty
r
required
supply
Power
ended pushpull output. by Stock No.
Output to 8 ohms. Order

Low

$7.77

"DIP"
6digit

28 -Pin
24 -Pin
MM5312
MM5313 6 -digit 28 -Pin
MM5314 6 -digit 24 -Pin
4 -digit 40 -Pin,
MM5316
MM5316-4 no alarm

$7.77

4 -digit

Alarm

'7.77
7.77
7.77
4.95

o
o

o
C

BRAND NEW LOWEST PRICES
3 -WATT

GENERAL ELECTRIC
3
AUDIO AMP

$2.50

sa.00
Delivery :1.5 watts continuous. 10 watts peak. Wit
heat inks; micro -mini size: a/ xl/axt/y". 9 to 30V use
ply. High sensitivity. N to 16 ohms.

6-8-12 DIGIT

FOR

LM -4250C Programable op amp
LM -75451 Dual peripheral driver
LM -75453 Dual peripheral driver

YOuróhnlen

$16.95

rs
tees
r
EST PRICES! yr

48 HR. SERVICE

Type

0 SN7400

5147401
3 5147402

]
0
0

5147404
5147405

SN7406

.27

.24
.79
.48
.27

.27

5147410
5147411

5N7415
5N7418
597417

.55
.89
2.25
.45
.45
.50

SN7423

.50
.29
.32

SN7412

5147413
5147414

0 597420
0 5147421
0 SN7422

5147425

0 5N7426
5147427

69
69
75
41
41

.89
.41
91

.91
.63
1.00
1 50
.95
2 50
44
.44

2.25
2.50

500

600

(TO.S)....$2.50

HI slew rate op -amp

2 50
2 50
2 95

..1.25

2.10
00

2 95

2.95
2.95

2 a5

2 95

.49
50
.33
.69

.44.

44
1.75
1.98
.89
1 00
1.00

739.739 Dual stereo preamp

741-741 Dual 741C (TO -5)
U ULN2300M Op amp with SCR
CA3065 Video Audio system
RC4195 Dual 15V Tracking V.R.

2.50
2.50
4136 Quad 741's (DIP)
RC.2556 Dual 555'.
2.25
1.00
O TVR-2000 Super 723, TO.5
BRAND NEW LOWEST PRICES (A) TO -5 or DIP
BUY ANY 10 -TAKE 15%
TAKE 25%
RUY ANY 100

$3.98

35 WATT AUDIO
AMPLIFIER BASIC

for §7

For Class AB use. Basic includes: Slgnetlr
540 30 transistor high power driver TO -5

IC",

with a pair of complimentary 35watt plastic transistors, i.e. 2N5296 non

256109 pop. With schematics, printed
circuit and parts board layouts.
and

CT5002
CT5005

;19
.31

5N7430

12
9

-Digits, 40 Pin ..
$5.95
-Volt vas'
r
n of 5001
7.77
.

....

9.99
12 -Digits 28 -Pin
with 3 -function memory.
8 -Digits,
6 -Digits,

4-Funes. LED
28 -Pin, 9V

4.95
4.9S

3
3
3

for $17.
for $21.
for $27.

for $12.
for $12.

_28

SN7437

.45

597443

.49
.19
1.00
1.00
1.00

5147444

1.00

5147441
5147442

SN7445

5147446
5147447

597446

S147450
5147451

.22

1.00
1.10
1.10
1.45
.27
.28
.28
.39
.28

3 5)47483
0 597465
0 597488
0 5117489

2.50
.49
2.95

5117465
5147470

.39
.49

SN7471

.26

1.81
5117491
1.35
5147492
.99
SN7493
.99
5147494 1.05
SN7495
.99
5147406
.99
51474300 1.55

El5974105

.55

31 ON

Type
Volts
LM -340-051
y

LM -340-081
LM -340-127
LM -340 -1ST
LM -340-18 T
LM -340.24 T

e v
12 v

18 v

0
13
0
0
0

5974106

0
0

.49

514741617

.95

5N74164 2.85

.95
.95
.95
.49

51474154 1.69
51.474155 1.29

1.45
1.45

1.45
1.85

1.59
5N74163 1.75

51174165 2.85
51474166 1.85

5974173 1.85
51474174 2.25
51474175

1.99

5974176 1.25
5974177 1.25

SN74180 1.10
SN74181 3.95
51474182 1.05
51174185 2.34
51174187 2.34
51474192 1.59
5974193 1.59
5974194 1.89
SN74195 1.10
51174196 1.20
51174197 1.10
51174198 2.45
51474199 2.45
51474200 7.50

INTEGRATED CIRCUIT
SOCKETS
14.Pin, DIP
....S.45

Your Cho Ice

each

Buy Any 3
Take 10%

READERS SERVICE CARD

5974108
SN74112
SN74113
SN74114

0 5974156
0 5974157
.95 0 51474158
.95
0 5974160

buy Any 3
Take 109,
Discount!

$1.75

Factory Marked

51474107

0
0
0
51174121
51474122 .55 0
0
0 5974123 1.09 0
0 5974125 .65 0
0 51474126 .89 0
0 51474139 1.25 0
0 5974140 2.50 0
0 51174141 1.19 0
0 5974145 1.19
0 SN74148 2.95
0 51474150 1.19
0 51174151 .99
0 5/174153 1.39

51474104 1.25

-220 Case 1 Ame
POSITIVE VOLTAGE

LM-340-06765

.99
1.19

3 597490

.26
.39
.39

5147462

.3S

1.25

.42
.52
.39
.91
.52
.79
.59

S9741112

SN7464

597461

.35
.31

0 SN7472
0 597473
SN7474
0 5147475
0 5147476
0 597478
0 597450
3 59741111

0
0
0
0
0
0
0

SN7453
SN7454
SN7455
5117460

PRICES

er shretA nn renuext "ONLI"

.24

5117432

0 SN7438
0 597440

0
0
0
0
0
0
0
0

TO
a

CIRCLE NO.

.95
1.25
1.50
1.98

200
300
400

Micro power 741 (TO.S)
Micro power 709 (TO -5)
FET Input op amp (TO -5)
Timer 2 u Seconds to 1 -hr. (A)
5 Times faster than 741C
Dual 741 (DIP)
Phase lock loops (DIP)
Phase lock loops (DIP)
Phase lock loops (DIP)
Phase lock loops (A)
566 Function generator (TO -5)
3 567 Tone decoder (A)
702C Hi -grain, DC amp (TO -5)
704 TV sound IF system
O 711C Dual dlff, comp (A)
723C Voltage regulator (A)
741CV Freq. comp 709 (Miel DIP)
748C Freq. adi. 741C (A)
753 Gain Block

1.25

NEW!
NATIONAL
LM -340T VR's

"-'mer"w-

NOVEMBER 1974

Jr):

res,

pTAmserAeteRT
MARR[p

FACTORY

531
O 532
533
536
555
556
558
560
561
0 562
565

MM5725
MM5736

Sala Order bv type number!

$.19
49
.24
.19

0
0
0
0
0
0
0
0

boards). $19.95
.

597403

0
0 5147407
0 5147408
0 557409

Key parts
DIGIT BASIC "MEMORY" KIT ff5
for 4 -memory calculator. Case with "slight touch keyboard", CT5006 memory chip, 6 MAN 3's, ON -OFF
switch, book, (extend key allows 12 digits), Pr

LINEAR

CT5001

ECONOMY

Inflation -Fi hting

Key parts include: CT5001
DIGIT BASIC ff4
chip, 4-3 digit readouts, factory etched PC board, case,
carrying case. 2 -resistor networks, decimal switch.
Wild Rover Keyboard with ON -OFF switch diagrams.
Sale $24.95

......

LOWEST PRICES ON

BASIC KIT ff1
c
all -function Ilex Key
includes case,
chip, 9 -digit
Keyboard, Cal Tech CT5002
Antes LED display with built -on individual magnitieis.
Plus sheets.
BASIC KIT f2
same as Basic Ifl except rnlculatui
chip is National 8 -digit 5M6725.
same as Basic p1 except calculator
BASIC KIT ff3
chip is National 6 -digit h1515736 and 75492.
12

QUADRACS!

10 -Amp Power
Tab Plastic Unit

LM 75491 Quad seg. driver, LED (DIP) ... 1.65
LM -75492 Hex digit driver, 250ma, DIP 1.85

CHIPS"

GUARANTEES

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"CALCULATOR

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2

....

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INTEGRITY

WITH DATA SHEETS
.

0
u

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ON A
MM5311

LM -733 Differential Video
LM -741 Freq. Comp. 709 (A)
LM-741CV Mini DIP 741C
LM -747 Dual 741 (A)
LM -748 Freq. adjustable 741C (A)
LM -1303 Stereo ore amp DIP
S LM -1304 FM Stereo Multiplexer
LM -1307 FM Multi. Stereo Dem, DIP
LM -1458 Dual 741'. mint DIPS, TO -5
LM -1496 Modulator, Demodulator
LM -3026 Differential Ni/te amp
o LM -3900 Quad "current mind'. amp

........

MAN-1

REFLECTIVE BAR TYPES
MAN
SLA-3P
a
2.10
3 for $5.
SLA-1 .33
By Opcoa, equal to
4.95
3 for 513.
SLA-3 .70
fir 6ti'A V-4 specs, Color - RED
SLA-11 .331 2.50
3 for $6. 1GreN-1

CLOCK CHIPS

.45
.36

LM -710 Differential amplifier (A)
LM -711 Dual Differential Amp (A)
LM -723 Voltage Regulator (A)
LM -725 Instrument Op Amp

MAN -3

SLA-21-

LED Readouts

$3.75

.27
.12

Resp

...
,

....

Char.

MAD

The most amazing audio offer for the hi -fi -era.
and an ideal unit for the family den, or any room in the
(muse, office, etc. Comes complete with hookup. escutcheon, and knobs. 5 separate controls: LOCl/NI:SS.
BALANCE, TREBLE. BASS, circuits switch for PIIONO,
TUNER, TAPE. StihE, AUX. 3 switches for SCRATCH
FILTER. (RUMBLE PII.TER, and POWER "ON -OFF" with
built-in lite. 4 -output transistors. each :ill watts. Separate accessory mounting panel for .I speaker :Itlarho rent, mike and musical instrument jack. tape. tuner.
and power jacks. 6 -fl. cord set for 115VAC. fill cycles.
3". Wt. 3 Ihs. With attr:aetiv,
Ile
s only 1:1 .x
multl.Ieolor escutcheon. v Made by leading US maker.

Type
MAN-1
MAN -3
MAN -4

II',

with printed
Per

or,

LM -301 Hi-perlormaace op amp (A)
.39
LM -302 Voltage follower TO -5
81
1.15
óLM -304 Neg. volt. Reg. 70.5
LM -305 Pos. Voltage Reg. TO -5
95
LM -307 Super 741 op amp (A)
39
LM -308 Hi -Q let type op amp TO -5
1 09
LM -309H 5V Volt -Regulator TO -5
1 05
LM -309K 5V Volt. -Reg. 1 Amp TO-3
1 65
LM -310 Voltage-Follower TO -5
1 25
LM -311 Hi -pert. Volt. Comp. (A)
1 09
LM -318 Prec. HI -Speed DIP
1 95
LM -319 HI -speed Dual Comp. DIP
.
1 50
-320
MINUS
LM
5. 12 or 24V V.R. 70.3 1 50
LM -322 Prec. Timer
1.75
LM -324 Quad (4.741s in DIP)
2.19
eLM -339 Quad Comparator. DIP
1.75
LM -340 Pas. V.R. T03 -1 -Amp 5, 6, 12.

AMPEREX

(All "LED" TYPES)

throughout.

60 -WATT STEREO
AMPLIFIER
BUY ANY 10 IC'S THIS TAKE 15%
BUY ANY 100 -TAKE 25%
R'D''
NATIONAL
TO -5, Dill
(LINEAR 0P AM PS or mini Uip
Sale
PRV
SCRS! TRIACS!
LM -300 POS V.R. (super 723) TO -5
$ .81
$ .75

60 -WATT STEREO
Wall "Slirn-LineType!
HIGH FIDELITY. Tape,
Record Player,
8 Musical Instruments!
AMPLIFIER
PA men.

7 -SEGMENT

hl.

INI

ped

Musical instrument amplifier at low, low price! Peak
power output 10 watts. Two input circuits areequalized for normal or solo guitar. The four controls are
VOLUME, TONE. TREMOLO INTENSITY and TREMOLO
SPEED. There are terminals on board for normally open
foot switch connection. Supply voltage 18vdc. Output
to 8 ohm hi -quality speaker. Input impedance 33,000
ohms. Current drain 20 mils. External power supply
required. Wt. 1 lb. With instructions, hookups and
diagrams. Size 8 x 25/e x 3.

20-20,000 Cycles

IC1

circuitry
per
Featuring solid tale 10
watts "peak" audio poreshuome
circuit cunstructIon. walnut
veneer grain with
channel. Handsome
for separate escutchWith
trimo
It6ADPsONES, TREBLE,
mountingnt items as STEREO
BALANCE, VOLUME controls,separatePHONO
BASS,DBALANCE,
with separate OFF -ON POWER
AND es. Chassis
epparatee
teh a:: Chassis size 111/x
left speaker phono type jacks, with
plate Ina::
tape of
convenience powerfeiontletamplifie
decks.d and
tape
with
`si
ogre (equipment using
stereo
external cables
-ft.
other equipment.
separate rON-OFF
powere
aandóautomatc
connections,
power plug.
turntabe
light
ligphonoht 'a
with handsome set of knobs. Wt. 2 lbs.

Sling.(A)

[locos

STEREO -AM -FM. MONO, FM STEREO. GUITAR, TAPE,
MIKE master control switch. LOUDNESS. BALANCE,
TREBLE. BASS controls, with power ON -OFF rocker
niteh, nd AFC ON -OFT. Designed for all audio-philes
as
all unit in DEN or FAMILY ROOM, or control unit by easy chair in family roorn, or f
who wish to design their own console or m dular WI vAll sells star., Printed ebr.l"y
tern. With fi ft. 115 VAC cord and plug. Only 13
7 x 31/2" deep. No escutcheon. bat we include template
5lld
p
all Pu.Pe., all nmuy srteml
for one, plus diagram.
wt. 3 lbs. With knobs.

-ry

lrZjrlSt ¡'i

music power
AM -FM -

AMPLIFIER

I4 -Pin. Side Mount 1.06
016 -Pin, DIP ..... .50
TO -5, 8 or 10.Plns. .29
0 a -Pin. (Mlnl DIP). .39

14 -Pin, Wire Wrap
16 -Pin, Wire Wrap

...69c
...89c

Rated: net 311
Terms: add postage
Phone Orders: Wakefield. Klass. (6171 215-3824
Retail: I6 -I8 Del Carmine St., Wakefield, hl ass.
(off Mater Street) C.O.D.'S 51A3' IIE !'IIONEII
20c CATALOG on Fiber Optics, 'ICs', Semi's, Parts

MINIMUM ORDER

$4.00

POLY PAKS

P.O. BOX

942E LYNNFIELD,MASS. 01940
101

BURGLAR -FIRE ALARM components, hardware. Free
Catalog -Information. Silmar, 133 S. W. 57 Ave., Miami,
Florida 33144.

BUGGED'"?

Rid Electronic Snoopers. Countermeasure
Equipment Catalog $1.00. Security, Box 671, Westwood,
New Jersey 07675.
LIQUID CRYSTAL. 3-1/2 digit wristwatch display. New,
with instructions for building wristwatch. Final close-out.
Less than original, factory wholesale price. $5.50 each.
Two for $10. Tricounty-Winslow, Inc., Box 5885, Grand
Central Station, New York, N.Y. 10017.
CIRCUIT board service. Circuit boards made from your
layouts. Send for information. Printed Circuits, 22 Maple
Avenue, Lackawanna, New York 14218.

MULTI -PURPOSE OSCILLATOR: 200-5000 HZ., Parts
below $8, Thousand uses, Plans $2. TECHNICAL
BOOKLET "Oscillators", $2.50. IC POWER SUPPLY, Plan
$1.90. Littleton Hobby Circuits, P. 0. Box 453. Littleton,
Mass. 01460.
FREE KIRLIAN image on 35mm slide and details on Kirlian
equipment. Systecon, Department 30, Box 417, West
Hyattsville, Maryland 20782. (301) 596-5654.

NEW COLOR TELEPHONES, booklets about connecting
telephones, and telephone accessories. Details 25 cents.

FIREPLACE heat exchanger. Use All Heat. Plans $3.00.
Jennell, 6030 O'Day Dr., Centreville, VA 22020.
LASER TUBE
$23.50; Five Laser Plans
$4.00; Catalog
$1.50, "PE 1074", Plasma Scientific, Box 1005,
Claremont, Calif. 91711.

Telephones, Box 29002-C, Queens Village, NY 11429.

Berkeley, CA 94701.

SOLARWIND ... The New Sun Power - Wind Power Newsletter ... News, Theory, Experiments, Projects, Plans ...
Sample Copy $1.00. Mamann Optics and Electronics.
Dept. K1, 836 South 113, West Allis, Wisconsin 53214.
ELECTRONIC COMPONENTS -all kinds, send for free
catalog. Epic, Box 20152A, Minneapolis, Minn. 55420.

UNSCRAMBLERS: Fits any scanner or monitor, easily
adjusts to all scrambled frequencies. Only 4" square
$29.95, fully guaranteed. Dealer inquiries welcomed. PDO
Electronics, Box 841, North Little Rock, Arkansas 72115.

ANTIQUE RADIO SCHEMATICS. Send SASE. Sterling, Box

DIAMOND NEEDLES and Stereo Cartridges at Discount
prices for Shure, Pickering, Stanton, Empire, Grado and
ADC. Send for free catalog. LYLE CARTRIDGES, Dept. P,
Box 69, Kensington Station, Brooklyn, New York 11218.

NOW: 2C

AMERICA

Free.

PHOTOLUME

TESLA COIL -40" SPARKS! Plans $7.50. Information 75
cents. Huntington Electronics, Box 2009-P, Huntington,
Conn. 06484.

AMAZING ELECTRONIC PRODUCTS -Pocket Laser, See In -The Dark, Scramblers, Penlight Strobe, Energy Devices,
TV Disruptor, Many More, All New. Catalog $1.00.
INFORMATION UNLTD., West St., Milford, N.H. 03055.
PROJECT PLANS. New projects every month. Send for
complimentary copy. Electronic Projects Newsletter, Box
1026P, Fremont, Calif. 94538.

supply plans, great for IC experimenters! 2
channel, each regulated 0-15 VDC at amp, 55.00. Easy to
build, parts available from us. B&F Industries, 3603
Glenrose Ave., Altadena, CA 91001.
POWER

P.O. SO%0.96
LOS ANGELES,CA 90099

KITS

UNIQUE
CANADIAN
ELECTRONICS
CATALOGUE
S1.00
(refundable on lst purchase)

featuring
SINCLAIR hi-fi modules and calculator
kits. We will include the new 32 -page
Project 80 hi-fi module construction
manual.

AMTRON electronic kits -over 100 types!
Speaker kits and components
American enquiries welcome!

OLaDSTORE 1l5-ELECTROIlICS

WANTED

NEVER BEFORE PUBLISHED FOR THE PUBLIC
year subscription S 3.00 --Sample copy 251

co..,

SAVE 50%. Build your own speaker systems featuring Norelco, Eminence and CTS. Famous brands from world's largest speaker factories at lowest wholesale prices. Write for
free catalog of speakers and electronic accessories.
McGee Radio Company, 1901 McGee Street, Kansas City,
Missouri 64108.

LEARN THE SECRETS OF YOUR TELEPHONE

TFLFTRONIC9

Information

GEN.

TROUBLE getting parts for projects? Let us buy them for
you. Parts buying service. Box 1026-P2, Fremont, Calif.
94538.

1FACTS
- One

PPD.

CORPORATION, PO Box 139, New York, N.Y. 10016.

HIGH FIDELITY

ROMS: $12.75.
ELECTRONIC DISCOUNT SALES, 138 N. 81st St., Mesa,
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202. 06878.

INTEL 8008: $59.45; 8038: $5.95; 1101 RAM: $2.25; 1103

GSIUBSCRIB.E

CIRCUIT design

TRIGGER SWEEP GENERATOR -improve your low cost
scope by adding solid state trigger sweep. Complete kit,

service, request quotation. TECHSERVAS, Box 1167,

7,000 SEMICONDUCTORS, 100's Electronic Circuit Kits.
Technical Reports, Energy Conservation, Computers. Cat.
50 cents. E/S Lab, Box 738, College Park, MD 20740.

DIAGRAMS, Radio, TV. etc., $2.00.

CITIZEN'S radio. Free discount catalog. Capitol Sound,
Box 3523. Des Moines, lowa 50322.
CARBON FILM RESISTORS. Brand new as low as 2-1/4
cents. FREE samples and specifications. COMPONENTS
CENTER-PE, Box 134, New York, NY 10038.

RAM: 54.50 2513, 2516: CHAR.

SPEAKER enclosure 10 x 15 x 6, walnut finish, $4.00 each
ppd. Complete case listing 50 cents. DlgtTel, Box 6585,
Toledo, Ohio 43612.

PLANS AND KITS

QUICKSILVER, Platinum, Silver, Gold, Ores Analyzed.
Free Circular. Mercury Terminal. Norwood. Mass. 02062.

HONEYWELL COMPUTER BOARDS

1736 AVENUE RD.,TORONTO,ONT.
M5M 3Y7. DEPT. PE -11

PRICES SLASHED

Due to the huge success of our anniversary sale we

',ió

F9121

Lirt.

F9082

Two popular HONEYWELL computer boards, filled with many
types of components.Transistors, diodes, precision resistors and
capacitors,zeners, heat sinks trimmers etc. Some of the F9121
boards have MADT high Freq. transistors.
4'/."x12"
STOCK NO.F9121
3 boards $2.00 9 boards $5.00
STOCK NO.F9082 2 boards $1.00 12 boards $5.00

EXOTIC COMPUTER BOARD GRAB BAG
ft
mil,rtr11
r ,`'..
a

úát

4í4':t4/?rit

JWiz

oi,7;J

.+-;1

This lot of boards are the very latest from G.E., Xerox &
other top manufacturers. These boards contain expensive
components, such as reed relays, SCRs, power transistors,
heat sinks, trimmers etc. All late (1973 & 1974) boards.
At least part on each board is worth more than our price
for the entire board. We have seen boards in this lot with
as many as 9 reed relays. Money back is not 100% pleased.
STOCK NO.F9934 7 different boards $10.00, 21/25.00
1

HIGH POWER AMPLIFIER TRANSFORMER
This transformer is ideal for high power applications.Winding
1, 64 volts ct @8 amps, tapped at 32 volts ct. @ 8 Amps.
Winding 2 18 volts ct. @ 8 amps. Winding 3, 400 volts @ .15 A.
This transformer easily delivers over 500 watts. 4'/9"x4"x4".
STOCK NO.F9905 Wt. 10 lbs.
$11.95 ea. 2/22.00
MINIMUM ORDER $5.00. Include postage, excess refunded. New
edition of our catalog now available.

A
102

DELTAYNELECTRONICS
BOX 1.

CO.

are extending the sale prices to December 21.
Our catalogues 25¢ Pa tzdabta. with. ls1. ord .r
POWER SUPPLIES. Use them in all your projects!
F0510 5v 1.5 amp. was $ 8.95 NOW Only $7.95
F1210 12v 1.5 amp. was $ 9.95 NOW Only $8.95
F1510 15v 1.5 amp. was $10.95 NOW Only $9.95
Predrilled epoxy board and all parts included except
transformer. Transformer PC-16 $4.60 extra.

Our unexcelled quality 5% carbon FILM %2
watt resistors now only .07c each, minimum of
5 each value. Get them while they last!!

All Electrolytic and film capacitors reduced 10%.
NEW ITEM!! We've got Hewlett Packard red
LEDs for only 39c each. Includes Panel mounting hardware. T-13/4 size. Part no. 5082.
If you're serious about quality then you'll
want our 'new MAN71 series of displays. They
are typically 50% brighter than the old MAN
7 series. We've got them in Red, Yellow and
f.
I, Green. All .3" char. ht. With each display we
will include one HP 5082 panel indicator LED. $4.00.
We also have 3 sizes of display bezels and filters that
will fit most of your needs. Plus we have 7400 series
logic, transistors and many other Brand New first
quality parts and kits. NO C.O.D.'s please.
Mastercharge and Bank Americard Accepted.

MASSACHUSETTS 01903
Phone (617) 388-4705

Tracy Design Corporation
15870 Schaefer

CIRCLE NO. 11 ON READERS SERVICE CARD

(373)

838 - zsoi

Detroit, Mi. 48227

CIRCLE NO. 38 ON READERS SERVICE CARD
LAR ELECTRONICS
AmericanRadioHistory.Com

.
LIVE 'IN THE :WORLD
OF' TOMORROW.... TODAY

And our FREE 164 PAGE CATALOG is packed
with exciting and unusual values in ecological and
plus 4,500 finds Ifor fun,
physical science items
study or profit ... for every member of the fámily.-

BETTER. LIFE
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A..

No. 50,225AV

IIb

"FISH WITH THE

"400 POUNDER"

Massive 12 lb. permanent magnet lifts 400
lbs-most powerful we've ever sold. Provides
instant handle for easy, safe metal carry, great
for retrieving metal parts. Releases quickly
pivoted side handle, sever magnetic grip!
Use for flame cutting, shearing, punching,
positive ground for welding; remote usage, etc.
Tie a line to it and go treasure hunting at sea! Powerful ceramic magnet lifts more
under water (best through 1" steel plate).
$65.00

MASSIVE NEW 576X

6" REFLECTOR
Great for astrophotography! Features 48" F. L.
f/8 Pyrex r0 parabolic mirror acc. to VA wave;

massive equatorial mount (usually found only
on8"); precision 2" I.D. heavy duty rack & pinion
focusing mount capable of supporting any
camera w/o special holder. Inch electric clock
drive w/ manual slow-motion control, deluxe widefield 6X finder wl crossline reticle; 3 eyepieces; 1", 48X Kellner; Va" 192X
Ramsden; Barlow to dbl & triple power. 24" wobble -free metal base.
No.

FOB.

"FISH" WITH A MAGNET
Go treasure hunting on the bottom! Fascinating
fun & sometimes profitable! Tie a line to our

Diverg....+

powerful new specially designed 150 lb. pull
Magnet
drop it overboard in bay, river, lake or
ocvari. Troll in along bottom your "treasured"
haul can be outboard motors, anchors,
other metal valuables. Has 6 stacked ceramic magnets. Lifts more than 150 lbs.
under water!

Stock No. 79,052AV

$325.00 Ppd.

3.0mW min- DEPENDABLE HI -POWERED LASER: 1.0mm beam dia., 0.8mRad
beam Diverg.

...
...

No, 71,135AV
(31/2x3W)
75-LB. PULL (1 LB.) W/ 3 CERAMIC MAGENTS
No. 71,150 AV
(1-11/16)(314")

bearings. Give your grounds unique

rural charm! Great centerpiece for
planter, flowers. Use to hold yard
light, house number, sign or as mailbox. For school, a fine "energy crisis"
does everything but pump water. Heavy
science project
gauge steel, durable outdoor finish; aluminum color w/red trim.

~MO

$11.50 Ppd.
í"

I Completely

new Catalog. Packed with huge selection of telescopes,

Stock No. 71,646AV

$24.95 Ppd.

AERONAUTICS FUN KIT (100 Experiments)
Stock No. 71,840AV

$15.95 Ppd.

COMPLETE 8 MAIL: WITH -_CHECK 'OR -M-,O:

EDMUND SCIENTIFIC CO.

300 Edscorp Building, Barringtoe, N.J. 08007

How Many

Description

Stock No.

Price Each

Total

MORE THAN

O
mi.1

magnets. magn,liers, prisms. photo Components.
croscopes,
many
Iecology and Unique lighting ,tems, parts, kits. accessories
hard -to -get surplus
100's of charts, illustrations. For hobbysts, e.perlmenters, schools, industry.
binoculars.

$6.95 Ppd.

w
4500 UNUSUAL
N:
164 PAGES

imooóli.

Price & technology breakthrough. Harness the
sun with these 2" dia. 500 mA@ .5V silicon cells
5 times more efficient per cost than ever
before! Need no plastic lens, are very flat, fit
almost any solar application. Hook up in series
for more voltage; parallel for more current.

GIANT FREE
CATALOG!

$10.95 Ppd.
$32.50 Ppd.
$44,95 FOB

(17" DESK MODEL)
No. 71.924AV
No. 85,229AV

14 LB.

130 EXPERIMENTS IN OPTICS , , ,
and photography! Optix® Experiments Kit is a complete optical and
photography lab for 130 exciting experiments. Lets you recreate the periscope, telescope, microscope, kaleidoscope! Build a 35mm reflex camera
with interchangeable lens system!
Make, develop photographic film! En¡oy the fun and fascination of having your own optics lab. Fully
illustrated 112-pg. manual, 81/2 x 11", clearly explains usage of
this stimulating kit's 114 precision engineered components.

SOLAR CELLS

MAIL,COUPON FOR,

FOOT

8 FOOT

THE MOST POWERFUL

$7.95 Ppd.

No. 71,923AV
41

$25.00 Ppd.

...
...

$11.00 Ppd.

WINDMILLS
Real -thing replicas show wind direction, wheel silently revolves on ball

Edmund's new electronic oral thermometer obsolete' glass mercury type. Seconds instead of
'
minutes, more accurate, much easier to read!
Put disposable cover (supply incl.) on flexible
.
probe, place under tongue, push button, dial
meter center, read temp fast in F.° & C.°.
92-106°F. (33-41°C.) in 1/a° increments,
97-101°F. to 1/10°. Safe, hygienic, no squinting. Compact metal case fits in
doctors', nurses' shirt pocket. Inds 9v trans batt., instrs.

No. 42,145AV ...(TAB LEADS)
PIE -SHAPED '/a 2" DIA. 100 mA. @ .5V
No. 42,146ÁV
(TAB LEADS)
15/16 OIA. CIRC. (1/16" THICK), 100 mA. @ .5V
No. 30,538AV
(WIRE LEADS)

$17.50 Ppd.

AUTHENTIC SCALED

TAKE TEMPERATURES
IN SECONDS

Stock No. 42,210AV

$150.00 Ppd.

FOB

Edmund quality, TEMoo mode, cold cathode for
long life. Completely self-contained units; solid
state Power supply; 110v AC. 0.3mW min
..
GREAT GENERAL PURPOSE LASER: 1.2mm
beam dia., 2.0mRad beam
Stock No. 7'9,061AV
$99.50 Ppd.
1.0mW min
HI -PERFORMANCE LAB LASER:P 1.2mm beam dia., 1.0mRad beam
Diverg.
Stock No. 79,050AV

$499.00

85,248AV (SHP. WT. 200 LB)

He-Ne LASERS FROM $99.50!

$8.50 Ppd.

(2 lbs.)

-lift

No. 85,238AV (131/2x5x5)

WAR SURPLUS

ELECTRIC GENERATOR
Brand new Signal Corps Model, Up to
90 volts by turning crank. Use in high
impedance relays. Charge ground &
bring up night crawlers for bait or
study. 2 Alnico Magnets alone now
worth more than original $15gov't cost.

°-ilYa.°...Araa?!w,l.F

PLEASE SEND

GIANT FREE
CATALOG "AV"

bargains.

Add Handling Chg.: WOO, Orders Under $5.00. 50C. Orders Oyer $5.05

EDMUND SCIENTIFIC CO.
700 Eeate0A

gaiI.l.g, Narringtem,

30 DAY
NOIfEY-BACK

I. 0/007

Please rush Free Giant Catalog "AV"

GUARANTEE
YOU MUST K
Tle!ttD
ATORN

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Name

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p
I

NOVEMBER 1974

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Mai
tOr
log
CIRCLE NO. 15 ON READERS SERVICE CARD

STATE

el
105

AmericanRadioHistory.Com

GOVERNMENT Surplus. How and Where to Buy in Your
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ELECTRONIC Equipment and Parts. Big 36 page Free
Catalog. Send for your copy today! Fair Radio Sales, Box
1105-P, Lima, Ohio 45802.

... Manufacturers Neéd
- :

Connectors etc., Catalog 25 cents. Computer Boards
10/$2.75 pp., ORION, Box 145, Springfield, Virginia 22150.

PERSONALS

Corporations Seeking New Products. You'll learn
how ideas become a reality!

D.C. 20021.

rack

EQUIPMENT,

chassis,

P.C.

tection

FREE PAMPHLET: "Tips on Safeguarding Your Invention."
Write: United States Inventors Service Company, 708-T
Carry Building, Washington, D.C. 20005.
FILE your own patent application. Complete information
and materials. Write: Inventor's Guide, 468-R, Goodspeed.
Road, Virginia Beach, Virginia 23451.

Directory of 500

INVENTORSI

FREE BROCHURE LISTING 1,000
CORPORATIONS which may be interested in your
invention. Many well-known manufacturers have engaged
us to locate new products. For Free brochure and
information regarding the promotion of your invention,
contact: Gilbert Adams Organization. Dept. 20L, 80 Wall
Street, New York, New York 10005.
INVENTORS! Don't sell or license your invention until you
receive our offer. Eagle Development Company, Dept. P11, 82 Wall Street, New York City 10005.

230 Park Avenue, New York, N.Y. 10017
I'd like to find out how to take action on my
idea. Send Free ."Invention Kit No.A-112"

Please Print

Name

Address

for patented, unpatented inventions.
Global Marketing Service, 2354-P Telegraph, Oakland,
California 94612.
CASH -ROYALTIES

TEKTRONIX 321A
PORTABLE ALL -TRANSISTORIZED
3", 5MHz TRIGGERED SCOPES
WITH 10:1 PROBE $495.00

'MINIATURE TRIM POTS
5K, 10K, 25K, 50K, 100K,
3/$2.00
$.75 EA.
7.MULTI-TURN TRIM POTS
r-

Similar to Bourns 3010 style 3/16"
1.

Va"

11/4" 50, 100, 500, 2000, 5000, 10,000

ohms.

3/$4.00

$1.50 ea.
PRINTED CIRCUIT BOARD

41/2"x61/2" single sided fiber
glass board, 1/16" thick, un

etched
5/$1.75
NIXIE TUBES

Similar to Raytheon 8650
tubes, with socket & data
sheet
$2.25 3/56.00

THESE PHOTO DIODE
FPA-711
ARRAYS ARE USED TO READ
SEVEN LEVEL TAPE 100 ma
SPACING
$5.95
TIS 73 N FET
$ 50
2N4891 UJT
S 50
ER900 TRIGGER DIODES 41$1.00

2N6027 PROG. UJT

$ 75

VERIPAX PC BOARD

1/16" single
paper epoxy board,

This board is

sided

41"x6/"

(standard veripax),
DRILLED and ETCHED which
will hold up to 21 single 14 pin
IC's or 8, 16 or LSI DIP IC's with
busses for power supply connections. Is also etched for 22
pin connector
$5.25

t
o,

FLY 100 VISIBLE LED
ME -4 IR LED

5.50
5.40

MCD-2 OPTO-I$OL
GREEN GAP OSL-16 LED
RED GAP OSL-3 LED
14 PIN DIP SOCKETS
16 PIN DIP SOCKETS

5 90

3.9, 4.7 OR 5.6

5 60

5.40
5.40
1.50

S.75

S30

.4 WATT ZENERS

3.9.5.6.6.80R12V.
Silicon Power Rectifier
PRV

100
200

.06
.07
.09

400
600
B00
000

.11

.15

.20

3A
.11

.16
.20
.25
.35
.45

I2A
.30
.35
.50
.70
.90
1.10

50A
.80
1.15
1.40
1.80

2.20
2.60

REGULATED MODULAR'
POWER SUPPLIES

+-15VDC AT 100 ma, 115VAC
INPUT
5VDC AT 1A, 115VAC
INPUT
IN 4148

LOS ANGELES

$19.95

$19.95
14/S1.00

Terms: FOB Cambridge
Mass. Send check or Money

Postage.
Order.
Include
Minimum Order $3.00

TORONTO

'0ERVER ?CHICAGO

C/MOS (DIODE CLAMPED)
74C 02
$ 55
$ 60
74C 10
$2.15
74C 157
74C 165
$3.50
$ 55
CD 4001
$ 65
CD 4002

2N2222
2N3055
2N5296
2N6109

CD
CD
CD

185/$1.00

NPN Si TO
NPN Si TO -3
NPN Si TO -220
PNP Si TO -220
2N4898 PNP Si TO -66
MJ2252 NPN Si TO -66
2N3638 PNP Si TO -5
2N2218A NPN Si TO -5

6V 30 OF TANT. 5/$1

20V 4.7UF TANT. 5/$1

$1.00
$ .50
$ .55
$ .60
$ .90
5/$1.00
4l$1.00

CD 4009
CD 4010
CD 4011

12V 1OUF ELECT. 51$1
50V 1000F ELECT $.40
25V 30ÚF ELECT 4/$1.00'
1103 1024 bit RAM
NEC 6003 2048 bit RAM
1101 256 bit RAM

805

4012
4013
4016
CD 4022
CD 4023
CD 4025
CD 4027
CD 4030

5311

$ 55

1.35

oiiFUf

7430

7432743774387440-

.21

7441-1.05
7442-1.00
7445-1.10
7446-1.15
7447-1.15
7448-1.20

74507472747374747475-

.18
.40
.43
.43
.75

...

CHIP

BCD
.

$8 50

CCZHARACgqTE5R

...$ 7.95

...$18.88
...$29.95

LINEAR CIRCUITS

.75
.75
.99
.95

lA REGULATOR

51.65

8220-1.50
74107- .50
74121- .60
747 -DUAL 741
74123-1.00
536-FET INPUT OPER. AMP.
74125-1.40
537 -PRECISION OP. AMP.
74126-1.40
LM 3900 -QUAD OP. AMP.
74150-1.15
LM 324-0UAD 741
74151- .95
560 -PHASE LOCK LOOP
74153-1.10
561 -PHASE LOCK LOOP
74154-1.65
565 -PHASE LOCK LOOP
74157-1.25
567 -TONE DECODER
74163-1.60
703-RF-IF AMP
74164-2.05
LM 370-AGC SQUELCH AMP
74165-2.05 .9555-2 s
HR. TIMER
74173-1.80 "3822 -TRANSISTOR ARRAY
74176-1.80
LM 380-2W AUDIO AMP
74177-1.80
LM 377-2W STERO AUDIO AMP
74181-3.60
LM 381 -STEREO PREAMP
74192-1.50
LM 382 -DUAL AUDIO PREAMP
74193-1.45
LM 311 -HI PER. COMPARATOR
74195-1.00
LM 319 -DUAL HI SPEED COMP.
75491-1.10
LM 339 -QUAD COMPARATOR

and triangular outputs good to
IMHz. Two of them can be used to
make an FM generator...$4.95

PRV

10A

100
200

.40
.70
1.10
1.70

.70
1.10
1.60

25A 1.5A
1.30 .40
1.75 .60
2.60 1.00

2.30

3.00

600

$ 56

S.35
S

51.75
5

$1.05
5.75
$2.60
$2.60
1.56
$2.20
52.60
$2.60
52.60
$2.95 ,`
5.55
,
51.15
5.98
5

51.45
52.60
51.75
51.75
S.95

51.25
$1.65

6A
.50
.70
.20

35A
1.20
1.60
2.20

3.00

145 NORFOLK ST. Cambridge Mass.

P.0_ BOX 74A
SOMERVILLE, MASS. 0214'3. TEL. (617) 547-4005,

SCR'S

TRIACS

400

S.58
S.35

11.75

-2

Similar to 8038C IC Voltage controlled oscillator, as featured in
Oct. 73 P.E. they have sine. square

.50
.02
2.39
.35

.80
1.00
.90
Minimum Order. 15.00
COLUMBIA ROAD, 11.19.
WASHINGTON, D.C. 20009
1776
1.00

LEARN ELECTRONIC ORGAN SERVICING at home all
makes Including transistor. Experimental kit -troubleshooting. Accredited NHSC, Free Booklet. NILES BRYANT
SCHOOL, 3631 Stockton, Dept. A, Sacramento, Calif.
95820.
LEARN WHILE ASLEEP, Hypnotize! Strange catalog free.
Auto -suggestion. Box 24-ZD, Olympia, Washington 98501.
DEGREE IN ELECTRONICS through correspondence. Free
catalog. Grantham, 2000 Stoner Avenue, Los Angeles,
California 90025.

SUNKEN AUDIO POWER AMPS

723 -40 +40V REGULATOR
301/748 -Hi Per. Op. Amp
LM 320 -5 or -15V REGULATOR
LM 376 -V to 37V POS REG.
741A or 741C OP. AMP
709C OPER AMP
340T-5, 12. 15, 18, 24V
POS. REG. TO -220
101 OPER. AMP.. HI PERFORM
LM 308 OPER. AMP., LOW POWER

7491-1.30

.55
.022
2.44
.40

INSTRUCTION

......511.50

CHARACTÉRxGENTATIC 511.50

LM 309K 5V

.60
.025
2.55
.50

$12.50

GEN

Si 1050 E 50 WATTS

7486- .48
7489-2.75
7490- .75

.65
.03
2.72
.50

OLD RADIO SHOWS on cassettes $1.50 per show. Free
Catalog. Radio Classics, Box 804, Mattituck. NY 11952.
1/2 INCH VIDEO TAPE. $7.25 per hour on 7" reel. Free
information. Oregon Magnetics. Box 13374, Portland,
Oregon 97213.

6.00

5316 -ALARM CLOCK

.65

-SOLID STATE.:SALES

SAXITONE TAPE SALES

$8.50

STROBE

Si 1010 Y 10 WATTS
Si 1025 E 25 WATTS

7483-1.10
7485-1.30

7492749374957496-

DIGIT

OUTPUT STROBE

profile calculator keyboard. A
2Vs" x 31/4" x 1/2" flex key.
195K-6 keyboard having 0-9, .,
K+C buttons with
off, on switch.
$6.00

7480-

1.75

CHIP

Conductive Elastometer low

.18
.18
.18
.18
.22
.22
.37
.37
.24
.18
.30
.45
.75
.37
.37
.18
.30
.33
.18
.30
.44
.37

5314 -CLOCK CHIP 6 DIGIT HOLD COUNT,

$4.75

ROM

740074017402740374047405740674077408741074117412741374167417742074267427-

orelco Cassette Cleaner
ascetic Paper Mallet Boxes
cotch Cassette SC90HE. Buy 2, get ONE FREE
0.1/2" Fiberglass Reels. Used
101/2" Metal. NAB Hole, Used
lus Postage by Weight and Zone

$ 55

$1.35
$

LABELS

CAE;5ETTE

Norelco
lain white cassette abe s. Norelco cassette cleaners, paper mailer boxes hot
metal or fiberglass reels.
ype plastic box. !emus brand cassettes. "Like new" 10.112"
loo 1000
1.9
10.99
end for open reel and cassette discount catalog.
.01
.015
.02
aoserle Labels (Multiples of 10)

$1.20
$1.25
$2.25

-CLOCK

HOD COfie.

8225 64 bit -write RAM $2.75
8223 -PROGRAMMABLE

TAPE AND RECORDERS

$ 55
$ 55

600

$4.75
59.50
$1.75

RENT 4 -Track open reel tapes -all major labels -3,000
free brochure. Stereo-Parti, 55 St. James Drive,
different
Santa Rosa, Ca. 95401.
1930-1962 Radio Programs. Reels, $1.00 Hour! Cassettes,
$2.00 Hour!... Mammoth Catalog, $1.25. AM Treasures,
Box 192F, Babylon, N Y. 11702.

Full Wave Bridges
MAN -1, RED OR YELLOW
6A
PRV
LED READOUT. 52.50
25A
.95 1.25 4.00
MAN -3 READOUTS 51.75 200
1.15 1.50 5.00
MAN -4 READOUTS 52.00 400

Send 20c for our catalog fea wring Transistors and Rectifiers;

106

Zip

í VANCOUVER

TRANSISTOR SPECIALS
2N256 PNP GE TO -3
$ .50
2N404 PNP GE TO -5
4/51.00
$ .95
2N1137B PNP GE TO -3
$ 1 95
2N1016A NPN Si TO -82
$2.50
2N2226 NPN Si TO -82
4/$1.00
MPS3393 NPN Si TO -92
$ .75
2N3866 NPN Si TO -5
5151.00
2N2369 NPN Si TO 18
$ .70
2N3767 NPN Si TO -66

TTL IC SERIES
74L00- .30
7476- .47

10 WATT ZENERS
=

SAN FRANCÍ$c

CAPACITORS

$.40 ea.

State

City

Washington Building, Washington, D.C. 20005.
PATENT Searches including Maximum speed, full airmail
report and closest patent copies. Quality searches expertly
administered with complete secrecy guaranteed. Free
Invention Protection form and "Patent Information." Write
Dept. 911, Washington Patent Office Search Bureau,
Benjamin Franklin Substation, P.O. Box 7167. Washington,
D.C. 20044.

RAYMOND LEE ORGANIZATION

MAKE FRIENDS WORLDWIDE through international
correspondence. Illustrated brochure free. Hermes, Berlin
11, Germany.

INVENTIONS WANTED

Marketing," and

Procedure". Washington Inventors Service, 422T

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If you have an idea for a new product, or a way to
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Send for our FREE "Invention Kit." It has a
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MANUALS for Govt Surplus radios, test sets, scopes. List
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INVENTORS: Protect your ideas! Free "Recommended

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%CC

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Jackson, Miss. 39209.

DIG ITAL:THEORY,DESIGN
CONSTRUCTION

LOGIC
NEWSLETTER'
SAMPLE COPY $ 1.00
LOGIC NEWSLETTER
PO B 252
WALDWICK,N.J. 07463

CIRCLE NO. 35 ON READERS SERVICE CARD
POPULAR ELECTRONICS
AmericanRadioHistory.Com

SCORE high on'F.C.C. Exams...Over 300 questions and
answers. Covers 3rd, 2nd, 1st and even Radar. Third and
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ALTAJ ELECTRONIC BARGAINS

LEARN design techniques. Electronics Monthly
Newsletter. Digital, linear construction projects, design
theory and procedures. Sample copy $1.00. Valley West.
Box 2119-B, Sunnyvale, California 94087.

CALCULATOR CHIP BONANZA!
THREE VERSIONS TO CHOOSE FROM

FCC LICENSE through tape recorded lessons. Also Radar
Endorsement. Radio License Training, 1060D Duncan,
Manhattan Beach, Calif. 90266.

Never before offered in USA. These are the
newest and easiest to use chips available to
the hobbyist today. Features: direct segment
drive for LED's, low power consumption,
single supply voltage, internal encoding of
keyboard inputs, internal keyboard debounce,
internal clock oscillator. Made by famous US
mfg. No one but ALTAJ offers calculator
chips with these sophisticated functions. All
are 28 Pin DIP. with specs. FLOATING DEC.

LEARN ELECTRONICS at home. FCC license, Communi-

cations Electronics, Satellite Communications. Free
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90028.

MUSICAL INSTRUMENTS
30% DISCOUNT name brand musical instruments. Free
Catalog. Freeport Music. 455N, Route 110, Melville, N.Y.
11746.

-8 DIGIT READOUT, MEMORY,

CHIP #2
FUNCTION

Escondido. Calif. 92028.

30%+DISCOUNT. Name Brand Musical Instruments. Free
Catalog. Continental Music, Dept. H, P.O. Box 3001,
Garden City, New York 11530.

(+,-,x, =,r-,nr)-$8.95

3 DIGIT LED READOUTS
Perfect for use with our calculator chips. 3
MAN -3 Readouts in one DIP. Properly multiplexed. New prime units. Like Litronix DL -33.
$1.25 ea. 3 for $2.95

Michigan 48197.
FREE CATALOGS. Repair air conditioning, refrigeration.
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MAILORDER MILLIONAIRE helps beginners make $500
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PIANO TUNING LEARNED QUICKLY AT HOME!
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FREE Secret Book "2042 Unique Proven Enterprises."
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5178.00 WEEKLY. Work. one hour daily. Free brochure.
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CITIZENS BAND

DEALER -DISTRIBUTORS

PC BOARD SPECIAL #3
Boards from computer eqmt. with the following items: 1-3.600 MHz Oscillator 5 VDC,
2 -Monsanto MCT2 Opto Isolator, 4-2N3642
Transistors, 1-2N2646 Unijuction, 2-7400,

1-7402, 1-7404, 2-7408, 1-7410, 1-7438,
7474, 2-7476, 1-7486, 3-7490, 1-7492,
3-7493, 1-74164, 1-74165, 1-74180, 1-9601
Plus 17 other DIP IC's. Limited quantity.
$4.95
Special Price
1-

REGULATED DC POWER SUPPLY
Brand new mfg. by WANLASS. Open Style.
DC Output 17 to 30 V. Rated 60 watts. Our
tests show these units will put out 12 VDC by
changing one resistor. Wanlass #OEM60-3.
Original cost $57.50. In original factory
boxes, with specs and schematic. Special
$19.95

JUMBO LED READOUT
.65 in. character. Twice the size of regular
readouts. Like Litronix DL747. Outperforms
SLA-3. Easy to read. Draws only 20 MA per
segment. Perfect for giant digital clocks.
$2.95 ea.

Send this Ad to:

AC LINE CORDS

PAL ELECTRONICS CO.
Ca.

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Mailorder business. Postcard brings details: Northeast
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HOW TO SELL BOOKS BY MAIL. FREE INFORMATION
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OPPORTUNITY PACKAGE! Three amazing business plans
Free details; Gray Bros., 4830 Só. 137 St., Suite 72U -t
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1

EARN :$ '500 WEEKLY
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OR MORE

Ft. Black.

wire.

for

HOBBYIST LINEAR SPECIAL

EARN $15,000 annually plus. Full year trial plan Import-

We bought too many too test. Includes many
useable devices. Buy untested and save.
LM380 2 watt audio AMP 8 for $1
LM3900 QUAD OP AMP 8 for $1
709C OP AMP
10 for $1
741C Mini DIP OP AMP 10 for $1

MINI CORE MEMORY SYSTEM
Mfg. by Dataram. Stores 180 words of 18 bits
each. With sense AMP's and associated
electronic drive circuits. A complete memory
system. We include 50 pages of data and
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schematics. BRAND NEW
Only $2.50

Now needed
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SAMPLE &
DETAILS

GT PRODUCTS. INC.. Dept

6156 Mission Gorge Ro.
San Diego. Calif. 92120

$29.95 ea.

SALE!
FACTORY NEW LED'S
Jumbo Red -Like MV5024

MALLORY FILTER.CAPS
2000MFD 30VDC
39c

SMALL SIZE

OPCOA SLA-1 LED READOUT
.33 in. Character. Left DEC. point.
Uses 7447 driver. Easier to read than
MAN -1 types. Factory prime units
$1.19 ea.

DIGITAL ALARM CLOCK IC
Through a special arrangement with
a famous U.S. MFG. we can offer
these MOS chips. This is the newest
and easiest to use alarm chip on the
market today. Features: 1. Single
supply voltage
2.
3.
4.
5.
6.

Led intensity control

Simple time set
4 or 6 digit led display
AM -PM indication
24 hr alarm with 10 min.
snooze
7. Outperforms MM5316
COMPARE THIS PRICE
WITH SPEC. SHEETS

$7.95 ea.

FAIRCHILD STYLE VOLTAGE
REGULATORS
Your Choice
1
AMP Output

Ea.
7805

7806
7812

5VDC 7815
6V DC 7818
12VDC7824

$1.25

15VDC
18V DC TO -220
24VDC CASE

---- -- -

C-MOS IC'S
RCA STYLE
44c
CD4016
CD4001
44c
CD4020
CD4002
44c
CD4049
CD4011
95c
CD4013

NEW!
89c
1.49
49c

C-MOS
7400 SERIES STYLE
1.25
49c
74C83
74C04
74C107

95c

LM 309K
95c
1
AMP 5VDC TO -3 Voltage regulator new
by national. Prime units.

ALTAJ ELECTRONICS
P.O. BOX 38544
DALLAS, TEXAS 75238
TERMS: Check or M.O. No COD.
Add 10% for PSTG and HDLG. Tex.
Res. .Add 5%

CIRCLE NO. 2 ON READERS SERVICE CARD
NOVEMBER 1974

for $1
5
Jumbo Green -Like MV5222
for $1
10 for
Mini Red -Like MV50
$1

MADE $40,000.00 Year by Mailorder! Helped others make
money! Free Proof. Torrey, Box 318 -NN. Ypsilanti,

Westminster,

recommended for experienced
hobbyists only. Limited quantity

Box 778

Array is mounted on two stacked 6 x
8 in. PC boards. Original cost $300
ea. With schematic. These 'are

BUSINESS OPPORTUNITIES

P. O.

SIX

various transistors, diodes, etc.

CHIP #3
8 DIGIT READOUT, MEMORY,
SIX FUNCTION (+, -, x, - %, 1/x) - $8.95

SPECIAL interest records available, produced by the
editors of the world's leading special interest magazines.
Send for free catalog. Record Catalog, CL, Ziff -Davis
Publishing Co., One Park Avenue, New York, N.Y. 10016.

CHIP #1
8 DIGIT READOUT, CONSTANT,
- $7.95
SIX FUNCTION (+ -, x, _ , %,

WHOLESALE! Professional Guitars, PA Systems. Altec
Speakers, 240W RMS Amplifiers. Free Catalog, Garvin,

SOLID STATE MEMORY ARRAY
Brand new, MFG. by Monolithic
Systems Corp. Consists of 16-1101
(256 Bit Ram) and associated drive
circuits. Drive circuits include 24
assorted 7400 series devices and

107

EXCLUSIVE for readers of

IElectronicsPopu
ar

DIGITALdescribed
CLOCK/CALENDAR
KIT!!
at left.

FREE

With all the options

DISC CAPACITORS
Div Capacitas fora wide range of anplml.o Iran
to low voltage transis a
PLEASE NOTE, In order te manten Our low ono. we must
74.411 that you order In EXACT mu tiple of 10 per Item:you mey. however, mix all different types And values
of rnenk maunders lot guneiry 11041ry.
Sol (d State Symons of len 1 complete selection of Ceramic

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LINEAR IC

QUAD 2 -INPUT PO5. NAND GATE
501
QUAD 2 -INPUT POS. NAND GATE WITH 0/C
504
QUAD 2 -INPUT POS. NOR GATE
500
QUAD 2 -INPUT POS. NAND GATE WITH 0/C
504
HEX INVERTER
_554
HEX IN VERTER WITH 0/C
550
QUAD 2 -INPUT P05. AND GATE
504
QUAD 2 -INPUT POS. AND WITH 0/C
504
TRIPLE 3 -INPUT POS. NAND GATE
500
TRIPLE 3-INP_U_T POS. AND GATE
500
TRIPLE 3 -INPUT POS. AND WITH 0/C
500
DUAL 4 -INPUT POS. NAND GATE
507
DUAL 4 -INPUT POS. AND GATE
500
DUAL 4 -INPUT POS. NAND WITH O/C
504
DUAL 4 -INPUT POS. NAND BUFFER
554
EXP. DUAL 2 -WIDE 2 -INPUT AND -OR -INVERT
50C
DUAL 2 -WIDE 2 -INPUT AND.OR-INVERT
504
DUAL 4 -INPUT EXPANDER
504
4 -2 -3 -2 -INPUT AND -OR -INVERT GATE
500
4 -2 -3 -2 -INPUT AND -OR -INVERT WISH 0/C
505
DUAL J-K M -S FLIP-FLOP
99c
DUAL D -TYPE EDGE -TRIG. FLIP-FLOP
990
DUAL J -K M -S F-F W/PRESET & CLEAR
99c
DUAL J -K M-5 F -F W/PRESET & CLEAR
990
DUAL J -K M'S FLIP-FLOP
990
DUAL J -K EDGE -TRIG. F -F W/SEP. CLK. & CLR.
990
DUAL -KEDGE -TRIG. F -F W/SEP. CLOCK
994
DUAL J -K EDGE -TRIG. F -F W/COM'. CLK. & CLR. 990
DUAL 4-INPUT POS. NAND BUFFER/DRIVER
550

_11 3

-22
J53
.53

-ice-

are discontinuing our line of Schottky TTL's and, while the
quantities last, they are offered at our cost.
that we cannot process back -orders for these Items
and proper credit will be issued for all items SOLO OUT.
Please note that Schottky's also have a Grouping Code of 1 and, while
there are no price breaks for them, they may be combined with your
other IC orders to take advantage of price breaks for standard TTL's and

.15

17
40

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74521
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74540
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mTorace

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ELECTROLYTIC CAPACITORS
cb

74151

All

TMp1

755

GET THE 'LED' OUT & SAVE!

for 154ment end overn0w LED
Thep: 0e 0,.ran0,4 t0 be
DRANO NEW, man1lecturer, FIRST RUN. yet Menke loony hone
power. we are 8810
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Are you confused with the wide range of prices
you see while reading through this or other
hobby magazines? Well, allow us to explain!
We at Solid State Systems are proud to offer
our customers ONLY factory FIRST -RUNS,
marked and identified with FULL manufacturer's name and part numbers. We have never
purchased a single "reject" or "seconds" unit.
The best we know, only one other hobby
supplier, also in Mid -West, has the same policy.
Most others usually buy below -spec, "functional only" units as scraps at a fraction of the
price and therefore are able to offer them at
lower prices.
The best test of this, is the fact that in the past
three years, we have never offered any "Didn't
have a chance to check them all" or "For
Experimenter's Only" items for sale in any of
our advertisements or Catalogs..
So, when shopping for parts, please remember:
Manufacturers test all their production units
and FACTORY TESTED is NOT the same as
FIRST RUN PRIME, Defective units were
tested tool

NIL

151,

Dear Customer:

FREE with each order totaling $250.00 or more if
postmarked before December 1, 1974.
PLEASE ORDER BY CATALOG NUMBER
03-12241.

INTEGRATED
CIRCUITS

DIODES
IN 770

wool

If.

164512

10003

10
17

_Inks.

-41

16005

-iRTai6r4S
TT16

7494

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15757.4

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.25

POS.

m3ii
35

00860

.19

1.6

Ill

14
10

.23

-3-

Ié
.13

i
i-7111f

410 supplied in 8', 14 , or 24-0(nDIP
(Dual in inel 0as
amic ',altar except
la NES 6. NE540 andc 5E540, which some in
TO -5 package. Voltage Regulators 51355410.
513120E. 513 50E, and 513240E are supplied
in TO -31 Diamald1 package.

All IC's

We give FREE data sheets

rust.

upon
for thou data duets that you NEED. ven for
those listed IC's that you fie 1071 buying.

YAW 54Q42 SYS4ENZ,

oaQo

6-s

108

POPULAR ELECTRONICS
AmericanRadioHistory.Com

YOU CAN SOLDER, YOU CAN
BUILD YOUR OWN

Clock/Ca en gar
SOLD Súz1L SYSTIMS0 Onto

has available a

CLOCK/CALENDAR kit containing over 120 separate electrical
components.
The clear, simplified instructions include step by
step construction procedures and ample illustrations
which will quickly take you through construction of
this versatile Clock/Calendar.

THE KIT FEATURES:
OF DATE WITH MONTH AND DAY displays month and day automatically, through
year, except for February 29.

* DISPLAY

* DISPLAY OF TIME ON 12 HOUR CYCLE - hours
and minutes displayed with A.M. and P.M.

stY car .

or.

indicators.

* A

24 HOUR ALARM OPTION - this also includes a
snooze button which delays alarm an additional 10

minutes.
* A 9 HOUR 59 MINUTE TIMING OPTION - this
allows operation of any pluggable 600 watt, 120
volt, 5 amp, 60 Hz electrical device such as a radio,
room light, stereo or coffee pot.

* EASILY VISIBLE SPERRY® DISPLAY

this

display is highly visible in a well lighted room.
An attractive case may be fabricated of wood,
plexiglas, metal or whatever you feel would make an
appropriate show -case for your finished kit.
TO

PLEASE NOTE: These kits do not include cases.

This kit when completed is a sophisticated device
which offers many additional features due to its
flexibility, here are two examples of what can be
done with this device:
1.

You may set the timer to play your radio for 15
minutes at bedtime, then the alarm allows you the
option of waking up to the radio in the morning all
automatically.

2.You may set the alarm to later start an appliance
which will operate for the duration of the setting
on the timer.

ORDER:

Order Number 01-12241 - BASIC CLOCK
minute appliance timer option. Price
Order Number 02-12241

This kit does not include the 24 hour alarm option or the 9 hour 59
$49.95

COMPLETE CLOCK - This kit includes all available options. Price

SEND YOUR ORDERS TO:
SOLID STATE SYTEMS, INC.

BOX 617
COLUMBIA, MISSOURI 65201

$65.00.

BwNKAMERICAR6

P. O.

master charge
E

OR PHONE (TOLL FREE)
11
NOVEMBER 1974

O,NQo

800-325-2981

CIRCLE NO. 36 ON READERS SERVICE CARD

- 800-325-2983
109

FREE
IC
With Every
Order*

ABOUT YOUR
SUBSCRIPTION

MAGAZINES

Your subscription .to POPULAR
is maintained on one of
the world's most modern, efficient
computer systems, and if you're like
990/0 of our subscribers, you'll never
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your subscription service.
We have found that when complaints do arise, the majority of them
occur because people have written
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at different times. For example,
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of POPULAR ELECTRONICS each month.
Other examples of combinations of
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This will greatly reduce any chance
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quickly.

$10

REDUCE YOUR PROJECT COSTS
MONEY -BACK GUARANTEE
24 -HOUR SHIPMENT
ALL TESTED AND GUARANTEED

CRAFT AUDIO

TRANSISTORS:
NPN:

2N3563 TYPE RF Amp & 0SC to 1 GHz (pl. 2N9181
2N3565 TYPE Gen. Purpose High Gain (TO-1061
2N3567 TYPE High -Current Amplifier/Sw 500mA
2N3691 TYPE GP Amp to 25mA and 50 MHz
2N3866 TYPE RF Pwr Amp 1-2 W @ 100-600 MHz
2N3903 TYPE GP Amp & Sw to t00mA and 30 MHz
2N3904 TYPE GP Amp & Sw to 100mA (T0921
2N3919 TYPE RF Pwr Amp 3-5 W @ 3-30 MHz
2N4274 TYPE Ultra -High Speed Switch 12ns
MPS6515 TYPE High-Gain Amplifier hFE 250
Assort. NPN GP TYPES, 2N3565, 2N3641, etc. 115)

6/S1.00
6/51.00
3/S1.00
6/S1.00
S1.50
6/51.00
5/$1.00
$3.00
4/51.00
3/$1.00
$2.00

PNP:

2N3638 TYPE Gen. Purpose Amp & Switch
2N4249 TYPE Low-Noise Audio Amp 10A to 50mA

ELECTRONICS

4/51.00
4/S1.00

isn't a lost art. Readers of the
Audio Amateur magazine are customizing and scratch building their
equipment with gusto and great results. Free prospectus tells all.
Box 30P Swarthmore PA 19081

MOVIE FILMS
8MM-SUPER 8-16MM MOVIES! Biggest Selection! Lowest
Prices! Free Catalog! Cinema Eight. Box PE. Chester,
Connecticut 06412.

FET's:
-CHANNEL (LOW-NOISE):
2N4416 TYPE RF Amplifier to 450 MHz (70.721
2N5486 TYPE RF Amp to 450 MHz (plastic 2N4416I
2N5163 TYPE Gen. Purpose Amp & Sw (T0.106)
254091 TYPE RF Amp & Switch (TO -106)
E100 TYPE Low -Cost Audio Amplifier
ITE4868 TYPE Ultra -Low Noise Audio Amp.
TIS74 TYPE High -Speed Switch 400
Assort. RF & GP FET's, 2N5163, 2N5486, etc. 181
P -CHANNEL
2N4360 TYPE Gen. Purpose Amp & Sw (TO -106)
E175 TYPE High -Speed Switch 1250
M104 TYPE MOS FET (Diode protected) 0.3 pF

EMPLOYMENT OPPORTUNITIES

2/S1.00
3/S1.00
3/$1.00
3/S1.00
4/$1.00
2/$1.00
3/$1.00
$2.00
3/51.00
3/S1.00
S3.00

LINEAR IC's:
309K Voltage Regulator 5V @ lA (70.31
380 2-5 Watt Audio Amplifier 34dB (DIP)
555X Timer los -1 hr, Dif. pinout from 555 (DIP)
709 Popular OP AMP (DIP/TO.SI
723 Voltage Regulator 3-30 V @ 1-250mA (DIP/TO-51
739 Dual Low -Noise Audio Preamp/OP AMP (DIP)
741 Freq. Compensated OP AMP (0IP/T0.5/MINIOIP)
2556 Dual 555 Timer sasec to hour (DIP)
LM305 Positive Voltage Regulator (T0-51
MC1458 Dual 74t OP AMP (MINI -DIP)
Assorted Linears-741/789/723, etc. (4)
1

51.90

51.50
.90
.39
.75
$1.00
$ .45
51.55
$1.25
$ .95
S2.00

N914 TYPE Gen. Purpose 100V/10mA
N3600 TYPE Hi Speed SW 75V/200mA
N4608 TYPE GP & SW 80V/400mA
1N3893 TYPE RECTIFIER Stud Mount 400 V/12 A
1N749 ZENER 4.3 Volt 400mW
15753 ZENER 6.2 Volt 400mW
1N755 ZENER 7.5 Volt 400mW
1N757 ZENER 9.1 Volt 400mW
1N758 ZENER 10 Volt 400mW
15965 ZENER 15 Volt 400mW
15968 ZENER 20 Volt 400mW
D5 VARACTOR 5-50 W Output @ 30.250 MHz, 7-70 pF
F7 VARACTOR 1-3 W Output @ 100-500 MHz, 5-30 pF
1
1

MAIL

10/S1.00

6/51.00
6/51.00

JOBS, Electronic Technicans, EE's, Tech Reps. Address
100 companies. US and overseas. Send S2.00. Marshburn,
Box 655, Wylie. Texas 75098.

REAL ESTATE
BIG...FREE...CATALOG! 272 pages! Over 2,500 top
in
FARMS, RANCHES, ACREAGES,

values

RECREATIONAL PROPERTIES, BUSINESSES, TOWN and
COUNTRY HOMES in 40 states coast to coast! Over 3,800
PHOTOS! UNITED FARM AGENCY, 612 -EP West 47th St.,
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RECORDS

2/S1.00
3/$1.00

4/$1.00
4/$1.00
4/$1.00
4/$1.00
4/$1.00
4/$1.00
$5.00
51.00

NOW! With every order of $10 or more, postmarked
OP AMP

prior to 12/31/74. FREE 739 or 749 Low -Noise Dual
included -$1 VALUE.

ORDER TODAY -All items subject to prior sale and prices subject
to change without notice. DATA SHEETS Included with all items.
WRITE FOR FREE CATALOG offering hundreds of semi.
conductors not listed here. Send 100 stamp.
TERMS: All orders prepáid. We pay postage. $1.00 handling
charge on orders under $10. Calif. residents add 6% sales tax.

A DVA

EMPLOYMENT INFORMATION

DIODES:
1

ELECTRONICS/AVIONICS EMPLOYMENT OPPORTUNITIES. Report on jobs now open. Details FREE. Aviation
Employment Information Service, Box 4240E. Northport,
New York 11768.

OLDIES. 45rpm. Free Catalog. Corny's Record Shop, Box
335TP, Mason, Ohio 45040.

RUBBER address stamps. Free catalog. 45 type styles.
Jackson's. Box 443G, Franklin Park, III, 60131.

MAGNETS
MAGNETS. All types. Specials -20 disc, or 10 bar, or 2 stick,
or 8 assorted magnets, $1.00. Magnets, Box 192-H,

Randallstown, Maryland 21133.

DO-IT-YOURSELF
ELECTRONICS

BOX 4181-J, WOODSIDE, CA 94062
Tel. (415) 851-0455
CIRCLE NO. 1 ON READERS SERVICE CARD

Let us know 8 weeks in advance so that you won't
miss a single issue of POPULAR ELECTRONICS.
Attach old label where indicated and print new
address in space provided. Also include your mailing label whenever you write concerning your subscription. It helps us serve you promptly.
Write to: P.O. Box 2774, Boulder, CO 80302, giving the following information:
['Change address only.
Enter new subscription.
Extend subscription.
1 year $6.98
Payment enclosed (1 extra BONUS issue)

Bill me later

FREE WINDPOWER HEAT Cuts fuel bills, beats shortages.

Encyclopedic windmill/generator report gives sources.
costs, instructions, capacities, specifications. Now $2.98
from Energy Unlimited, Dept. 611, 219 Thorndike Street,
Palmer, Mass. 01069.

TREASURE FINDERS

PLASTICS
FAMILY FUNI OUTDOOR ADVENTURE! Find valuable
coins and treasure with world famous metal detectors. Free
illustrated booklet. Detectron, Dept. PE, Box 243, San
Gabriel, Calif. 91778.
TREASURE FINDER locates buried gold, silver, coins.
treasures. 5 powerful models. $19.95 up. Instant financing
available. Free catalog. Dealer inquiries invited. Relco,
Dept. A-33, Box 10839. Houston. Texas 77018.

¿4M4roue?

RUBBER STAMPS

LABEL

-a,

r,w-AFFIX
d

w
rb

áz
-

a o

CASTOLITE pours like water, hardens like glass without
heat. Crystal clear, colors. Embed flowers, seashells,
mementos, anything. Make fine gifts. Form flexible molds
over any pattern, size. Reproduce your own designs in
plastics, candlewax, metal, plaster, cement. Send 50 cents
for illustrated Manual and New Mold Catalog. Profitable.
CASTOLITE, Dept. 74M/PE, Woodstock, III. 60098.

ELECTRICAL SUPPLIES & EQUIPMENT

HYPNOTISM

Portable Platers, Supplies and
"Know -How." Build your own tanks for nickel, chrome,
etc. Easy -to -install PVC liners. Rectifier components -all

SLEEP learning. Hypnotic method. 92% effective. Details
free. ASP Foundation, Box 23429EG, Fort Lauderdale,
Florida 33307.
FREE Hypnotism. Self -Hypnosis. Sleep Learning Catalog!
Drawer H400, Ruidoso, New Mexico 88345.

Ó
-

o
O

a,z

n
O,

o
PLATING

Equipment,

sizes. Schematics, parts lists, formulas, operating
instructions for all plating. Guaranteed to save you 25%75%. Some good units for sale. Write for details. Platers
Service Company, 1511 -PE Esperanza, Los Angeles, Calif.
90023.

AMAZING self-hypnosis record releases fantastic mental
power. Instant results! Free trial. Write: Forum (AA11), 333
North Michigan, Chicago 60601.

110

-16;

E
E

Add') postage: $2 per year outside U.S., its poss. & Can.

POPULAR ELECTRONICS
AmericanRadioHistory.Com

Quality

Popular Electronic

Electronic Components

HOME ENTERTAINMENT FILMS

MINIATURE ALUMINUM

- -

make
COLOR ACTION SPORTS FILMS (Also B& W)
a
great gifts in Super 8 and Standard 8. Treat yourself
friend. In color. 516.95 each plus 50 cents postage; 57.95
plus 50 cents B&W for 200' reel. Select from Columbia,
Castle and Sponlite Catalogs at 25 cents each (stamps or
coins, please). Be on time for Christmas, send your
quarters today. SPORTLITE, Elect-11 Dept., 20 North
Wacker Drive, Chicago. Illinois 60606.

NOVEMBER 1974
ADVERTISERS INDEX

2.2 UFD:30V
3.3 UFDr35V
4.7 UFD/35V

SERVICE NO.

44
3

Alpha Electronics

Altaj Electronics

107

Ancrona Corp

Audioanalyist, Inc
Audio-Technica U.S., Inc

CREI

Clifford's Hi -Fi Wholesalers

Cobra Product of Dynascan Corporation
Continental Specialties Corp

Delta Electronics Co

102

Delta Products, Inc

Digi-Key Corporation

EICO

Edmund Scientific Co
Edmund Scientific Co

89
105
112
98

Electronics
GTE Sylvania

Great American Sound Company, Inc., The

Greenlee Tool Co

20
21

29, 30, 31

Heath Company

Illinois Audio
International Electronics Unlimited

99
100

Johnson Co., E.F.

Kroch's & Brentano 's

Lafayette Radio Electronics

McIntosh Laboratory, Inc

MITS, Inc

Midwest Hifi Wholesale

24
8

NRI Schools

Phase Linear Corporation

Pickering

Poly Paks

Radio Shack

SAE,

Shure Brothers Inc
Solid State Sales

& Co

101

THIRD COVER
16

Inc

27
106

Solid State Systems, Inc
Southwest Technical Products Corp

Tracy Design Corporation

39
40

Tri-Star Corp
Trigger Electronics

108, 109
67
102
6

U.S. Pioneer Electronics Corp

SECOND COVER,

Vl Products

Vintage Radio

NOVEMBER 1974

Warehouse Sound
CLASSIFIED ADVERTISING

FOURTH COVER

...99,

100, 102, 106, 107, 110, 111

330 UFD/25V

24c

44c

35c

32c

37c

30c

27c

49c

39c

35c

12c

470 UFD/16V
470 UFD/25V

33 UFD/'6V

15c

12c

Itc

1000 UFD/16V

49c

39c

35c

33 UFD/25V

17c

13c

12c

..75c

60c

55c

47 UFD/16V

17c

14c

13c

1000 UFD/25V
2200 UFD/16V

60c

55c

19c

15c

14c

UFD/25V....

'0.

75c

lea

1185

.165

E5930..

T0.1o6

.21

.185

.165

.21

.185
.160

.165
.145

E1023690
EN2907.

10.106
70.106

.21

.18

2193192..

TO. 96

.22

.185
.185
.190
.190
.175
.175
.175
.175
225

.165
.165
.175
.175

.740
.290

.220

.21

.72

.190

'0- 98

.175

.190

.70

.175

.160

10-105

.20
.22

.175
190

T0.105

.20

.175

.160
.175
.160

753394..

"0406

.22
.25
.27
.37

.190
.225
.240
.790

2115137.. 10.106

.77
.19
.19

.240
.170
.170

25s139.. 10.106

.19

.110

.171
.200
.770
.260
.220

.21

TO. 96

253565.. 10.100
253636A. T0.105
10.105
253641.

.20
.20

253645.. TO -105
253904.. T0 92

.20
.25

T0. 92

.21

.175

.22

10.106

"0106

90.

2194124

254401.. TO
755087 . 10

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92
92

.32
.17

10.106
10.106
205134,
255138.. 10.106
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.260
.220
.150
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150

.170
1.30

1.35

.200

170

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253055..

.160
.160
.160
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.240
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2915129.

.150
.150
.150

255457..

.350

.380

.44

TO.

1.09

020

TO-

.375

Curren. Gain of 5.000

IOmA.

320

.290

WATT CARBON COMP.

1/4

&92

45/2

RESISTORS

of the 70 standard 10% values (10-5.6M) 'l. W Resistors
(350 pcs_) Sorted by value 512/set 2.4 ore S11/set 5-9 are 510/set.
5 each

,,u

I!0.0í11n

.. J

inL..

In-

00ílld,. i4,rrid,á,q,.

P, ti

189 89(8

3011

..P,rifirutinn í!30n.

,tul.! tf- I.

25 V. DISC CAPS
Value

.001....

3.5c

.022

6c
9c

3.5c
3.5c
5.3c
7.5c

.047....
.047....

6c
9c

12c

7h,r

,, 6
u

0..00!(117111.

100

blvdvl
,

VOLTAGE REGULATORS

1130

5V
12V

1131

15V

1129

1.80 ea.

LEE -APOLLO

.t1

600mA

500mÁ .11
450mA

Litronix 1100 Calculator

DISPLA Y

$5.00
5 V. common 9

pin tube base

Winter Edition

This latest edition helps you get it
together with a score of mind -absorbing, build -it -yourself projects
all with complete construction plans,
including parts lists and printed circuit board patterns, Many products
are unique designs, not available
anywhere else. And in all cases, you
save money by'building your own!
1975 Winter Edition $1.25 3146.
Back issues available: 1974 Spring $1.25 #41, 1974
Winter $1.25 #64, 1973 Spring $1.25 #2, 1971
Winter $1.50 4133, 1970 Spring $1.50 #14.
Order by number from
N.Y., N.Y.
Ziff -Davis Service Div., 595 Broadway
10012. Enclose an additional 35c per copy for postage
and handling. (Outside U.S.A. all magazines are
$2.50 per copy, postpaid.)

-I

(PAYMENT MUST BE ENCLOSED WITH ORDER°

8 Pin DIP Solder 35c

éÉ0

14 Pin DIP

FREE i;
SPECIAL
INTEREST
RECORD
CLQG

CATOne

Park Ave., New York, N.Y. 10016.

PRICE

S29.95

24 Pin DIP Solder 51.25

',....-17.,

LINEAR INTEGRATED CIRCUITS
... 51.00

10/1 9.50

567 Minidip TON DECODER
53.57

10/530.00

723 Dip VOLTAGE REG 51.15

101510.00

741

10/570.50

748 Minidip OP

555 Minidip TIMER

565 DIP
558

747 Dip DUAL OP AMP 51.10

53.57

10/130.00

Minidip DUAL OF AMP
Minidip

804

10/5 7.50

AMP... 504
AMP... 000

10/5 4.51
10/S 5.50

DIGITAL TTL
ION

74075
74015

/4020

.. 32t

204

32c

7437N
'4311

32c

,64

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284

35c

311

35c

31,
44,

14030

7400,
74051

740611

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14070
14061

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740... 3.

..32c

741101

741111..35c
74131
14161
74175

636

744301. 51.51
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324

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7454,4

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324

284

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05,

12,

501

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70)

174

7475N

for

11.20

741810 53.38

424
99c

74182551/7 51.04
10192451/0 51.60

53.00

35c

14123011.11

52c

454

51 43

52c

75,

741019 51 61
741501151 S6

51 30

5160
741964f2.75 5141

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124

741515s120

S1.01

'419.3110

14131
7474N

11.74

1414445703 51.80

5114

7416511 51.4e

1411111

37c

51.74
51.14

51.07

741210

360

14102N 51.95
141434 51.05

S1.30
51.19

51.07

334

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