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of 14024 14278 ee ° Popular Electro rocs AmericanRadioHistory.Com Introducing the mobile that can move And ike all Cobras it comes equipped you out of the world of the ordinary with such standard features as an easy - and into the world of the serious CB'er. to -read LED channel indicator. The Cobra 138XLR Single Sideband. Switchable noise blanking and limiting.

Sidebanding puts - p An RF/signal strength meter. And you in your own I SB LSr Cobra's exclusive DynaMike gain control. private world. A - d ' You'll find the 138XLR SSB wherever world where there's Cobras are sold. Wnich is almost every- less congestion. t, where. Because Cobra's got a nationwide More privacy. J network of dealers and Authorized More time to talk. - Service Centers offering sales, installation, It's all possible because instead of 40 service and advice. So come on in. channels you get your choice of 120 And move on up. channels. 3oth AM and SSB. And instead of 4 watts of legal power you get 12 watts of legal power. So you get almost double the range of AM. obra With the 138XLR Single Sideband Punches through loud and clear. there's less background noise and less Cobra Communications Products interference. So there's cleaner, clearer DYNASCAN CORPORATION reception. Because like all Cobras, the 6460 W. Cortland St., Chicago, Illinois 60635 Wnte for color brochure 138XLR SSB is engineered to punch EXPORTERS: Ernpre Plamvrew. N Y CANADA: Atlas Electrorucs Toronto tnrough loud and clear. Even in crowded metropolitan areas. CIRCLE NO. 7 ON FREE INFORMATION CARO 1 .JA

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AmericanRadioHistory.Com New integrated circuit technology and a major electronic breakthrough brings you the world's smallest citizens band transceiver.

Scientists have produced a personal com- SUPERIOR FEATURES munications system so small that it can easily Just check the advanced PocketCom fit in your pocket. It's called the PocketCom features now possible through this new circuit and it replaces larger units that cost con- breakthrough: 1) Incoming signals are amp- siderably more. lified several million times compared to only MANY PERSONAL USES 100,000 times on comparable conventional An executive can now talk with anybody in systems. 2) Even with a 60 difference his office, his factory or job site. The house- in signal strength, the unit's automatic gain incoming The PocketCom measures approximately '/" wife can find her children at a busy shopping control will bring up each signal to x 1 %" x 5Z" and easily fits into your shirt center. The motorist can signal for help in an a maximum uniform level. 3) A high squelch pocket. The unit can be used as a personal The salesman, the sensitivity (0.7 microvolts) permits noiseless emergency. construction communications link for business or pleasure. foreman, the traveler, the sportman, the operation without squelching weak signals. hobbyist-everybody can use the PocketCom. LONG RANGE COMMUNICATIONS GIVE IT A REAL WORKOUT Remember the first time you saw a pocket The PocketCom's range is limited only by calculator? It probably seemed unbelieveable. its 100 milliwatt power and the number of The PocketCom may also seem unbelieveable metal objects between units or from a few so we give you the opportunity to personally blocks in the city to several miles on a lake. examine one without obligation. Order only Its receiver is so sensitive, that signals several a basis. Then really test miles away can be picked up from stronger two units on trial them. Test the range, the sensitivity, the citizens band base or mobile stations. EXTRA LONG BATTERY LIFE convenience. Test them under your everyday VERY SIMPLE OPERATION The PocketCom has a light -emitting diode conditions and compare the PocketCom with To use the PocketCom simply turn it on, low -battery indicator that tells you when larger units. your 'N' cell batteries require replacement. extend the antenna, press a button to trans- After you are absolutely convinced that the The integrated circuit requires such low mit, and release it to listen. And no FCC PocketCom is indeed that advanced product power that the two batteries, with average license is required to operate it. The Pocket - breakthrough, order your additional units, 14 use, will last weeks without running down. Corn has two Channels-channel and an crystals or accessories on a priority basis as optional second channel. To use the second one of our established customers. If, however, channel, plug in one of the 22 other citizens the PocketCom does not suit your particular band crystals and slide the channel selector to requirements perfectly, then return your units the second position. Crystals for the second within ten days after receipt for a prompt and channel cost $7.95 and can only be ordered courteous refund. You cannot lose. Here after receipt of your unit. is your opportunity to test an advanced space-age product at absolutely no risk. EXECUTIVES POLICE MOTOR ISTS A COMPLETE PACKAGE Each PocketCom comes complete with mercury batteries, high performance Channel 14 crystals for one channel, complete instruc- tions, and a 90 day parts and labor warranty. The PocketCom components are equivalent to To order by mail, simply mail your check for 112 transistors whereas most comparable a $19.95 per unit $39.95 for two) plus SHOPPERS HIKERS FOREMEN (or units contain only twelve. $2.50 per order for postage, insurance and The PocketCom can be used as a pager, an handling to the address shown below. (Illinois intercom, a telephone or even a security residents add 5% sales tax). But don't delay. device. Personal communications is the future of A MAJOR BREAKTHROUGH MULTIPLEX INTERCOM communications. Join the revolution. Order your PocketComs at no obligation today. The PocketCom's small size results from a Many businesses can use the PocketCom as breakthrough in the solid state device that a multiplex intercom. Each employee carries a made the pocket calculator a reality. Scien- unit tuned to a different channel. A citizens tists took 112 transistors, integrated them on band base station with 23 channels is used to NEW LOW PRICE! a micro silicon wafer and produced the page each PocketCom. The results: an inex- Credit Card Buyers Call Toll -Free world's first transceiver linear integrated cir- pensive and flexible multiplex intercom cuit. This major breakthrough not only re- system for large construction sites, factories, $1911 duced the size of radio components but im- offices, or farms. proved their dependability and performance. unit NATIONAL SERVICE 'Sold originally for $40 per unit. ZEE IR The PocketCom is manufactured exclusive- ly for JS&A and is the unit currently used on the hit TV show, Charlie's Angels. JS&A is NATIONAL BEEP -TONE PAGING SYSTEM America's largest supplier of space-age prod- SALES You can page another PocketCom user, ucts-further assurance that your modest in- within close range, by simply pressing the vestment is well protected. The PocketCom GROUP PocketCom's call button which produces a should give you years of trouble -tree service, Dept. PE One JS&A Plaza beep tone on the other unit if it has been left however, should service ever be required, Northbrook, III. 60062 (312) 564-9000 in the standby mode. In the standby mode simply slip your 5 ounce PocketCom into its CALL. TOLL -FREE 800 323-6400 handy mailer and send it to our prompt na- the unit is silent and can be kept on for weeks In Illinois call . (312) 498-6900 without draining the batteries. tional service -by -mail center. ©JS&A Group, Inc ,1977

CIRCLE N0. 56 ON FREE INFORMATION CARD FEBRUARY 1978

AmericanRadioHistory.Com akn

Hobbyist or professional, there cords or jumpers needed-just NO. OF 14 -PIN DIP SUGG. OTHER * are probably a lot of circuits you MODEL TIE -POINTS CAPACITY LIST FEATURES lengths of ordinary #22-30 AWG build just for the fun of it. And a lot PB-6 630 6 $15.95 Kit -10 -minute solid hookup wire. assembly you'd like to build, but never get Circuits go together as quickly as PB-100 760 10 19.95 Kb-with larger around to. Capacity you can think them up. And parts One reason is the cost of parts. PB-101 940 10 29.95 8 distribution are re -usable, so as your "junk box" buses, higher Parts you buy for one project, but capacity builds, you build more and more can't re -use... because you haven't PB-102 1240 12 39.95 Large capacity, projects for less and less money. moderate price time to take them carefully apart. Before you invest in your next PB-103 2250 24 59.95 Even larger Or because of heat and mechanical capacity: only project, invest in a CSC breadboard. damage that occur when you do. 2.7C per tie-poInt See your dealer or order by phone: PB-104 3060 32 79.95 Largest capacity: Now, there's an easier way that lowest price 203-624-3103 (East Coast) or 415- can save you big money on parts per tie -point 421-8872 (West Coast) - major P8.203 2250 24 80.00 Built-in 1% -regu- and hours on every project, as well: lated 5V, IA low- charge cards accepted. You've got Proto-Board ripple power nothing to lose...and lot Solderless supply a to gain. Breadboards. PB-203A 2250 24 129.95 As above plus CONTINENTAL SPECIALTIES CORPORATION Now, assembling, testing and separate ''n -amp +15V and -15V modifying circuits is as easy as internally adLst- able regulated pushing in-or pulling out-a lead. outputs IC's, LED's, transistors, resistors,. 70 Fulton Terrace, 3ox 1942, New Haven, CT 06509 'Manufacturer s suggested list 20-624-3103 TWX 710-465-1227 Prices capacitors... virtually every kind of and specifications subject to change without no ice WEST COAST: 351 California St., San Francisco, CA 94104, 415-421-8872 TWX 910-372-7992 component...connect and inter- GREAT BRITAIN: CSC UK LTD. connect instantly via long -life, nickel - Spur Road, North Feltham Trading Estate, Feltham, Middlesex, England. silver contacts. No special patch 01-89(-8782 Intl Telex: 851-881-3669 MEXICO: ELPRO, S.A., CIRCLE NO. 11 ON FREE INFORMATION CARO Mexico City 5-23-30-04 CANADA: Len Finkler Ltd.; Ontario 1977, Continental Specialties Corporation

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Feature Articles

Coming 21 TURNTABLE DRIVE SYSTEMS /.Julian Hirsch Next 46 NOW: TRANSFER PRINTED PC PATTERNS WITH NO CAMERA OR CHEMICALS! / G.D. Fisher Month New direct -transfer film has a number of uses. 58 THE NEW MICRO/MINI CASSETTE TAPE FORMATS / Ivan Berger PRACTICAL GUIDE TO 60 OSCAR: COMMUNICATIONS SATELLITES FOR EVERYONE / Harry L. Helms, Jr. HOME MULTI -TRACK You can use Oscar transmissions without being a licensed ham. TAPE RECORDING 65 HOW TO UPGRADE A BASIC ELF MICROCOMPUTER / Edward M. McCormick Software for TTY, tape cassette read/write, music, etc. MICROPROCESSOR MICROCOURSE, PART I Construction Articles EXPERIMENTING WITH CIRCULAR SWEEP 41 LOW-COST EPROM PROGRAMMER / Dan Vincent Unit programs 1702A, 4702A, and 8702A EPROM'S inexpensively. HOW TO DESIGN & BUILD 48 BUILD AN AUTORANGING DIGITAL CAPACITANCE METER/ David H. Dage POWER SUPPLIES Autoranges from 1 pF to 1 /.tF and I µF to 4000µF. 55 BUILD A STEREO BLEND CONTROL / Paul E. Miller TEST REPORTS Varies channel.separation to suit your taste. Model PS -X5 Turntable 74 USING EXISTING HOUSE WIRING FOR COMPUTER JVC P-3030 Stereo Preamp REMOTE CONTROL, PART 3 / Dan Sokol, Gary Muhonen, and Joel Miller Dahlquist DQ-1 W Low -Bass Construction and software. Module Columns

15 STEREO SCENE / Ralph Hodges The Digital Countdown and Other Timely Matters. 78 SOLID STATE / Lou Garner POPULAR ELECTRONICS, February 1978, Vol- ume 13, Number 2, Published monthly at One Park The Microwave Challenge. Avenue, New York, NY 10016. One year subscrip- tion rate for U.S. and Possessions,$12.00; Cana- 82 EXPERIMENTER'S CORNER / Forrest M. Mims da, $15.00; all other countries, $17.00 (cash or- The Schmitt Trigger. ders only, payable in U.S. currency). Second Class postage paid at New York, NY and at additional 84 HOBBY SCENE Q&A / John McVeigh mailing offices. Authorized as second class mail by the Post Office Department, Ottawa, Canada, and 92 COMPUTER BITS / Leslie Solomon for payment of postage in cash. POPULAR ELECTRONICS including ELECTRON- Music Generators and Other Items. ICS WORLD, Trade Mark Registered. Indexed in the Reader's Guide to Periodical Literature. 97 AMATEUR RADIO COPYRIGHT o 1978 BY ZIFF-DAVIS PUBLISH- The Ideal Novice Ham Shack. ING COMPANY. ALL RIGHTS RESERVED. Ziff-Davis also publishes Boating, Car and Driv- er, Cycle, Flying, Modern Bride, Popular Photogra- phy, Skiing and Stereo Review. Material in this publication may not be repro- Julian Hirsch Audio Reports. duced in any form without permission. Requests for permission should be directed to Jerry Schneider, Rights and Permissions, Ziff -Davis 27 GARRARD MODEL GT25 AUTOMATIC RECORD PLAYER Publishing Co., One Park Ave., New York, NY 10016. 29 SANSUI MODEL AU -717 INTEGRATED AMPLIFIER Editorial correspondence: POPULAR ELEC- 32 SHERWOOD MICRO/CPU 100 FM TUNER TRONICS, 1 Park Ave., New York, NY 10016. Edi- torial contributions must be accompanied by re- turn postage and will be handled with reasonable care; however, publisher assumes no responsi- bility for return or safety of manuscripts, art work, Electronic Product Test Report or models. Forms 3579 and all subscription corre- spondence: POPULAR ELECTRONICS, 85 TEN-TEC CENTURY/21 HAM CW TRANSCEIVER Circulation Dept., P.O. Box 2774, Boulder, CO 80302. Please allow at least eight weeks for change of address. Include your old ad- dress, enclosing, if possible, an address label Departments from a recent issue. The publisher has no knowledge of any 4 EDITORIAL / Art Salsberg proprietary rights which will be violated by the making or using of any items disclosed In this The Sound Recording Centennial. issue. 6 LETTERS 8 NEW PRODUCTS MPA 14 NEW LITERATURE Member Audit Bureau of Circulations 95 SOFTWARE SOURCES 119 OPERATION ASSIST FEBRUARY 1978 3

AmericanRadioHistory.Com Popular Electronics®

JOSEPH B. MUSICS Publisher

ARTHUR P. SALZBURG Editorial Director LESLIE SOLOMON Editorial Technical Editor

JOHN R. RIGGS Managing Editor

IVÁN BERGER Senior Editor THE SOUND RECORDING CENTENNIAL

ALEXANDER W. SURAWA It's 100 years since Edison was granted a U.S. patent on his "." Features Editor Although it wasn't really the first talking machine (Edison's patent application was EDWARD I. BUXBAUM for an "Improvement in Phonograph or Speaking Machines"), it marked the Art Director beginning of the audio recording industry. JOHN McVEIGH A variety of refinements followed to improve sound quality of repeatable -playing Associate Editor recordings. But milestones-embarking in a new direction that displaces other ANDRE DUZANT methods-are of most importance. One such benchmark was Emile Berliner's Technical Illustrator development of the lateral record disc and its reproducing machine, the CLAUDIA TAFARO Gramaphone, in 1888. Production Editor The next milestone was electrical recording, made in 1925 by the Victor Talking Machine Company. Gradual improvements in the record DORIS A. MATTHEWS -playing medium, Editorial Assistant playback machines, et al., continued until the introduction of the variable reluctance magnetic pickup and 331/2- and 45 -rpm fine -groove discs in the late Contributing Editors Hal Chamberlin, Lou Garner, Glenn Hauser 1940's. Here we had another revolution in the making -the beginning of "high

Julian Hirsch, Ralph Hodges, Forrest Mims fidelity." I witnessed this significant development point, as many of you did. Ray Newhall, Wilfred Scherer Interestingly, when CBS (developer of the LP record as we know it today) bought JOSEPH E. HALLORAN Columbia Records in 1938, it commenced to make all recordings at both 78 -rpm Advertising Director and 331/2 -rpm speeds, using the latter as "safeties" in the event a 78 -rpm master JOHN J. GORTON was damaged. So there was a large LP record library just waiting for the day when Advertising Sales the new -speed records would be introduced to the public.

LINDA BLUM The last true milestone for disc sound recording occurred in the late 1950's, I Advertising Service Manager feel, with the introduction of the stereophonic disc. It used Alan Dower Blumlein's FRANCES VERKES 45-45 system, developed about 25 years earlier. (Perhaps at some future time I'll Executive Assistant look back and say that the 1969 and 1970 demonstrations of qúadraphonic

records were next, but since quadraphony hasn't displaced stereo at this time, I EDGAR W. HOPPER Publishing Director won't consider it yet.) Of course, it wasn't the singular advent of stereo that accounted for public ZIFF-DAVIS PUBLISHING COMPANY Editorial and Executive Offices recognition of its more realistic sound reproduction, nor was stereo alone One Park Avenue. New York, New York 10016 responsible for the burgeoning growth of the hi-fi component industry. Actually, it 212-725-3500 was a I Philip B. Korsant, President part of series of happenings, much of which occured in what consider to be Furman Hebb, Executive Vice President hi-fi's "big accomplishment decade"-the 1960's. During this period, for example, John R. Emery, Sr. Vice President, Finance and Treasurer solid-state hi -fl equipment challenged vacuum -tube designs; stereo FM was Phillip T. Heffernan. Sr. Vice President Edward D. Muhlfeld, Sr. Vice President launched; the Dolby professional noise reduction system was adopted by many Philip Sine. Sr Vice President recording studios; 8 -track cartridge and cassette systems were entered into the Lawrence Sporn, Sr. Vice President. Circulation and Marketing Frank Pomerantz, Vice President, Creative Services marketplace; electronic music infiltrated pop music, spurred by the enormous Arthur W. Butzow, Vice President. Production sales success of the "Switched -on Bach" LP; new recording engineer techniques George Morrissey Vice President Sydney H. Rogers, Vice President were employed; and so on. Sidney Holtz, Vice President Now we are enjoying the benefits of all those little continual pushes and shoves Albert S. Traina, Vice President in technology that enable reproduced sound to inch forward toward even better Paul H. Chook, Vice President Edgar W. Hopper, Vice President audio while we await another burst of advancement. Will it be digitized recording? Robert N. Bavier, Jr., Vice President Four -channel FM? Stereo AM broadcasts? An automatic room acoustics delay Charles B. Salon. Secretary line? Phono pickups using new video disc technology such as a laser device? A W. Bradford Briggs, Vice Chairman new record material chemical mix that improves record discs as much as new tape formulations enhanced cassettes?

ZIFF, CORPORATION Or will technology turn inward and refine a discarded principle? After all, a William Ziff, Chairman direct -drive record playing system in the 1920's was abandoned for many years in I. Martin Pompadur, President favor of the idler -wheel rim drive. Now the former is growing in popularity. Today, a Hershel B. Sarbin, Executive Vice President few recording outfits even ignore computer-controlled equipment and tape Midwestern Office machines, now pursuing direct -disc recording; and some very few amplifier The Pettis Group. 4761 West Touhy Ave., manufacturers still use vacuum tubes. Judging from what sound recording history Lincolnwood, Illinois 60646, 312 679-1100 Thomas Hockney, Michael Neri, Gerald E. Wolfe revealed in the past, one never knows what strange twists the future will bring. Western Office 9025 Wilshire Boulevard, Beverly Hills, CA 90211 213-273-8050; BRadshaw 2-1161 Western Advertising Manager: Bud Dean Japan: James Yagi Palace Aoyama; 6-25, Minami Aoyama 6 Chome, Minato-Ku, Tokyo 407-1930/6821. 582-2851

4 / POPULAR ELECTRONICS

AmericanRadioHistory.Com B tter s eo records are 2h¢ res ,) te playback. pick-ups

EXPANDED CONTACT AREA

EXPANDED CONTACT AREA

© Stanton Magnetics, Inc., 1977 Sca,nirig Electron Beam Microscope photo of Stereohedron Stylus; 2000 times magnification. Brackets point out wider contact area. Enter the New Professional Calibration StañdaÑ,!ánton's 8815

The recording engineer can only produce a product as good as his ability to analyze it. Such.analysis is best accomplished through the use of a playback pick-up. Hence, better records are the result of better playback' pick-up.. Naturally, a calibrated pick-up is essential. There is an additional dimension to Stanton's new Professional Cal- ibration Standard -cartridges. They are designed for maximum record protection. This requires a brand new tip shape, the Stereohedron®, which was developed for not only better sound characteristics but also the gentlest possible treatment of the record groove. This cartridge pos- sesses a revolutionary new magnet made of an exotic rare earth com- pound which, because of its enormous power, is far smaller than ordinary magnets. Stanton guarantees each 881S to meet the specifications within exacting limits. The most meaningful warranty possible, individual calibra- tion test results, come packed with each unit. Mike Reese' of the famous Mastering Lab in Los Angeles Whether your usage involves recording, broad- the Calibration Standard, the 8815 says: "While maintaining or home entertainment, your choice sets new levels for -tracking and high frequency respónse. It's casting an audible imprówement. We use the 881S exclusively for shóuld be the choice of the professionals ... the calibration and evaluation in our operation" STANTON 881S. sraNron For further information write to Stanton Magnetics, Terminal Drive, Plainview, New York 11803 CIRCLE NO. 51 ON FREE INFORMATION CARD 5

AmericanRadioHistory.Com calculators ("The HP -25 as a Clock and Tim- and 1. Enter three times to fill the stack with er," August 1977). Just before I received my 1's. Press clx and run the program for one

copy of PE, I had written a two-step timing minute using an accurate timing source. At program which had more resolution than Mr. the end of a minute, a number of about 500 Peters'. In my program, the elapsed time is should be displayed. Multiply its reciprocal by not displayed until the timer is stopped. 60 to obtain the constant for your calculator, To use it you must first go through an ini- which will be used each time the program is

tialization process that takes about a minute. run in place of the 1 in the first initialization. This need be done only the first time the pro- Since the display with this program is in gram is run. Load Letters the following: seconds and tenths of seconds, use f fix 1 no- STEP KEY CODE tation. If you wish to start at some time other 00 than zero, key in this time before pressing R/S. Always press f prgm before running the TIMER HAS MORE RESOLUTION 01 + 51 program. Greater accuracy in starting is ob- I wish to commend POPULAR ELECTRONICS 02 GTO 01 13, 01 tained if you depress R/S before the starting for publishing articles about programmable Return to the RUN mode. Depress f, prgm, time and then releasing the key at the starting time. -Leigh Klotz, Jr., McComb, MS.

MORE ON HANDLING MOS "How to Handle MOS Devices Without De- stroying Them" (August 1977) presented Get it some valuable information but contained two ¡GettFairchild Technology Kits misleading and inaccurate statements. First, FTK 0001 0.5" Common Cathode Digit $ 1.75 although the zener-diode protection circuit in FTK 0002 .05" Common Anode Digit 1.75 Fig. 3 is sométimes used in discrete MOS- FTK 0003 .357 Common Cathode Digit 1.65 FET's, I have never seen it incorporated into a MOS IC. The FTK 0004 0.8 Common Cathode Digit 3.40 other error is the warning for readers not to use multimeters to MOS FTK 0005 0.8 Common Cathode Digit 3.40 test FTK 0100 Clock Calendar with Radio devices. IC manufacturers, such as RCA and Applications Solid State Scientific, recommend the use of 35.00 common VOM's for simple testing of their FTK 0101 6 -Digit Wall Clock/Calendar 55.00 CMOS devices and publish specific instruc- FTK 0106 Auto Clock Calendar 40.00 tions for such testing.

10% OFF ALL TTL, including 7400 #s L, S, H and LS I agree with the author that conductive E & L SK10 Breadboard Socket ... SAVE $1.50 15.00 plastics are invaluable for safely handling MOS devices. I have used all of the products O IMSAT 80$0 Computer Kit 599.95 Motorola MED6800 DII Computer mentioned and found them to be quite help- Kit 235.00 ful. Vector Photo -resist Printed It is unfortunate that manufacturers' and Circuit Kit 12.75 dealers' minimum -order requirements make them too expensive for most hobbyists. The Velostat kit mentioned in the article is a good value. As an additional service to POPULAR ELECTRONICS readers, we are offering I/á' (6.4 -mm), thick Velostat Ian.... the books that show you how! foam for 3p/sq in. plus 25t postage/order, with no minimum E MlcroComputer Primer $ 7.95 purchase requirement. This material can be E & L Bugbook Vol III ... Save $1.00 14.00 adapted for 99% of antistatic uses. -J. L. E & L Bugbook Vol I & II ... Save $2.00 15.00 Mitchell, WFCO, Box 148, Runnemede, NJ E & L Bugbook Vol V & VI ... Save $2.00 19.00 08078. Understanding MicroComputers 9.95 MicroComputers at a Glance 9.95 D/A AND A/D CONVERTERS Osborne Vol I Basic Concepts 7.50 In "How's and Why's How to of D/A and A/D Con- Program MicroComputers 8.95 verters" (April 1977), the circuit in Fig. 3 is in- TTL Cookbook 8.95 correct. There is a resistor across virtual Computer Technicians' Handbook 8.95 Build Your Own Working Robot 5.95

computer depot; inc. 53 55 (3,53) 3515 West 70th Street, Minneapolis, Minnesota 55435, (612) 927-5601 i Just clip -this entire ad and send, along with check or money order. OUT Or, if you. prefer, charge to your MasterCharge or Visa Account. NAME ADDRESS ground of the op amp, which makes no sense at all. Plus, for the binary ladder effect to work CITY STATE ZIP _ properly, the logic -0 input must be grounded O I enclose my check or money order in the amount of $ when the switches are not connected to log- Credit my VISA" masse cnage account No. ic -1 (VIÑ). The circuit should look like the one TONIOINvi shown here. -Craig Keefer, Nashua, NH.

NO. 6 CIRCLE 10 ON FREE INFORMATION CARD POPULAR ELECTRONICS

AmericanRadioHistory.Com t' SOURCEBOOK An Extraordinary Offer to introduce you to the benefits of Membership in OF ELECTRONIC t ORGAN CIRCUITS ;...r.... .d...».,...... -...,.r. :..1111 11* í"°.rr..ra.-+w. ELECTRONICS BOOK CLUB 843-158 p -Sourcebook of Elec- ironic Organ Cyrcmts (57.95) " .. take of these unique L ^." , a. any ¿ electronics books 742-476p.Pofessionál,Elec; -. tticalrE4ectron c Engineer's Li -- (values to '568) for only cense Study Guide (510.9-15) each rR®assr`- with a Trial Membership ín the Book Club that guarantees to gygCTRiC31J$tCTae ENGINES" save you 25% to 75% on a wide selection of electronics books S3II0Y =r R meson a v"_a V. xoss - 811-280 p.-The Complete Handbook ST WOO of oVideocassette Recorders ($9.953 101 416 p., Iyax11"-Elxtronic $irctjit .a; resqn Handbook -4th Ediion (517.95)

( " ; --r ; Troubles hoom\ r How to x Or-. ELECTRONIC I E1eCárOrt ' HRNDDOOK TUG G(JMPLGtG i¿ ('. CIRCUI Equipment YIDOGASSTTE DESIGN tatC Top, TestRDER6RREGO 51¿ Ra °tara sor/ Iv.., ND80414 Dt®gzlhi . PA,"" it º 995-182 p.-Beginner's Guide t3 A#ffT by avsxlbe p8 the to' Microprocessors ($8.95) - brle 680-252 p.-How to Troubleshoot & Re- for e Word ,pair Electronic Test Equipment (j995) Warker F rd. `714-252 p.-Radio Astronomy; , _fir :_for the Amateur ($8.95) 1785-294 p.-Mixrópeoeessor/Mi- -, Han dbook(59.95kL croprogramming t :J _ MicroWave master. . oven REP . r Handbook & erreOV How to Use Ir ` SeNe irrroploa I. pllF efin9 AF & IF b 362-446' p.-Microwave Oven Ho,bbiI 0 pf09 Electronic circuits service 8lieparr(512.95) pier Signal GeneratorG U1.. rtwE(p i1vl,ur.M^ 0.`nP 1 for ey (í+^fN P r - f r.'. ti i No(leiirtf nc. 800-602 p-rlaster Handbóok, , lTikj/TT e i 952-382 p.-Micro roeessoa'?' o1 1301 Pra:tical Electronic' . " ' T - ? ' r ,Programming lor pComputer r rcr.its ($12.95). 955-308 p.-Modern Dlgi-a I ($12.95) Hobbyists 927-382 p-How to Use Al &t F ;,,,,,.y. Communications (510.95) a p,TR.ex= KpityMK S nerators ($8.95) ° , - 1 -,------975-32 p -The "Compulátor" ` y -.-fr°- 882252 p.=Transistor, Book-Eui)d Super Calculators & Ignition Systems -(58.95) Minicomputer Hardware With Cal- ? , ` -.-.. i - GTRc3NIGs cu lot ar ch es (slo 9s) t YOU14 1 D c GU °oól= R 8I7II Pracdtl i0lturN -State t " OWN SOW cal i BOOK- fe 1411/11=á PtWer YNÍSÓIVTQt .'a. w. ro e a1 n S 4 Radio 6slalalera MRgn1D a u cuculur CB aeva°e áwú° win Ms Trcwt'1 lr,y , r . .co. H6LtiEB 4 - ,,.. L o leal .Snlid-State 'T - , F Refar ^ : By DAVID _.`. ,.891-192 p.-Prat -a y, F. No' vkf . DC Power f{ By a > im ,,,,,,-ice Supplies 159.95) 1,. .,,,,.,yr - ' i -s ódá .y,--. I X k 754-238 p -Practical CE 541-236 p.-Build Your Own `1 l 836- 94 p.-Optoe le c t r ddrc I Troubleshooting,& Repair ($8 'i Working Robot (58.95) ' book-Witt Tested .Projects, (58.951

May we send you your choice of 4 of these prac- =NZ=MIWEINMIN tical time -and -money -saving books as part of Facts. About Club Membership j an unusual offer of a Trial Membership in Elec- ELECTRONICS BOOK CLUB tronics Book Club? Tbe 4 introductory books of your choice carry publishers , Here are quality hardbound volumes, each retail prices of up to $56.80. They are yours for only 99c each Blue Ridge Summit, Pa. 17214 especially designed to help' you increase your (plus postage/handling) with your Trial Membership. , You will receive the Club News, describing the current know-how, earning power, and enjoyment of elec- Seledien Alternates and other books, every 4 weeks (13x Flease open my Trial Membership in ELECTRONICS BOOK tronics. Whatever your interest in electronics, times a year) CLUB and send me the 4 books circled below. I understand you'll find Electronics Book Club offers practical, If you want the Selection, do nothing, it will be sent to you , the cost of the books I have sellected is only 99c each, plus a quality hooks that you can put to immediate use and autcrnatically. If you do not wish to receive the Selection, a if small shipping charge. If not delighted, I may return the benefit. you want to ader one of the many Alternates offered, you ' my books mitten 10 days and owe nothing, and have Trial This extraordinary offer is intended to prove to sitn.ly give instructions on the reply form (and io the en- you through your own experience, that these very velooe) provided, aid return it to us by the date specified. This g Membership cancelled. I agree to purchase at least four you at least 10 days in which to return the form. If, real advantages can be yours...that it is possible to dateal ows additiona0 books during the next 12 months, after which I keep up with the literature published in your areas because of late mail delivery, you do not have 10 days to make , may cancel my membership at any time. a decision and so receive an unwanted Selection, you may of interest, and to save substantially while so doing. return it at Club expense. r , 101 680 714 742 754 785 800 As part of your Trial Membership, you need pur- To complete your Trial Membership, you need buy only four 12 811 836 841 843 882 chase as few as foui tooks during the coming eadditional monthly selections a alternates during the next 12 , months. You would probably buy at least this many months. You may cancel your Membership any time after you 891 927 952 955 962 975 995 a anyway, without the substantial savings offered purchase these four books. , through Club Membership. Al books-including the introductory Offer-are fully re- ) To start your Membership on these attractive turnable after 10 days if you're not completely satisfied. Name Phone All Looks are offered at low Member prices, plus a small terms, simply fill out and mail the coupon today. s postage and handling charge. 1 g You will receive the 4 books of your choice for Address 'Unending Ionia If you continue after this Trial Member- 10 NEED -day inspection. YOU SEND NO s ship. you will earn a Dividend Certificate for every book you , City MONEY. If you are not delighted return the books 1 purchase. Three Certificates plus payment of the nominal sum within 10 days and your Trial Membership will be of $1.99 will entitle you to a valuable Book Dividend of your cancelled without cost or obligation. choir which you may choose from a list provided Members. State Zip Foreign and Canada add 10%) PE ELECTRONICS BOOR CLUB. Blue Ridge Summit. Pa.17214 (Valid ter new Members only. -28

CIRCLE N0. to ON FREE INFORMATION coAR FEBRUARY 1978 , 7

AmericanRadioHistory.Com hardware, and installation instructions. Ad- BERK-TEK MINIATURE RG 8/U CABLE dress: Controls, Inc., Consumer Sales, Box A miniature replacement for RG 8/U coaxial 522, Logansport IN 46947. cable is now available from from Berk-Tek, Inc. The new,. low -loss cable, trade -marked "RG 8X," is 40% smaller than RG 8/U, and

ZENITH TV REMOTE CONTROL TESTER A device for testing television remote control New Products transmitters, Model 852-240, has been an- nounced by Zenith Radio Corp. A LED is il- Additional information on 'nett; products luminated when it receives an ultrasonic, covered in this section is available from the manufacturers. Either circle the item's continuous sine wave of up to 50 kHz that is code number on the Reader Service Cárd strong enough to operate a TV remote con- inside the back cover or write to the man- trol. The tester can be used on all Zenith re- 41^ P/ ufacttirer at mote -control transmitters, mechanical as well the address given. many times more flexible. It has 95% braid as electronic handhelds, and other brands shielding and a 19 -strand center conductor. producing a 50 -kHz output signal. It includes Power handling capacity is more than 1 kW at an output jack for use with a frequency coun- 27 MHz. Nominal attenuation is said to be ter. Address: Zenith Parts & Accessories DAVID HAFLER PREAMPLIFIER 1.35 dB at CB frequencies, a gain of as much Div., 11,000 Seymour Ave., Franklin Park, IL The David Haller Company has announced as 2 dB over typical RG 58/U cables. Ad- 60131. its first product,. a stereo preamplifier and dress: Berk-Tek, Inc, Box 60, Reading, PA control unit: Available in both kit and assem- 19607. bled form, the new DH -101 preamplifier is an all -push-pull design with distortion said to be REMOTE SWITCHING BY CB KENWOOD RECEIVER The "CB Auto Light" is a solid-state remote - The Model KR -4070 AM/stéreo FM receiver control switch which can be activated by a CB has an amplifier section rated at 40 watts - signal from up to 300 ft away. The unit can be rms/channel continuous into 8 ohms from 20 used to turn on garage and outdoor lights by to 20,000 Hz., with 0.1% maximum THD. The keying the CB microphone. $26.95. Address: preamplifier section has a 73 -dB S/N ,and Kronotek Corp., Bonnie Dell Industrial Park, varies from standard RIAA equalization by no 231 Rt. 17, Rutherford, NJ 07070. below 0.061%, and correspondingly low su- more than ±0.3 dB. Tone controls have cen- personic iritermodulation distortion. Control ter -off positions. The tuner section, with a 1.9 features include volume, balance, bass, tre- µ V IHF usable sensitivity, has a 3 -gang, var- NEW REVOX iable capacitor in its FET front end.. Linear - ble and selection by indicator-type pushbut- Á new, 10'fí" -reel recorder, Model B77, has phase, 4 -element ceramic i -f filters are said to tons of two phono inputs, one tuner and ohe been added to the Revox line. The B77 is cur- aux input, and two tape monitor circuits with nr, rently available with '/a -track or 'h -track dubbing facilities. A stereo -mono and tone - heads and speeds of 33/4 and 71/2 ips, but a flat switch are also provided. The unit is sup- 71/2r15-ips version will be available this year. plied with an international power transformer, Features include several switch -selected in- and can operate at all voltages from 100 to puts for each channel, a direct drive capstan -tYyky ..

CIRCLE NO. 95 ON FREE INFORMATION CARO around the hole as it drills; all other specifica-

8 POPULAR ELECTRONICS

AmericanRadioHistory.Com The Sinclair PDM35. A personal digital multimeter for only 549.95 Technical specification DC Volts (4 ranges) Range: l mV to 1000 V.

Accuracy of reading 1.0% ± 1 count. Note: 10 M f i input impedance. AC Volts (40 Hz -5 kHz) Range: l V to 500 V. Accuracy of reading: 1.0%± 2 counts. DC Current (6 ranges) Range: I nA to 200 mA.

Accuracy of reading: 1.0%± 1 count. Note: Max. resolution 0.1 nA. Resistance (5 ranges) Range: lfl to 20Mí1.

Accuracy of reading: 15%± 1 count. Also provides 5 junction -test ranges. Dimensions: 6 in x 3 in x 11/2 in. Weight: 61/2 oz. Power supply: 9 V battery or Now everyone can afford to Operation from replaceable battery Sinclair AC adapter. own a digital multimeter or AC adapter. Sockets: Standard 4 mm for A digital multimeter used to Industry standard 10 M f 1 input resilient plugs. mean an expensive, bulky piece of impedance. Options: AC adapter for 117 V equipment. 60 Hz power. De -luxe padded The Sinclair PDM35 changes Compare it with an carrying wallet. 30 kV probe. that. It's got all the functions and analog meter! The Sinclair credentials features you want in a digital The PDM 35's 1% of reading Sinclair have pioneered a whole multimeter, yet they're neatly compares with 3% of full scale for a range of electronic world -firsts - from packaged in a rugged but light comparable analog meter. That programmable pocket calculators pocket-size case, ready to go makes it around 5 times more to miniature TVs. The PD I35 anywhere. accurate on average. embodies six years' experience in The Sinclair PDM35 gives you The PDM35 will resolve 1 mV digital multimeter design, in which all the benefits of an ordinary digital against around 10 mV for a time Sinclair have become one of multimeter - quick clear readings, comarable analog meter - and the world's largest producers. high accuracy and resolution, high resolution on current is over 1000 Tried, tested, ready to go! input impedence. Yet at $49.95 times greater. The Sinclair PDM35 comes to it costs less than you'd expect to pay The PDM35's DC input you fully built, tested, calibrated and for an analog meter! impedance of 10 M i i is 50 times guaranteed. It comes complete with The Sinclair PDM35 is tailor- higher than a 20 ki i/volt analog leads and test prods, operating to made for anyone who needs make meter on the 10 V range. instructions and a carrying wallet. And rapid measurements. Development The PDM35 gives precise getting one couldn't be easier. Just fill field engineers, service engineers, digital readings. So there's no need to in the coupon, enclose a check/ MO lab technicians, computer specialists, interpret ambiguous scales, no for the correct amount (usual 10 -day radio and electronic hobbyists will parallax errors. There's no need to money -back undertaking, of course), find it ideal. reverse leads for negative readings. and send it to us. With its rugged construction There's no delicate meter movement and battery operation, the PDM35 is to damage. And you can resolve Inc, perfectly suited for hand work in the current as low as 0.1 nA and measure Sinclair Radionics Galleria, field, while its angled display and transistor and diode junctions over 115 East 57th Street, New York, N.Y. optional AC power facility make it 5 decades of current. 10022, U.S.A. just as useful on the bench. ' lo: Sinclair Radionics Inc, Galleria,115 East 57th Street, New York, N.Y.10022, U.S.A. What you get with a PDM35 2 I Please send me (qty) PDM35(s) Name 31/2 digit resolution. ©$49.95 plus $1.05 postage and Sharp, bright, easily read LEI) insuranceeach $ Address display, reading to ± 1.999. (qty) De -luxe padded carrying cases) @S4.95 each $ City Automatic polarity selection. (qty) AC adapter(s) © $4.95 State. Resolution of 1 mV and 0.1 nA each $ I enclose order made out to Sinclair (0.00011.1A). check/MO Zip Radionics Inc (indicate total order value. Direct reading of semiconductor Add sales tax for NYS deliveries). $ forward voltages at 5 different currents. I understand that if I am not completely satisfied measured up to 20 vli i. with my PDM35, I may return it within ten days Resistance iinlairleaders in fingertip electronics for a full cash refund. World 1% of reading accuracy.

FEBRUARY 1978

AmericanRadioHistory.Com The drills and mills are $10.50 each in high- quency response is down 3 -dB at 50 speed steel, $12.50 each in carbide. Ad- Hz. Effective system Q is 1. Maximum dress: A.F. Stahler Co., P.O. Box 354, Cuper- power handling capacity is 100 watts continu- tino, Ca 95014. ously driven to clipping 10% of the time on normal music source material. Dimensions '41 are 181/2"x 10"x83/4"(46.4x 25.4 x 22.2 cm); weight is 17 lb AR BOOKSHELF SPEAKER (7.7 kg). $95. 11 CIRCLE NO. 97 ON FREE INFORMATION CARD The Acoustic Research Model AR -17 has a speaker system with 8" acoustic -suspension woofer and a 11/4" ring -radiator tweeter, with TRIPLET 3 1/2 -DIGIT DMM the crossover at 2000 Hz.The 8 -ohm system Triplett Corp's Model 3300 pocket-size digital has a two -position high-range level control multimeter measures 5 3/8"L x x 1 tions are 3'W 3/8"D the same as for the drills. The and is said to produce 86 dB SPL for 1 watt (13.7 x 7.6 x 3.5 cm) and has a 3 1/2 -digit RSDT-DIP16 template stamp set is $12.50. output on axis at 1 meter. Claimed low-fre- LED display with 0.3" (7.6 -mm) digits. The in- strument has a single selector switch for ac and dc voltage ranges of from 200 mV to

NEW LSI TECHNOLOGY 600V, resistance ranges of 200 to 20M ohms, FREQUENCY COUNTER TAKE ADVANTAGE OF THIS NEW STATE-OF-THE-ART N- COUNTER FEATURING THE MANY BENEFITS OF .4.I..- CUSTOM LSI CIRCUITRY. FEATURES AND SPECIFICATIONS: DISPLAY: E RED LED DIGITS .4. CHARACTER HEIGHT GATE TIMES: 1 SECOND AND IJ10 SECOND PRESCALER WILL FIT INSIDE COUNTER CABINET ti At, I, RESOLUTION: 1 HZ AT 1 SECOND. 10 NZ AT 1110 SECOND. FREQUENCY RANGE: 10 HZ TO 60 WIZ. IRS MHZ TYPICAL]. Yt I1 SENSITIVITY: 10 MV RMS TO 50 MHZ. 20 MV RMS TO AO MHZ TYP. r4 ip INPUTPUT IMPEDANCE: 1 SEGOHM AND 2O PF. mu SIC 'B PROTECTED INPUT FOR OVER VOLTAGE PROTECTION.] aa\aa 1P,.{ 11 ACCV RACY: 1 MA .0001%]:AFTER CALIBRATION TYPICAL. "(.B E._ STABILITY: wiTHIN 1 PPM PER HOUR AFTER WARM UP I.DO1". %TALI P . M IC PACKAGE 6 - COUNT. ]ALL SOCKETED! - I..1. ' . ' INTERNAL POWER SUPPLY: 5 V DC REGULATED. rr ° - - tINPUT POWER REQUIRED: Alt VDC OR 115 VAC AT 50/60 HZ. I11 54. /w"` POWER CONSUMPTION: A WATTS IT FCSOC IS COMPLETE WITH PREDRILLED CHASSIS ALL HARDWARE AND STEP-BY-STEP INSTRUCTION I '"° WIRED A TESTED UNITS ARE CALIBRATED AND GUARANTEED

, KIT#FC-50C 60 MHZ COUNTER WITH CABINET & P.S... 1 1995COMPLETE! ' KIT #PSL-650 650 MHZ PRESCALER ]NOT SHOWN] 29.95 MODEL #FC-50WT 60 MHZ COUNTER WIRED, TESTED 8 CAL. 165.95 MODEL#FC-50/ 600 WT.. 600 MHZ COUNTER WIRED, TESTED & CAL. 199.95

AUTO BURGLAR 60 HZ. XTAL TIME BASE ALARM KIT Will enable AN EASY TO ASSEMBLE AND EASY TO INSTALL Power Rea: 5-15V ALARM PROVIDING MANY FEATURES NOT Digital Clock Kits NORMALLY FOUND KEYLESS ALARM HAS (2.5 MA. TYP.) PROVISION FOR POS E GROUNDING or Clock -Calendar Easy 3 wire hookup SWITCHES OR SENSORS WILL PULSE HORN Kits to Operate RELAY AT ,HZ RATE OR DRIVE SIREN KIT Accuracy: ± 2PPM PROVIDES PROGRAMMABLE TIME DELAYS (corn 12V DC. FOR EMIT. ENTRY A ALARM PERIOD UNIT (Adjustable) MOUNTS UNDER DASH . REMOTE SWITCH 1"x2"PC Board #TB -1 CAN BE MOUNTED WHERE DESIRED CMOS RELIABILITY RESISTS FALSE E ALARMS 51. Complete Kit rR PROVIDES FOR ULTRA DEPENDABLE ALARM #ALR-1WT *495 Wir & Cal $9.95 ° DO NOIRE FOOLED BY LOW PRICES. THIS IS TOP OUALITY COMPLETE KIT WITH ALL PARTS INCLUDING DETAILED DRAWINGS AND IN STRUCTIONS OR AVAILABLE WIRED AND TESTED ° TESTED PLEXIGLAS CABINETS and ac and dc current ranges from 2 to 200 SEE T HE WORKS Clock Kit Great for Clocks or any LED Clear Plexiglas Stand Digital project. Clear -Red mA, all full-scale. Typical dc accuracy is said

6Big.4"digits Chassis serves as Bezel to `.'1,Increase to be 0.5%. The new DMM features automat- contrast of digital ,' 120124 hr. time ic polarity indication -on dc measurements. 3 set switches ABINET I displays. The probes have insulating boots. Plug transformer 3"H,6Y4"W,5Y"D Black, White or safety Ad- allparts included ditional safety features include Clear fuse protec- Plexiglas is CABINET II Cover tion for both probe and meter and a design Pre-cut S. drilled 294"H,5"W,4"D $6.50 ea. with no exposed metal parts. The snap Kit 0850-4 C P -in RED OR GREY PLEXIGLAS FOR DIGITAL BEZELS . "Battery-Pac" supplied can be recharged Sae: 6"H,4'h"W,3"D 3"x6"x1/8" 950 ea. 4P3 within the tester or separately, using the ac VARIABLE REGULATED Fairchild Super Digit .11103ll_; LEO _1_o_1. adapter/charger supplied. $175. 1 AMP FND359 ..00TS! CIRCLE NO. 98 ON FREE INFORMATION CARD POWER SUPPLY KIT 1 ; 7 legmewra LED °, 12 VOLT AC or FROM A to 14V xED Lan MODEL SHORTIECIRCUIT PROOF I DIrect Jrpin 02001 DC POWERED 723 IC REGULATOR . replacement for 6 JUMBO .'RED LED'S BEHINDREDFILTER LENS WITH CHROME RIM 2N3055 PASS TRANSISTOR popular FND-70. b SET FROM FRONT A HIDDEN Es .12124 -Hr. TIME FORMAT ,R 40 -CHANNEL STYLISH CHARCOAL OF MOLDED NIGH TEMP. PLASTIC CB "ONE HANDER" CURRENT LIMITING AT 1 Am D. POWER INPUTGE CIRCUITRY WIRE Na POLARITY HDGKuP , OPRiuTIONAL CONNECTION TO BLIINK DISPLArI KIT IS COMPLETE INCLUDING II 95 Oa, 10 56.50 The new, 40 cif TOP DUALITY PC BOARDS A COMPONENTSnllevINSTRUCTIONS, -channel version the Realistic DRILLED 8 SOLDER PLATED MOUNTING BRACKET INCLUDED ns vc FIBERGLASS PC BOARD AND .° 4 96 "One -Hander" mobile CB transceiver, like its ALL PARTS TRANS. SET OF6 FND-359 COBPLETE KIT 27EÁ OaNE *2.5397.5; ILess A 23 -channel predecessor, has o FORMER) KIT PS -01 58.95 WITH MULTIPLEX ASSEMBLED UNITS WIRED I TESTED all operating ORDER }001 WT ]LESd ºvol BATTERY) . TRANSFORMER a PC MOTE 24V CT call' BOARD 56.95 lor 12-4,0.6 ilS M. provlGe 300MÁ Al 12v and ° 1 Amp al SS. $3.50 OPTOELECTRONICS, INC. BOX 219 HOLLYWOOD, FLA. 33022 PHONE [305] 921-2056 / 921-4425 -.----'! ORDERS TO USA & CANADA ADD 5% FOR SHIPPING, HANDLING 8 INSURANCE. ALL OTHERS ADD 10%. '' Ia..,M... _0-..w ADDITIONAL 51.00 CHARGE FOR ORDERS UNDER TL_m. 515.00 - COD FEE 51.00. FLA. RES. ADD 4% TAX.

CIRCLE NO. 35 ON FREE INFORMATION 10 CARD POPULAR ELECTRONICS

AmericanRadioHistory.Com °. in "^w ,,. Begin your risk -free membership The Electronics Book Service EX@,C~\c with this reference that CONTAINS HUNDREDS .Ce~:\ZZCIs 4 TIPS THAT ELIMINATE HOURS OF TIME . anclyook 15k. OF TxrxveSailers AND TOIL IN TROUBLESHOOTING, THAT CAN and 5`cio<

trouble- Instant answers to hundreds of questions that This treasury of come up every day. Here is the practical efficient way in shooting tips provides Now all the technical data you need to know-but which the ELECTRONICS BOOK can't carry around in your head-will be readily ac- ready solutions to prob- cessible to you. In an instant, you'll have the an- SERVICE operates: swers to such questions as: lems in every major area of 1. When you enroll as a member, you electronics. It contains How can a tube be identified if the numbers are missing? receive-for only $1.98, plus postage and How can a TV set be repaired with an inexpensive probe? handling with tax where applicable-your hundreds of time -saving What is the first and most important step in designing copy of the ELECTRONIC TECHNICIAN'S a printed circuit board from a schematic drawing? HANDBOOK OF TIME-SAVERS AND shortcuts and techniques How do you check transistors, rectifiers, scr's, triacs and unijunctions without elaborate equipment? SHORTCUTS. This is the. only obligation for troubleshooting all you are committed to make. Lavishly illustrated! types of electronic equip- 2. You are under no obligation to ac- For further aid, you'll have OVER 140 ILLUS- cept any minimum number of selections ment-and over 140 dia- TRATIONS AND DIAGRAMS that make these shortcuts easy to learn, easy to use. Like these: within any time limit. You can take as as And, grams and illustrations that Simplified methods of reading capacitor values. many or as few you wish. you may resign at any time with no obligation make them easy to use. Fast ways of testing electronic components. Circuits and diagrams for constructing simple, effective once you have paid for your copy of the The ELECTRONIC TECHNICIAN'S HAND- ELECTRONIC TECHNICIAN'S HAND- BOOK OF TIME SAVERS AND SHORTCUTS is troubleshooting instruments. surely the hardest working partner you could have. A special troubleshooting table that helps locale faulty parts or BOOK OF TIME-SAVERS AND SHORT- It simplifies and speeds up every job you tackle- circuits-SAVING YOU A WORLD OF TIME. CUTS. enables you to get more done, in less time-and, to the 3. On selections you do accept, your as a result SENDS YOUR EARNINGS UP FAST! To introduce you Electronics Book Service. membership entitles you to a discount This handbook regularly sells for $12.95. But from the publisher's list price. This dis- you can now get it for lust $1.98. It's our way of Whatever you' interest in electronics-whether introducing you to the Electronics Book Service, you're an engineer or technician in industry, the op- count Is available to members only and the no -risk book club that is currently keeping erator of a radio-TV repair service, or a hobbyist- provides you with substantial savings. membership in the Electronics Book Service can over 50,000 technicians, trouble shooters and 4. Every four weeks we'll send you a help advance your career, add to your income, en- hobbyists informed of the most useful new the current hooks in the field of electronics-without ever hance the enjoyment of your hobby. free bulletin describing selec- obligating them to buy a single one! The Electronics Book Service screens hundreds tion. If you want the selection, no action of books on the subject, selects those which are is required; it will be shipped to you auto- The ELECTRONIC TECHNICIAN'S HAND- the most useful and valuable, and reports to you TIME-SAVERS AND is BOOK OF SHORTCUTS every four weeks on books which can be yours at matically. If you don't want it, just return typical of the practical selections we offer our mem- generous savings. Your membership is an ideal the card enclosed with the bulletin. bers. It gives you solid, expert help on all kinds of way to keep in touch with the onrushing advances 5. You have at 10 It to least days to decide troubleshooting problems. shows you how in electronics and its applications. save time-and money-and work. whether you want the selection or not. Return the card so we receive it no later Just look at the kind of help you get: Remember, the Electronics Book Service has NO MIN- IMUM PURCHASE REQUIREMENTS, unlike ordinary than the date specified. If you don't have your work with resistors easy. Shortcuts for making book clubs. Once you've paid 51.98 for the ELECTRONIC 10 days to answer and receive an un- Time saving techniques for use with capacitors. TECHNICIAN'S HANDBOOK OF TIME-SAVERS AND need to any further se- wanted selection, return it at our ex- Tested techniques for your work with Inductors. SHORTCUTS, yon don't purchase lections! pense. Work -saving methods for accomplishing more with vacuum tubes. 6. Each bulletin also describes a num- Proven techniques for working with solid state devices. Why delay? Mail the coupon below to get your ber of alternate or additional selections Key steps to soldering and desotdering. copy of this $12.95 handbook for only $1.98-and to receive all the benefits of membership in the also available to you at the special dis- Successful wiring methods. Electronics Book Service on a RISK -FREE trial ba- count price for members. Guidelines for designing and making printed circuits. sis. Fill out and mail your coupon right away. Time saving shortcuts for chassis construction. Faster ways to select and use test instruments. Practical shortcuts in breadboarding. FILL OUT AND MAIL THIS COUPON TODAY. Easy -to -use chemicals that bring magical results. r PLUS HUNDREDS OF OTHER SHORTCUT TROUBLE- ELECTRONICS BOOK SERVICE SHOOTING TECHNIQUES. Dept. 6651-81(0) Cuts hours of time and toil Englewood Cliffs, New Jersey 07632 from your toughest jobs. Please enroll me in Electronics Book Service on a risk -free trial basis. I am to receive all announcements, free of charge, and will be entitled to full privileges as a Member without Showing you successful ways to solve problems quickly, this handbook cuts the toughest trouble- obligation to buy any specific number of club selections. As my first selection under this shooting jobs from days to hours. And your other trial membership, send me the ELECTRONIC TECHNICIAN'S HANDBOOK OF TIME- jobs from hours to minutes. It gives you fast, prov- SAVERS AND SHORTCUTS for only $1.98. en techniques-in a concise, straight -to -the -point way. Name For example, have you wanted to check a capa- citor under working voltages? But couldn't be- Address cause you didn't have specialized equipment handy? Chapter Two shows you how to do it- LCity ------State------Zip with only a VTVM!

FEBRUARY 1978 CIRCLE NO. 17 ON FREE INFORMATION CARD 11

AmericanRadioHistory.Com Pioneer's new RT-707 has a lot more in In addition, the drive -system of the common with today's most sophisticated 10 - RT-707 is unaffected by fluctuations in line inch tape decks than it does with most 7 -inch voltage and won't deteriorate with age like, tape decks. belt -drive. And because it doesn't generate Because unlike other 7 -inch tape decks, heat like the belt -driven "dinosaurs" it doesn't the RT-707 isn't filled with 15 year old ideas. need a fan. So all you'll hear is music with a - clarity crispness not THE MOST ACCUMITE and possible on any 7 -inch, DRIVE SYSTEM: or many 10 -inch tape decks. DIRECT-DRIVE. Our direct -drive system also makes pitch Instead of the old control possible. Which allows you to regulate fashioned belt -drive the speed of the tape, giving you everí greater system, the RT-707 is control over your recordings. driven by a far more BEYOND THE RANGE accurate and efficient AC The extraordinary direct -drive system. OF MOST 7 -INCH TAPE DECKS. Servo direct -drive capstan motor. This motor In the past, the most you'd expect from generates its own frequency to monitor and any 7 -inch tape deck in terms of frequency help correct even the slightest variation in tape response was respectability. But with speed. Which all but eliminates wow and tecinology like this it's not surprising that flutter. Pioneer's engineers have gone far beyond that. Our super -sensitive Gheads, for instance, will pickup and

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AmericanRadioHistory.Com deliver frequencies from 20 to 28,000 Hertz. hook the RT-707 up to a timer, so you can make And our pre -amp section is built to handle 30 recordings even when you can't be there to more than any other 7 -inch tape deck supervise them. _ __ without distorting. So you can capture all the But frankly, all; the -revolutionary thinkin depth and presence of each and every that went into the RT-707 wouldn't mean muc instrument. if it weren't also built to fit comfortably,into your But great sound isn't everythin g budget. It is. See your Pioneer dealer for a AWHOLE NEW WAY OF LOOKING 3 AT TAPE DECKS. closer look at this extraordinary 7-inch tape deck. is As you can see, the RT-707 =We think you'll find the only smaller and more compact than things that the RT-707 has in common: other tape decks. It's also rack- - with other 7-inch tape decks is the 'size mountable. -But unlike any other -tape of the reels. And the size of the price. deck, it's stackable. So it'll fit right in Fidelity Components with the rest of your components. High GD IIPIONEER° AUTO -REVERSE AND OTHER EXTRAS. WE BRING IT BACK ALIVE. 01977 U.S Pioneer Electronics, B5 Oxiord Drive, Moonachie; New lersey 07074 - CIRCLE N0. 52 Dti FREE INFORMATION CARD While many tape decks have Unlike others, die RT707 can be auto -reverse, chances are you won't stacked or rack -mounted. find it on other comparably priced equipment. FREQUENCY RESPONSE: @ 7R ips 20-28,000 Hz SPEEDS: Tape 714 Ips (19 art/sec.)3% ips (30-24,000 Hz 2 3 dBJ. (9.5 cm/sec.) 2 0.05%. - FLUTTER: @7i; FG AC Servo -drive Or a repeat button that lets you listen to your WOW AND ips 0.05 (WRNS) - MOTORS: direct motor ' drive). 6 -pole Inner -rotor SIGNAL- TO -NOISE RAT10: More than 58 dB. el (capstan tapes endlessly._ Or circuitry that allows you to 'special Induction motor it 2 (reel drive). HARMONIC DISTORTION-. No more than 1.0%. REFERENCE TAPE: Scotch #206. iltpl~i/ ,t'f4r3,~at, ir 0+er3f iI atr -.Z, T,^Iá

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AmericanRadioHistory.Com controls-volume, squelch, power, illuminat- ed channel -select dial and talk button-on the microphone. The one control on the re- motely located transceiver selects either the built-in speaker, the microphone/speaker, or an external speaker. The main transceiver circuitry includes built in noise blanker and limiter. Receiver sensitivity is rated at 0.5 µ V for 10dB S+N/N; adjacent channel rejec- tion, 60 dB; audio output, 4W. Measuring only New Literature 7"L x 5 1/4"D x 1 1/2"H (17.8 x 13.4 x 3.8 cm), the main chassis is easily hidden; an op- tional, 16 1/2 -foot (5-m) extension cable al- EIA CONSUMER GUIDE TO TV SAFETY lows it to be concealed in the trunk. Price is A revised "Consumer Guide to Television $169.95; optional extension cable is $29.95. Safety" has been published by the Electronic CIRCLE NO. 99 ON FREE INFORMATION CARD Industries Association/Consumer Electronics Group. The Guide offers a number of basic steps to be followed by consumers for safe NORTH STAR HORIZON COMPUTER and efficient operation of TV receivers. Send This S -100 -bus computer with built-in micro - self-addressed, stamped envelope to: Sally floppy disk memory is available in two mod- Browne, Director. of Consumer Affairs, EIA/ Consumer Electronics Box , Your records will last els. Both have 4 -MHz, Z80A microprocessor, Group, P.O. 1 longer. Empire car- 16k of RAM, serial interlace and 12 -slot 19369, Washington, DC 20036. motherboard. Horizon -1 has a single, North tridges are designed to track at TURNER CB ACCESSORIES CATALOG lower forces. This imposes less Star micro -floppy drive, while Horizon -2 has a weight on the record insuring dual drive. The system can store 90k bytes, Turner Division of Conrac Corp. has an- nounced availability of a new CB accessories longer record life. and can load or save a 10 kilobyte program in catalog. The four -page color brochure details less than two seconds. Horizon -1 is $1599, the new CB kit; $1899 assembled. Horizon -2 is $1999, company's "Whip -Flip" antitheft Your records will sound kit; $2349, assembled. antenna mounts and "Insta -Mount" mirror better. Distortion is a with easy on/off construction that allows for 2 CIRCLE NO. 100 ON FREE INFORMATION CARD mere .0005 at standard groove adjustment to vertical and horizontal mirror velocity. Therefore, reproduc- struts. Also listed are a variety of mounts tion is razor sharp with no available for both stainless steel and fiber- DREMEL COMPACT VISE wavering or fuzziness. glass antennas that are designed to work The new Model 2214 D -Vise by Dremel is a with Turner and other brands of antennas. compact, die-cast vise designed for secure Address: Turner Division, Conrac Corp., 716 More cartridge for positioning of small objects. Its jaws open up Oakland Rd. N.E., Cedar Rapids, IA 52402. 3 your money. We use 4 poles, 4 coils and 3 magnets INTEL MICROCOMPUTER MANUAL in our cartridges (more than The MCS-48 TM single -chip microcomputer any other brand). user's manual includes the 8048 microcom- puter with ROM program storage, the 8748 Inspection from head with EPROM (erasable programmable) pro- 4 to toe. Every Empire "7 gram storage, the 8035 microcomputer and cartridge, regardless of price, the 8243 I/O expander. Sections cover mi- is fully inspected both visually crocomputer operation, the use of compatible ° ;. and technically. Tests include `[S' 8080 and 8085 system peripherals and standard memory components for expansion, frequency response, output q balance, channel separation and both hardware and software application and tracking. examples. Data sheets and instruction sets are also included. Address: Intel Corporation, Literature Department, 3065 Bowers Avenue, Diamond control. Santa Clara, CA 95051. At Empire we cut, 5 to 2 1/2", with precision -machined guide bars RCA PRODUCT GUIDE grind, polish and mount the supported at 3 points to assure parallel jaw diamonds to our own exacting alignment, equalized work pressure and wob- A 40 -page guide, MPG -180, covers the com- specifications. We insure total ble -free operation. Removable, V -grooved plete line of IC's, support systems, and ac- quality of the product from jaws and soft jaw protective pads are fur- cessories that constitute the RCA CDP1800 start to finish by buying only nished for holding delicate and odd -shaped Cosmac microprocessor family. Included is a the highest quality gems. parts. The D -Vise provides a full hemisphere description of the CDP1802 microprocessor, of positioning locations, with 180° tilt and 360° covering features, architecture, ratings, char- For more good reasons to buy swivel. A twist -lock ring on the base locks the acteristics, timing diagram, and 'instruction an Empire cartridge, write for head swivel in any position. The base can be summary. Along with a discussion of the sup- your free catalogue: used portably, or attached permanently by its port systems and accessories for usage with EMPIRE SCIENTIFIC CORP. three mounting holes. The D -Vise is priced at the CDP1802 microprocessor, the guide in- Garden City, N.Y. 11530 $21.95. With the addition of the Model 2215 cludes a cross-reference section that lists holder for Dremel Moto -Tools, it is $24.95. RCA types equivalent to other manufactur- Mfd. U.S.A. WIFE Address: Dremel Div., Emerson Electric Co., ers' devices. Address: RCA Solid State Divi- 4915 21st St., Dept. PR, Racine, Wis. 53406. sion, Box 3200, Somerville, NJ 08876. CIRCLE NO. 18 ON FREE INFORMATION CARD 14 POPULAR ELECTRONICS

AmericanRadioHistory.Com achieve high-fidelity reproduction. This

point is debatable, I think, but it certainly does seem true that a record/playback process as excellent as today's digital technology is able to put the deficiencies of mediocre playback equipment in the background and let you appreciate the Stereo Scene music. (See diagram on page 20.) The 3M/BBC 32 -tracker comes as part of a mastering "system," along with By Ralph Hodges a four -track mix -down recorder. Price (gulp!): about $150,000. But cost not- AND OTHER TIMELY MATTERS THE DIGITAL COUNTDOWN withstanding, I observed a number of open checkbooks and poised pens. Re- 6 gaff MAY be able to get your feet cal recording studio's electronics look cordngs made with this system could be wet, but that doesn't mean you rather bad. can walk on water," remarked a col- The machine operates at 45 ips and its tracks down on 1 -inch tape, league as he contemplated the flash lays 32 1111-- flood of , reproducing, which actually amounts to a savings in d.: 1. and control systems featured at 1977's tape when you consider that an analog 5 oo:. New York Audio Engineering Society studio recorder running at 30 ips (for . A I Convention last November. His point maximum signal quality) must use 2 - was well taken, but many thoughtful inch tape for a typical maximum of 24 people now believe that you won't nec- tracks. The tracks run linearly (i.e., lon- essarily take a bath when you try, either. gitudinally, side by side) along the length The previous year's convention was of the tape, and one track suffices for enlivened by some stunningly good digi- each of the 32 audio channels, including tal tape recordings presented by Dr. all necessary error detection and correc- 3M Mastering System of , but tion information. The sampled input sig- there was very little else of substance, nal (the sampling rate being 50 kHz) is reaching you fairly soon. And 3M is al- unless you count the almost -omnipre- recorded in groups of sixteen -bit bytes. ready talking about a consumer digital sent digital delay and reverberation de- Along with this signal, parity bytes are recorder. Undoubtedly the tape will still vices designed to process signals re- recorded as well as a cyclicall redundan- have to run at 45 ips, but the cost will not corded in analog form. What made digi- cy check (CRC) word. The CRC check be anything like $150k. Look for it, per- tal the star of this year's show? Read on. word is used to tell if the 16 data bytes haps, in a year or two. are good; if not, the parity information in The First Studio Digital Record- other groups along with other data bytes The Digital Disc. Of more than seven er. It is not strictly true that the astonish- are used to reconstruct the missing in- reported digital products (for consumer ing machine developed through a joint formation. The data and parity used to use) exhibited at 1977's Tokyo Audio effort of the 3M Company and the British reconstruct missing data are spaced Fair, only a few made it to New York, but Broadcasting Corporation is the first dig- apart on the tape in such a way that- they gave a fine account of themselves. ital studio recorder. Nippon Columbia according to 3M's studies-an error in The most prominent was the PCM Disc (Denon) has had one in use for some both data bytes is statistically unlikely. system, an adaption of the /MCA years, the BBC has produced several for The studies further show that if an error video disc for audio purposes worked its own use, and Mitsubishi and others afflicts the parity bits, both signal bytes out in a joint effort by Teac, Mitsubishi, have made significant contributions. But will probably escape unscathed be- and Tokyo Denka. Like the Philips/MCA the 3M/BBC extravaganza is the first of cause of the scheme used to space the recording, the PCM Disc is scanned its kind likely to be purchased by the re- information along the tape. (and recorded as well, through a photo- cording companies most people patron- Whether the above description means graphic process) by a radial -tracking is ize. It fits right into the studio as if it were anything to you or not, the sound of the laser. PCM (pulse -code modulation) an ordinary analog recorder, and offers recordings this machine is capable of of course virtually synonymous with digi- up to 32 tracks of audio recording. making certainly would. A recording of a tal, but communication of the actual Basic (preliminary) specifications in- close-miked solo piano (difficult for any code used was a bit obscured by the clude a frequency response of 30 Hz to recording technique) that the 3M people language barrier. It's my impression that 15 kHz ±0.3 dB (response is down a few brought to the convention was utterly eight bits provide the fine details of sam- dB at 20 Hz and 20 kHz), a dynamic captivating in its vigor and effortless re- pled amplitude, while four additional bits range exceeding 90 dB, and harmonic alism. In fact, all around the conven- constitute a "multiplier," if you will, so and intermodulation distortion for any tion's many digital demonstrations there that the musical material is dealt with in audio frequencies or combination there- were astonished comments that the mu- several discrete dynamic ranges rather of measuring less than 0.03 percent sic was immensely satisfying despite the than in one continuous . I throughout the system's dynamic range! admitted inferiority of the loudspeakers balk at reporting other half-understood Wow and flutter, crosstalk, and print - and associated equipment being used. details, but let it be said that the com- through are, of course, unmeasurable. If Many have claimed repeatedly that the bined system (disc record, record play- - it isn't obvious already, I should point out poor program material available is the er, and the admirably compact electron that these specifications make the typi- principal factor defeating our attempts to (Continued on page 20)

FEBRUARY 1978 15

AmericanRadioHistory.Com I

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AmericanRadioHistory.Com NRI offers you five TV /Audio Servicing Courses NRI can train you at home to ser- provide profes-ter= f vice. Color TV equipment and sional tools and audio systems. You can choose "Power -On" from 5 courses, starting with a equipment along 48 -lesson basic course, up to a with NRI kits Master Color TV/Audio Course, engineered for complete with training. designed -for -learning With the 25" diagonal solid state Master color TV and a 4 - Course, speaker SQ" Quadra- for phonic Audio System. instance,

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FEBRUARY 1978 19

AmericanRadioHistory.Com (Continued from page 15). playing time per side) is in the works. An the musical lines was so precise on the ics built into its base) boasts a dynamic approximate price of $10 per disc has digital recording (at all signal levels)- range in excess of 98 dB and harmonic been suggested. Too bad the quality of and the presentation of depth and space distortion of under 0.1 percent overall. the' professionally produced master so convincing-as to provoke revolu- Participants in the convention were tapes will probably not be up to what's tionary rumbles from all auditors. It played a recording whose source was- achievable with the aforementioned U- would be ironic if the emergence of the at least in part-a Sony U-Matic video Matic/PCM audio tape recorder, which 3M/BBC recorder, the first studio multi - cartridge machine with a PCM adapter. is also envisioned as a consumer prod- tracker worthy of the designation, were So portable is this ensemble that it was uct. to coincide with a return to two- or three - track recording. Digital Recordings. Software (re- cordings available to consumers) is a Quadraphonic Capers. To the out- major hurdle to be overcome by any new side world it may appear that develop- recording system, naturally. Even if you ment work on four -channel sound has have the ability to design flawless re- stopped dead in its tracks. This is not the cording equipment, you may not have case, however; in fact, it begins to seem much succe'ss with it at public demon- that the real work is just beginning. Only strations unless you can afford to put a within the last few years have the vari- large and important musical event in ous quadraphonic disc systems been front of its microphones. As reported last able to make good on their promises of month, the direct -to -disc record compa- four discrete -sounding high-fidelity nies are beginning to manage this. And channels. Teac's PCM Disc Machine. so are the digital advocates. To date, it is JVC that has made the At the convention, Soundstream's Dr. most visible progress. The JVC re- actually lugged out into the field to rec- Stockham achieved just this with a ren- search group started with binaural head- ord the departure of a steam locomotive dition of Rimsky-Korsakov's Capriccio phone sound and its remarkable ability from a country railroad station. In the in- Espagnol with the Boston Pops Orches- to persuade the listener that he has door playback setting I don't think we tra, Arthur Fiedler conducting. The re- been transported into the recording en- could have tolerated much more dynam- cording project was actually sponsored vironment. From that point of departure ic range than was provided (from the by Crystal Clear, one of the direct -to - they developed the Q-Biphonic Proces- delicate chirruping of birds to the caustic disc outfits, but the engineer, fellow col- sor, a device that came startlingly close blast of the steam whistle). The only au- umnist Bert Whyte, backed himself up to simulating the binaural experience dible noise present on the recording re- with Stockham's superb digital recorder, with loudspeakers, given an appropri- portedly-and believably-came from as well as with one of the best analog ately processed recording. At the con- the microphone pitiful preamplifiers, tape recorders available. vention, JVC appeared with a recording - analog devices that were. they The several versions of the perfor- studio adjunct to their system. It was in- The PCM Disc machine is intended to mance made by different recording me- tended to interface with the recording be a consumer-available product. Ten- dia should afford an oppórtunity for rich console and create a Q-Biphonic record- tative price for the audio -only version is and important comparison. As yet I have ing out of a multi -track production. in the neighborhood of $600, and it will heard only the digital (Stockham) ver- Again, details are very sketchy. How- plug right into your present preamplifier. sion, but I am satisfied. The recordings, ever, it is possible to make a few educat- The software, it is hoped, will come from all made simultaneously from the same ed guesses. One of the factors widely arrangements made with major record three -microphone pickup, seem des- believed to contribute to the sta.-fling re- companies to permit the release of mas- tined to generate even more public out- alism of binaural sound is the right ear's ter tapes to the PCM Disc duplicators. rage about current multi-miking prac- inability to hear the signal that is being The disc itself is presently single -sided, tices, at least insofar as they are applied delivered to the left headphone earcup, but a double -sided version (30 minutes' to classical music. The representation of and vice versa. (When listening to loud- speakers, both ears ultimately hear the signals from both speakers, which is un- MINIMMIMMEMEMMEM natural when we're trying to create a MMIWWWWWWWW1 Harmonic "phantom" image divorced from either WWWWWWWWWW~ distortion of speaker.) The Q-Biphonic recording processor reportedly first tailors the mul- 20 1111~1~~11~11~ analog and M.EMEMMM.MEMEM digital systems ti -channel signals at its input to simulate a binaural presentation and then sub- 40 compared. Skirts "NALOGnr. (MOd.. on analog jects the result to a "crosstalk canceller" n products are due that conditions it for loudspeaker listen- -60 21~1~~n1~ to pitch ing. The final recording is played back 1~1115~1~1~MIM ambiguity, which I,AI! d1111rr J1!!IIAPI M!w1 through four loudspeakers in a typical -80 WWWLWW WWWWWWWW can be heard. quadraphonic configuration. Without overcommitting myself, I think 100 111~1~~~ I can say that the JVC system is capable 1D2dBHEADROOMOWS ..N E of the most devastatingly effective four - MEMIIME ME i channel reproduction yet. O 0 2 KHz 5 KHi 8 KHi 12 KH, 16 KHz 20 KH,

20 POPULAR ELECTRONICS

AmericanRadioHistory.Com Julian Hirsch HIRSCH/HOUCK LABORATORIES 77: Audio Reports

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a ,, TURNTABLE DRIVE SYSTEMS

wTHEN direct -drive turntables were first intro- idler drive was the traditional way to do this. A rub- duced several years ago, they were expensive ber puck, contacting the motor shaft and the inside of but had appreciably less rumble and wow than most the platter rim, accomplished the speed reduction, existing belt and idler driven models. The direct - and transmitted enough torque to the platter so that drive record player had a glamorous image that en- the record dropping mechanism could be operated hanced its appeal to the buying public (and still does) without stalling the motor or unduly slowing down even beyond its undeniably excellent performance. the turntable. Now, the price of direct -drive motors has dropped to Good turntable performance depends on the isola- the point where they can compete with most good - tion of the platter system from the motor vibrations quality conventionally driven turntables. This proc- and from the inevitable torque pulsations of any mo- ess has been accelerated by the development of sever- tor with discrete poles. Even with soft suspension al variations of the original concept by different com- bushings for the motor and a fairly soft idler wheel, panies, introducing more competition into the proc- there are practical limits to how much of this un- ess. (At first, all turntable manufacturers bought their desired vibration can he filtered out of an idler drive. direct -drive motors from Matsushita, who developed Also, with the basic motor revolution rate of 30 times them in their present form.) per second, the fundamental rumble frequency is 30 To appreciate the initial appeal of the direct -drive Hz. Harmonics of that frequency extend well into the concept, one must examine the state of the record audible range, of course. player art in the 1960's. Record changers (which were For years, it has been recognized that a belt drive even then being called "automatic turntables") were, can provide better isolation from motor vibration as always, powered by 4 -pole induction motors or, in than is feasible with a rubber idler wheel. The soft, some deluxe models, hysteresis synchronous motors. compliant belt, made of fabric or rubber, acts as a In either case, the motor turned at about 1800 rpm; filter to prevent the higher vibration or flutter fre- and a speed -reduction device was needed to convert quencies from affecting the turntable system. Belt that to the 331 or 45 rpm required by the platter. The drive is also relatively simple and inexpensive to

(A) Belt Drive. The flexible belt. (B) Idler Drive. Simple and reli- (C) Direct Drive. This design does "soaks up" much of the motor's vi- able, this drive has supplied the not provide high isolation, but low bration and speed variations, so high. starting torque needed for rec- operating speeds' insure that rum- that a well -designed belt -driven ord changers for many years. How- ble will occur only at very low fre- turntable usually can provide ex- ever, its isolation between platter quencies where it can he easily and tremely low rumble and flutter. and motor is low. effectively filtered out.

FEBRUARY 1978 21

AmericanRadioHistory.Com "If youre going to learn electronics, you might as well learn it right!"

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o `Don't settle for less. Especially when it comes to career training... because everything else in your life may depend on it. That's why you ought to pick CIE!"

22 POPULAR ELECTRONICS

AmericanRadioHistory.Com More than half of CIE's courses you've probably seen ad- Pick the pace that's right prepare you to pass the government- vertisements from other for you. administered exam. In continuing electronics schools. Maybe you CIE understands people need surveys, nearly 4 out of 5 CIE gradu- think they're all the same. to learn at their own pace. There's no ates who take the exam get their They're not: pressure to keep up ... no slow Licenses! CIE is the largest indepen- learners hold you back. If you're a For professionals only. dent home study, school in the beginner, you start with the basics. world that specializes exclu- If you already know some elec- CIE training is not for the hobby- sively in electronics. tronics, you move ahead to your ist. It's for people who are willing to own level. roll up their sleeves and go to work . to build a career. The work can be Meet the Electronics Enjoy the promptness of hard, sure. But the benefits are Specialists. CIE's "same day" grading worth it. When you pick an electronics cycle. Send for more details school, you're getting ready to invest When we receive your lesson and a FREE school some time and money. And your before noon Monday through Satur- catalog. whole future depends on the educa- day, we grade it and mail it back- Mail the card today. If it'.s gone, tion you get in return. the same day. You find out quickly cut out and mail the coupon. You'll That's why it makes so much how well you're doing! get a FREE school catalog plus com- sense to go with number one ... with CIE can plete information on independent the specialists ... with CIE! prepare you for home study. For your convenience, your FCC License. we'll try to have a CIE representa- There's no such thing as For some electronics jobs, you tive contact you to answer any ques- bargain education. must have your FCC License. For tions you may have. If you talked with some of our others, employers often consider it a Mail the card or the coupon or graduates, chances are you'd find a mark in your favor. Either way, it's write CIE (mentioning name and lot of them shopped around for their government -certified proof of your date of this magazine) at: 1776 East training. Not for the lowest priced specific knowledge and skills! 17i Street, Cleveland, Ohio 44114. but for the best. They pretty much knew what was available when they picked CIE as number one. We don't promise you the moon. We do promise you a proven way to < build valuable career skills..The CIE faculty and staff are dedicated to that. When you graduate, your di- ploma shows employers you know what you're about. Today, it's pretty hard to put a price on that. - Because we're special- ists, we have to stay lb - rc t ahead. 4+ lf r At CIE, we've got a position of '_t f . leadership to maintain. Here are ~ . co* 8 . some of the ways we hang onto it .. . ú At Our step-by-step learning `4 '1a includes "hands-on" training. At CIE, we believe theory is important. And our famous 1`4 Auto -Programmed® Lessons teach ;^1 you the principles in logical steps. But professionals need more Patterns shown on TV and oscilloscope screens are simulated. than theory. That's why some of our courses train you to use tools of the trade like a 5 MHz triggered -sweep, MIMI solid-state oscilloscope you build yourself- and use to practice trouble- Cleveland Institute of Electronics, Inc. shooting. Or a beauty of a 19 -inch CIE 1776 East 17th Street, Cleveland, Ohio 44114 diagonal Zenith solid-state color TV Accredited Member National Home Study CoUncil you use to perform actual service z operations. YES .. . I want the best of everything! Send me my FREE CIE school catalog-including details about troubleshooting courses-plus my FREE package Our specialists offer you of home study information. personal attention. , PE -56 Print Name Sometimes, you may even have a question about a specific lesson. , Address Apt Fine. Write it down and mail it in. Our experts will answer you , City promptly in writing. You may even State lip get the specialized knowledge of all , the CIE specialists. And the answer Age Phone (area code ) you get becomes a part of your per- , Check box for G.I. Bill information: Veteran Active Duty manent reference file. You may find MAIL TODAY: this even better than having a class- , room teacher. FEBRUARY 1978 25

AmericanRadioHistory.Com build (the most complex part of it is the speed -change er -price models from the Japanese manufacturers mechanism, usually a fork that shifts the belt to a diff- who favor direct drive for their higher -priced units. erent shaft diameter). For these reasons, among oth- Mechanically, belt drive is hardly more complicated ers, it has been the practice for some time for design- than direct drive, consisting as it does of a motor, a ers of single -play turntables to use belt drive. The. belt, and a platter-three parts in all. There is also the performance specifications of these turntables are al- complete elimination of the complex electronic cir- most always better than those of idler -driven turntá- cuitry that is required to run a direct -drive motor, bles, and their prices can be very competitive. making the belt -drive system as reliable as any type For many years, no belt -driven record player could over the long term. change records automatically. This problem arose be- Some belt -drive models have a speed vernier ad- cause, among other reasons, the diameter of the shaft justment, usually by electronic means. In these, an of a high-speed motor, through which all of its torque oscillator and amplifier drive the motor instead of a was transmitted to the belt and platter, was very direct connection to the power line; the vernier mere- small in relation to the turntable diameter. In recent ly adjusts the oscillator frequency. These units may years, this difficulty has been resolved-in many or may not have feedback stabilization (most do not), cases by using a relatively low -speed motor, whose which requires a tachometer generator on the platter driving shaft diameter was larger and thus able to to supply the feedback signal to the amplifier. The transmit more torque to the platter without slipping. overall complexity of an electronically driven belt - This also has the advantage of reducing the rumble to drive turntable is not much different from that of a di- a subsonic frequency. Another approach, especially rect -drive unit, nor is its price. Simpler adjustable - when a 4 -pole motor is used, has a low -torque record - speed belt drives use an expanding drive shaft diam- dropping and arm -indexing mechanism. eter to adjust the speed. While these developments were taking place, di- From a practical standpoint, belt drive can be every rect -drive motors were appearing in growing num- bit as good as direct drive. Its rumble and flutter can bers. Presently, there are several different construc- be made just about as low if the mechanical assembly tions used in these motors, depending on their manu- tolerances are held to the same close limits. Even facturer. Some are dc motors, while others use ac though the direct -drive motor's basic vibration rate is power. All are servo motors, from which a signal pro- only 0.5 Hz (at 331/2 rpm), harmonics may be present portional to speed is fed back to the driving amplifi- at much higher frequencies, well into the audible ers to maintain a constant speed. The feedback can be range. A good belt -driven design, especially with a in the form of a frequency or a voltage, either being low -speed motor, can achieve very similar results. It comparéd to a reference of the same type. A variation is easier to isolate the turntable system from external of the original direct -drive motor (which was con- vibration with belt drive since the motor can be fas- structed as a complete unit with a protruding shaft tened rigidly to the supporting base, and the platter that acted as a center spindle when the platter was and arm can be linked as a unit and floated on a com- placed on it) is the motor which uses the platter itself pliant suspension to prevent transmission of vibra- as the rotor element. This was first introduced by tion. A direct -drive turntable, on the other hand, can- Matsushita (Technics), and more recently in a some- not suspend only the platter and arm on spring what different form in a Fisher turntable. It hás a cir- mounts, but must float the entire motorboard or, in cular band of magnetic material around the inside of most cases, the entire record player. Rarely is this as the platter, on which are magnetized a number of per- effective as the systems used with the better belt - manent magnetic poles. (There are 120 of them in the drive players. (When the turntable suspension is Fisher unit.) The stator windings and pole pieces are loose enough to provide good isolation, the record on the motorboard, close to the magnetized strip on player tends to have a "bouncy" feel when handled.) the platter. The interaction between the field from the Since mechanical assembly precision is the key to stator and the permanently magnetized poles causes good performance, do not expect a low-priced belt - the platter to rotate. Pickup coils (like tape -recorder driven record player to match the performance of a heads) close to the magnetized strip sense the motion good direct -drive unit (or even of a low-priced direct - of the platter. The voltage generated in them supplies drive player). Alternatively, a really good belt -drive the feedback control signal to the electronic section. turntable will be able to outperform all but the finest This is unquestionably the simplest type of turntable, direct -drive models. (It may be as expensive as they from a purely mechanical standpoint, having only are, however.) There are differences in direct -drive one moving part-the platter itself! Of course, there motors as well, so one cannot expect a $200 direct - is considerable electronic complexity associated with drive turntable to match the performance of one cost- a direct -drive motor. In newer designs, however, ing twice as much. However, the differences are like- most or all of this is in a single LSI chip, which pro- ly to be so small that they cannot be heard. vides potentially greater reliability and lower cost Quite recently, "quartz lock" turntables have been than a similar circuit made of discrete components. announced by several manufacturers. Originally very In spite of the marketing appeal of direct drive, expensive, they have now entered the medium- and belt -driven turntables are still very much on he low-priced categories as well. A quartz -lock system is scene (the Garrard GT25 tested for this month's re- a direct -drive turntable in which the turntable speed ports is a good example). In fact, the record player is referenced to a signal derived from a quartz -crystal lines of all major manufacturers include belt -driven oscillator. This gives it, for all practical purposes, ab- models, and belt drive is used extensively in the low- solute speed accuracy and stability. On many quartz -

26 POPULAR ELECTRONICS

AmericanRadioHistory.Com lock a units, vernier speed adjustment is also provid- drive motors. This is of more importance to a broad- ed. In the lower -price players, this is done by disen- cast station than to most home users. The high torque gaging the quartz -crystal control and substituting a also makes the speed independent of heavy loads, conventional dc voltage as a reference for the turnta- such as record cleaning devices, which is of more in- ble speed, as with any ordinary direct -drive motor. terest to hi-fiers who wish to clean discs while they Some high-priced units can shift speed in small dis- rotate on a platter. crete steps, using synthesizer techniques to maintain Throughout all this evolutionary process in crystal record- accuracy and stability at all times. player drives, the old idler system has been the one to Most people have no need of the extremely accu- lose the most ground. It is rarely found nowadays ex- rate speed of a quartz lock system. One characteristic cept in the lowest priced record players. For serious of many of is a them very high motor torque, al- or professional applications, which once called for a though there does not seem to be any fundamental heavy duty idler driven turntable because of its abili- reason why the same torque could not be achieved ty to come up to speed rapidly, the newer quartz - without the quartz reference. Their high torque en- locked turntables have a clear advantage. For home ables these turntables to start up, or to change speed, music systems, at almost every price level, either belt in a fraction of a second, compared to the delays of or direct drive is far superior to an idler -driven turn- several seconds that are common with other direct - table-and they now dominate the market.

GARRARD MODEL GT25 AUTOMATIC RECORD PLAYER

Belt -drive player can handle up to six discs automatically The middle control has settings labelled and features a very -low -mass tonearm. OFF, MANUAL, AUTOMATIC, and REPEAT. To its rear is a two -position record index- ing knob, for 7" and 12" (17.8- and 30.5 - cm) records. At the front of the control panel is a knob that initiates the auto- matic cycling of the player, by a momen- tary movement to its AUTO START/ REJECT setting. (It is spring loaded to re- turn to its original position.) The tonearm consists of a mildly S- shaped aluminum tube and a very light perforated magnesium four -pin, locking - type bayonet head shell. A rotating counterweight also carries the tracking force scale that is calibrated from 0 to 3 grams at 0.25-gram intervals. The CUE lever, located near the base of the arm, operates through a curved horizontal bar. Also near the base of the arm is an antiskating dial, with two scales calibrat- Garrard's new tail price of the Model GT25, including ed for elliptical and CD -4 styli. HIRSCH- "GT" HOUCK series could base and dustcover, is $159.95. Although the tonearm is quite conven- easily be mistak- tional in appearance and is a LABS . full 9" (22.9 REPORT en for convention- General Description. The belt actu- cm) from stylus to pivot, its very low ef- 1.21 al single -play rec- ally turns a smaller 51/2" (14 -cm) diame- fective mass is rated at 12 grams. As is ord players. A close examination, how- ter central platter made of molded plas- the case with the other GT series play- ever, will reveal that these are automatic tic. The larger cast metal platter rests on ers, the Model GT25 also features an record players that are capable of play- it, and the center hole accommodates automatic control mechanism made of ing up to six discs. The one visible clue either a short single -play spindle that Delrin, a rugged, self-lubricating plastic that the GT series of players have auto- turns with the record or a long multiple - that makes it unusually quiet in opera- matic functions is the vertical post near play spindle. When records are loaded tion. The "Delglide" system is driven the tonearm pivots. on the long spindle, their edges are sup- from the turntable shaft through a sepa- The Model GT25 tested here falls in ported by the post near the tonearm pi- rate belt under the motorboard. the middle of the line of five Garrard GT vot, but the dropping action is entirely The operation of the record player is series players, all of which are belt driv- through the center spindle. straightforward. For manual single play en. It measures 175/s"W x 133/4"D x Basic operation of the player is via operation, the record is placed on the 73/4"H (44.8 x x 34.9 19.7 cm) and three knobs on a metal plate located platter, the` control knob is turned to weighs 16 lb (7.3 kg). The suggested re- along the right side of the motorboard. MANUAL (which starts the motor) and FEBRUARY 1978 27

AmericanRadioHistory.Com the tonearm is cued by hand. After play- ance of the Model M95ED cartridge at ing, the arm automatically returns to its about 9 Hz, a nearly ideal frequency, rest position and the motor shuts off. Al- with an amplitude of about 6 dB. ternatively, the control can be set to AU- The cueing lift mechanism operated TOMATIC, which also starts the motor. smoothly, but the tonearm drifted out- plug in Then when the front knob is moved to ward somewhat during its descent, re- AUTO START/REJECT, the arm indexes to peating about five or six seconds of the the selected diameter and the record is record each time it was lowered. The an- played. If the first control is set to RE- tiskating calibration was accurate, yield- PEAT, at any time, the record being ing equal distortion on both channels and go played will be repeated until the unit is when set to match the tracking force. shut off manually. To play a stack of rec- The turntable speed was slightly slow, ords, the long spindle is inserted into the about 1% at 331/2 rpm and 0.3% at 45 hole in the center of the platter, the re- rpm. It did not change detectably with cords are placed on the spindle and line potentials between 95 and 135 soldering edge post, the center knob is set to AU- volts. The unweighted rms rumble was TOMATIC, and the AUTO knob is turned. -35 dB, including vertical components, The signal outputs in the rear of the and -39 dB with vertical rumble can- player are in duplicate. There is the con- celled out. Applying ARLL audibility ventional pair of phono jacks, with an weighting resulted in a -54 -dB rumble adjacent ground terminal as well as a measurement. The major rumble fre- DIN socket. The signal cable supplied quencies were 30 and 60 Hz, with other with the player is fitted with a mating DIN discrete components detectable at 10 plug at one end and phono plugs at the and 20 Hz. The wow was 0.1% (also an other end. The power cord also plugs unweighted rms measurement), and into the player. flutter was a low 0.035%. The flutter was predominantly found at frequencies be- Laboratory Measurements. After low about 10 hertz. we installed a Shure Model M95ED car- The mechanical operation of the play- tridge in the tonearm, using the plastic er was smooth, quiet, and trouble free. jig supplied with the record player, the The "Delglíde" mechanism was quiet, tracking error was less than 0.5°/in. for as claimed, with none of the clicking and playing radii from 2" to 6" (5.08 to 15.24 other noises that usually accompany the cm). The arm could be balanced unam- operation of an automatic record player. biguously, since the slightest movement However, we could hear a distinct sound from the rotation of the platter, apparent- WITH d^ of the counterweight made a plainly vis- ible change in the height of the tonearm ly originating under the motorboard. near balance. This suggests a very low When a record dropped on to the platter THRIFTY vertical bearing friction. After balancing it made the usual "thump." When the in accordance with the instructions, the cover was lowered, the player was at MARKSMAN IRONS calibration of the tracking force scale least as quiet as any automatic record was exact at forces up to 1.5 grams and player we have used. The automatic cy- had a maximum error of 0.1 gram at its cle required about 14.5 seconds to com- highest settings. plete, which is typical of most automatic ayWeller The capacitance to ground of each players. signal channel, measured with the car- The record player's soft rubber feet for instant action. Five Pre -tinned tips tridge shell removed, was about 115 pF. were reasonably effective in isolating different ratings for technicians and -4 cartridges, but base -conducted vibration. The player's hobbyists. Heat- and impact -resistant This is suitable for CD handles grip comfortably. Premium, a higher capacitance might be prefer- most sensitive frequencies for transmis- stainless steel barrel for strength, able for some stereo cartridges. (Higher sion through the feet were at 30 Hz and corrosion resistance, and more even capacitance cables can easily be sub- about 100 Hz, but the overall degree .of Cone shape, screw- temperatures. stituted for the plug-in cable supplied.) isolation was roughly what we have driver, chisel tips; Soldering Kit, Hot on other automatic record Knife Kit for wire stripping and plastic The claim of low arm mass was verified measured cutting. Full -view card pack lets you by measurement. With the Model players mounted in a similar fashion. see and read about these UL -listed, M95ED cartridge mounted in the shell, factory -pre -tested irons before you the total mass of the tonearm, referred User Comment. The Garrard Model buy. to the stylus, was only 17 grams. Sub- GT25 left us with some definite impres- See your local distributor or write... o tracting the 6 -gram cartridge mass left a sions. It cannot be dismissed as just net tonearm mass of only 11 grams. another record player. For one thing, it is Weller-Xcelite This is by far the lowest mass we have surprising to find the lowest mass pivot- Electronics Division measured on any conventional pivoted ed tonearm we have so far encountered tonearm and is especially impressive on on a very moderately priced record play- The Cooper Group ° a moderately priced record player. The er. (The other players in the Garrard GT COOPER P. O. BOX 728, compli- line also use a similar tonearm design.) APEX, NORTH CAROLINA 27502 arm mass resonated with the CIRCLE RO. 54 ON FREE INFORMATION CARD ELECTRONICS 28 POPULAR

AmericanRadioHistory.Com In spite of the lack of fanfare about the the Model GT25 are as straightforward (flutter was not audible on piano record- pivot design, the free-floating arm im- as can be and result in the promised ings). The only aspect of its perfor- pressed us as having exceptionally low performance. (It is surprising how few mance that left us less than enthusiastic pivot friction. Although Garrard rather record players can be set up properly was one it shares with the majority of modestly suggests that this player is without external aids.) Even the anti - record players we have used-the out- suitable for use with cartridges rated to skating dial is one of the small handful in ward drift of the tonearm during the cue- the arm han- track at 3/4 gram or more, that category our experience whose calibrations ing descent. Fortunately, includes just about every cartridge agree with the tracking force when ad- dles so easily that it can be cued by known to us. Our experience suggests justed for equal distortion on both chan- hand without "getting away" from the that the tonearm on the Model GT25 is nels with high velocity records. user (again, not something that one compatible with any cartridge presently Although the measured rumble and finds on every record player, by any manufactured, no matter how compliant flutter of the Model GT25 were not ex- means). it may be. ceptional, they do reflect competent per- In sum, the Model GT25 is an excel- We especially appreciate a record formance. We also found the player to lent medium-priced record player. It pro- player whose setup is free of guesswork be compatible with extended -range vides a level of performance that is and built-in errors. Setting the stylus speaker systems (rumble was not audi- wholly consistent with the full range of overhang and balancing the tonearm of ble) and with critical program material modern phono cartridges.

CIRCLE NO. 101 ON FREE INFORMATION CARD

SANSUI MODEL AU -717 INTEGRATED AMPLIFIER Medium -high -power amplifier has impressive transient -handling ability. near the knob identify the input selected. A large VOLUME knob operates a 32 -

step attenuator, with 1 -dB steps near the .... top of its range, 2 -dB steps at lower set- i tings, and still larger steps near the bot- tom of its range. The TONE controls 1 owd P - (BASS and TREBLE) are each 11 -position . *:...1 ' ... ;' m -1 Buttons next to the knobs _`-m ' ' step controls. are used to select turnover frequencies. t _, . For BASS, the choice is 200 or 400 Hz; for TREBLE, 3 kHz or 6 kHz. A SPEAKERS switch activates either, both, or neither of two pairs of speaker outpúts. There is Sansui's newest power amplifier section is fully direct - a PHONES jack on the panel, land a lever HIRSCH- and finest inte- coupled, from the POWER AMP IN jacks at switch for POWER. HOUCK grated stereo am- the rear of the unit, to the speaker out- The TAPE circuits of the AU717 are ex- LABS through the feedback loops as ceptionally comprehensive. Mechanical- REPORT,, plifier, the Model puts, and AU -717, is said to well. Normally, the power amplifier in- ly interlocked buttons connect either the have been designed to "solve audible puts are internally connected to the selected program SOURCE or the TAPE problems of Transient Intermodulation preamplifier outputs, but a slide switch PLAY signals to the amplifiers. There are Distortion (TIM)." Although there is still breaks that connection; a third switch provisions for two tape decks, with a but- much controversy about audible effects position places a capacitor in the input ton allocated to each. The exceptional of TIM and other slew -rate induced dis- circuit to handle situations where a d.c. part is the COPY switch, a knob near the tortions, it is generally recognized that a component could be present in the sig- buttons, which controls the signal fed to very high slew rate-the ability to deliver nal fed to the power amplifier inputs. the recorders. In its SOURCE position, the a large change of voltage to a load in a Differential amplifier circuitry is used tape recorders are fed the signal from very short time-is desirable for low throughout the AU717, including its pho- the INPUT SELECTOR switch. But other TIM. Interestingly, the specifications in no preamplifier and tone control stages. settings of the coPY switch feed the re- the AU -717's instruction manual make Like some other contemporary amplifi- corders from any of the AU717's inputs, no mention of slew rate! However, the ers, the AU717 has completely separate regardless of the INPUT SELECTOR'S set- more conventional specifications are im- power supplies, including power trans- ting, or from any of the three tape re- pressive enough in their own right. formers, for each channel. corder inputs (which are not controlled The Model AU -717 measures 17"W x The amplifier is finished entirely in by the INPUT SELECTOR switch). Thus, 153/3"D x6543"H (43 x 38.9 x 16.8 cm), black, with legible white markings and one can record from the tuner (for exam- and weighs about 39 lb. (17.8kg). Its red index lines on the black knobs. A ple) while listening to a record, tape or suggested retail price is $450. small red LED glows on the panel when other program source. Of course, one power is applied, blinking on and off can listen to any other program through General Description. The Model while operating conditions are stabiliz- the amplifier while dubbing from one AU -717 is rated to deliver at least 85 ing. The INPUT SELECTOR, located at the tape deck to the other or monitor the watts per channel to 8 -ohm loads, be- upper right of the panel, provides a playback from either tape deck with the tween 20 and 20,000 Hz, with less than choice of two high=level and two mag- appropriate TAPE PLAY button. Finally, 0.025% total harmonic distortion. Its netic -ph ono sources. LED indicators there is an OFF setting that removes all 29 FEBRUARY 1978

AmericanRadioHistory.Com 1.0 I I 1 1 V I' I'J I J I I

I SANSUI AU SANSUI AU -717 -7I7

REFERENCE POWER (85 1 0.5- 1402 TOTAL HARMONIC DISTORTION 0.5 HALF POWER( -3201 - - 80/700011z (4.1)1M DISTORTION - LOW POWER I-10201

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002 102 I1 I J 0.1 0.2 0 5 , 5 10 20 50 00 50 100 200 500 1M81 2MHz 5MHz 10 H, 20 CONTINUOUS AND EQUIVALENT MH FREQUENCY IN Hz (CYCLES PER SECOND) SINE -WAVE POWER OUTPUT PER CHANNEL IN WATTS Total harmonic distortion and 60/7000 -Hz IM distortion. Harmonic distortion at three power levels.

signals from the TAPE OUT jacks in the quencies. So far as we could determine, time as about 1 microsecond, from the rear of the amplifier, in order to prevent the distortion of the amplifier was negli- AUX input through the entire preamplifier any possible loading of the amplifier cir- gible compared to the measured values and power amplifier combination. A cuitry by the tape decks when you are of 0.03% or slightly more. 2-11F capacitor shunted across the 8 - not recording. -At maximum gain, the AU -717 could ohm load slowed down the rise time to 6 The BALANCE control is a small knob, be driven to a reference output of 10. microseconds, but did not produce any with a center detent, located below the watts by 49 millivolts at the high-level in- instability. The slew rate of the AU -717 VOLUME knob. Lever switches drop the puts, and 0.84 millivolts at the PHONO in- was by far the fastest we have yet mea- volume by 20 dB (MUTING), engage the puts. Unweighted S/N ratio, referred to sured-about 60 volts per microsecond. LOUDNESS compensation, turn on the 10 watts, was a very good 83.4 and 77.1 One distortion test that evaluates an HIGH filter (with a 6 dB per octave slope dB, respectively. The phono preamplifi- amplifier's high frequency power han- above 10 kHz) Or the SUBSONIC FILTER er, in spite of its very high gain, over- dling ability is a difference -tone IM mea- (cutting off at 6 dB/octave below 16 Hz), loaded only at the very high input level of surement using two tones near the up- and bypass the tone -control circuits. 380 millivolts. Tone control characteris- per limit of the audible range, such as 19 In the rear of the AU -717 are insulated tics were very good, affecting only a lim- and 20 kHz. Driven to within 0.2 dB of spring clips for speaker connections, ited portion of the frequency range. The the clipping point by such a signal, the and the various signal input and output loudness compensation boosted both AU -717 produced a 1,000 -Hz distortion jacks, plus preamplifier output and main low and high frequencies at low volume component some 75 dB below the level amplifier input jacks and the slide switch settings. Although compensation was of either tone and no other visible distor- that couples them. There are three a.c. somewhat excessive, using the MUTING tion components within the 80 -dB range outlets, one of which is switched. switch to drop audio gain by 20 dB, it of our Hewlett-Packard spectrum was possible to operate the VOLUME analyzer. This is, by by any standard, Laboratory Measurements. The control at a higher setting and thus re- excellent performance, especially for an AU -717 did not become unduly warm duce the loudness compensation to integrated amplifier. during the one hour preconditioning pe- more suitable levels. riod at one-third power. Fully heated, the The filter slopes at 6 dB per octave, User Comments. Sansui's Model outputs clipped at 100 watts per chan- were too gradual to be very effective, al- AU -717 integrated amplifier is a splen- nel, driving 8 -ohm loads at 1,000 Hz. though the SUBSONIC filter began to did example of melding high electronics Into 4 and 16 ohms, the amplifier deliv- show its effect at about 50 Hz and prob- technology with a sense of packaging ered 128 and 64 watts, respectively. ably reduced subsonic output substan- panache. As one of Sansui's new "DC" The 1,000 -Hz harmonic distortion was tially. The HIGH filter response was down stereo amplifier models, its advanced exceptionally low at most power levels. 3 dB at 7,000 Hz. RIAA phono equaliza- circuit designs are impressive. More im- It was under 0.004% from 0.1 watt to 80 tion was at least as accurate as our portant, it has resulted in impressively watts output, reaching 0.01% at 100 measuring instruments, with less than fine laboratory measurements and the watts, just before clipping occurred. In- ±0.5 dB of error over the extended range test sample did not add any sound of its termodulation distortion was 0.036% at from 20 to 20,000 Hz. It did not change own. Reinforcing this attribute, there are 0.1 watt, and a nearly constant 0.015% detectably when measured through the no switching transients or other unwant- over most of the power range up to 90 inductance of a phono cartridge. ed side effects caused by use of its watts. The full -power THD was less than It was in its transient handling, though, switches or controls. 0.016% from 40 to 20,000 Hz. Although that the Sansui AU -717 was most im- Control flexibility is excellent, though it appeared to rise at lower frequencies, pressive. The rated rise time of 1.8 mi- not unlimited, and the controls operated this reflects the increased distortion of croseconds would be considered very smoothly. The relay protective systems our Radford test oscillator at those fre- good; however, we measured the rise proved to be among the better ones

30 POPULAR ELECTRONICS

AmericanRadioHistory.Com ékthné.toi.thé Réá1.Wor1d .

o. . a. - re with the Real -World Interface from The Digital Group

A computer should have a purpose. Or as many Includes cable and paddlecard for connection to dual purposes as you can imagine. Because a computer 22 on Digital Group CPU back panel. Two 22 -pin belongs in the real world. edge connectors included Requires two output ports and one input port And now, the Digital Group introduces the Real - World Interface. A system component that's actually a AC Controller system in itself, and specifically designed to help you Eight output devices (2N6342A-2N6343A, -12 amp get your computer to control all those tasks you Triacs); Each output 240V AC max, 12A max RMS know a computer can control so well. Control AC motors, lamps, switches, etc. Opto -isolated (MCS-2400 or equivalent) Automate your sprinkler system. Heat and cool your home. Guard against burglars. Shut off lights . . . It's DC Controller all a part of the Real World, easily controlled with the Eight output devices (2N6055) each output up to Digital Group Real -World Interface. 50V and up to 5A Control DC motors, switches, solenoids, etc. Our Real -World Interface is initially made up of three May use internal +12V DC for load or external DC basic components - motherboard and power supply, up to 50V DC parallel CPU interface and cabinet - plus three types of plug -ins: AC controller, DC controller and Price prototyping card. The recommended software For the motherboard and power supply, parallel packages are Conyers, Assembler or Maxi -Basic, in CPU interface and cabinet, our kit price is only that order. $199,50, or $260 assembled. Now that's down to earth. Some of the features include: We've only just begun our Real -World Interface System. There are many more plug -ins and Motherboard & Power Supply applications coming along soon. So write or call The 12 slots - 11 control cards, one for the interface Digital Group now for complete details. card +5V DC±5% @ 1A, +12V DC ±5% @ 1A, -12V DC And welcome to our world. ±5% @ lA contained on board May be free-standing (with care) o Parallel CPU Interface I All buffering for Data Out (25 TTL loads), Address (25 TTL loads) and Data In (10 TTL loads) P.O. BOX 6528 DENVER, CO 80206 (303) 777-7133

CIRCLE NO. 13 ON FREE INFORMATION CARD

AmericanRadioHistory.Com around, always cutting the output before professional look upon the model, an high -power control amplifier and the any damage could occur during our ex- appearance often desired by the more flexibility of choosing one's own FM tun- aminations. serious audio enthusiast. er. Considering its power rating, low dis- The AU717's black -color enclosure In sum, the AU717 is highly recom- tortion and price class, there are only a and rack -mounting adaptor bestow a mended for those who wish a medium - very few competitors in the race.

CIRCLE NO. 102 ON FREE INFORMATION CARO

SHERWOOD MICRO/CPU 100 FM TUNER channels when a weak stereo signal is Microprocessor provides programmed tuning and display of station's call sign. received, thus reducing the noise level. The Sherwood has three tuning modes. The most obvious of the few controls on the front panel is a conven- tional -looking tuning knob, but with an 8....m 1...... - 1133 unconventional feel. It turns with unusu- al lightness and freedom because it op- erates no mechanism at all. Instead, it is Y. linked only to a flywheel and a notched metal disc which resembles a, multi - bladed fan. The "blades" interrupt a light This remarkable used in this country or for the even -num- beam as the knob is turned, sending HIRSCH- bered channels used elsewhere. For control pulses to the microprocessor. HOUCK new FM -only tun- LABS er is the second high rejection of image and spurious re- Like many digital tuners, the Micro/ REPORT of two audio com- sponse, a six -section, varactor-tuned CPU 100 also offers autoscanning oper- ponents we've front end tracks with this synthesized lo- ation. Above the tuning knob are pairs of examined to incorporate a microproces- cal oscillator. There are two, separate i -f small contacts marked LEFT and RIGHT, sor. (The other was the ADC Accutrac amplifiers, one each for normal- and though perhaps DOWN and UP would record player.) But it won't be the last. wide -bandwidth operation. have been more accurate. A touch on The microprocessor adds many unusual The detector, which recovers the au- the LEFT pair starts the tuner scanning features, such .as a display that shows a dio information from the FM signal, is downward from whatever frequency to station's call letters as well as its fre- also digital; a true pulse -counting type. It which it had previously been tuned. If it quency, a unique self -diagnostic test generates a pulse each time the re- encounters a signal strong enough to program, and a four -station memory - ceived signal crosses the zero -voltage override the muting circuit, it stops. If no tune system that is unusually easy to axis, then averages these constant - signal is received before the tuner program. Even without the microproces- width, constant -amplitude pulses to- reaches the lower end of the FM band, it sor, though, the Sherwood Micro/CPU gether to produce the audio signal. flies balck to the starting frequency and 100's receiving circuitry would be novel The detector's averaged output is pro- scans upward from there. If nothing is enough to merit special attention in its portional to the FM frequency, which found in that part of the band either, it re- own right. Its tuning, for example, is all - varies with the transmitter's audio input, turns to the original frequency and electronic, with no variable capacitors or so the detector is extremely linear, and stops. Between the LEFT and RIGHT turn- potentiometers. And a high proportion of reproduces the modulating waveform ing contacts is a pair of contacts labeled its circuits are digital. with great accuracy. STEREO, which sets the tuner to respond The tuner has a satin -finished alumi- From the detector, the signal goes to only to stereo signals when in scan num' front panel, a black metal cabinet, a phase -locked -loop multiplex demodu- mode; a second touch restores normal and walnut -grain wood side panels. It is lator. This is followed by the audio mut- automatic stereo/mono operation. approximately 20" W x 15" D x 6 3/8" H ing switch and an automatic high -blend More unusual is the tuner's MEMORY (508 x 37.9 x 16.2 cm), and weighs 34 lb circuit that partially combines the two feature, capable of storing the frequen-

(15.4 kg). The manufactuer's suggested +10 '¡AUDIO OUTPUT price is $2000. 1 r L! 0dDIVOLT_ SHERWOOD MICRO/CPU 100 FM TUNER General Description. The Micro/ 10 NORMAL IF BANDWIDTH CPU 100 is digitally tuned, with a crys- 2 IHF USABLE SENSITIVITY tal -controlled, phase -locked digital fre- MONO 9.84B1 (1 65V) STEREO:154B1 (3.0pV) quency synthesizer generating only the 76 30 frequencies needed for accurate tuning. w 40 Tuning moves in 200 -kHz steps from s one channel frequency to another, with ó 5 a minimum rated accuracy of 0.0024%. 6 Since frequencies between channels are never no -channel 7 covered, center 1 w i.n.+w 50CB QUIETING SENSI7 VITY NOISE meter is necessary. A switch on the rear -BO MON0:120B (2.2yV) AT 4.5% THD i® STERE0:30dB1(179V) AT 0.56% THD panel programs the synthesizer for .); - 90 il; . .1 the odd o 10 20 30 40 5 60 V6 80 90 100 either -numbered station fre- INPUT dBf quencies (92.1 MHz, 92.3 MHz, etc.) IHF usable sensitivity with normal i -f bandwidth.

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AmericanRadioHistory.Com transmitting antenna. +10 1 AUDIO OUTPUT i Additional controls are concealed be-

I o O4B=1 VOLT hind a hinged door at the bottom of the SHERWOOD MICRO/CPU 100 FM TUNER control panel. These include audio out- 10 WIDE IF BANDWIDTH put level adjustments (there is also a

2 1 IHF USABLE SENSITIVITY MON0:130Bf (2.400 pair of fixed -level outputs), the muting 1 STERE0:154B(13 OyV) I threshold adjustment, and switches for

: I .. . . f . :, ...... Ii. -MONO _ _ _ STEREO MUTING, AUTOSTEREO FILTER, STEREO/ , . I. MONO mode, DE -EMPHASIS (from the ,. ) I 1' :_ ...... i` . NOISE + DISTORTION .. I. normal 75 microseconds tb the 25 mi- ...... r...... « '''1... ''''. .. croseconds required when using a 6 -*, Dolby decoder with the tuner) and the

7 ...... F NORMAL/WIDE selectivity selector.

5008 QUIETING SENSITIVITY NOISE ..' Although it has nothing to do with the -8 .MONOI2dB (2.2yv)AT 0.7% THD STERE030EBf (17yV) AT 0.63% THD . tuner's performance, the tuner has a ,I , -9 1 1 1 ! 0 20 30 40 50 70 90 unique capability to analyze and check INPUT OB} out its own operation. Its built-in "com- IHF usable sensitivity with wide i -f bandwidth. puter" can do this far more rapidly than a human technician could do. It even dis- cies of four stations and returning to any To program this call -letter display, you plays the part numbers of defective IC of them at a touch. Storing them in the first tune in a station, then press a con- stages on its alphanumeric display. For memory requires no punched cards or tact pair marked ALPHA. Turning the tun- this purpose, specially programmed other physical programming, a depar- ing knob will not change the station, but read-only memory (ROM) IC's are used. ture from previous practice. Instead, will light up the first character of 'the dis- Substituting one for one of the IC's on when the tuner is set to the desired play with a series of characters, begin- the computer board, and turning on the channel, a pair of fixed contacts marked ning with "A". When the first letter of the power, causes a rapidly changing dis- STORE is touched, followed by a touch of station's call sign is reached, a touch of play of numbers and letters on the panel one of the four pairs of MEMORY con- the STORE contact places it in the first of the tuner. The test is completed in tacts. (A neon lamp behind each contact position, and the letter "A" now appears about a minute. If all goes well, the glows when it has been activated.) To to its right. The knob is turned again until words "TEST DONE" flash alternately return to that station at any future time, the second letter of the call sign ap- on the display Until it is shut off. only a touch of the appropriate MEMORY pears. That letter is stored, and the proc- Another ROM is used in a similar contact is required. This memory infor- ess continues until the full four -character manner to check the operation of the mation is retained when the tuner is call is displayed. Now the knob returns tuner's non -computer functions. This turned off. Even when it is unplugged, to its normal tuning function-with the ROM scans rapidly through the tuner's according to Sherwood, the memory difference that, whenever that frequency full frequency range. All of the functions holds its contents for up to a year with- is reached, the programmed call letters related to the touch contacts are out power. appear between the frequency digits checked out in sequence, to the accom- The MICRO/CPU also has three and the "dial" scale. paniment of an impressive display of ways of indicating to which station it is The tuner's memory can store up to flashing lights and changing digits. The tuned. As you'd expect in a digital syn- 48 call signs, enough for most listening speed of the checkout is controlled by thesis tuner, there is a numerical fre- areas. To erase a call sign, display it and the tuning knob; at its slowest, it took quency display-0.5" (12.7 -mm) red tOUCh ALPHA and MEMORY A Ín succes- only about 5 seconds, and at the fastest, characters, behind a dark section at the sion. That call sign then disappears, and it was done several times per second. right side of the tuner's display panel a new one can be programmed if de- As a nice final touch, setting the EVEN/ above the tuning knob. In the center of sired. When the full 48 signs have been ODD switch to EVEN causes a message the panel is a conventional -looking dial, stored, any attempt to add another will to pass across the alphabetic display, calibrated from 88 to 108 MHz in 1 -MHz cause the word "FULL" to flash on the from right to left, reading "THE QUICK steps. But instead of a moving pointer, display for a few seconds. BROWN FOX JUMPED OVER THE this dial has a moving spot of light, a red At the left side of the panel are il- LAZY DOGS BACK." This shows that LED glowing beneath the calibration line luminated SIGNAL and MULTIPATH me- the display is operating properly. nearest to the tuned frequency, and ters. The former reads relative signal shifting as one tunes. strength, over a very wide range, while Laboratory Measurements. Most Between these two displays is the tun- the latter fluctuates in proportion to the of the performance measurements were er's most remarkable and distinctive fea- amount of multipath distortion present in made twice, using both NORMAL and

ture, a four -character alphanumeric dis- the received signal. This MULTIPATH me- WIDE i -f bandwidths. The IHF usable play, with 3/8 -inch -high LED characters ter is not only one of the very few such sensitivity was exceptional: 9.8 dBf or that can display a standard computer - meters that actually work, but it is in our 1.6 µV in mono and 15 dBf (3 µV) in terminal character set, with numbers, opinion the best of the lot we've seen, by stereo. A more important specification is upper-case letters, and a variety of logi- a wide margin. Even a trace of multipath the 50 -dB quieting sensitivity, which de- cal and punctuation signs. When you distortion produces a visible pointer de- fines the weakest signal that will actually firF+ use the tuner, nothing appears on flection! When the antenna is oriented produce a listenable output. This mea- this display. But it can be programmed so that this meter is stationary,. one can sured 12 dBf (2.2 µV) in mono and 30 to display the call letters of the stations be sure that the program is virtually as dBf (17 µV) in stereo. Both are very to which you regularly listen. free of distortion as it was when it left the much better than average, even for very

FEBRUARY 1978 33

AmericanRadioHistory.Com good tuners. These figures were essen- CPU 100 exhibited one of the best cap- tially Para -Power the same with both i -f bandwidths, ture ratios we have ever encountered. (Parametric except for IHF usable sensitivity, which AM rejection was also very good: 68 Equalizers by SAE) improved to 13 dBf (2.4 µV) in mono dB at 65 dBf (wIDE) and 72 dB at 45.dBf when we used the WIDE setting. (wIDE). Image rejection was greater than Distortion was 0.1% in mono and we could measure, exceeding 106 dB. 0.13% in stereo for a 65-dBf (1,000-µV) The alternate channel selectivity was input and the NORMAL i -f bandwidth. Not a very good 87 dB with NORMAL i -f band- surprisingly, the WIDE bandwidth setting width, and 38 dB with WIDE. Whereas improved the monophonic distortion still most tuners exhibit slightly better selec- further, to 0.07%. (The tuner's distortion tivity to one side of the tuned frequency is therefore very close to the residual than to the other (published selectivity distortion of the Sound Technology sig- measurements are usually an average nal generator we used, which is rated at of the two sides), the Sherwood's i -f re- 0.1%.) With L - R stereo modulation, sponse was almost perfectly symmetri- stereo distortion was 0.4% at 100 Hz, cal. Adjacent -channel selectivity mea- 0.067% at 1,000 Hz, and 0.089% at surements were 8.4 and 4.8 dB.

6,000 Hz with NORMAL i -f bandwidth. The lowest muting threshold was SAE has long been involved Corresponding figures for the WIDE set- about 15 dBf (3 µV); the muting could in the field of tone equalization. ting were measured at 0.56%, 0.10%, also be shut off entirely, of course. On From our pioneering efforts and 0.056%, respectively. our test sample, even the 30,000-µV in variable turn over tone The Micro/CPU 100 delivered an maximum output of our signal generator controls to our more recent amazing 82.5 -dB S/N in mono, and 75 did not trigger tuner operation with the advancements in graphic dB in stereo, in either i -f bandwidth muting threshold set at maximum. Auto- equalizers, we have continually mode. In contrast, the finest tuners and matic stereo switching threshold was at searched for and developed receivers we more flexible and responsive have tested so far have 15 dBf (3 µV). And hum and noise in the tone networks. From these rarely exceeded 72 dB in mono or 70 dB tuner output were unusually low -80 dB efforts comes a new powerful in stereo. The Sherwood, in fact, below 100% modulation. tool in tone equalization - showed us that our signal generator's the Parametric Equalizer. residual noise was much lower than we User Comment. The Sherwood MI- Now you have the power of had believed! (And note, on our sensitiv- CRO/CPU 100 is an FM tuner that will precise control. ity graph, how quickly the signal reaches titillate even the most hardened audio- Our 2800 Dual Four -Band 70 dB of quieting-even in stereo, phile. Its extremely ingenious tuning where 43 and 1800 Dual Two -Band Para - only dBf is sufficient.) system has been paired with a tuner metrics offer you controls that The tuner's stereo frequency reponse whose performance transcends that of not only cut and boost, but also was also remarkable. It was so flat most other "super tuners" in many re- vary the bandwidth and tune (±0.3 dB from 30 to 15,000 Hz) that we spects, and rivals them in others. the center frequency of any wondered how the tuner could possibly Furthermore, the tuner's physical han- segment of the audio range. have a low-pass filter in its multiplex out- dling is as smooth as its performance. With this unique flexibility, put, since such filters usually cause a Once the novelty of programming the any problem can be overcome frequency roll -off around 15 kHz. But channels has worn off, one soon begins precisely, and any effect there was such a filter, capable of sup- using the tuner as it was created precisely. meant to be pressing the 19 -kHz pilot carrier to a sat- used, with a mere touch of a finger on a With either of these equalizers, isfactory -62 dB. It takes an exceptional. MEMORY contact, an effortless slip of the you have the power to correct filter to have this much effect at 19 kHz, tuning knob to select a station. The self - any listening environment or yet have so little at 15 kHz. The stereo checking feature might never be overcome any used, listening prob- crosstalk curve was almost as flat as the but it does suggest lems that you are faced with. some of the potential frequency response curve. It was -45 in combining hi-fi with Whether you need a third computers. octave notch filter, tailored dB ± 1.5 dB from 30 to 5,000 Hz, and A $2000 price tag is still formidable for bandwidth to resurrect a still a very good -40 dB at the a tuner. But the lucky few who can afford vocalist, or a tailored cut to 15,000 -Hz upper limit. In WIDE, we had one (and who use it with a good FM roof bury an overbearing bass, the expected the crosstalk to be even lower, antenna) will be able to take comfort in control flexibility of Para- but it was essentially unchanged except the knowledge that whatever they hear metric Equalizers can fill these between 10,000 and 15,000 Hz, where it from the MICRO/CPU 100 will be limited needs and many more. And of fell to 36.5 dB. in quality only by the broadcast station's course, as with all SAE prod- The capture ratio at the NORMAL transmitting equipment and program ucts, they offer the highest bandwidth setting was a very. good 1.06 material-neither of which is likely to ap- in sonic performance and dB at a 45-dBf (100-µV) input, and 1.25 proach this tuner's signal quality in .the quality of construction. dB at a 65-dBf input. With the WIDE set- foreseeable future. The MICRO/CPU For Complete Information Write: ting, it was almost immeasurable. The 100's most distinguished attribute is its best estimates we could come up with ability to pull in more truly listenable were 0.7 and 0.6 dB at the two signal broadcast signals than has previously levels. Scientific Audio Electronics, Inc. Capture ratios of this magnitude been possible. And what better praise P.O. Box 60271 Terminal Annex, Los Angeles, CA 90060 are nearly impossible to measure accu- can a tuner have than that?

rately; suffice it to say that the MICRO/ CIRCLE NO. 103 ON FREE INFORMATION CARD CIRCLE NO. 4A ON FREE INFORMATION CARD 34 POPULAR ELECTRONICS

AmericanRadioHistory.Com 'rice/Performance no one else has put together.

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t =t.tt7dinC3+It.11t . dllntu Ica 2111 ' nY8K0 o =..

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. ; - . +. -wr IMSAI Introduces the PCS-80/30 Integrated Video Computer

3 mHz microcomputer Peripherals: Gentleman: 3K ROM monitor Printers, floppies-mix and match; Send me the IMSAI PCS-80/30 User Manual, price 2K standard, mini and high performance $5.00.1 understand that the $5.00 may be applied 0 RAM towards the purchasr. ora PCS-80/30 Video double density floppy disks on the same computer System. 8 expansion slots s"siem (an industry first), 'h" drive, CRT and TV monitors. Check/Money Order enclosed. Amt S 14 mHz integrated intelligent Charge my DIBAC f M/C CRT (24 x 80) Exp'Date; Intelligent Keyboard Send today for your copy of the 250 -page IMSAI PCS-80/30 User Manual. Price Sig -. - Parallel interface $5.0O.,The cost of the manual may be

2 serial interfaces applied towards your purchase of a PCS- Name - - _ - _ Graphic and edit CRT . 80/30 Integrated Video Computer. Use Addrss-n the coupon provided. functions City - 28 amp power supply State/Zip

All for $1499* assembled IMSAI^ 14860 Wicks blvd. San Lumdrá. CA 94577 and tested. Software: - ASSEMBLER, DOS, TTY and ACR

BASIC, Commercial/Scientific BASIC, The Standard of Excellence . FORTRAN IV and more. in Microcomputer Systems ºFd; IMSAI Manufacturing Corporation Memory Options: + 14860 Wicks Blvd ?^ . .. San Leandro, CA. 94577 4, 16, 32 and 64K RAM memory boards. (415) 483-2093 TWX 910-366 7287

'U.S. domestic pnce only. PCS-80/30 ktt available. Otter PCS-80 kits start at $099. Wiens and specifications subject to change without notice.

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IN-CIRCUIT TRANSISTOR TESTER TROUBLESHOOTER COMPU-TRAINER VOM

_. :_>'o- :e :7Y:. :id Rx

7P. :YIP"' :7). Q Slt

0-.S3 u7. SOLID-STATE OSCILLOSCOPE

ALL NEW NTS/Heath G R-2001 -. DIGITAL SOLID-STATE COLOR TV 315 sq. in. PICTURE EaE

Simulated TV Reception) ELECTRO -LAB

As an NTS student you'll acquire the know-how This electronic gear 'is not only designed for train- that comes with first-hand training on NTS profes- ing; it's field -type - like you'll meet on the job, or sional equipment. Equipment you'll build and keep. when you're making service calls. And with NTS Ourcourses include equipment like the NTS/Heath easy-to-read,'profusely illustrated lessons you,learn GR-2001 computerized color TV (25" diagonal) the theory behind these tools of the trade. varactor read-out with diode tuning and digital from 12 NTS courses covering a widerange selection; (optional programming capa- Choose channel of fields in electronics, each complete with equip- bility and digital clock avail.). ment, lessons, and manuals to make your training more practical and interesting. Also pictured above are other units - 5" solid state oscilloscope, vector monitor scope, solid-state ster- Compare our training; compare our lower tuition. eo AM -FM receiver. with twin speakers, digital multi - We employ no salesmen, pay no commissions. You meter, and more. It's the kind of better equipment receive all home=study information by mail only. that .gets you better equipped for the electronics All Kits, lessons, and experiments are described in industry. full colo. Most liberal refund policy and cancella-

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SIGNAL GENERATOR DIGITAL 5" OSCILLOSCOPE SOLID-STATE 2 -METER FM MULTIMETER SOL D -STATE TRANSCEIVER & POWER SUPPLY POCKET RADIO tion privileges spelled out. Make your own com- ---lowEnEm --- r NATIONAL TECHNICAL SCHOOLS Dept. 205028 parisons, your own decision. Mail card today, or 4000 South Figueroa St., Los Angeles, Calif. 90037 clip coupon if card is missing. Please send FREE Color Catalog and Sample Lesson. ' NO OBLIGATION. NO SALESMAN WILL CALL. Q Color TV Servicing Q Electronics Technology NO OBLIGATION. NO SALESMAN WILL CALL B IS W TV and Radio Servicing Computer Electronics Q Electronic Communications Basic Electronics APPROVED FOR VETERAN TRAINING o FCC License Course Q Audio Electronics Servicing Get facts on new 2 -year extension NAME AGE SCHOOLS ADDRESS APT NATIONAL CITY STATE TECHNICAL -TRADE TRAINING SINCE 1905 Please fill in Zip Code for fast service Resident and Home -Study Schools ' Q Check if interested in G.I. Bill information. 4000 So. Figueroa St, Los Angeles, Calif. 90037 Q Check if interested ONLY in classroom training in Los Angeles.

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AmericanRadioHistory.Com 800/2 IS ERE

WTd 6800 SYSTEVlER

The 6800/2 uses our new A2 processor board with socket 20 Ma. TTY compatible interface may be configured to op- space for 8K bytes of ROM/PROM. This makes it possible erate serially at the following baud rates: 110, 150, 300, to use the 6800 in applications where ROM programs are 600, 1200, 2400, 4800 and 9600. Complete interrupt con- useful without purchasing an expensive PROM accessory trol is available through the user's software. board. The A2 board has a DIP switch selector that allows 4K Static MEMORY- you to replace any 8,K block of memory above the RAM The 6800/2 comes wth 4K of static RAM memory on our memory that extends to 32K with memory external to the MP -8M board. The memory may be expanded to 8K by the processor board itself. This lets you develop special pro- addition of eight more memory chips. No additional parts grams that will later be put in PROM in a normal RAM are needed. Full buffering of all data, address and control memory card where it can be modified and debugged. The lines is a standard feature. Memory expansion to 32K of A2 board has a crystal controlled baud rate oscillator and a continuous RAM memory and up to a 48K mixture of separate clock driver oscillator whose frequency may be ROM/RAM is possible with this system. changed with a programming resistor. The A2 processor board gives you the maximum possible flexibility ACCESSORY BOARDS- in setting up a computer system. Do you have a special job? Our accessory boards make it SVVTBUG® Monitor- possible to use the 6800/2 for almost any type of computer The 6800/2 is supplied with our new SWTBUG® monitor. application. We have our MP -T interrupt timer with soft- This new monitor is software compatible with the earlier ware interrupt selectable output. Our MP -N calculator inter- Mikbug® monitor used in the 6800. All major subroutine face that allows you to do arithmetic functions in hard- entry points are identical. SWTBUG° features a resident ware. Our MP -R EPROM programmer that programs and MF-68 Minifloppy disk boot, single level breakpoints, verifies EPROMs right in the machine-and more coming. vectored software interrupt, generation of punch end of 6800/2 Kit $439.00 ppd Cont. U.S. tape formatting and automatic interface configuring for 6800/2 Assembled $495.00 ppd Cont. U.S. either the MP -C control interface or MP -S serial interface. ACIA Type Interface- SWTBUG is a registered trademark of Southwest Tech. Prod. Corp. The 6800/2 uses our MP -S serial interface. This RS -232 and Mikbug®is a registered trademark of Motorola, Inc.

SOUTHWEST TECHNICAL PRODUCTS CORPORATION 219 W. RHAPSODY SAN ANTONIO, TEXAS 78216

CIRCLE NO. 49 ON FREE INFORMATION CARD 40 POPULAR ELECTRONICS

AmericanRadioHistory.Com Popular Elcc.t ron ics' FEBRUARY 1976

; - BY DAN VENCENT

pRCGRAMMING erasable need: ptete), it's anticipated that more and only memories (EPROM's): has more electrorics enthusiasts will use generally been beycnd the .each o' erasable (and reprogrammable) ROM's, most electronics expe=unenters ow ig to where mistakes can be corrected as well the high .cos: of the machine required to as an entire program changed should do the 'op. Thus exoermenters "cave this become necessary. been virtuafy limited to P1ROM S, in TI -e EPROM Programmer is designed which fLse lints are burned out and to operate with the highly popular 256- which, therefore, car never be repro worc-by-8-bit 1702A, anc associated grarnmed. New, with the low -cos: fami y (4702A, 8702A), EPROM's. Note EPROM orograrnme- presented _here that it is not compatible with other similar .,$40 withou- power supply, $80 corn - devices such as a - 7C1 or 1702. Also, PART 1

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AmericanRadioHistory.Com Fig. 1. System clock is IC1. Countdown chain and IC1 develop correct system timing for 1702A. LED1 is optional pulse timing monitor.

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PARTS LIST I C3,C8- 0.01-µF, 25-V ceramic capacitor C4-0.001- µF, 10%, 25-V ceramic capacitor a C5-10- µF, 15-V electrolytic

1 -NIA 4 'a D7 -9.I -V, 10%, 1-W zener diode (1N4739 Z rm I'ia - or similar) ~ULLLL n D8-Red LED (optional) N IC1-555 timer CO U CO IC2,1C3,IC5,1C6-74161 binary counter a IC4-74160 decade counter z >-W IC7-74164 8 -bit shift register 1C8-7400 quad 2 -input NAND gate Q6,Q7,Q8,Q10-MPS-A05 60-V silicon npn transistor The following are 1/4-W, 10% resistors unless otherwise noted: R 10-2000 ohms, 5% _ R 11-33,000 ohms, 5% + M R I2-5600 ohms M R13,R14-I000ohms R 17,R 19-220 ohms R 18-4700 ohms Misc.-Suitable chasis or enclosure, heat sink, thermal grease, transistor insulating hardware, #6-32 mounting hardware, line

cord, grommets, fuse holder, 5 -volt at 1 - ampere power supply. Note-See Parts List for Fig. 5 for availability of kits.

7 JI z o 2I>J o al+ ol L

the programmer is a write -only machine, though the monitors share some com- for convenience and speed to have a the assumption being that, if you're pro- mon instructions, some have more (or monitor program in ROM (read-only gramming the device, you already have better) features than others. Without a memory) so that it's all there when 'you some type of reading provision. monitor, of course, the basic computer turn the computer on, and data will not Perhaps the greatest utility for can't "do something" when it's turned be lost if there's a momentary loss of line EPROM's among experimenters is in on. power or when computer is turned off. the microcomputer field. For example, One could load monitor data from a Some computers have built-in ROM there is a host of different monitors avail- cassette tape machine, naturally, but monitors; many do not have monitors, able for every microprocessor chip. Al- this is a cumbersome method. It's best so the computer owner must either buy

42 POPULAR ELECTRONICS

AmericanRadioHistory.Com t PARTS LIST VDD FIG IS/ VGG VvVWVV---fi µF, 25-V ceramic capacitor C6 -0.0I- `PROG transis- -wvwN-* Q 1 1 ,Q 12,Q 13-MPS-A05 silicon npn 131 161 241 R28-R30=47K R26 R27 tor ADDRESS SWITCHES ADDÚPS LOSE ICTCHES 10K 10K PROG VGG VDD R2I ,R22,R23,R24,R25,R31-1000-ohm, I/4 - UP=LOGIC I watt, 10% resistor S2 SIg...9111 0 LSB DO R26,R27-10,000-ohm, 1/4-W, 10% resistor R28,R29,R30-47,000-ohm, 1/4-W, 10% re- sistor S2 through S I7-Spdt toggle switch S 1 S I 8-Spdt momentary (break-before -make) toggle switch +5V 6 A2 D2 R21 IK

NC SIB PLSE PULSE D

FIG I 5 O1yF

o 4 SO1 D4 PROGRAM SOCKET S01 -25 -pin IC socket (preferably zero inser- tion -force) Note-See Parts List for Fig. 5 for availability of kits.

S16 8 / A6 D6

+5

A7 MSB D

12 VCC Fig. 2. Circuit T/C 14 CS provides switch CONT 22 FIG I VCC 15 23 address and data VBB VCC +47V inputs. Pushbutton VBB in insert starts up programming.

a ROM monitor, have a supplier prepare the memory cán be electronically repro- Circuit Operation. The 1702A ROM's or program his own. grammed. Once programmed, it will EPROM itself is fully static, easily inter- The latter route, using EPROM's maintain data when power is removed, faced, requires no clocks, and is input/ could be the least expensive in the long but unlike a fuse -link ROM, it can lose output TTL compatible. The three -state run if a person continually upgrades his data if exposed to strong UV light. output buffers are rated for one full TTL system whenever a better program or The EPROM Programmer described load. However, it does require a -9 -volt monitor comes along. An EPROM can here-which costs about t/3 to %4 of com- supply in addition to the conventional 5 - be erased and reprogrammed very easi- mercial models-complements the ap- volt operating supply. ly. The device's bit pattern can be pealing economic picture of the popular The Programmer can be built as a erased (all set to "zero") by 'exposing 1702A. The device's original tag was stand-alone device using switches for the chip's transparent quartz window to about $100, where today its cost ranges address and data selection, or as a TTL- ultraviolet light. In essence, the UV from $3 to $12, depending on quantity compatible peripheral for use with either light's photons displace electrons that purchased and source. In addition, since switches or microprocessor ports. The were induced in the silicon gate to form commercial houses charge as much as circuit shown in Fig. 1 provides all the the equivalent of "1's" in the bit pattern. $40 to program an EPROM, doing it your- timing necessary for the Programmer. Then, using the EPROM Programmer, self can represent a substantial saving. The 33.3 -kHz clock, generated by /C1 ,

FEBRUARY 1978 43

AmericanRadioHistory.Com ( VDD FIGI' VGG FIG I T/C PROG - VJJJJJv - CONT 131 16 R64 -R66 47K PROG VGG VDD 014 -021 4 022-029 MPS -A05 A0 LSB DO MPS -A05

DO A0 R40 -R47 IK

DI Al

6 A2 D2 13 tiWv.A.N-D2 A2

17 A3 03

9 -~-D3 A3 S02

8 4 D4 i

D4 A4

5

05 A5

A6 D6I10

A6

MSB D7

PROGRAM SOCKET D7 A7 R48 -R55 R56 -R63 47K 47K IC9,IC10=74LS86 VBB BB FIG 5

+47V

FtG5

Fig. 3. TTL option PARTS LIST is used with switch address and 1C9,IC10-74LS86 quad 2 -input exclusive- R48 through R66 -47,000 -ohm, 1/4-W, 10% data inputs or OR gate resistor Q14 through Q29-MPS-A05 60-V silicon S02 -24 -pin IC socket (preferably zero -inser- accept data from microcomputer. npn transistor tion -force) R32 through R47-I000-ohm, t/4 -W, 10% re-) Note-See Parts List for Fig. 5 for availability SistOr of kits.

is routed to 8 -bit shift register IC7 and to the power -up initialization for the chain. tion of the divide -by -430 counter. The a synchronous counter chain consisting Circuit action begins with the pro- output of this divider is taken from pin 11 of IC2 through 106. Integrated circuits gramming command (PROG), a nega- of IC4 and is a 77.52 -Hz (33.3 kHz/430) IC4, IC5 and IC6, in conjunction with tive -going pulse used to asynchronously signal having a 20% duty cycle with 2.58 IC8D, form a divide -by -430 counter clear IC2 and IC3. The pulse width ms on and 10.32 ms off. This waveform whose carry output enables a divide - should be limited to less than five mil- meets the VDD /VGG programming by -32 counter formed by 1C2 and 1C3. liseconds. The Qb output of 1C2 (pin 13) duty cycle restrictions of the 1702A Capacitor C5 and resistor R12 provide is inverted by IC8C to control the opera- EPROM. Also, the 2.58 -ms pulse falls

44 POPULAR ELECTRONICS

AmericanRadioHistory.Com under the 3 -ms maximum specified for the 1702A programming pulse. This signal is applied tó the serial in- + 5V 12 13T 15 221 231 put of 1C7 and causes its eight to outputs PROG VCC VBB VCc VCC sequence high in 30-µs intervals, the pe- / LSB 4 LSB riod of the clock. Output B of IC7 begins D0 5 the programming cycle by turning on the DI Fig. 4. 6 +47 -volt supply through Q2 of the pow: D2 7 Illustration D3 er supply. This action sets the address ADDINRESS DATA shows READ 1702A 8 and data lines to their proper levels. The D4 OUT pin out 9 address is complemented at this time. D5 for 1702A. 10 Thirty microseconds later, VDD and D6 II VGG move to their negative levels D7 con- { MSS MSB trolled by output C of IC4 driving transis- VGG VDD tors 07 and 08. Output D (T/C or true/ 16 24j complement) of IC7 follows on the next 9V clock pulse and inverts the address lines READ CONNECTIONS to their true state. Outputs E, F, and G of IC7 are not used. When output H goes high, it is AND'ed with output A by IC8A. This output is inverted by IC8B to drive changed-a logic 0 during read. ming command through pushbutton

Q6 and provide the program pulse to The small insert schematic in Fig. 2 is switch S18 . Sol (Fig. 2 or 3). used to manually generate the program - These conditions are stable until the TTL Input Option. The circuit shown termination of the 2.58 -ms pulse. At this in Fig. 3 is similar to the switch option point, output A of IC7 goes low, thus circuit shown in Fig. 2, except that the ending the program pulse. Then output switches are replaced by 16 transistors B disables the +47 -volt supply. The shift and 8 exclusive -OR gates. Program- register ( IC7 ) is completely cleared in HOW AN EPROM WORKS ming voltage levels are the same as six more clock pulses. those described in the switch option. During the last 30 microseconds of The 1702A belongs to a family of electri- The transistors provide logic inversion the 2.58 -ms pulse, a carry is generated cally programmable, ultraviolet -light -era- as well as high -voltage isolation so that by 1C4, causing the divide -by -32 counter sable, read-only memories. Each memory conventional TTL logic levels can define cell in the ROM has the appearance of a ( IC2, IC3) to advance. This sequence address and data selection. flip-flop with a new element-a "floating repeats until the end of the 32nd itera- The gates in 109 and I010 are turned gate," that is isolated from the silicon sub- tion, when pin 13 of IC2 goes true and on by the T/C signal to invert the ad- strate by a narrow band of silicon dioxide shuts down the counter through IC8C. (glass). This element is riot connected to dress at the proper time. Resistors R48 The total elapsed time for programming anything electrically.. The output signal through R66 provide leakage -current one 8 -bit word is therefore about 413 from each flip-flop, a 1 or a 0, depends on paths and insure good dynamic re- ms. This period can be monitored by the the charge (or lack of it) on the gate. sponse. optional status indicator (formed by Q10, The application of a train of electrical The address lines present one "LS" - pulses to a cell "charges" the floating gate, R18 , R19 and LED1 ) shown in Fig. 1. load to the driving circuit and should be and causes the associated flip-flop to pro- no problem to interface to .a microcom- duce a 1 at its output. This charge on the Switch Option. Address and data se- puter. The data lines must be driven by floating gate leaks off after many ten's of lection during programming are provid- circuits capable of sourcing at least 1 years. Since there is no electrical connec- ed by the 16 spdt switches in Fig. at 1.7 V. TTL will shown tion between the floating gate and thé re- mA Standard devices 2. A logic 0 on the address lines is mainder of the ROM internal circuit, the handle this, as well as many of the LSI accomplished by switching the line to charge is not affected by the removal of the I/O chips designed for microprocessors. the collector of Q1 1. Using the VCC as a chip's operating power. Switches, connecting the inputs to the reference, this will result in a level of The upper surface of the chip has a +5 -volt line or ground, may be used. -47 volts during the program pulse quartz window that is transparent to ultravi- when the address true/complement olet (UV) light. If strong UV light is allowed 17O2A Data. The read connections for (T/C) signal from I07 is high, thus se- to pass through the window, it will displace the 1702A (and family) are shown in Fig. lecting the true address. Placing the ad- the electrons from their shallow energy lev- 4. The EPROM may be erased by expo- els on the floating gate and cause them to dress switch in the 1 position ties that sure to high -intensity short-wave ultravi- migrate to the silicon substrate where their line to the complement of the signal olet radiation of 2537 angstroms. The charge is neutralized. Typically, it takes present at the collector of Q12 , resulting several minutes of strong UV exposure to recommended integrated dosage is 6W- in a logic 1. erase a device, and conventional room seC/cm2. Depending on the ultraviolet For data input, connecting an output lighting will not do the job-though expo- light source, the erasure may take from line to ground through the data switch sure to direct sunshine may. After the UV 10 to 20 minutes. O results in a -47-volt level during the pro- exposure, all the cells go to a 0 output. gram cycle. This programs a logic 1 on Note: Part 2 of this article, next the selected address output. Connection month, will describe the power supply, pc to the VCC line will leave the bit un - board, and construction.

FEBRUARY 1978 45

AmericanRadioHistory.Com SINGLE STEP

TRANSFER PRINTED PC PATTERNS NO' WITH NO CAMERA OR CHEMICALS! BY G.D. FISHER

EVERY experimenter and hobbyist definition artwork with no stretching or tion. Do not Use steel wool or abrasive dreams of being able to transfer an distortion. Hence, they can be used in powder cleaners. etching and drilling guide from the print- any type of pc -pattern layout. ed page to a pc blank without the mess. Preparation of the Board. The cop- and bother of chemicals or photography. Working With the Film. Using the per must be free of oil and contaminants. Now yoU can do just that with a new di- direct -transfer film is extremely simple. This is best accomplished by scrubbing rect -transfer film that has a number of First, you cut the PCP -A film_to a size with scouring powder, then rinse the other uses of interest to the experiment- just slightly larger than the etching guide blank under running water and allow it to er who builds. his own projects. ybu are transferring. If the guide is rela- dry completely. Then 'dip the blank into Called PCP -A Contact Film, this new tively small (up to about 5" square), peel lacquer thinner or board developer and plastic film has an adhesive on one side away the entire backing from the film stand it on edge to air dry. that permits it to be placed directly over and apply it directly to the paper on When the board is dry, select a well - printed artwork. Then, the only "chemi- which the guide is printed, taking care to ventilated and dust -and -lint -free location cals" needed tb complete the transfer get it down right the first time because in which to work, and lay it copper -side are soap and water. once it touches the paper, it cannot be up on a couple of thicknesses of news- The PCP -A Contact Film is available lifted. For larger guides, peel the back- paper. Switch to safe lighting. (You can

in sheets of various sizes and in three ing only partway and work slowly until . use a yellow bug lamp or indirect light packagings. The small package contain- the film is completely down on the guide. from a 15 -watt incandescent lamp no ing six 6" x 4" pieces of film is $5.49; the Once the film is down, use a smooth, less than 8' away for safe -lighting condi- medium package with four 9" x 6" blunt instrument to burnish it in place tions.) Always use safe -lighting condi- pieces is $6.95; and the large package and force out all air bubbles. (Do NOT tions during sensitizing and until a sensi of three 12" x 9" pieces is $7.95. It is lance the air bubbles, either in the paper tized pc blank is developed. made by Printed Circuits Products Co., guide or the plastic film.) This done, There are basically two types of 116 Harwood, Box 4034, Helena, MT place the artwork in a dish of warm, aerosol photoresist sensitizers on the 59601. soapy water for 15 to 20 minutes. Then market. The one that permits you to use Guides made from the film are used start to rub off the paper with your finger, the film guide directly is called "positive" as exposure masks for photosensitized stroking back and forth with just enough photoresist, such as GC Electronics' No. 'printed -circuit blanks. They yield high - pressure to assure good cleaning ac- 22-230 (use only GC No. J4-630 devel-

46 POPULAR ELECTRONICS

AmericanRadioHistory.Com oper). While you can use "negative" any event, do not place the source closer Finishing the Board. The etched phbtoresist, you must first reverse the than 12" (30.5 cm) from the frame or board can now be stripped with a lac- image on the film guide before you can you will run the risk of "under cutting" quer -thinner -soaked cotton ball. Follow expose the pc blank. (Note: Some mag- and lose the sharp quality of the pattern. up with a vigorous scrubbing with scour- azines, including POPULAR ELECTRON- Once the blank is exposed, you can ing powder and steel wool and a thor- ICS, print etching -and -drilling guides in switch back to normal lighting. Open the ough rinsing. both the positive and negative formats. contact frame, remove the exposure Trim the board to the required size In the positive format, the copper trace mask and set it aside, and immediately and then drill all holes. Since most pc pads and lines are black on white, while immerse the exposed blank in board de- board drilling is with small -size drill bits in the negative format the pads and lines veloper solution, copper side up. (Note: (No. 58 throúgh No. 64), it is best to use are white -on -black. If you transfer the do not use plastic trays for the developer a Moto Tool or a battery -powered hand negative format on your film, use only because the solution will dissolve most drill, such as the Radio Shack No. negative resist and its appropriate de- plastics. Use only glass or metal trays.) 64-2178 drill to obtain maximum control veloper; do NOT reverse the image. Agitate the developer gently over the and minimize bit breakage. Of course, if Transferring the positive format to film blank with a slow tilting of the tray. After you have a drill press, you can use it if requires the use bf positive photoresist a short time, you will begin to see the cir- it will accept very small size bits. or a reversal to use negative resist.) cuit pattern taking form. Continue to agi- Last but not least, you can tin plate Spray the resist onto the copper sur- tate until the resist is completely re- your finished board with plating solution, face of the PC blank in continuous, even moved from the areas to be etched and such as Dynachem No. EBS-250 (Dyna- strokes from a distance of about 10" the copper shows through bright and chem Corp., 2632 Michelle Dr., Los An- (25.4 cm) away. The sensitized blank shiny. Remove the blank from the devel- geles, Cal). The tin plating seals the can then be air-dried overnight while ly- oper and rinse it under slowly running copper traces against the elements to ing flat (switch off all lighting, including water to stop the developing process. resist corrosion and makes it easier to the safe light, during this period), or it Do not touch the blank, except by its solder when wiring the board. can be force dried in a warm (about 150° edges, at this time or attempt to dry it F) oven for 20 to 30 minutes. Do not with a cloth or paper towel as the resist More Film Uses. The ability of the rush the forced drying by using higher will be soft and easily damaged. You PCP -A film to retain its adhesive proper- heat; if you do, the resist will bake on can let the blank air dry overnight or ty after the transfer process can be put and lose its photosensitive properties. place it in a 150° F oven for 20 to 30 min- to good use. For example, you can copy Needless to say, when you transfer the utes to force -dry it and set the resist. the component -placement guides that wet blank to the oven, use safe lighting Pour the developer back into its con- generally accompany etching and drill- all the way. tainer for later use. The developer can ing guides in published literature and be used several times, until it becomes stick them down right on the boards be- Processing the Blank. The next saturated. You will know the saturation fore mounting the components. (If the step is to expose the sensitized blank point has been reached when the devel- guides are a different size from the either directly through your previously oper no longer removes the resist from boards, as is frequently the case, you

prepared film guide or through a sepa- an exposed pc blank. . can stick them to an inside surface of the rate reversed exposúre mask (see To etch the board, you must use a enclosure used for the projects.) Once above). plastic or glass tray. Never use a metal you put down the guide, seal its edges to It is best to use a contact frame to pan because the corrosive action of the the board with clear lacquer, punch keep the exposure mask in intimate con- etchant will eat it away. Place your pc through all holes with an awl or other tact with the PC blank during exposure. blank in the tray and pour over it the sharp instrument, and mount the com- (Exposure frames are available from etchant to a depth of 1/4" to ih" (6.4 to ponents in their respective locations. most pc supplies dealers.) Alternatively, 12.7 mm). Left alone, the etchant (ferric Anóther good use for the film is to you can sandwich the mask and blank chloride or ammonium persulfate) will transfer custom meter scales from the together with two sheets of plate glass- completely remove unwanted copper printed page to standard meter move- not plastic-and hold them together with from a pc blank measuring up to 5" ments. Just place the film over the print- a clothes pin at each corner. square in 10 to 30 minutes, depending ed scale, burnish it down, and rubber ce-

. From this point on, until you are direct- on the quality of the etchant. You can ment it to the meter movement. ed to do otherwise, use only safe -light- speed up the etching process by rocking You can also transfer custom front - ing conditions. Now, place your sensi- the tray to agitate the etchant, preheat- panel decals, make custom keytops, tized blank in the contact frame, copper ing the etchant (place the bottle in very etc., as desired. The film is designed to side up. Place the exposure mask over hot water for 10 minutes or so, never in a pick up and transfer just about anything the blank and close the contact frame. pan and heating over a burner), and us- on a printed page, including colors. In all To expose the blank, you can use any ing a heat lamp over the tray. cases, once the film is down, seal its good source of strong ultraviolet radia- Leave the pc blank in the etchant bath edges with clear lacquer. Also, if the de- tion, such as direct sunlight, a photo- only long enough to remove all unwant- cal is to be applied to a painted surface, flood lamp, fluorescent lamp, efc. It is a ed copper. If you leave it in the bath too it is best to place it down while the paint good idea td make up a few test pieces long, the etchant will begin to undercut is still tacky. of sensitized blank to determine the the copper traces. When etching is com- Decals made with the transfer film are proper exposure time for the UV source pleted, use a pair of plastic tongs to re- virtually scratch -proof. In addition, since you decide to use. Times will vary from 2 move the board from the tray and thor- the transfer images are on the adhesive to 15 minutes, depending on the intensi- oughly rinse it under running water to side of the film, they cannot wear away ty of the UV radiation from the source. In stop the etching action. when they are touched. O

FEBRUARY 1978 47

AmericanRadioHistory.Com BUILD AN antoranging zero

nf C meter Digital pacitance ti .t Meter

BY DAVID H. DAGE

Autoranges from 1 pF to 1µF and from 1µF to 4000 µF. Updates readings automatically.

THE DIGITAL -READOUT capaci- in a simple RC network can be ex- and displayed directly as capacitance. tance meter described here is a pressed by the equation: The two comparators, flip-flop, transis- most useful instrument when one has to VC = Vp (1 - e-t/RC) tor, reference voltage sources, and an determine values of unmarked capaci- where Vp is the voltage across the ca- output driver are all contained in one tors or those with unknown codes, or pacitor when fully charged, R the re- package-the common 555 timer IC. when checking the tolerances of marked sistance in ohms, C the capácitance in The meter's autorange circuit func- components. Its autorange function farads, t the time in seconds, and e the tions during a single capacitor discharge greatly simplifies what would ordinarily exponential constant or base for natural cycle. If the three -decade counter over- be a measurement chore without this logarithms (approximately equal to flows, the reference frequency input is feature. Moreover, the meter's accuracy 2.718). If we let a capacitor that has automatically divided by ten. Simultane- of over 1% (dependent on the toler- charged to a known voltage discharge ously, the decimal point in the digital dis- ances of a few passive components) through a fixed, stable resistance to play is shifted one position to the right. If

from 1 pF to 40001.1.F enhances its utili- some given voltage, the discharge time necessary, the process is repeated once ty. The project is easy on the budget, will be directly proportional to the com- too, as low-cost 7400 series logic and ponent's capacitance, which then can Interior photo of prototype. 555 timer IC's are used throughout. be readily determined. To operate, simply turn on the unit, The meter described here employs connect a capacitor to the test terminals, this method of measurement, which and read the digital value displayed for readily lends itself to use with a digital any capacitor up to 1 F. Switching a readout and eliminates null adjustments. mode switch from nF to µF extends the As shown in Fig. 1, the capacitance to autorange function to 4000 µF and be measured is charged through RA and beyond, limited only by the leakage RB. When the voltage across the capa- characteristics of the test capacitor. citor equals VREF, comparator A sets the flip-flop, turning on the transistor. How it Works. Traditionally, capaci- The capacitor then discharges through tance has been measured on an ac RA until the voltage across it drops to bridge by balancing known components one-half VREF. At this point, comparator against the reactance of an unknown ca- B resets the flip-flop, which in turn cuts pacitance at a given, fixed frequency. off the transistor. The capacitor then However, instruments are now appear- starts to charge up to VREF, and the cy- ing which employ a different method to cle is repeated. determine capacitance-they measure A reference oscillator output at a fixed time. Here's how. frequency is gated by the flip-flop output Mathematically, the voltage across a signal. The gated reference pulses are capacitor discharging through a resistor counted by a digital counter, decoded,

48 POPULAR ELECTRONICS

AmericanRadioHistory.Com plied by a Colpitts oscillator made up of DISPLAY IC4, L1, and C18 through C21. Signals from the reference oscillator and timers V+ REFERENCE COUNTER -D OSCILLATOR IC6 and IC20 are combined by dual flip-flops IC12 and IC13. One half of IC12 synchronizes the output of IC20 with the 1.4 -MHz reference frequency, Fig. 1. Block diagram of providing dual -phase (O and O) outputs. the capacitance meter. The other half of IC12 and IC13 select Circuit determines unknown one discharge pulse from IC20 after the capacitance by measuring output of autocycle timer IC6 goes high. time it takes to discharge.. The flip-flops disable IC6 until the dis- PARTS LIST charge pulse is completed. The reference oscillator output is gat- C I -4000-11F, 16-V electrolytic capacitor R3 -100 -ohm pc mount trimmer potentiome- ed by IC7 so that it passes to the count- C2,C4,C8 through C16, C23-0.01-µF disc ter ceramic capacitor R4 -1000 -ohm, I% tolerance, 50 ppm/°C ing stages during one discharge period C3 -0.0033-11F, 10% Mylar capacitor metal film resistor of Cy per measuring interval. Monosta- C5 -0.1µF disc ceramic capacitor R10 -25,000 -ohm, panel mount linear taper ble multivibrator IC14, when triggered by

C6,C I7 -4.7-µF, 16-volt tantalum capacitor potentiometer +v°C 16 The following are 1/4 -watt, 5% tolerance car- R6 C7 -220-µF, -volt electrolytic capacitor IOOK 41 R1 C18 -0.01-µF, 5% polystyrene capacitor bon composition resistors. 3 R7 C19-820-pF, 5% polystyrene capacitor R5-1000 ohms 100 C20-470-pF, 5% polystyrene capacitor R6, R7-100,000 ohms CI C2I-220-pF, 5% polystyrene capacitor R8, R9-1500 ohms 4.7pF C22 -0.005-11F, 10% Mylar capacitor R 1 I .R 12,R 13-100 ohms DI ,D2-I N4002 silicon diode R14. R15-3300 ohms D3 through D5-IN4154 or HEP R0600 sili- R16 through R20-470 ohms TO IC20 PIN +v°° con fast -recovery diode R2: I , R1:2, R3:3, R5:4, R4:6, R7:5, R6:7 TP-FO. TP-R DISI through DIS3-DL707 common -anode, (one set for each of three decades) -330 seven -segment LED display ohms

S 1 -pole, 3 -position rotary Fl, F2 -1/4 -ampere fast -blow fuse -3 switch RI3 ICI,1C2,1C3,ICI7,1CI8,IC19-7490 decade TI -16 -volt center -tapped transformer loon

counter Misc.-Suitable enclosure, banana jacks or RII loon posts for terminals, cir- IC4,1C 15-7404 hex inverter binding Cx printed 3 IC5-74125 Tri-State quad buffer cuit board, fuseholders, knobs, hook-up CUR- 13PN 106,1C20-555 timer wire, IC sockets or Molex Soldercons, hard- .011,F1 470 P 220 P IC7,1C8,IC22-7400 quad Two -input NAND - ware, solder, etc. "CM gate Note-The following items are available from TO leO P151 1C9,1C10,1C11-7447 BCD to seven -segment Dage Scientific Instruments, Box 1054, Li- OFF RIO decoder/driver' vermore, CA 94550: CM -6 complete kit of R9 ZERO IC12,1C13-7474 dual D edge -triggered flip- parts, including tested IC's, cabinet, hard- nF 1.5K 250 flop ware, miscellaneous items, calibration ca- IC 14,1C21-74121 monostable multivibrator pacitor, and assembly manual, $69.95 in IC 16-7493 4 -bit binary counter U.S. and Canada. CM -68 partial kit in- 1C23-LM309K 5 -volt regulator cludes etched and drilled double -sided pc TO IC3 PIN 2 *SEE TEXT LI-13-µH inductor board, 13-1aH inductor, polystyrene capaci- Fig. 3. Oscillator, sync., LEDI, LED2-20-mA light emitting diode tors (C18 through C21), calibration capaci., and reset circuits. R I -100,000 -ohm pc mount trimmer potenti- tor, and assembly manual for $20 in U.S. ometer and Canada. U.S. residents add $I postage R2-I-megohm, I% tolerance, 50 ppm/°C and handling, Canadians add $2. Californi- the leading edge of the synchronized metal film resistor ans add sales tax. discharge pulse, resets decade coun- ters 1C16 through 1019 and dividers IC1 or twice, resulting in four automatically + through IC3. When SI is in the nF posi- D4/ RS selected ranges. Additional overflow F2 tion, the width of the reset pulse gener- I/4A ! TP-5 pulses are displayed by two LED's locat- ated by IC14 is controlled by the setting 03 IC20 TO IC12 PIN 12 ed to the left of the display. IH 4154 .. of ZERO trimmer potentiometer Rio. This allows the to keep CI CI Ult. user stray capa- Refer to the appropri- citance out of the measurement. Circuit Details. R2* .01PT .IR4.7V IM ate schematic (Figs. 2 through 6) for the OFn 7 The gated reference signal is divided F following detailed circuit description. SIR nF by decade counters IC1, 1C2 and I03. Free -running 555 timer IC20 (Fig. 2) is Output signals from these counters, at C3 the basic capacitance measuring circuit, .00339F 1/1000th, 1/100th, and one -tenth the in- comprising the comparators, reference DS IN4154 put frequency, are applied to Tri-State *CLOSE -TOLERANCE COMPONENTS voltages, flip-flop, and discharge transis- logic switch IC5 (Fig. 5), which passes Fig. 2. Input stage has tor described previously. The timer's dis- free -running 555 timer. the appropriate pulse train to decade charge period is used to measure the counter IC19. Overflow pulses from this component under test. When MODE A second free -running 555 timer, IC6 BCD decade counter are applied to switch S1 is in the nF position, the dis- Fig. 3), is employed in an autocycling counter IC18, whose overflow pulses in charge periód is determined by R1, R2, circuit which automatically updates the turn are counted by 1C17. Binary coded and Cx. In the µF position, the interval is capacitance measurement. The refer- decimal outputs from these three dec- determined by R3, R4, and CX. ence frequency (about 1.4 MHz) is sup- ade counters are decoded by IC9, IC10 FEBRUARY 1978 49

AmericanRadioHistory.Com STRIP - o°RAP UNWRAP REGULAR WRAP wire wrapping center MODIFIEDWRAP

Ittro _ °, !pgil.(hret+ Wire-wrapping, stripping, unwrapping tool for HOBBY WRAP AWG 30on.025 (0,63mm) Square Post. Regular Wrap . TOOL WSU-30 $6.95 !e tl'I[:-« kl Modified Wrap WSU-30M $7,95 ?-`x°

WIRE -WRAPPING TOOL HBIIY.WIIAP ba-tt.".4i Model BW-630 -. For .025" (0,63mm) sq. post 11§.L "MODIFI ED" wrap, positive La ...a Layiái indexing, anti-overwrapping T device. ,'..r:.. ` Pm ' 'Battery,á: 4 For AWG 30 BW-630 $34.95. For AWG 26.28 BW-2628 $39.95. _ - wire Wlapping' 1i

Bit for AWG 30 BT -30 $3.95 COMPLETE Bit for AWG 26-28 BT -2628 $7.95 WITH BIT -° for quality electronic parts and tools. -es ..AND SLIiEVÍs ° - °USE"C" SIZE NICAD BATTERIES (NOT INCLUDED) eo . e n

WIRE -WRAPPING KITS ROLLS OF WIRE Wire for wire -wrapping AWG-30 Contains: Hobby Wrap Tool WSU-30, (0.25mm) (50 ft.) Roll of wire KYNAR' wire, 50 ft. roll, silver plated, solid Prestripped wire 1" to 4" conductor, easy stripping. lengths (50 wires per package) 30 AWG Blue Wire 50ft Roll R 3080050 $1 98 stripped 1" both ends. AWG 30 Yellow Wire 50ft Roll R-300.0050 $1 98 AWG Wire Wrapping Kit. (Blue) WK 2-B$12.95 30 White Wire. 50(1 Roll R 30W 0050 $1 98 Wire Wrapping Kit. (Yellow) WK 2Y $1295 30 AWG Red Wire 500 Roll R 30R 0050 $1 98 ti Wire Wrapping Kit. (White) WK 2,W $12.95 Wire Wrapping Kit (Red) WK 2,R $1295

WIRE DISPENSER With 50 ft. Roll of AWG 30 WIRE -WRAPPING KIT KYNAR' wire -wrapping wire. Cuts the wire to length. Strips 1" of insulation. Contains: Hobby Wrap Tool WSU-30, Refillable (For refills, see above) Roll of wire R30B-0050, (2) 14 Blue Wire WD30-B $3.95 Yellow Wire DIP's, (2) 16 DIP's and Hobby Board WD -30-Y $3.95 -4 H -PCB -1. White Wire WD -30-W $3.95 Red Wire WD -30-R $3.95

30 AWG blue Wire. 1"long 30850010 S99 30 AWG Yellow Wire 1"Long 301500/0 Wire -Wrapping Kit WK -3B (Blue)I$16.951 $99 PRE CUT 30 AWG White Wire 1"Long 30W 50010 S99 PRE STRIPPED WIRE 30-AWG Red Wire 1' Long 30.R 50 010 1,99 30-AWG Blue Wne 2 Lang 30 B 50 020 SI 07 Wire for wire. 30-AWG Yellow Woe 2 Long 30 Y 50 020 S1 07 White wrapping,AWG30 30 AWG Wire 2" long 30 W 50 020 51 07 WIRE -WRAPPING KIT 30 AWG Red Wire. 2' Long 30 R-50 020 5) 07 (0.25mm) A KYNAR' 30 WG dlue Wue. 3" Loner 30 B-50030 S1 16 wire, 50 wires per 30 AWG Yellow Were, 3" long 30 Y 50 030 $1 16 package stripped 30 AWG White Wire 3 long 30-Wó0.030 5116 3 AWG Red Wire 3 Long 30 R 50 030 1,116 Contains: Hobby Wrap , Tool WSU-30 M 1" both ends. AWG 30 Blue Wire 4" Lang 30 B 50 040 $1 23 Wire Dispenser WD -30-B, (2) 14 DIP's, 30 AWG Yellow Were, 4" Long 30 Y 50 040 SI23 (2) 16 DIP's, Hobby Board H -PCB -1, 30 AWG White Woe. 4- long 30 W50 040 SI 23 30 AWG Red Wire 4' Long 30-R 50040 51 23 DIP/IC Insertion Tool INS -1416 and 30 AWG 8'i e Wue. 5" Long 30 8 50 050 SI30 DIP/IC Extractor Tool EX -1 5 30 AWG Pence. Wire 5" Long 30 Y 50-050 5130 30 AWG White Wire 5" long 30 W 50 050 SI30 30 AWG Red Wire 5" long 30R50050 $1 30 30 AWG Blue Wire 6 long 30 B 50 060 SI 38 30 AWG Y'"ow Wire 6' long 30 Y 50 060 SI 38 6. Wire -Wrapping Kit IWK-4B (Blue)1$25.99 30-AWG White Wine 6' Long 30W 50-060 St 38 30 AWG Red Wire. 6" long 30 R-50 060 SI 38

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AmericanRadioHistory.Com ..

DIP SOCKET

Dual -in -line package, 3 level wire - wrapping, phosphor bronze contact, KIN' pins .025 (0,63mm) sq., DIP/IC .INSERTION!''TOOL PIN STRAIGHTENER F b gold plated .100 (2,54mm) center spacing. y

14 Pin Dip Socket 14 Dip $0.79 16 Pin Dip Socket 16 Dip $0.89

RIBBON CABLE ASSEMBLY SINGLE ENDED With 14 Pin Dip Plug SE14 24 $3.55 24" Long (609mm) STRAIGHTEN PINS j . = RELEASE PICK- UP" With 16 Pin Dip Plug SEI6-24. $3.75 14-16 Pin Dip IC Inserter IN 3-1416 I $5.49 24" Long (609mm)

DIP/IC EXTRACTOR TOOL DIP PLUG WITH COVER FOR USE WITH RIBBON CABLE

Extractor Tool EX -1 $1.49 14 Pin Plug & Cover 14-PLG $1.45 16 Pin Plug & Cover 16-PLG $1.59

QUANTITY. 2 PLUGS. 2 COVERS ul P.C. BOARD The 4 x 4.5 x 1/16 Inch board is made of glass coated EPDXY Laminate and features solder coated 1 oz. copper pads. The board has provision onstandard .156 for a 22/44 two sided edge connector, with contacts RIBBON CABLE ASSEMBLY spacing. Edge contacts are non -dedicated for maximum flexibility. ENDED The board contains a matrix of .040 in. diameter holes on .100 inch DOUBLE enters. The component side contains 76 two -hole pads that can accom- modate any DIP size from 6-40 pins, aswell es discrete components. With 14 Pin Dip Plug -2" Long DE 14-2 $3.75 Typical density is 18 of 14 -Pin or 16 -Pin DIP's. Components may be soldered directly to the board or intermediate sockets may be pied for With 14 Pin Dip Plug -4" Long DE 14-4 $3.85 or wire-wrappieg. soldering With 14 Pin Dip Plug -8" Long DE 14-8 $3.95 Two independent bus systems are provided for voltage and ground on both sides of the board. In addition, the component side contains 14 With 16 Pin Dip Plug -2" Long DE 16-2 $4.15 wir- individual busses running the full length of the board for complete With 16 Pin Dip Plug -4" Long DE 16-4 $4.25 g flexibility. These busses enable access from edge contacts to distant components. These busses can also serve to augment the voltage or With 16 Pin Dip Plug -8" Long DE 16-8 $4.35 ground busses, and may be cut to length for paricular applications.

Hobby Board H - PCB -1 $4.99

TERMINALS .025 (0,63mm) Square Post PC CARD GUIDES 3 Level Wire -Wrapping Gold Plated Slotted Terminal WWT-1 $2.98 Card Guides TR-1 $1.89 Single Sided WWT 2 $2.98 QUANTITY - ONE PAIR (2 pcs.) Terminal IC Socket Terminal WWT-3 $3.98

Double Sided WWT-4 $1.98 PC CARD GUIDES & BRACKETS Terminal 25 PER PACKAGE

TERMINAL INSERTING TOOL For inserting WWT-1, WWT-2, WWT-3, Guides & Brackets TRS-2 1-$3.79 and WWT-4 Terminals into .040 (1,01 min) Dia. Holes. QUANTITY - ONE SET (4 pcs.) INS-1 $2.49

PC EDGE CONNECTOR

STRIP TOOL 44 Pin, dual read out, .156" (3,96 WIRE CUT AND mm) Contact Spacing, .025" (0,63 mm) square wire -wrapping pins. Easy to operate.,. place wires (up to 4) in stripping slot with ends extending beyond cutter blades ...press tool and pull cut and stripped to proper .wire -wrapping.. length. The hardened steel cutting blades and sturdy construction of z P.C.. Edge Connector CON -1 $3.49 the tool insure long life. Strip length easily adjustable for your applications.

am°4sTle yr. - ws ADJUSTABLE MODEL "SHINER" LENGTH DESCRIPTION Price P.C.B. TERMINAL STRIPS NUMBER OF STRIPPED WIRE The TS strips provide positive screw activated clamp. INCHES TO INCHES wire 14.30 AWG (1.8-0, Ing action. accommodate sizes 24 ga. and 1k." 14." $ 25mm).Pi ns are solder platedcopper,.042 Inch (1mm) Wire Cut Strip Tool 5T-100-24 8.75 on .200 centers. diameter, into (5mm) 26 ga. Cut and ST -100.20 1N." - 1 -<." $ 8.75 Wire Strip Tool TS- 4 $1.39 4 -Pole 26 ga. Wire Cut and Strip Tool ST -100-26-875 T/e - 11/4" ,$ 8.75 8 -Pole TS- 8 $1.89 28 ga. Wire Cut and Strip Tool sr -100.28 T/6 - 11/e' $11.50 12 -Pole TS -12 $2.59 30 ga. Wire Cut and Strip Tool sT-100-30 Vt.' - 11/e" $11.50 THE .801E List Of CO AND Stein FOOLS REEF NOT APPLICABLE FOR WWI( OR- TEFLON iNSUUTlon

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a CIRCLE NO. 33 ON FREE INFORMATION CARO FEBRUARY 1978 51

AmericanRadioHistory.Com +Vcc duces the line voltage to a convenient feed -through pads are accessible to the alee© value. The low -voltage ac is rectified by sides of the sockets. Molex Soldercons as they can be sol- '( 0'°DI I` D1 and D2 into pulsating do and present no problem, D193 RI8 R20 The 42 /d ,4 DL707 smoothed by Cl. A regulated do output dered on both sides of the board. at +5 volts is provided by IC23. Al- feedthrough points are identified by cir- R2:1, RI:2, R3:3, 85:4, R4:6,117:5,86:7 1 - guide 33081 though the regulator IC can provide a cles on the component placement ampere output, the capacitance meter (Fig. 8). circuitry requires only about 700 mA. Sockets or Molex Solercons are man- datory for the LED displays and decod- Construction. For the most part, the er/drivers. By cutting a socket length- circuit is not critical and any assembly wise or using Molex Soldercons on the A R C D IC17-IC19 technique can be used to reproduce it. outside pin rows, as shown in Fig. 9A, a 7490 However, the measuring circuit compris- trough is provided under the displays and into which the cur- Fig. 4. Display and drivers. ing IC20 and its associated components decoder/drivers is critical, and should be properly shield- rent -limiting resistors are placed. Num- and IC11 (Fig. 4), which also drive sev- ed and decoupled from the other stages. bering the holes from the center both up en -segment displays DIS1, DIS2, and Etching and drilling and parts placement and down will allow quick resistor place- DIS3. Current limiting for each display is guides for a suitable printed circuit board ment. For example, the leads of R2:1 performed by resistors R2:1, R1:2, R3:3, are shown in Figs. 7 and 8. occupy the second hole up and the first R5:4, R4:6, R7:5, and R6:7. (This meth- The pc board holds all components of hole down. (See Fig. 9B.) Use small, IA - od of identifying the resistors is dis- cussed in the Construction section of the article.) +1,«44 Now we'll examine the capacitance TP-C a 3 9 ee eee 314 L L 10 e" 9 11 II meter's autorange circuitry (Fig. 5). IC1 IC: 14 Io 14 7490 7490 749Ic3 0 Overflow pulses from the last BCD dec- 12 12 ICS 74125 ade counter (1C17) are applied to 4 -bit -;r 12 21 binary counter IC16. This IC has four 6 5 4 7 weighted binary outputs, A, B, C, and D, TO COI PIN 8Ll RI8,4700 T01014 PIN6 which are inverted by IC15. Lines A, A, NCC R19,47011 -RIS.3.SK 2 T0 015 PIN N.1. B, and B are decoded by the NAND R20R f RI4,l.3K NJvWIi3 NNVA 2 2 14 gates in IC8 to provide control signals R17,4700 tr 11:,0 for the Tri-State logic switches in 105 LED2 7490 and selection of the proper display deci- 31 5 mal point. Outputs C and C either sink or 101,8 7404 7498 vc4 block current from overrange indicators 14 I4J 1411.5191r.9 4 5 9 ai LED1 and LED2. 6 Ice II 10 7400 º 1 1C22 Assume that counters IC17 through 1221°', e; 10` 14121 7400 999 pulses and the IC19 have counted 13 display reads ".999." Upon receipt of the next pulse, the decimal point is shifted of meter's autorange circuit. one position to the right and the display Fig. 5. Schematic reads "0.00." Tri-State switch IC5 then the capacitance meter, less those in the watt resistors and, where necessary, in- passes the =10 reference output of IC3 power supply. It is a double -sided board sulate leads with sleeving. to decade counters IC17 through íC19. on which many connections must be The critical components on the board One-shot IC21 and IC22 then produce a made between the top and bottom foil are L1, C18 through C21, which deter- pulse which advances the most signifi- patterns. If you cannot make plated mine the frequency of the reference os- cant counter and (leftmost) display by through holes, you must use wire feed- cillator, and R1 through R4 which with one so that the displays now read throughs to make the necessary con- IC20 form the basic capacitance mea- "1.00.11 If necessary, this process is re- nections. Component leads must be sol- suring circuit. peated once or twice, resulting in an au- dered on both sides of the board when High -quality polystyrene capacitors torange function of 1000:1.. After the pads are available. and metal -film fixed resistors with tem- third counting sequence, the overflow Sockets or Molex Soldercons should perature coefficients of less than 50 pulses cycle the two overrange LED's to be used to hold the integrated circuit and ppm/°C should be used. These compo- indicate a count of 1000 pulses. display packages. However, it is impos- nents, together with IC20, will determine The 7400 series IC's require +5 volts, sible to solder leads to pads on the com- the long-term accuracy of the meter and which is provided by the projects's pow- ponent side of the board when they are measurement error as a function of tem- are er supply (Fig. 6). Transformer Tl re - under an IC socket. Because of this, all perature. If high -quality components used and the meter is properly calibrat- ed, its accuracy will be at least 1% at I PC IBOARD room temperature. 1941102 Fig. 6. Power al b+VCC supply circuit

117 V c7----ce-cls.cz3 .1?1,2201,F .01PF has a voltage Checkout and Calibration. A prop-

D2 ' regulator IC. erly functioning unit will respond as fol- CI C2 FI IN9002 40004F .OIPF 1 1/4A lows, and should then be calibrated. Ro- 16V CT ' I SIA tate R1, R3, and R10 fully counterclock- I / ELECTRONICS 52 POPULAR

AmericanRadioHistory.Com wise, set S1 to the nF position and apply a few picofarads (.003 to .030 nF). Connect a reference capacitor with a power to the project. The display will Slowly rotate the ZERO potentiometer known value of 0.68-µF to the Cx termi- light and within 2 seconds will reset to counterclockwise until the display reads nals of the meter. The display will count ".000." Rotate ZERO potentiometer R10 ".001." Rotate the control slightly coun- up for about one-half second and stop at fully clockwise. The display will indicate terclockwise until it reads ".000." some value which is not critical at this FEBRUARY 1978 53

AmericanRadioHistory.Com time. Place Si in the µF position. The C10 R C11 R13R12 R11 CB C18 C2o C21 C19 I display will read a similar value, but will not appear to flicker. Finally, place a 5000 -to -8000-11F capacitor across the LED1 C23 Cx terminals. Within a few seconds, the C16 display will advance and the overrange R18 C17 LED's will cycle top on only, bottom on LED2 only, both on, both off, and repeat the R10 sequence. The meter is now ready for R6 calibration. R17 C7 The most direct method of calibration R2o is to measure a reference capacitor R16 C22 whose value is about 0.7 p.F. A precision R9 capacitor will be very expensive, so if R19 R8 you have access to a precision (0.1% or R 115 better) capacitance bridge, measure the 51 value of a good -quality Mylar capacitor on it. If the capacitor is used at approxi- mately the same temperature as the bridge environment, it will be a suitable reference component. C14 C5 C4 D3 D4 R5 R2 D5 R4 R3 C3 RI The 0.7-1.i.F capacitor will be used as a R15 C12 C15 C13 reference for both the nF and µF switch Fig. 8. Component placement guide. Numbered circles are feedthroughs. positions. Setting one point for each po- sition is all that is required, as absolute matches the value of the reference com- Connect the capacitor to be measured linearity is provided by the project cir- ponent. Then, S1 should be placed in across the Cx terminals. Polarized ca- cuitry. The reference oscillator's mean the nF position and R1 adjusted for the pacitors must be oriented positive to output frequency is designed to be same displayed capacitance. positive, negative to negative. Do not slightly high when only C18 and C19 are connect charged capacitors to the pro- included in the circuit. If trimmer potenti- Using the Meter. Apply power to the ject. Although the input circuitry is pro- ometers R1 and R3 cannot be adjusted project by placing Si in the nF position. tected with clamping diodes and a fuse, to bring the display reading into agree- Zero the display by slowly rotating the charged capacitors might damage the ment with the value of the reference shaft of R10 counterclockwise until the project. component, install C20 and/or C21. Ca- display reads, ".001," advancing the Capacitance is displayed in either nF libration is now a matter of merely con- control slightly more until a ".000" read- or µF, depending on the setting of Si. necting the reference capacitor to the Cx ing is obtained. Once zeroed, no further Values greater than 1000 nF should be terminals, placing Si in the µF position, adjustments are necessary. The µF po- read in the µF position. Capacitance and adjusting R3 until the display sition does not require zeroing. greater than 1000 µF is determined by observing the overrange LED's to the left of the display. Because these -two LED's cycle every 3h second, they are easily observed. If the top LED glows, 1000 µF is indicated; if the bottom LED glows, 2000 µF; if both, 300011.F. This sequence will then repeat, with two dark LED's representing 4000 µF; the top LED glowing, 5000 µF; the bot- tom LED, 6000 µF; both on, 7000 µF; Fig. 9. A trough is provided both dark, 8000 µF; and so on until the the for current -limiting cycling stops. Values up to several thou- resistors as shown in (A). sand microfarads can be measured. The Diagram at (B) shows how numbering the holes allows upper limit is determined mainly by ca- quick resistor placement. pacitor leakage, and to a lesser extent by your patience! Capacitors, with high leakage will never charge to VREF, and thus will not trigger the discharge cycle. When using the capacitance meter with Si in the nF position, treat the read- ing as if it were in picofarads if the deci- mal point is to the left. That is, ".084" should be read as 84 pF, and ".003" as 3 pF. With a little experience, you will quickly become familiar with the auto -

(B) range function and the behavior of the overrange LED's.

54 POPULAR ELECTRONICS

AmericanRadioHistory.Com BY PAULE. MILLER

NL °

f

AUDIO designers usually try to maxi- tentiometer is used for R9 and R10. mize their products' stereo separa- When the potentiometer wipers are at tion. There are times, however, when a one extremity of their travel, the stereo measure of crosstalk between channels separation and spatial location of the in- is desirable. For example, the disquiet- put signals are preserved. At the other ing "orchestra in the cranium" effect ex- end, there is still no introduction of perienced with stereo headphones can crosstalk but the channels are trans- be mitigated by reducing the program posed. Adjusting the wipers for the cen- material's channel separation. The ter of their travel gives a complete stereo blender described here allows "blend," with both inputs mixed equally the user to vary channel separation to and fed to both outputs. Between the suit his taste. Also, the two channels can center and either extreme, partial blend- be transposed with adjustable separa- ing of the two channels is obtained. tion-left input to right output, and vice The voltage dividers have an insertion versa. The blender employs inexpen- loss of approximately 4.7 dB. This loss is sive components, and can be bypassed compensated for by the gain introduced at the touch of a switch. by IC2A and IC28. To ensure that the voltage divider losses and op amp gains About the Circuit. The schematic cancel each other, resistance tolerances diagram of the stereo blender is shown should be kept fairly close. If this is in Fig. 1. The heart of the circuit is con- done, no audible change in volume will tained in .two variable voltage dividers, Vary channel occur when the project is switched on or comprising R1 through R4 and R9 for separation to suit out of the signal path. the left channel, ánd R5 through R8 and Another reason for using close -toler- R10 for the right channel. Input signals your taste ance resistors lies in an important char- are applied to the voltage dividers via acteristic of the voltage dividers. That is, coupling capacitors Cl and C2 and volt- with this the overall output should remain con- age followers IC1A and IC1B. stant regardless of the setting of the dual A dual 10,000 -ohm, linear -taper po- inexpensive circuit. potentiometer BLEND control. Actually,

FEBRUARY 1978 55

AmericanRadioHistory.Com the signal level at the output will be 3 dB components' nominal values. a 1- µF capacitor has a reactance of below the input when the BLEND control Signals from the op amps are coupled approximately 8000 ohms. Therefore, is at its mid -position. But this loss is to the output jacks via capacitors C3 and the circuit should drive a load with a fair- compensated for by the fact that the in- C4, which also block any dc offsets gen- ly high input impedance-a condition puts are mixed equally and fed to each erated by the gain stages. Fairly large satisfied by most power amplifiers and output. To maintain this relationship, ac- values are required if output imped- tape deck record preamplifiers. tual resistances should be close to the ances are to be kept fairly low. At 20 Hz, The output coupling capacitors must

RI 24K

JI CI J3 LEFT RI I INPUT .0683JF 470K LEFT ON OUTPUT

8 SIA +9V +9V I9F OFF

R19 R2I IM 180K SIB +9V --a

BLEND

ICI=* R17 IC2=* 3.9M 9 V--- O R5 SIC 24K J2" J4 RIGHT C2 RIGHT INPUT .068 VF OUTPUT

4 SID C4 w .L -9V -9V IyF

R20 R22 PARTS LIST

1 I M K BI.B2-9-volt transistor batteries (battery powered \ersion only) CI .C2-0.068- µF Mylar capacitor C3.C-1-I-µ' monolithic or nonpolarizcd Fig. 1. Schematic diagram of the stereo blend. electrolytic ICI .IC2 N1C1458 or 5558 dual op amp 11 through 14-RCA phono jack The following are I/4 -watt, 5% (or better) fixed resistors.

R I ,R-1.R5,R8-24.000 ohms R2,R3.R6.R7-10.000 ohms RII through R 14-470.000 ohms R 15.R 17-3.9 megohms R 16,R 18,R 19,R20-1 megohm R21 .R22-180.000 ohms R9,R 10-dual 10.000 -ohm, linear -taper po- tentiometer SI-4pdt (battery powered version) or dpdt (line powered version) toggle or slide switch Misc.-IC sockets or Molex Soldercons, Fig. 2. Ac power supply features zener diode regulation. printed circuit or perforated hoard, shielded or coaxial cable, hookup wire, suitable en- closure, battery clips, battery holders, ma- RECORDER OR chine hardware, solder, etc. PREAMP BLENDER POWER AMP

L L IN L OUT L IN AC SUPPLY PARTS LIST LINE OUT{ R IN R R OUT R IN C I .C2-2200- µF, 25 -volt electrolytic capaci- tor BLENDER DI through D4-IN4001 rectifier

1)5, Dó 9.1 -volt, 1 -wan zener diode F1 -1/2 -ampere fuse Fig. 3. Connecting the II-Neon indicator assembly with integral project to your system. current -limiting resistor

R 1 , R2 -270 -ohm, I /2 -watt. 10% tolerance carbon composition resistor S I-spst sv. itch T1 -24 -volt center tapped. 85-mA transform- er (Stancor No. 1'8394 or equivalent) Misc.-Line cord, fuse holder, terminal INTEGRATED AMP strips. strain relief, hookup wire, machine hardware, solder, etc.

56 POPULAR ELECTRONICS

AmericanRadioHistory.Com be nonpolarized because the ac signals are not riding on a large dc level. The author suggests the use of monolythic capacitors because of their high capaci- tance -to -volume ratio. Other types can be used if space permits. Nonpolarized electrolytics, which are commonly used in speaker crossovers, are readily avail- able in unit quantities. Much smaller coupling capacitors are used at the project inputs. Although they have fairly high capacitive reactance at audio frequencies, the resistance of R19 and R20 and the very high input imped- ances of the voltage followers prevent significant signal attenuation. Two 9 -volt transistor batteries power the circuit of Fig. 1. Total current drain is fairly low, so fairly long battery life can be expected if the project is used inter- mittently. However, you might prefer to power the project from the ac line. A suitable regulated bipolar supply is shown schematically in Fig. 2. In the battery -powered version, S1 is a 4pdt switch. The circuit is inserted into the signal path and the batteries con- nected to the op amps when the switch is placed in its oN position. The batteries are disconnected and signals at the in- put jacks routed directly to the output jacks, effectively removing the project from the signal path, when the switch is 11. placed in the OFF position. In the line - powered version, S1 becomes dpdt switch and is used only to insert or re- move the circuit from the signal path. To keep the line -power ac away from the low-level signal lines, a separate spst Revolutionary! switch is used to control the primary of the power supply. Sound -shaping taping mike. Construction. The circuit can be as- sembled on either a printed circuit or perforated board. Shielded wire or small diameter (RG-174-U) coax should be used for all signal leads. If the line -pow- ered supply is to be housed in the same Never before -a single microphone that gives you the versatility of enclosure as the signal processing cir- 16 microphones! Four tiny frequency filter switches built into the new cuitry, the two should be physically iso- Shure 516EQ E-Qualidyne. Microphone let you tailor sound for studio lated as much as possible. A metal utility effects in virtually any recording situation: flick a swfitch to add sizzle box should be used to house the project. 11 to vocals . . . flick another switch to highlight the sound of a bass drum. You .94 for Use. The blender should be connected can even compensate the acoustic response of a room right from the to your audio as in - system shown Fig. 3 microphone! In all, the 516EQ creates by means of shielded patch cords ter- 16 different response variations that minated with suitable connectors. As can add a new, professional sound to mentioned earlier, it can be used to .); every tape you make. Available singly make listening through stereo héad- or in pairs for stereo recording. Ask to phones more enjoyable. The project hear a recorded demonstration at your also allows home recordists to introduce partiicipating Shure dealer. interesting special effects when taping Shure Brothers Inc. ® program material. Imaginative users will 222 Hartrey Ave., Evanston, IL 60204 no doubt find other applications. S"H U . O In A. C. Simmonds & Scns Limited .R.. Canada: - ' - -

FEBRUARY 1978 Manufacturers of high fidelity components, microphones, sound systems and related circuitry.

CIRCLE NO. 47 ON FREE INFORMATION CARO AmericanRadioHistory.Com b6'al - N ° _.-'in.é N..,, '10 s71 Th-i11 l

\ "

BY IVAN BERGER

APE buyers used to have three tape Cartridge System. The 8 -track car- Open -Reel System. Open -reel re- formats to choose from. Now they tridge system uses tape 1/4 inch wide, corders normally use 1/4 -inch tape, too, have eight! In addition to open -reel, cas- running at 33/4 inches per second in an which must be manually threaded from sette, and 8 -track, new formats have endless loop that feeds back into the one reel, over the tape deck's heads and been added: the large and four hub of the cartridge's single, built-in reel. capstan, and onto another reel. Most sub -compact cassette systems, the lat- The tape's eight tracks all run in the home machines record in stereo on four ter designed primarily for portable dicta- same direction. The tape heads shift po- tracks, interleaved so that tracks 1 and 3 tion and note -taking. sition as each set of tracks is played, se- make a stereo pair going in one direc- quencing automatically to the next set. tion, while tracks 2 and 4 carry another compact Cassette System. The Stereo 8 -track cartridges have four pairs stereo program going the opposite way. standard compact cassette system uses of tracks, playing tracks 1 and 5 togeth- Some machines reverse automatically thin tape about 1/7 inch wide, running at er, then tracks 2 and 6, and so on. to play the second track pair. Running 17/s inches per second from one hub Quadraphonic 8 -track cartridges have speeds of 71/2 and 33/4 inches per sec- within the cassette to the other. Mono- two sets of four tracks. Stereo record- ond, and a maximum reel size of 7 phonic cassettes have two tracks, one in ings can also be played on quadraphon- inches are also typical. There are many each direction. To play the second side, ic tape machines. variants to suit special needs, however. the cassette must he removed, flipped Recorders for 8 -track tapes are far Many decks now use all four tracks in over, and reinserted, unless the ma- less common, as the frequent breaks re- one direction, either for quadraphonic chine can play in two directions. Stereo- quired for track -switching make it dif- use or to record four synchronized phonic cassettes have four tracks, each ficult to fit music in without unwanted in- tracks for later mixdown to a stereo pair. stereo pair side by side so that both will terruptions, and the absence of rewind Still other decks divide the tape into two he reproduced when played on a mono- or truly fast fast -forward (it's only about wider tracks for improved signal-to- phonic machine, and so that a stereo double normal playing speed) make re- noise ratio. "Full -track" monophonic re- deck can play monophonic tapes checking what's been taped most incon- corders, using the whole tape for one through both of its channels. Four-chan- venient. Blank tapes are available, in channel, are also available though no! cassettes have been demonstrated, 30 -to -100 -minute lengths, though the they're hardly common nowadays. but have not really reached the mar - blanks are not as widely available as Reel size and tape speed vary, too. km Tapes are available in several cassettes are. Prerecorded tapes, on While the 7 -inch reel carries from 1200 lengths: C-30 (15 minutes per side, 30 the other hand, are probably easiest to to 3600 feet of tape, depending on the minutes total), C-60, C-90, and C-120 find in this tape format, though classical tape's thickness (thicker tapes are stur- are the most common. selections are rare. dier and less prone to "print -through" of

58 POPULAR ELECTRONICS

AmericanRadioHistory.Com signals from one layer to another), more ond on 1/4 -inch tape, it offers higher fidel- used by Norelco, , Scors, La- and more machines carry 101/2 -inch ity than is possible from cassette tape at fayette, Penny's, Compur-Hermes, reels with double this capacity. Battery - a similar level of development. Stereo Webcor, Montgomery Ward, Unitrex, operated, open -reel portables usually recordings are made in a format similar Radio Shack, and GE (who calls its ver- have a 5 -inch maximum reel -size capac- to the cassette's with the two tracks of sion a "micro"), uses a '/s -inch tape ity, with half the capacity of the normal each stereo pair running side by side, whose speed varies. The tape is pulled reel. Most recorders offer two speeds, each pair running in a different direction. by the take-up spindle, and the amount but many offer three; these speeds may However, a fifth track between the two of tape pulled through by each spindle range from a high of 15 inches per sec- stereo pairs can be used for control sig- revolution increases as the tape builds ond to a low of 15/16 inch -per -second. nals, such as digital location markers for up on the take-up reel. The mini -cas- With each halving of speed, fidelity dimi- each taped selection. sette is a monophonic system that re- nishes but the amount of time a given The tapes load like cassettes, which cords for 15 minutes on one track, then tape will play is doubled. A standard 7 - they resemble in all but size. But where must be flipped over to record 15 more inch reel will play for 30 minutes in each the cassette player's heads must enter minutes on the other one. Extra -length direction at 71 inches per second. Tim- the cassette shell for playing or record- cassettes using thinner tape are also ings for other speeds, tape thicknesses, ing, the Elcaset machine pulls the tape available from GE and Certron (20 min- and reel sizes can be calculated from out of the shell and brings it to the utes per side) and American headset this. heads. This allows for more accurate (26 min./side). Open -reel tape is the preferred medi- tape positioning, increasing fidelity The Olympus Micro -cassette system, um for truly serious recordings for sever- again. It also means that Elcaset tapes shared by Lanier, Panasonic, and Sony, al reasons. Its wider track and higher can be edited more easily than cas- is capstan -driven like most other tape speeds mean greater fidelity, including settes, at least with regard to removing recorders. It operates at a steady speed, more extended frequency response, undesired sections. Splicing tapes from in this case 15/16 inch per second. The better signal-to-noise ratio, more "head- one reel onto another may be more dif- tape is 1/7 inch wide, and plays for 30 room" for high recording levels without ficult than with open -reel, however. minutes per side, for a 60 -minute total. distortion (especially at higher frequen- Elcaset tapes are available in lengths Panasonic and Olympus have two - cies), and lower wow and flutter. And of 60 to 90 minutes; prerecorded tapes speed versions which can also run 60 open -reel tape is easily edited. Open - are not yet available. Also, there are few minutes per side at 15/32 ips. reel is also easily adapted to a multiplic- machines available to play Elcaset Courterport makes a thin -tape, 45 ity of special uses. Broadcasters, for in- tapes, and they are quite expensive. minute -per-side Micro-cassette and stance, use 101/2 -inch -reel machines op- another 2 -speed Micro -cassette record- erating at 15/16 inch -per -second to rec- Subcompact Systems. Sub -com- er. (But they also make a 2 -speed model ord up to 25 hours of programming on a pact cassettes are the Elcaset's oppo- using the Norelco Mini -cassette.) single reel as an automatic log of what site in many ways. Smaller than conven- The system may yet has gone out over the air. Most commer- tional cassettes, and with noticeably turn into a rival of the larger Compact cial recordings originate on open -reel less fidelity, they were developed for dic- Cassette judging from some new mod- tape, and a trend is growing towards se- tation and note -taking on the run. Here, els now appearing. One new Olympus mi-professional home studios using the their low fidelity is little disadvantage, Pearlcorder model has a built-in FM/AM larger open -reel decks. and their ultra -small size is a major radio, and another takes plug-in, acces- The major inconvenience of open -reel benefit. sory AM and FM tuners. tape is the necessity of threading it. So far, however, there are at least four Sankyo's Micro -mini is a similar cas- sub -compact tape systems, each incom- sette, so far not shared with any other Elcaset System. The Elcaset, a new patible with the others. The two most company, which also records 30 min- arrival, seeks to combine the major ad- popular sucn systems are the Philips Mi- utes per side. Tape width is 5/16 and it vantages of open -reel and cassette ni -cassette and the Olympus Pearlcord- runs at a speed of 15/16 inch per second. tape. Operating at 33/4 inches per sec- er Micro -cassette. The Philips system, Another one -company tape is the De- Jur Amsco Stenocassette 30 which re- cords for 30 minutes straight through; it records on one side only. A tape -posi- tion counter is built into the cassette, not the machine. When selecting a sub -compact sys- The most portable tem, be sure that it will be compatible tape formats are the new "mini"and with sub -compacts owned by any others "micro" tapes, used you intend to exchange tapes with. Take in machines like extra care when buying blank tapes, too, this Olympus to be sure they are the type that fit your Pearlcorder. machine. Prerecorded tapes are not available for any of these miniaturized tape systems, as in their present state of development they're not too suitable for music reproduction. However, neither was the compact cassette when it was first introduced. O

FEBRUARY 1978 59

AmericanRadioHistory.Com HÁNCES are yob haveheard.of the

OSCAR communications. satellites - built by and for radio amateurs. Yét only a handful of amateurs and SWL's háv ever -made use of the OSCAR'S. This might be due, in part, to the mistaken_ idea that expensive, complex equipment

is required and that esoteric space con-,- ° munications techniques must be em- ployed. Another possible explanation s the (again, wrongful) notion that only D- censed hams can make use of OSCAR satellites, leaving nothing to offer the

SWL or casual radio hobbyist.. .

° . The truth of the matter is that a receiv- er covering the amateur 10 -meter bard (28-29.7. MHz) and a wire antenna are. .all you need to get started in OSCAR cornmunicátions. Although having amateur license certainly increases o -- CAR enjoyment, unlicensed SWL's ca--b participate in OSCAR communicatiors and collect enviable QSL's for 'their e- forts. Many students have used OSCAR as a basis for award -winning science far projects: In fáct, the OSCAR program fers to the gene -al public the easiest, most direct access ofany space science endeavor-truly .space technology .for the people!

What's áñ OSCAR? OSCAR is a-i acronym 'for Orbiting Satellite Carrying

Amateur' Radio: ' OSCAR'S . are space satellites designed and constructed. bar ° radio amateurs On a nonprofit, nongov- ° ernmental basis'. They hitch a ride inb

. orbit during launches of 'scientific cr communications satellites, replacing tha dead weight ballast ordinarily used b tailorthe weight of the uppermost boos:- " er stage. Early OSCAR'S were designed to.give amateurs and other radio hobby-

ists experience .tracking and tuning in . signals from orbital satellites. The en--° phasis has now shifted to designing and launching "orbiting repeaters".which re-,

`ceive signals from amateur stations on .

Earth and retransmit them from space, . greatly extendinc the normal range of , trre ground stations. Participation tst amateurs is international in scope; wit-i operators in more than 100 countries ac- tively transmittinc and receiving signals

. : :through the various_OSCAR satellites.

° ° The Beginnings. Amateurs and SWL's have' beer involved in space communications ever since October 1957, when the Soviet Union launched . .a

Sputnik I into orbit. Owners of genera - coverage receivers were able to tune the 20 -MHz ."beep -beep -beep" beacon° POPULAR ELECTRONICS

AmericanRadioHistory.Com signals of Sputnik as it passed overhead dle most any type of signals received in- in orbit. cluding SSB-CW, AM, RTTY, or SSTV.

The strong signals from Sputnik I told OSCAR vii was launched on Novem- amateurs that a beacon satellite operat- ber 15, 1974. Its 910 -mile (1456 -km) ing in the ham bands was feasible. Fur- high polar orbit is virtually identical to ther exploration of the possibilities with that of OSCAR VI. OSCAR Vii carries a NASA indicated that such a satellite mode -A transponder similar to that on could be carried aboard a regularly OSCAR vi, but operates on slightly differ- scheduled launch in place of the ballast ent frequency ranges. In addition, os - normally used. A group of California CAR vii has a mode -B transponder, hams went to work and produced Os - which receives signals on 432.125

CAR I, the world's first nongovernmental through 432.175 MHz and retransmits satellite. OSCAR I was launched into a them on 145.975 through 145.925 MHz. polar orbit on December 12, 1961 from Mode B was an unexpected, rousing Vandenberg Air Force Base in Califor- success, providing signals far stronger nia. Even though its 144.98 -MHz CW than those on mode -A. Moreover, it beacon had a power output of only 100 proved to be far easier to access, with milliwatts, more than 5000 reception re- several stations working through the sat- Stations 1 and 2 can ports were received from 28 countries ellite with as little as 50 milliwatts output! communicate through OSCAR 7 during the 20 days it operated. OSCAR I's or OSCAR D only when satellite Many foreign stations can be found on beacon had a typically amateur touch, is in shaded area between points A mode B, and the day is not far off when sending out the simple message "HI", and B. Circles represent possible someone will work more than 100 coun- the traditional Morse code expression communication areas tries through the OSCAR satellites. for laughter. for land stations. The latest in the series, OSCAR D, is

OSCAR II was launched on June 2, scheduled for launch early in 1978 and 1962, and was essentially a repeat of CAR V, launched on January 23, 1970. should be aloft by the time you read this. OSCAR i. Results of the first two missions Although not a relay satellite, it did test Like OSCAR vi and vii, OSCAR o will have convinced amateurs that the time had several new control and transmissions a mode -A transponder aboard. A new come to try their hand at a true com- systems that would play an important feature will be a mode -J transponder, munications satellite. The result was OS- part in later OSCAR missions. Underlining designed and built by a group of ama- CAR iii, launched March 9, 1965 and be- the international nature of the OSCAR teurs in Japan, who have formed the coming the world's first free -access, ac- program, the satellite was designed and Japanese AMSAT Association. In mode tive communications satellite. OSCAR iii built in Australia. J, the satellite will receive signals from accepted signals from Earth at approxi- Earth between 145.9 and 146.0 MHz mately 144.1 MHz and retransmitted The Second Generation. Increas- and transmit them back to Earth within a them on 145.9 MHz with an output pow- ing complexity of the OSCAR satellites 435.1 -to -435.2 -MHz passband. er of one watt. Almost 100 amateur sta- made impossible the informal "back- The Soviet Union has announced that tions in 16 countries took advantage of yard" construction procedures used for it witl shortly place its first amateur satel- the new mode of communication, estab- the first few in the series. In 1969, AM - lite into orbit. Called RS -1, but desig- lishing several records in the process. SAT, the Radio Amateur Satellite Cor- nated OSCAR viii by AMSAT, the satellite HB9RG in Switzerland and DL6EZA in poration, was founded in Washington, will use passbands similar to those em- Germany became the first nongovern- D.C., to design and build future OSCAR ployed by OSCAR VU in mode A. The ment stations to establish contact by satellites. OSCAR v was the first satellite uplink passband of the first Russian sat- communications satellite, and W1 BU to be launched under AMSAT auspices. ellite will be 145.8 through 145.9 MHz, and DL3YBA made the first trans -Atlan- The first of the new generation of os - and the downlink is announced as 29.3 tic amateur contact via satellite. OSCAR CAR'S from AMSAT was OSCAR vi, through 29.4 MHz. Operators who have iii functioned for only 15 days before its launched into a polar orbit on October gained experience with OSCAR VI and vii batteries failed. OSCAR iv, launched on 15, 1972. Although designed for only should have no trouble using RS -1. December 21, 1965, was the first ama- one year of service, it continued func- The latest information about the oper- teur satellite to use a repeater that cov- tioning until June 1977. OSCAR vi carried ational status of any of the OSCAR sat- ered two different bands. It received sig- aboard a transponder, as opposed to ellites can be obtained from AMSAT

nals at 144.1 MHz and retransmitted the repeaters carried aboard OSCAR'S III headquarters or from the American Ra- them with an output power of three watts and iv. A transponder is designed to re- dio Relay League and its bulletins over on 431.938 MHz. Unfortunately, a mal- ceive and retransmit a band of frequen- station W1AW. The addresses of both function in its booster rocket caused it to cies, not one specific pair. The OSCAR vi organizations can be found in the box go into'a highly elliptical orbit with a very transponder operated in what is known accompanying this article. low perigee. Only a dozen confirmed as mode A. In this mode, the OSCAR sat- two-way contacts were made before the ellite receives signals from ground sta- Using Oscar. The first step in getting satellite re-entered the atmosphere and tions in the 2 -meter band and transmits acquainted with .the OSCAR'S, whether burned up. One of these, however, be- them back to Earth in the 10 -meter you're an amateur or SWL, is to develop tween K2GUN and UP2ON, was the first band. OSCAR vi received signals from the capability of receiving signals from direct satellite communication between 145.9 to 146.0 MHz and relayed them the satellites. The various CW telemetry the United States and the Soviet Union. back on 29.45 to 29.55 MHz. Transpon- beacons operating on frequencies giveh The last of the early OSCAR'S was os - ders aboard the OSCAR series can han- in the Table are good targets. Most peo -

FEBRUARY 1978 61

AmericanRadioHistory.Com ple will find the 10 -meter beacons the any listening location in the world. This trial stations (if any). Suddenly, the bea- easiest to hear, at least at first. is an ideal time for the beginner to listen con frequencies and downlink passband Almost any receiver with coverage of for its beacon. will "come alive" with signals. The sig- the 10 -meter amateur band (28.0 Plotting OSCAR orbits and predicting nals will become stronger as the satellite through 29.7 MHz) can be used to re- when the satellites can be heard are approaches, then drop off as the satel- ceive the OSCAR CW beacons. However, beyond the scope of this article, but the lite becomes more distant from the lis- some older receivers might not have techniques involved are not difficult and tener. They will "break off" just as sud- adequate sensitivity to copy the bea- require no advanced mathematics. denly as they became audible. cons. This can be remedied by adding W1 AW broadcasts orbital information cn Newcomers to OSCAR are often con- an outboard preamplifier covéring ten a regular basis, and AMSAT offers a fused by the effects of Doppler shift. As meters. Suitable preamps are available computer printout of orbital predications the satellite approaches a ground sta- from many amateur equipment suppli- for the entire year. Simple tracking de- tion, the frequency of signal coming from ers, or you can build one yourself. Most vices are available from both ARRL and the satellite appears higher than the ac- modern solid-state receivers are suffi- AMSAT that enable precise tracking of tual transponder output frequency. ciently sensitive to copy the beacons When the satellite is directly overhead, without help from additional equipment. the received frequency and the actual No fancy antennas are needed. The frequency will be the same. As the satel- old reliable dipole, cut for 10 -meters will lite moves away from the listening loca- do an excellent job. Plans for a 10 -meter tion, the received frequency will seem to dipole can be found in any edition of The decrease. This is similar to the effect no- Radio Amateur's Handbook, available at ticed when a train whistle changes pitch virtually any library. as the locomotive passes by. WHERE TO GET An omnidirectional CB antenna will Doppler shift increases with frequen - MORE INFORMATION also work well in most cases. This au- cy. Signals on 10 meters will not be thor has received the 10 -meter beacons greatly affected, but the phenomenon AMSAT. The Radio Amateur from an apartment QTH using just sev- Satel- must be taken into account when tuning lite. Corporation, Bbx 27, Washington, eral feet of random wire fed to his receiv- for the 145- and 435 -MHz beacons. DC - 20044. Membership is $10 per er through an tuner.. The point Many amateurs are bothered by Doppler antenna year, including qúarterly newsletter. is is when they first to that nothing fancy necessary. Just AMSAT is a nonprofit corporation *and shift attempt transmit try to have the antenna resonant at 10 solicits tax-deductible contributions to through one of the OSCAR'S. Adjusting meters and outside, if at all possible. defray costs of the OSCAR satellites. It their transmitters to compensate for the Both OSCAR vii and D travel in polar or- also actively solicits reception reports "drift" they hear, they end up "waltzing" bits. OSCAR VII is approximately 910 of OSCAR CW beacons and issues all over the transponder passband! For- miles (1456 km) above the Earth's sur- QSL cards to confirm correct reports: tunately, simple mathematical formulae. face and OSCAR o is planned to orbit at Also available are attractive cértifi_ enable amateurs to predict and accu- approximately 575 miles (920 km). The cates and awards to amateurs using rately compensate for Doppler effects. the OSCAR series. higher altitude of OSCAR vii means that it The OSCAR beacons send telementary ARRL. The American Radio Relay provides greater communication range information in .CW at a rate of 20 words League, 225 Main St., Newington, CT than OSCAR D. When OSCAR VII is within 06111.'The national association of ra- per minute. Although this is rather fast, approximately 2450 miles (3920 km) of dio amateurs transmits latest OSCAR signals can be recorded and later de- if your location, its CW beacons should be information " in búlletins on station coded, even one does not know Morse audible. The lower orbit of OSCAR D will W1AW. Complete schedule of bul> code. (See "End that Utility Futility," give it a range of approximately 155d letins available for stamped self_ July, 1977 POPULAR. ELECTRONICS.) The miles (2480 km). You can plot the addressed envelope. Publications of telemetry gives details about internal ranges for yourself by drawing circles interest to OSCAR users include Get= characteristics of the satellites, such as ting to Know OSCAR From the with radii of 2450 and 1550 miles (3920 Grbund battery voltage and satellite tempera- Up and Specialized Communications and 2480 km) centered on your location. ture. AMSAT encourages reports on re- Techniques for the Radio Amateur. Whenever one of the OSCAR'S passes ception of the telemetry beacons, and within its respective circle, you should offers free technical sheets to interested be able to hear it. (See diagram.) persons so that they can interpret the How long you will be able to hear each data for themselves. AMSAT also offers satellite also depends on how close it is QSL cards to anyone who correctly re- to your listening location. The OSCAR'S ports reception of any of the OSCAR sat- might be audible for only a minute or two ellite beacons. These will be of particular whenever their orbits just cross the edge interest to the SWL, as many all -band of your "listening circles." The greatest the OSCAR satellites, allowing prediction SWL clubs give country status to "outer period of audibility will occur when the to within a few seconds of when the sat- space." At present, the only way to 'Se- OSCAR'S pass overhead. When this hap- ellites will first be heard and when the cure a verification from outer space is pens, you can hear the satellites for up signals will be lost. through an OSCAR reception report to to 25 minutes at a time. Due to orbital AMSAT! You can send your reports to characteristics, éach OSCAR will be with- What You'll Hear. While the satellites AMSAT at its Washington address. in range at least four times every day. are still out of range, you'll find the bea- After you have become adept at re- OSCAR vii has one overhead pass each con frequencies and transponder out- ceiving the beacons, you can start tun- day between 6 and 10 p.m., local time at puts completely quiet except for terres- ing the transponder passbands for ama -

62 POPULAR ELECTRONICS

AmericanRadioHistory.Com TABLE OF effective radiated power be used for The omnidirectional verticals so popu- uplink transmissions to OSCAR. Thus, a lar in 2 -meter FM work will give excellent OSCAR SATELLITE FREQUENCIES 10 -watt, 2 -meter transceiver feeding an results when receiving mode -B signals. antenna with 10 dB of gain will give 100 Mode -B and J directional transmitting OSCAR VII watts of effective radiated power. Higher antennas should be mounted on rotors Mode A: signal levels overload OSCAR transpon- for best results and either be elevated at Uplink: 145:900-146.000 MHz ders and can shorten the useful life of an angle of approximately 30 degrees or Downlink: 29.450-29.550 MHz the satellites. Most OSCAR work is via have a separate elevation rotor. Beacon: 29.450 MHz. Mode B: SSB or CW, with other modes restricted A mode -J uplink can use the same Uplink: 432.125-432.175 MHz to special tests authorized by AMSAT. equipment as that for mode A. For mode Downlink: 145.975-145.925 MHz For overhead passes, many have B, many amateurs use a frequency trip- Beacon: 145.972 MHz found that verticals used in 2 -meter FM ler with an existing 2 -meter transmitter work well. But serious OSCAR users em- to convert a 144 -MHz signal to 432 OSCAR D ploy beams mounted on rotors to follow MHz. Such an approach is suitable only Mode A: the satellite as it passes overhead to en- for CW work; for SSB, a more complex Uplink: 145.850-145.950 MHz sure a good signal into the satellite. transverter must be used. Recently, Downlink: 29.400-29.500 MHz Some employ a separate rotor to commercial transceivers for 432 -MHz Beacon: 29.400 MHz change the beam's elevation because SSB/CW have been introduced, and ad- Mode J: the path of an OSCAR orbit is usually lo- ditional manufacturers are planning for Uplink: 145.900-146.000 MHz OSCAR Downlink: 435.100-435.200 MHz cated well above a beam's horizontal the higher frequencies. Beacon: 435.095 MHz plane: Others compromise and leave the beam elevated at an angle of 30°. Coming Up: Phase III. Exciting as Phase III (to bé launched in late 1979) To minimize signal fading, some ama- OSCAR communications are, there are Mode J: teurs use antennas employing circular limitations. Maximum communications Uplink: 145.850-145.990 MHz polarization. Omnidirectional antennas time is now limited to about 25 minutes, Downlink: 435.150-435.290 MHz with circular polarization have an effec- and range is relatively short by the General Beacon: 435.145 MHz tive negative gain, so more than 100 stancards of 20 and 15 meters, the Engineering Beacon: 435.300 MHz watts of output power must be fed into prime hf DX bands. However, all of this Mode B: them to give efficiency equal to a small will change dramatically in 1979, when Uplink: 435.150-435.290 MHz beam and rotor. Antenna polarization is the first of the OSCAR Phase Ill satellites Downlink: 145.850-145.990 MHZ not critical 'in OSCAR work because sig- is launched. Like their predecessors, General Beacon: 145.995 MHz nals from Earth are rotated in polariza- these OSCAR'S will travel in polar orbits, Engineering Beacon: 145.845 MHz tion by the Earth's magnetic field as they but will have an apogee of 24,000 miles pass through the ionosphere. Also, os - over the North Pole. This will allow all CAR vii and D are tumbling as they orbit, amateurs in the Northern Hemisphere to causing further polarization shifts. communicate with each other-without fading, skip zones, or ionospheric distur- Mode B and Mode J Techniques. bance! This type of hemispheric com- As noted earlier, OSCAR'S vii and D make munications is presently impossible on teur stations communicating with other use of 145- and 432 -435 -MHz frequen- any other amateur band. What's more, amateurs through the satellite. Unlike cies for their uplink and downlink trans- most amateurs will be able to work some amateurs, OSCAR communicators missions, as shown in the Table. Some through the Phase Ill satellite for tend to be excellent QSL'ers, and AM - amateurs and many SWL's may find it approximately 14 to 16 hours each day. SAT has set up an OSCAR QSL bureau. necessary to add equipment to their Phase Ill will also be easier to use shacks to cover these other modes. than the previous OSCAR satellites. The Transmitting through OSCAR. The mode -B downlink can easily be relatively slow movement of the Phase Anyone holding a Technician or higher received on a 2 -meter multi -mode trans- Ill satellite through the sky will eliminate class amateur license can use the os - ceiver or on a general -coverage receiver the need for complicated beam and rotor CAR satellites for two-way communica- equipped with a 2 -meter converter. antenna systems for maximum perfor- tions. As with receiving, elaborate equip- Mode -B signals from OSCAR vii have mance. With Phase Ill, any apartment ment is not really necessary. been quite strong, much more so than dweller with a view of the northern hori- Mode A is again the best place to mode -A; and mode -J is expected to be a zon will be able to enjoy fade -free com- start, with many amateurs using one of similar improvement. Mode -J's 435 - munications with most of the world, us- the new multi -mode 2 -meter transceiv- MHz downlink transmissions will require ing only simple gear and less than 100 ers to transmit into the OSCAR (the an outboard converter ahead of an hf re- watts of output power. "uplink") and their usual receiver or ceiver or multi -mode vhf transceiver. Phase Ill's orbit will be highly elliptical. transceiver to receive the signals re- Most 2 -meter and 435 -MHz converters A synchronous orbit-one that keeps transmitted by oscAR (the "downlink"). produce output signals in the 10 -meter pace with the Earth's rotation so that the Others use transverters to convert their amateur band, and can be obtained satellite appears stationary-was ruled transmitter's output (usually in the 10 - from amateur equipment dealers. (For out because of the limited number of meter band) up to 2 meters. High power most amateurs and SWL's, the addition amateurs it would serve. Three satellites isn't necessary to work through OSCAR of two such converters will be the only in synchronous equatorial orbits-hav- and is not really desirable. AMSAT re- extra equipment needed for reception of ing satellite -to -satellite communications quests that no more than 100 watts of all three OSCAR downlink passbands.) links-would be necessary for global

FEBRUARY 1978 63

AmericanRadioHistory.Com sen sa+artx- .f'c . <-0,4¿ kl)' lf'lC/%PAei n.ñ $ld.,a5, communications. A synchronous orbit

edá11 over the North Pole is physically impos- 1hY7r sible, so AMSAT was forced to select from compromise orbits. More than 90 per cent of the world's amateur popula- tion resides in the Northern Hemisphere, so an elliptical orbit giving maximum coverage of the Northern Hemisphere was chosen. As mentioned earlier, the. apogee of the Phase Ill orbit will be approximately 24,000 miles over the North Pole and the perigee will be 910 miles over the South Pole. While in the Southern Hemisphere, the satellite will function much like the current OSCAR VII and D satellites. Underscoring the international char- acter of Project OSCAR, Phase III will be launched late in 1979 by the European Space Agency from the Guiana Space Center in French Guiana, South Ameri- ca. Amateurs in Japan, West Germany, Britain, and the United States are all joining in the effort to build Phase Ill. Currently, discussions are being held

Model AT15Sa/H Dual Magnet concerning the launch of a second Stereo Cartridge premounted in Universal tone arm head shell. Phase III satellite in 1980 or later aboard the Space Shuttle. Phase Ill will make use of frequencies in the same general range as the mode -B and mode -J frequencies cur- rently in use. This is in agreement with AMSAT's policy of not rendering ob- solete gear currently being used for os - CAR communication.

AMSAT and the Future. If you're in- terested in keeping up with the latest To find news on the OSCAR program and helping out how much its future development, you should con- sider joining AMSAT. Dues are $10 per better our cartridge year, which includes a subscription to the quarterly AMSAT Newsletter. AM - sounds, play their SAT also engages in numerous fund- raising projects to help pay the costs of demonstration record! the OSCAR program and will gladly sup- ply additional information on request. There are some very good test Audio-Technica cartridge that The address is Box 27, Washington, DC and demonstration records avail- meets your cost and performance able. Some are designed to show objectives. Then listen. 20044. off the capabilities of better -than - Find out for yourself that when Be sure to report reception of any of average cartridges...and reveal the it comes to a duel between our the OSCAR'S to AMSAT to get one of weaknesses of inferior models. cartridge and theirs...we're ready. their QSL cards. And why stop at mere We love them all. Even when they choose the weapons! listening? A Technician class amateur li- Because the tougher the What you'll hear is the best record, the better our Dual Magner" kind of proof that our Dual Magnet cense, with its leisurely five -words -per - cartridges perform. Bring on the design and uncompromising minute code speed, allows you to work most stringent test record you can craftsmanship is one of the most other amateurs through OSCAR. Several find. Or a demanding direct -to -disc attractive values in high fidelity. manufacturers are currently designing recording if you will. Choose the For their records...and yours! walkie-talkies to work through Phase Ill. Just imagine the fun of being able to hold five -hour ragchews with amateurs audio technica in Japan and Europe through a hand- o o INNOVATION PRECISION INTEGRITY held radio once Phase Ill is aloft! That's AUDIO-TECHNICA U.S., INC. what the future holds when you're in- Dept. 28P, 33 Shiawassee Avenue Fairlawn, Ohio 44313 In Canada: Superior Electronics, Inc. volved in OSCAR communications. O

64 POPULAR ELECTRONICS

AmericanRadioHistory.Com E f l

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IF YOU OWN a basic (256 bytes of Cassette Storage. The "Kansas to reduce the 0 -signal output down to RAM) Elf computer, for less than $5 in City" tape cassette standard uses 8 cy- the level required by the cassette re- hardware costs you can: cles of 2400 -Hz tone for a logic "1", and corder MIC or AUX input. The values of Read and, write data using a con- 4 cycles of a 1200 -Hz tone for a logic these resistors have to be determined ventional cassette tape machine. "0". Eleven bits are required for each by experimenting with your own record- Create musical programs. byte. F.rst, there is a 0 to indicate the be- er. (Try 47k as the value for the series Communicate with a TTY. ginning of transmission, followed by resistor. You may or may not need the Measure frequency/time intervals. eight 1's and 0's to form the actual data resistor to ground.) The transistor circuit Memory prenumbering. by:e, and finally two 1's to finish. The accepts the tone data from the cassette Here's how to upgrade an Elf to byte rate is about 27 per second. recorder, using a 2N2222 to provide accomplish the foregoing. These ap- The hardware required for a simple clean data for the EF2 input of the Elf. plications require a 2 -MHz crystal, or the cassette interface is shown in Fig. 1. The program shown in Table I writes timing programs modified. Ncte that a resistor network is required the 152 bytes in locations 68 through FF

9Y EDWARD Al.. McCORMIGY 4""1"5""m

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AmericanRadioHistory.Com yrnr TABLE I. PROGRAM TO READ FROM MEMORY TO CASSETTE. onto the tape in about six seconds. When the program runs, it first gener- Loc Instr Remark Loc Instr Remark ates a 2400 -Hz tone for the leader. After recording the leader for about 10 sec- 00 El X=1 33 F8 01 continue mark onds, depress the IN pushbutton to initi- 01 7A Turn Q off 35 A6 ate the data recording. At the conclusion 02 F8 68 Set first core 36 FO Start by getting of the data, a trailer tone should also be 04 Al address 37 A4 byte, recorded. 05 F8 00 Clear 38 F8 09 setting shift Table II's program will read the bytes 07 A6 reg 6 3A A5 ' count in reg 5, 08 A7 reg 7, eob sw 3B 30 4B going to space from the tape into locations 68 through 09 F8 10 Generate a mark, 3D 87 Branch if end FF. The RUN switch should be turned on OB A2 8 cycles at 3E 3A 5A of byte only when the cassette is playing back OC F8 01 2400 hertz 40 85 If not, reduce the 2400 -Hz leader. When the data is OE A3 41 FF 01 ' shift count and encountered, it will be displayed. The OF 30 11 43 A5 branch if end tape recorder should be stopped while 11 31 16 If Q on, turn 44 32 53 ' of byte on the trailer. 13 7B it off, if 46 84 Go to mark or Depressing the IN pushbutton causes 14 30 19 off, turn it 47 76 space according the program starting at,68 to be execut- 16 7A on 48 A4 to bit of byte 17 30 19 49 33 09 ed. When the RUN switch is turned off, 19 83 Variable delay 4B F8 08 Generate a space, the Elf is ready to read another program lA FF 01 * to balance 4D A2 4 cycles at from the cassette. To re -execute the 1C 3A lA half cycles 4E F8 OE 1200 hertz program presently residing at 68, tem- 1E 82 Repeat if cycle 50 A3 porarily change the byte at memory lo- 1F FF 01 count not 51 30 11 cation 01 from 02 to 68. 21 A2 * zero 53 F8 01 At end of byte, CASSETTE 22 32 2E 55 A7 set eob switch RECORDER LEVEL ADJ 24 F8 07 Fixed delay 56 F8 20 and start double AUX/MIC ' INPUT ww+n 26 FF 01 58 30 08 mark +5V 28 3A 26 5A F8 00 When end of byte, 2A 30 2C 5C A7 display byte and 18K 2C 30 11 5D 64 if end of core,

2E 86 End of mark 5E 81 go to mark, if not, 2N2222 EF2 2F 3A 3D * test 5F 32 01 get next byte 31 If IN SPKR/ 1.8 K 3F 09 up, 61 30 36 and return EARPHONE OUTPUT TABLE II. PROGRAM TO READ FROM CASSETTE INTO ELF MEMORY.

Loc Instr Remark Loc Instr Remark

00 30 02 Optional branch 32 FC ED Branch if mark Fig. 1. Simple interface between Elf 02 El X=1 34 3B 3F and cassette recorder. 03 F8 68 First "load -to" 36 7A If space, turn 05 Al address 37 FO Q off, 06 F8 80 Put a one in 38 F6 shift output 20-mA Interface. The circuit shown 08 A7 reg 7 39 51 * byte and set 09 F8 08 Put shift count 3A F8 59 delay for in Fig. 2 provides an interface between OB A5 in reg 5 3C A2 2.5 ms the Elf and a 20-mA current -loop device OC 7B Turn on Q 3D 30 49 (such as a TTY). The signal from Ct OD F8 00 Clear byte to 3F 7B If mark, turn drives the current loop, while the signal OF 51 be loaded 40 FO Q on, add one from the external current -loop device 10 35 10 Loop on marks 41 F6 to byte, shift drives the EF3 input of the Elf. 12 3D 12 * in header of 42 51 it, restore ' A program to read and write to this in- 14 F8 00 tape or 43 it 87 and terface is shown in Table Ill. When first 16 FC 01 between 44 F4 set delay executed, the program from 00 through 18 35 16 bytes 45 51 * for 2.9 ms 3E causes characters read from the key- 1A FC ED 46 F8 68 to be into 1C 3B 10 48 A2 board or tape reader written lE F8 B3 If space, start 49 85 Continue if not successive memory locations starting at 20 A2 * 5 ms delay 4A FF 01 all 8 bits in 7A. Whenever the memory is filled, or 21 7A 4C A5 ' byte the IN pushbutton is operated, the pro- 22 82 Do delay using 4D 3A 22 Continue if not gram reverts to the section between 3F 23 FF 01 duration in 4F 64 all core loaded, and 6F that reads from memory to the 25 C4 reg 2 50 81 display byte, current -loop device. This program illus- 26 3A 23 51 3A 09 * and return trates the basic input/output technique 28 35 28 Determine if 53 7A If core loaded, and can be adapted for specific needs. 2A 3D 2A mark or 54 3F 54 turn off Q and Note that the system will read all eight 2C F8 00 'space at 56 37 56 execute program bits from a byte of memory and will 2E FC 01 'sampling 58 30 68 ' when IN down 30 35 2E time punch all eight bits. Similarly, all eight 66 POPULAR ELECTRONICS

AmericanRadioHistory.Com bits on the tape will be read to memory. However, striking a key on the TTY en- ters only seven information bits since it Memory Prenumbering. As a practi- is an ASCII device. The printer will ig- cal matter, it is often advantageous to nore the eighth (most significant bit). "prenumber" all memory before entering Thus, Elf programs must be initially en- data into the Elf. When the program tered via the switches or from a hex key- shown in Table IV is entered and run, pad. each memory location's contents is the address of that location. As a result, you can watch the hex display when manual- TABLE III. PROGRAM TO READ FROM TELETYPE TO AND ELF VICE VERSA ly entering programs to see if the next unused location is where it should be, or Loc Instr Remark Loc Instr Remark whether you have entered too many or too few bytes. This approach can be 00 F8 28 Delay subr exit 37 F8 76 Else set delay very useful in debugging programs. 02 A6 *inreg6 39 301E for 9 ms 03 7B Turn on Q 3B 64 Display byte 04 El X=1 3C 81 TABLE IV. PROGRAM TO 05 F8 70 First read -to 3D 3A OB Read next byte PRENUMBER MEMORY. 07 Al ' address 3F F8 70 First read -from 08 F8 80 Put a one in 41 Al address Loc Instr OA A7 reg 7 42 7A Start space OB F8 00 Clear mx 43 FO Store output 00 E2 OD 51 44 A4 byte 01 F8 09 OE F8 08 Shift count to 45 F8 09 Shift count to 03 A2 10 A5 ' reg 5 47 A5 reg 5 04 82 11 3E 19 Start if EF3=0 48 F8 4F Set subr exit 05 52 13 3F 11 Loop if IN up 4A 56 06 64 15 37 15 Loop if IN down 4B F8 76 Set delay for 07 30 04 17 303F Branch otherwise 4D 30 1 E '9 ms 19 F8 29 Set subr exit 4F 84 Modify output 1B 56 50 76 according to 10 F8 B2 Set 13.5 ms delay 51 A4 bit in byte 1E C4 Delay loop subr 52 33 57 1F C4 54 7A 20 C4 55 30 58 21 C4 57 7B 22 C4 58 85 Return if not 23 FF 01 59 FF 01 all 8 bits 25 3A 1 E 5B A5 Music. It is possible to program the Elf 27 30 00 Subr exit 5C 3A 4B to reproduce the notes of the musical 29 FO Form byte 5E 7B Start mark scale by connecting a speaker system to 2A F6 ' according 5F F8 66 Set subr exit the output line and using the program 2B 51 'to EF3 at 61 56 shown in Table V. 2C 3E 31 sampling 62 F8 ED Set delay for The music program requires two data 2E 87 time 64 30 1E 18 ms 2F F4 66 64 Display byte bytes for each note played. The first byte 30 51 67 81 just put out determines the duration of the note, 31 85 Branch if all 68 32 05 All core go to read while the second byte determines the 32 FF 01 8 bits read 6A 3F 42 Else start next byte pitch. Table VI shows the hexadecimal 34 A5 6C 37 6C Loop if IN down values for whole -note duration and the 35 32 3B 6E 30 05 Return to read pitch of various notes. These byte pairs TERMINAL STRIP must immediately follow the music pro- 22011 2OmA DEVICE +5V gram shown in Table V-that is, it must start at hex AC. To illustrate, data for the PUNCH/PRINTER ELF first eight bars of Neil Simon's "Feeling Groovy" is listed in Table VII. O The music tempo depends on the hex value stored in memory 77 of Table V. The larger the hex value, the slower the EF3 tempo. The usual range is from hex 10 KEYBOARD/READER Fig. 2. Interface between Elf to hex 20. and a 20-mA Incidentally, the music program starts current -loop at hex 68; thus it can be recorded on a device such cassette. However, this leaves space for as a TTY. only 43 notes in a basic Elf. If the pro- 9V gram starts at 00, then 91 notes can be stored.

FEBRUARY 1978 67

AmericanRadioHistory.Com : Includes MUSIC PROGRAMMING 'Functional . Tilt Stand!

TABLE V. PROGRAM TO PLAY MUSIC.

NEWÉICO Loc Instr Remark Loc Instr Remark /L DMM 68 E5 X=5 89 3A 87 indicates 69 F8 AC Put first data 8B 89 Repeat as often OHLY7995ONLY .d 6B A5 'in reg 5 8C FF 01 tempo Introductory Offer-FREE-AC ADAPTOR as 6C FO Stop if data 8E A9 indicates The first and only lab accuracy por- 6D 3A 70 is 00 8F 3A 99 table DMM Kit featuring MOS/LSI 6F 00 91 88 Repeat as often IC economy and reliability. Mea- 70 A8 Store duration 92 FF 01 ' as duration sures DC/AC Volts, Kilohms, DC/ 71 15 AC milliamps in 21 ranges. Polarity in reg 8 94 A8 indicates indicators and overload protection 72 64 Display pitch, 95 3A 76 are provided, and 0.5 inch LED dis- 73 25 store it in 97 30 Al -read digital plays give easiest -to 74 FO ' reg 7 99 C4 Delay to make readout to 1999. The 270 features a 75 A7 9A C4 basic 0.5% DC accuracy, 10 Meg - alternate ohm input impedance, low voltage 76 F8 10 Store tempo 9B 30 9D paths take drop in all current ranges and auto- 78 A9 'in reg 9 9D 30 9F same time matically -flashing overrange indi- 79 87 Stop alternating 9F 30 79 Assembled $109.95 cator. 7A FC B4 'Qifarest Al 7A When note done, FREE '78 EICO CATALOG 7C 33 86 A2 15 * turn off Q, Check reader service card or send 500 7E 31 83 If Q on, turn A3 F8 OE and insert for first class mail. See your local EICO 80 7B it off; if A5 B3 short quiet Dealer or call (516) 681-9300, 9:00 81 30 86 ' off, turn it A6 23 interval a.m.-5:00 p.m. EST. Major credit cards 83 7A on A7 93 between accepted. EICO EICO-108 New South Rd 84 30' 86 A8 3A A6 notes Hicksville, N.Y. 11801 86 87 Repeat as often AA 30 6C Get next note

CIRCLE NO. 1d ON FREE INFORMATION CARD 87 FF 01 ' as pitch Put Professional Knowledge and a COLLEGE DEGREE in your Electronics Career through HOME TABLE VI. HEX VALUES FOR TABLE VII. PORTION OF SIMON'S WHOLE NOTE DURATION "FEELING GROOVY". STUDY . -. AND PITCH OF MUSICAL NOTES. Loc Data Loc Data Note Dur Pitch AC 31 1F D6 31 1F D 93 12 AE 2C 24 D8 29 2A C# 8B 14 BO 83 24 DA 83 24 Earn Your C 83 15 B2 25 2D DC 25 2D --d .7'^' B 7B 17 B4 52 2A DE 29 2A DEGREE A# 75 19 B6 2C 24 EO 57 24 by correspondence, while continuing your A 6E 1B B8 25 2D E2 25 2D present job. No commuting to class. Study at your own pace. Learn from complete and G# 68 1D BA 94 2D E4 94 2D explicit lesson materials, with additional G 62 1F BC 17 4C E6 17 4C assistance from our home -study instructors. F# 5D 22 BE 1D 3B E8 31 1F Advance as fast as you wish, but take all the F 57 24 CO 31 1F EA 31 1F time you need to master each topic. Profit E 52 27 C2 29 2A EC 29 2A from, and enjoy, the advantages of directed D# 4E 2A C4 5724 EE 57 24 but self-paced home study. D 49 2D C6 25 2D FO 25 2D The Grantham electronics degree pro- C# 45 30 C8 2C 24 F2 2C 24 gram begins with basics, leads first to the 'C 41 33 CA 2C 24 F4 2C 24 A.S.E.T. degree, and then to the B.S.E.E. B 3E 37 CC 5724 F6 57 24 degree. Our free bulletin gives complete A# 3A 3B CE 3A 19 F8 49 12 details of the program itself, the degrees A 37 3F DO 75 19 FA 49 12 awarded, the requirements for each degree, G# 34 43 D2 57 24 FC AF 19 and how to enroll. Write for Bulletin E78 . G 31 47 D4 2D 4C FE 00 Grantham College of Engineering Rest 2D 4C 2000 Stoner Avenue 'Middle C P. O. Box 25992 Los Angeles, CA 90025 Worldwide Career 7Yiaining thru Home Study

CIRCLE NO. 20 ON FREE INFORMATION CARD 68 POPULAR ELECTRONICS

AmericanRadioHistory.Com MA 872, i ` ntroller TABLE VIII. FREQUENCY COUNT PROGRAM. Imp te0

Loc Instr Remark Loc Instr Remark L °

00 3F 00 Wait for IN to 25 C4 02 37 02 be operated 26 3015 04 F8 2C Store values 28 F8 01 Zero side. 06 A2 for one 2A A3 ' no count ® `TheAnswer 07 F8 32 second 2B 30 2D ' @ dam' For... 09 B2 2D 3015 ' 0 DR 10k; `student OA F8 00 Clear freq 2F 14 One side, Hobbyist oC A4 ' count 30 F8 00 ` add to freq R OD B4 32 A3 ' count Manufacturer= OE A3 33 30 15 8700 Processor: 6503 MPU. Wear free "ActiveKeyboard". Micro -Diagnostic!) Extensive OF 3E 13 Wait for 0-1 35 E I Display high documentation. FullySocketed. 11 3611 * transition 36 F8 46 ' order User Subroutines, 13 3E 13 38 A 1 ' byte of Piebug Monitor: 15 22 Exit if end 39 94 ' freq Relative address calculator, Pointer High -low. Back -step key. 16 92 of second 3A 51 ' count Load & Dump by 17 32 35 3B 64 Cassette Interface: file #. Positive indication of operation, Tape 19 83 Monitor if on 3C . 21 ' motion control. lA 32 22 zero or 3D 3F 3D Wait for IN to Applications systems from $90 (10unit quantity) 1C 36 2F one side 3F 37 3F ' be operated Development systems from 6149 (single unit) lE C4 One side, 41 84 Display low TELL ME MORE I want to see for 1F C4 after count 42 51 ' order byte myself that the 8700 is The Answer, 20 30 15 43 64 ' freq cnt ( ) Please send documentation $10 enclosed,

22 3E 28 One side, 44 30 00 Start over ( ) send price lists & FREE Catalog of other 24 C4 no count PAIA kits. name: Address: Frequency Counter. The input cir- and displays the most significant byte of City: State: zip cuit used to read from a cassette (Fig. that count. Operating the IN pushbutton DEPT.2-P 1020 W. Wilshire Blvd. 1), can also be employed to make the Elf switch again displays the least signifi- ELECTRONICS Oklahoma City. OK 73116. act as a limited range frequency counter cant byte to be displayed. Operating the CIRCLE N0. 36 ON FREE INFORMATION CARO when the program shown in Table VIII is IN switch again results in a second fre- entered and run. quency count, etc. When the IN pushbutton is operated, The input signal should overdrive the the program counts the number of cy- 2N2222 to ensure clean 0's and 1's. The cles occuring in a one -second interval maximum frequency is about 5800 Hz.

TABLE IX. PROGRAM TO MEASURE TIME INTERVALS.

Loc Instr Remark Loc Instr Remark

00 3F 00 Wait till IN 16 F8 26 Display high

02 37 02 sw depressed 18 Al * hex position 04 F8 00 Clear registers 19 92 ' of interval 51st ANNUAL 06 A2 lA 51 'count CATALOG 1B 07 B2 64 260 PAGE 08 A3 1C 21 ¡,m RADIO, TV 09 3E OD Wait for first 1D 3F 1D Wait for IN is; ;1 & ELECTRONIC OB 36 OB O to 1 1F 37 1F * sw depressed CATALOG-YOUR OD 3E OD crossing 21 82 Display low BUYING GUIDE FOR OF 12 Add when 22 51 ' hex position EVERYTHING IN ELECTRONICS; 10 36 OF EF3=1 23 64 ' of interval STEREO, HI-FI, TV'S, RADIOS, TAPE RECORDERS, 12 12 Add when 24 30 00 Repeat CB, KITS, TOOLS, BOOKS & ELECTRONIC PARTS. 13 3E 12 EF3=0 26 Storage WRITE FOR IYOUR:=FREE 15 E1 Exit at end COPY. NOW: z , Interval Timer. Using a similar input the hex readouts is in 16 -microsecond BURSTEIN=APPLEBEE technique, the program shown in Table units. Accordingly, the maximum count 3199 MERCIER, KANSAS CITY, MO. 64111 IX allows the Elf to be used as a simple with this program is about one second. DEPT. PE 2 interval timer. The program can be modified for deci- NAME When the IN pushbutton is depressed, mal display and longer time intervals. O the Elf waits for the next 0 -to -1 crossing, ADDRESS and then measures the time to the next A future issue will show other alterna- CITY 0 -to -1 crossing. The count displayed in tives for upgrading an Elf Computer. STATE ZIP J FEBRUARY 1978

AmericanRadioHistory.Com Advanced Electronics

Most people think there are only two levels of careers in electronics: the technician level and that of the degree engineer. Be There is, however, a third and very im- the portant level. It is that of the engineering technician or practical engineer. The growing importance of this career level has created what might well be called the "New Professional" in electronics. If you look at the various levels of em- "New ployment in electronics, you will under- stand why this "New Professional" is so important. The average technician is a person who has had vocational training in elec- tronics. He understands the basic prin- rofessionar ciples of electronics so he can trouble- shoot, repair and maintain equipment. He usually works under close super- vision in performing his duties. The engineer has college training in electronics. He usually supervises tech- in e1ectro:ics nician personnel and is responsible for planning and developing of electronic equipment and systems. Frequently, however, engineers are more heavily trained in the scientific principles of electronics and less in their practical CREI trains you at home application. The engineering technician, by con- trast, is a specialist in the practical appli- for one of the most important cation of electronics. His training usually consists of a two-year college program career levels in electronics- in electronic engineering technology. In many organizations, the engineering tech- plus offers you special nician handles several of the respon- sibilities of the degree engineer. He often has the title of engineer. arrangements for engineering CREI programs are designed to give you at home the same level and depth of degrees training you receive in a two-year col- lege program in electronic engineering technology. CREI programs are, in fact, more extensive than you will find in many colleges. And CREI gives you the opportunity to specialize in your choice of the major fields of electronics. Unique Design Lab CREI gives you both theory and prac- tical experience in circuit design with its Electronic Design Laboratory Program. The professional equipment included in this program allows you to construct, test out and correct the circuits you de- sign until you have an effective circuit. This Lab Program helps you under- stand advanced electronics. It also gives you practical experience in many other important areas of electronics, as in pro -

70 POPULAR ELECTRONICS

AmericanRadioHistory.Com Career Training at Home

totype construction, breadboarding, test and measurement procedures, circuit operation and behavior, characteristics of electronic components and how to apply integrated circuits. Send for this FREE Book Only CREI offers the unique Lab Pro- gram. It is a complete college Lab and, we believe better than you will find in describing your.. opportunities most colleges. The "Lab" is one of the factors that makes CREI training inter- and. CREI college -level esting and effective. And the profes- sional equipment in this program be- in comes yours to keep and use throughout programs electronics your professional career after you com- plete the training. Engineering Degree I CREI offers you special arrangements for earning credit for engineering de- grees at certain colleges and universities as part of your home study training pro- gram. An important advantage in these arrangements is that you can continue your full time job while "going to col- lege" with CREI. This also means you can apply your CREI training in your work and get practical experience to

qualify for career advancement. . .r .Co Wide Program Choice CREI gives you a choice of specializa- tion in 14 areas of electronics. You can select exactly the area of electronics <" your field. You can spe- best for career ' .`o`+c_ cialize in such areas as computer elec- \, tronics, communications engineering, microwave, CATV, television (broad- cast) engineering and many other areas of modern electronics. Free Book In the brief space here, there isn't room to give you all of the facts about CREI college -level, home study programs in electronics. So we invite you to send for qualified to our free catalog (if you are Mail card or write describing qualifications to GI Rill program). The catalog has take a CREI CREI programs over 80, fully illustrated pages describing electron- CAPITOL are approved your opportunities in advanced for training of ics and the details of CREI home study RADIO veterans and programs. ENGINEERING .servicemen under Qualifications INSTITUTE the G.I. Bill. he take a CREI col- You may eligible to Center lege -level program in electronics if you McGraw-Hill Continuing Education are a high school graduate (or the true 3939 Wisconsin Avenue Northwest equivalent) and have previous training Washington, D.C. 20016 or experience in electronics. Program arrangements are available depending Accredited Member National Home Study Council upon whether you have extensive or minimum experience in electronics. 73 FEBRUARY 1978

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jY S Fig. 7. Etching and drilling Y Y Y Y guides for the double -sided pc hoard are shown above

E half' size. Component layout is shown al the left. R 0 07I v - -C.A-71 02 DOT . Tx WO, -Rle- 0191- Ox D I -RI- -RSx- , bd5-9 -01* -R5- -.-x) r -C710- -US -- - -4127- .- mo f un C28 cx9 Y -C411- Ox0 Y -Rx-- -96- -424 -RIx-- -R - {e i -RIO- " a0 a1 Om ,C9. -711- .512 -CR 1- -012- a A 01 E 0 oa ux D. 05 - 13j2 7x1 --.11-

".i I I .15 JI r GNO 51 50 Ax 94 Ux ©19xx

Controller is software -oriented to give ing on where he has placed his board on that contains a series of conditional the user broad flexibility in use. The soft- the I/O map. These assumptions are: loops that wait for a valid response from ware set is in two parts: (1) a group of (a) the data input port is jumpered for 5; a specific remote. The following varia- subroutines designed to provide a for- (b) the data output port is jumpered for bles in subroutine 2 have these mean- mat for the user to develop software par- 5; (c) the status port is jumpered for 4; ings: (a) E is the main error flag and, if ticular to his application, and (2) a pro- (d) the remote is jumpered for ad- this routine returns to the main program gram to determine the background error dresses 52 and 53. with E = 1, then there was an error that rate and eliminate it. Both programs are Subroutine 1 inputs the data at the could not be corrected within the con- written in BASIC for ease of use and are status port and masks out all but TMBT straints of this subroutine; (b) P contains shown in Table II. (which is equal to 16). When TMBT is the data that is transmitted to the remote

Subroutine 1 is a loop that waits for true, it returns to the main program. If plus 128 (bit -7 = 0); (c) X is the data in the transmit buffer to clear (TMBT = 1). TMBT is false, it remains in the loop to the status port that is updated during the Several assumptions are made, and the continue the search for a true TMBT. subroutine; (d) D is the data received user may have to change these depend - Subroutine 2 is the polling subroutine from the remote. It is valid when the sub -

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AmericanRadioHistory.Com routine returns to the main program, if AC O INPUT and only if, E = 0. PC BOARD Variables C and Cl are the condition- O al counters that determine how many LOAD GMD SI S0 O-- times the controller is allowed to try for a successful poll of the remote. These var- iables are absolutely necessary other - III N.O. PUSHBUTTON SWITCH

SA I/4 SA A TABLE II Fig. 8. External wiring that connects the pc board to the ac line and controlled sockets. Subroutine 1

1000 X=INP(4) : IF (X AND 16)=16 THEN .RETURN I I 1010 GOTO 1000

Subroutine 2 WHITE GREEN 5000 C=0 : C1=0 : E=0 117V AC BLACK 5010 OUT 5,P : GOSUB 1000 5015 GOSUB 8000

5020 X=INP(4) : IF (X AND 8)=8 THEN GOTO 5200 5030 C=C+1 : IF C > 5 THEN GOTO 5100 wise a failure in the remote (for example, the same. If not, re -poll the remote. If the 5040 GOTO 5020 a remote not connected to the power bits are the same, read the poll bit to de- : IF C1 > 5 THEN 5100 C1=C1+1 GOTO line) would keep the program in the loop termine the actual status of the remote. 5150 and hang up the system. The actual error rate varies according 5110 GOTO 5010 Subroutine 3, a simple FOR/NEXT to operating conditions. The conditions 5150 REM you can put an error flagging routine here loop, is a time waster that keeps data affecting the error rate are as follows: (a) from "bdnching up" at the remote. Distance from the transmitter-the far- 5160 E=1 : RETURN 5200 D=INP(5) The main program calls these subrou- ther apart the controller and the remote, 5210 IF(X AND 7).> 0 THEN GOTO 5100 tines to poll each remote and determine the weaker the signal. (b) Many resi- 5230 IF (D AND 63) <> (P AND 63) THEN its status. It then instructs the remote to dences are wired with 220 -volt, 3 -phase GOTO 5010 change its status and finally checks power, which means that there are two 5240 RETURN again to insure that the command was 117 -volt circuits available. The transmit- properly executed. The main program ted signal can be detected on the other Subroutine 3 keeps track of errors and the number of phase, but greatly attenuated. A 8000 REM time waster times the cycle is executed, printing out 0.01-µF, 600 -volt capacitor across the 8010 FOR N=1 TO 15 the error rate every 25 cycles. If the con- 220 -volt line will correct this problem. (c) 8020 N1=N1+1 ditional loops in subroutine 2 are set to High -amplitude, wideband noise, gener- 8030 NEXT N : RETURN 1, the user will get a good feel for the ated by older brush -type ac motors, can Main Program number of errors he would experience cause problems. If you can't replace the a 10 DIM'R(2),A(2) with no error corrections (line 5030 motors, then you will have to live with

. . . . . 20 Á(1)=52 : A(2)=53 C> 1, line 5100. Cl > 1). the problems. (d) Impulse noise caused 30 FOR 1=1 TO 2 Armed with this knowledge, the user by high -current inductive devices (refrig- -. 40 R(I)=A(I1+128+64 can change the conditional loops until erators, air conditioners, etc.) when they 45 P=R(I)-64 - the point of zero errors is reached. Typi- turn on and off is a random factor that 50 GOSUB 5000: REM Call the polling cal error rates with only one pass are 5 can produce single -bit errors. Fortunate- routine - to 8%. With this as a background error ly, this type noise is rapidly -55Z=Z+E of just as at- rate, four passes will make the error rate tenuated as the useful digital signal. (e) 60 T1=(D AND 64) less 70 IF E=1 THEN GOTO 50 than 0.01%. Triac noise, usually produced by poorly Errors induced by noise from the ac designed light dimmers, can raise the 80 OUT 5,R(I) : GOSUB 1000

90 GOSUB 8000 : REM time waster line are a fact of life. Fortunately, the error rate. 100 GOSUB 5000 computer can be taught to recognize The variables in the main program are 105 Z=Z+E and correct errors in transmission. If an as follows: (a) A(I) is an array that cori- 106 IF E=1 THEN GOTO 150 error is detected by a remote, it ignores tains the addresses of all remotes; (b) 110 T2=(D AND 64) the command. If an error rate exists in R(I) is the toggle command for the re- 120 IF T2=T1 THEN GOTO 80 response to a poll, it is easily detected. mote channel and is equal to A(I) plus 130 CO +C0+1 : REM CO counts the num- For example, first test bits 1, 2, and 3 128 plus 64; (c) P is the poll command ber of times through the loop bf the status port. If any of these three for each remote and is equal to R(I) mi- 135 IF CO/25 <> INT(CO/25) THEN 1, (d) T1 GOTO 150 bits is a then an error has been de- nus 64; and T2 contain the poll 140 PRINT "CYCLES =";CO;" ERRORS tected. Read the input port to clear the status of the remote before and after it =";Z;" % =";(Z/CO)'100 RDA bit, but ignore the data. If all three has been toggled; (e) D is the data from

150 NEXT : GOTO 30 bits are 0, then compare bits 0 through 5 the remote; (f) Z is the total number of with the address polled. They must be errors that have been detected. O FEBRUARY 1978 77

AmericanRadioHistory.Com Solid State

By Lou Garner THE MICROWAVE CHALLENGE

'T WAS once considered quite a job to design and build a tra effort. You'll have to be willing to develop most of your own circuit operating at frequencies as high as 500 MHz. Today, projects "from scratch," for there are few, if any, "easy -to - however, one can buy off -the -shelf equipment capable of han- build" microwave project kits. You'll have to be willing to dig dling the mid-gigahertz range (1 GHz is 1,000 MHz). And it's into such standard reference books as Microwave Integrated' time electronics hobbyists started investigating the many ap- Circuits by Jeffrey Frey (published by. Artech House, Inc., a plications of these solid-state microwave devices. subsidiary of Horizon House -Microwave, Inc., 610 Washing- Loosely defined, the microwave region is considered to be ton St., Dedham, MA 02026) and to study manufacturers' data only those frequencies from 1 GHz up, although many engi- sheets and application notes. You'll also have to pay close at- neers feel the term should include all three of the FCC -desig- tention to detail and be willing to try to perfect your designs. nated ultrahigh frequency (uhf -300 MHz to 3.0 GHz), super - Fortunately, the rewards are equal to the challenge. Not high frequency (shf-3.0 to 30.0 GHz), and extremely high fre- only will you gain the deep satisfaction that comes from com- quency (ehf-30.0 to 300.0 GHz) bands. Certainly, the behav- pleting really tough projects, but you'll enjoy the excitement of ior of radiated signals is similar in all of these bands and there working at the forefront of technology. You'll work with power is considerable overlap in the techniques used for circuit de- transistors that have strap -type leads instead of pins, such as sign and construction. There is little if any difference, for ex- Motorola's new MRF838, MRF840 and MRF842. Character- ample, in circuits used at 800 MHz and those at 1.1 GHz. ized for operation in the 806-947 MHz uhf FM band, this family Interestingly, the microwave industry was one of the first to of devices can deliver from 1 to 20 watts continuous output use semiconductor devices commercially-in the form of. when operated on 12.5-V dc supplies, furnishing power gains high -frequency diode detectors-but has not even yet made a of 6 to 8 dB. You'll work with other transistors no larger than a complete transition to solid-state designs. There are many match head, with tiny strap -type leads arranged like a "T," as commercial all -solid-state microwave test instruments, receiv- shown in Fig. 1. Typical devices in this group are the members ers and other equipment operating above 100 GHz. of the MP 1000 family of microwave transistors manufactured From a practical viewpoint, there is virtually no limit to the by AND (770 Airport Boulevard, Burlingame, CA 94010). Of variety and number of potential solid-state microwave projects these, the MP 1001, MP 1002 and MP 1004 are npn silicon for the skilled and determined experimenter, even if these are epitaxial planar transistors, while the MP 1003 is a pnp type. restricted to low- and medium -power designs. With an appro- The MP 1001 has a maximum frequency of oscillation of 10.0 priate amateur radio license, for example, one can develop GHz, typical, and the MP 1004 has a rated fT of 7.0 GHz. (The and assemble two-way microwave communications systems series is moderately priced, incidentally. The MP 1001, for ex- and model remote control equipment. ample, sells for only $6.00 each in unit quantities.) But this is Dozens of different and exciting items could be developed only the beginning. Waiting in the wings are some really for advertising displays, trade shows, school or regional exhib- high -frequency devices. Scientists and engineers of the Mu- its, Science Fairs, and similar presentations or competitions, sashino Division of Nippon Telephone and Telegraph's Elec- including such projects as . demonstration radar systems, tronic and Communications Laboratories in Japan have devel- point-to-point communication links, speed detectors, wireless oped a prototype GaAs FET with a maximum oscillation fre- digital transmission systems, or, with a dash of imagination, quency of 100 GHz! perhaps even a working model of a satellite radio' relay sys- On the discouraging side, most gallium -arsenide (GaAs) mi - tem. Other possible low -power microwave projects include short-range wireless microphone systems, intrusion and bur- glar alarms, auto close -approach anti -collision systems, level controls, motion detectors and controls, and vehicle or object identification systems. In addition, as an experimenter be- comes more and more involved with microwave designs, chances are he'll want to develop his own test equipment, 2 since commercially manufactured microwave test instruments are quite expensive. One thing is certain-despite its potential for interesting and exciting projects, the microwave arena is no place for the nov- ice. Offering a genuine challenge to the serious and more Pin 1. Base advanced hobbyist, it requires much of the knowledge of a 2. Emitter trained engineer, and the precise skills of a master machinist, 3. Collector with patience and attention to detail. If you accept the challenge, you'll have to put forth. some ex - Fig. 1. Sketch of "micropill" transistor.

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AmericanRadioHistory.Com crowave FET's are somewhat expensive, even though manu- TRAPATT, IMPATT, pin, nip, Gunn, step recovery, and factured with a semiconductor material similar to that used in Schottky barrier diodes, varactors and YIG's. Of these, the low-priced light emitting diodes (LED's). TI (Texas Instru- TRAPATT, IMPATT and Gunn diodes exhibit the equivalent of ments, Inc., P.O. Box 5012, Dallas, TX 75222), for example, a "negative resistance" characteristic and are used extensive- offers a family of GaAs MESFET's at unit prices ranging from ly in microwave oscillators. Pin and nip diodes are used for $60.00 each for the MS801 to $250.00 each for the MS803. switching and in attenuators, modulators and limiters. But the latter device is a real workhorse, capable of delivering Schottky barrier diodes are used as switches, mixers and de- a minimum of 1 watt output at 8 GHz, with at least 4 dB gain. tectors. Varactors are voltage -variable capacitors used for Prices are coming down, however, for the MS803 originally tuning and in frequency multipliers, harmonic generators etc. was priced at $1,000.00 each! The YIG's are perhaps the most fascinating of all the de- Other major semiconductor manufacturers also have made vices you'll meet. Solid state, but not semiconductors in the recent cuts in the prices of their microwave transistors. Varian usual sense, they are found in microwave circuits as tiny, Associates (611 Hansen Way, Palo Alto, CA 94303) has highly polished spheres of single yttrium -iron -garnet crystals slashed the price of its VSX 93505, a 2 -to -26 GHz FET, from (hence the acronym, YIG). Exhibiting a property known as fer- $150.00 to $115.00 each. The AFT 2000, a low -noise FET rat- rimagnetic resonance, they serve in filters, oscillators and am- ed past 12 GHz manufactured by Aertech Industries (825 Ste- plifiers. In practice, r -f input and output coupling loops are ar- wart Drive, Sunnyvale, CA 94086) has been chopped down ranged at right angles to each other around the YIG sphere, from $105.00 to $75.00 each. Hewlett-Packard's Microwave with a strong magnetic field applied at right angles to both. Semiconductor Division (1501 Page Mill Road, Palo Alto, CA Normally, there is little or no coupling between the two loops. 94304) has recently reduced the price of the HFET-1000 from At a specific frequency, however, determined by the strength $142.00 to $99.00 each. Intriguingly, the new lower prices for of the magnetic field, there is a strong interaction between the microwave transistors closely approximate the prices original- loops, with substantial r -f energy transfer possible. The YIG, ly charged for the first commercial transistors. then, acts as a selective coupling element which can be tuned In addition to new types of transistors, you'll find yourself by varying the strength of its applied magnetic field. They may working with a variety of unusual components. There are di- be used between two amplifiers as a tuned filter or between odes that seem to be special-purpose screws and semicon- the input and output of an amplifier or negative resistance de- ductor devices that look much like small pills or cartridges. vice to form an oscillator. If a varying magnetic field is used, You'll learn to install leadless capacitor chips that have to be one can frequency -modulate the oscillator's output or sweep a handled with tweezers and soldered by their edges. You'll en- band of frequencies. YIG's are effective at frequencies into the counter and use devices with strange and intriguing names- mid-GHz range.

COflflrÉ.t wi a ltle ilIpfromAP. ; Intra-Connectór = tl 4 otra -Switch

-

Intra-Connector and Intra-Switch do right in to switch each line, independently. So it's systems what our IC Test great for diagnostic and quality testing, terrific for for flat cable programming or selective line inhibiting. Clips do for DIPs, which can do a lot Intra-Connector and Intra-Switch are available for you. in 20, 26, 34, 40 and 50 contact versions. To stock up fast on these great new A P Intra-Connector mates in -line with standard items call our Toll -Free number 800-321-9668. double row socket connectors. It has one set of fe- male contacts, but two sets of male, at right angles. So it provides instant line -by-line probeability, and, allows for attachment of test probes, Faster and easier components or an additional connector. is what we're all about. Intra-Switch plugs right in line, too. But small, dependable slide switches are built

A P PRODUCTS INCORPORATED Box 110. 72 Corwin Dr., Painesville, OH 44077 (216) 354-2101 TWX: 810-425-2250

NO. 1 ON FREE INFORMATION CARO 79 FEBRUARY 1978 CIRCLE

AmericanRadioHistory.Com 0.20 0.20 0.55 0.60 0.70 0.60

0.025" I/ I - ! C3 r Fig. 2. A microstrip 50A . / 1=='° INPUT } --1. R microwave amplifier 5011 test circuit. 0.025" RFC RFC

C4 I I -05 l +VCC - VrC You may have been intrigued by Harold As you increase your knowledge of microwave technology, Reader's Circuit. Railroad Sound Synthesizer in last Decem= you may want to start working with resonant cavities. These Wright's Model would rather tackle something a little simpler are circuit elements which are fabricated using the skills of a ber's issue but might like to try the inexpensive model precision machinist rather than those of an electronics techni- for a start. If so, you whistle circuit shown in Fig. 3. Submitted by read- cian. At the beginning, however, you'll probably confine your train steam (606 Lake View, South Milwaukee, WI projects to those using stripline or microstrip circuitry. A strip - er Ralph O. Bentley the circuit requires only two active devices, an LM389 line is essentially a single conductor transmission line support- 53172), general-purpose npn transistor, Q1. Designed ed above a fixed ground plane: In its simplest form, it is a thin IC and a small 12 -volt dc source, thé circuit can conductor etched on one side of a double -clad circuit board, for operation on a standard board. The LM389 was described in Our with the unetched side serving as the ground plane. By vary- be assembled on pert State" column. Manufactured by the ing the width of the line at different points, one can create ef- September, 1976 "Solid Corporation (2900 Semiconductor fective circuit elements and match impedances. National Semiconductor CA 95051), the device comprises three A representative stripline microwave amplifier circuit layout Drive, Santa Clara, transistors and a ten -transistor is shown in Fig. 2. Suggested as a test amplifier for their uncommitted general-purpose in 18 -pin DIP. DME375 and TSP400 microwave transistors by the Com- low -power audio amplifier an IC's uncommitted transistors as munications Transistor Corporation (301 Industrial Way, Sari Ralph has used two of the coupling their outputs to the Carlos, CA 94070), the circuit is assembled on a Duroid mi- RC phase -shift audio oscillators, section lat pin 16. The remaining crostrip line with a 10 -mil dielectric, type D-5880. Either the input of they audio amplifier and used as a white -noise gen- DME375 or the TSP400 may be used in the circuit without transistor'is didde-connected applied to external transistor 01, where modification. Capacitors Cl and C2 are 0.6-to-6-pF variable erator, with its output is amplified and applied back to the audio am- units, C3 and C4 are 82-pF chip capacitors, and C5 is a the noise ,signal through another capacitor. Each phase -shift os- 200-µF, 50 -volt electrolytic. The circuit is designed for opera- plifier section individually "tuned" with a 50k potentiometer, tion on a 50 -volt dc power supply. The nominal operating fre- cillator can be a common 100k potentiometer serving to establish tonal quency is 1090 MHz (or 1.09 GHz), although it can be used as with The amplifier's gain is controlled by a potentiometer low as 1.02 GHz and up to 1.15 GHz with the DME375. If op- balance. between pins 4 and 12. Capable of delivering up to erated as a pulse amplifier (10 µsec at a 1% duty cycle), the connected nW to a 16 -ohm PM loudspeaker, the amplifier provides circuit can deliver a peak output of nearly 400 watts to a 50 - 500 output for most uses. ohm load. ample Standard components are used in the design. Except for the So, if you're bored with compUter technology, turned..off by all resistors can be either one -quarter or one- the popularity of CB, and have' achieved near perfection in potentiometers, watt types, at the builder's option. The electrolytic, which your audio designs, try the microwaves for a real challenge. half

50K IOOK 50K

Fig. 3. Inexpensive circuit for a model train steam whistle sent in by a reader.

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AmericanRadioHistory.Com e

,PROFESSIONAL AIDS DESK TOPIINSTANT DATA SYSTEM should be a 15 -volt unit, is identified by a polarity sign, while all SHELF FILES . c.' FIND THOUSANDS'

low tubular ' other capacitors can be either -voltage ceramics, .'KEEP MAGAZINES, . IF FACTS AT paper, or plastic -film types. A spst pushbutton control switch o .CATALOGS, -MANUALS, COMPUTER SPEED,. should be'connected in series with one of the power leads. :JOURNALS, DIRECTORIES j; After assembly and the customary check for possible wiring a AND REPORTS NEAT, - ,.JI:: errors or accidental shorts, one minor adjustment is required -ORGANIZED " ' ' ,r-- ', before the unit is ready for use. With the power on, advance the 100k potentiometer until the signals from both oscillators i can be heard through the loudspeaker, readjusting the gain ; control if necessary. Adjust the individual 50k pots until zero NO beat is achieved or until a single low -frequency tone can be FILING OR REFILING COMPACT. heard. Afterwards, adjust for the desired tonal balance using EVER! EASY -TO-DO the 100k pot alone. The modern rapid way to locate count less facts at your desk without thumb ing thru files. Specially coded cards Device/Product News. If you're in to high -power projects are used to record any information you data, Eliminate the clutter want close at hand - technical and price is no object, RCA's Electro -Optics and Devices case hist., bibli, of loose magazines, formulas, abstracts, a family of catalogs, etc. Find ographies. Obtain just what you need group (Route 202, Somerville, NJ 08876) has new group what you want, in seconds -any separates auto by inserting a rod. No silicon power devices that should really turn you on. Dubbed when you want it matically simply filing no me. by utilizing these slow inefficient cross ... no special training Transcalent devices, the new units have heat pipes bonded handy shelf or chanical parts ... minimum set up time. directly to the semiconductor wafers, and feature high current desk top files. STOAT ON SKIM ... Available in 6 sizes capabilites, high blocking voltages, light weight and small size. from Reader's Digest 0 DAY MONEY BACK GUARANTEE to newspaper size. The Transcalent family currently comprises three series of de- Constructed of ONLY heavy duty Basic $3800 POSTPAID vices: the P95000EB 250-A rectifiers with blocking voltages to fibreboard. - package V, 100-A npn transistors, and the Attractive blue ONSANITSTOUea0SK (200 cards, 1200 the P95200EE4 front panel. Adehesive hand notcher, FREE P95400EB 400-A thyristors (SCR's) with blocking voltages to identification labels sorting rods, included. instructions). LITERATURE 1200 V. Potential commercial applications for the devices in- Popular letter size: 11 r/2x9x 3]/e Additional cards: ON REQUEST 10 for $15.89 1000 for $57.00 clude welding control, induction heating, electroplating, vehi- 25 for $28.97 Other sizes available postpaid. Sample Card Available cular drives, heavy-duty power supplies, and motor speed Request Catalog Information Retrieval System, Div. of control -wherever high voltages and high currents must be PROFESSIONAL AIDS CO.. PROFESSIONAL AIDS CO. 1 S. WACKER DR., SUITE P-177 1 S. WACKER DR., SUITE P-1 77 controlled. CHICAGO, ILL. 60606 CHICAGO, ILL. 60606

Motorola Semiconductor Products, Inc., (P.O. Box 20912, CIRCLE NO. 40 ON FREE INFORMATION CARD IRCLE NO. 55 Phoenix, AZ 20912) has introduced a new breed of transistors with improved power handling capabilities. Identified as Pow- erbase devices, the transistors feature a unique "base WIREWRAP spreading resistance ring" which produces more uniform cur- PRECUT WIRE WIRE WRAP SOCKETS rent flow through the epitaxial-base region, thus reducing de- 1_9 10-24 259925 100-249 250-999 10-5 8 rolls? Why buy wire on Ben' 41 38 35 .31 29 .27 e2 39 .36 32 .29 .27 structive "hot spots." Offered in standard TO -3 packages, the 8 WIRE IS: l4 dn' PRECUT STRIPPED ó pin' 46 .43 .39 35 32 30 include the 2N3055H, the MJ5015, the Al .44 .41 new Powerbase units Fast - No more Cutting 8 stripping by hand 18pIn' .63 .58 54 20 84 ,78 lO 63 59 ,54 Reliable - Good, clean, uniform strip pin 2N3773, and the 2N6609, with the latter two devices an npn/ 22 pin 130 1.20 1.10 95 .90 84 Econcmlcal - Cheaper than using bulk wire 24 pin 91 .84 .78 68 .64 59 pnp complementary pair. 1.15 1.08 .95 .89 82 Precut Bulk Wire 28 pin 1.25 Wire 40 pin 165 155 1.42 1 25 1.15 t 09 roll 51 99 4c/lt. Motorola also has announced a new quad linear IC which 100 pos of r at S 62 34,[/11. 5011 at Gold 34evel Closed Entry Sockets 1 100 11. roll al 2 95 3e/11. 1 W pcs of K" at 06 2c/11. End 6 Side Stackeble All prices include gold combines two different functions in a single package. Desig- Wire KII 1 al 56 95 = 2 1/3c/11. Tin sockets and 210081 sockets available the unit comprises two operational nated type MC3405/3505, 30 Kynar skipped r' on ach end. Lengths are cverall WIRE WRAP TOOLS Colors Red.Blue.Green.Veilow,BlackOrange,Wnile amplifiers similar to type MC3403/3503 with a pair of dc com- Wire packaged in plastic bags. Ada 25C/Ienglh for tube - - 100 500 1000 5000 14 -pin DIP's, f. parators similar to type LM339/139. Supplied in 210 In. 78 2.40 4.30/K 1,89/K In. 82 2.60 4,71/K r22/0 4 "- 3 - ' n. the MC3405 has a specified operating temperature range of 351 M. 86 2B0 5.12/K 4.55/0 4 In. .90 3.00 5.52/K 4.86/0 is V 0°C to +70°C, while the identical (electrically) MC3505 4'n in. 94 3.21 5.93/K 5.210( 1- 5 in .98 3.42 634/K '..52/0 1.02 365 6.75/8 1á.66/K $34.95`', specified for -55°C to +125°C. 511n. 6 in 1.06 365 7.15/0 119/O Semiconductor Corporation has developed a se- HOBBY WRAP National 1 6v, in, 15 105 7.57/K 8.52/K Model BW 630 ^ - 7 ,n 1.20 4.25 7.9010 685/K ries of 2.5 -volt reference IC's that perform as if they were zen- 7H in 125 44s 6.39/0 7.1170 With Free Wire Kit 1 e In. 1.29 4.65 8.80/0 7.53/0 (56.95 Value) regulators. The result is a 2.5 -volt reference diode er shunt 8'4 in. 132 465 111.21/K 7.64/0 Batteries 5 Charger9 511.00 9 ,n 136 505 9.152/K4.17/K that can be used as either a positive or negative reference de- 9'a in 1.40 5.25 10.03/K aso/K WSU 30 Hand Wrap -Unwrap Strip Tool 5.95 10 in 145 551 1044/K 683/K WSU 6.95 features an adjustable breakdown voltage and 30M. for Modified Wrap vice and which Addl. in. .10 .41 62/K 66/K BT 30 Extra Bit 2.95 temperature coefficient. Identified as the LM136/236/336 se- WIRE KITS INTERCONNECT CABLES ries, the units operate over an input current range of 300 µA to Ribbon cable Connectors for connecting boards to front panels. or board to board. to operate with a minimum temperature 2 519.95 10mA. When trimmed 1 56.95 SINGLE ENDED DOUBLE ENDED coefficient, the LM336, typically, has a variation of only 2.5 mV 250 3" 100 4s 250 2's' 250 4', no 6- plc 250 3'n- 100 5' 500 3` 250 5" tá0 6W t4 p,n 16 pin 24 pin 14 pin 16 pin 24 100 a 100 6" 500 3'5- 100 5'N' IW 7" over the commercial temperature range, and is guaranteed 6 8.. 114 1.34 2.05 214 2:5 3]1 5pp a 1 250 It Moll Bulk 1.33 1.44 2 24 233 235 3.92

24- 1 52 1 65 2.63 2.52 2.76 4.31 mV, maximum. The dynamic impedance of the LM136 series One Choose Coiar 48- 1.91 206 3.40 2.91 3.17 5.08 or A s°nment is a low 0.6 ohms, maximum. Although basically 2 -terminal devices, the series includes an optional third terminal for trim- sunder52IandCOI:is.ang PAGE DIGITAL Orders under 825 and COD's, add 52 ming to precise application requirements. The devices are ELECTRONICS Fo B. e Labers,l (Ai)ped Pordl1et Class, add 51 supplied in 3 -lead TO -46 metal packages, with the LM336 135 E. Chestnut Street 4A We accept Visa 8 Mastercharge shipped same day also available in a TO -92 plastic package. O Monrovia, California 91010 most orders Phone (213) 357-5005 Dealer Inquiries Invited 10111 FEBRUARY 1978 CIRCLE NO. 37 ON FREE INFORMATION CARO

AmericanRadioHistory.Com Connect a voltmeter between the wiper II of R1 and ground so you can measure the trip voltages. Then rotate the potenti- : ometer's shaft so the wiper approaches

I Experimenter's ground. The LED will go off. As you slowly rotate R1 in the oppo- Corner site direction, the LED will suddenly switch on and the meter will read about

1 volt. When you rotate R1 back toward By Forrest M. Mims THE SCHMITT TRIGGER

THE SCHMITT TRIGGER is a bista- negative feedback voltage which re- ble (two-state) circuit with several quires that the input voltage from R1 rise useful applications, including threshold somewhat beyond the logic 1 threshold detection, signal conditioning, and sine - before the output of gate 1 changes to -square wave conversion. In this col- states. When this happens, the output of iNPt/T va4.7.¢GE umn, we'll look at some practical circuits gate 2 immediately 1 switches from 0 to Fig. 2. Hysteresis curve after we've learned the Schmitt trigger's and the LED turns on. for a Schmitt trigger circuit. operating principles. When the wiper of R1 approaches Fig. 1 shows how you can make a ground, positive feedback voltage from ground, the LED will switch off when the Schmitt trigger from two of the inverters R3 requires that the input voltage from meter reads about 0.5 volt. in a 7404 IC or half of a 7400 quad 131 be somewhat lower than that which Here are the exact trip voltages I mea-

NAND gate. The Schmitt trigger consists normally switches the output of gate 1 sured using the components shown in of the two logic elements and resistors from logic 0 to 1. When the output of Fig. 1 and a 5 -volt power supply: R2 and R3. Voltage divider R1 provides gate 1 goes high, the output of gate 2 a variable input voltage to the Schmitt immediately switches from 1 to 0 and Trip Voltages trigger, and the LED indicates when the the LED turns off. 7400 7404 circuit has triggered. The result of this feedback path is two ON 1.12 1.08 If we assume R2 is disconnected from distinctive switching voltages for the cir- OFF .47 .58 the wiper of R1, what happens? The cuit. The LED turns on at one voltáge, TTL gates we're using interpret an open and then turns off at another, somewhat The 7413 Dual Schmitt Trigger. input as a logic 1. Therefore, the first lower, voltage. Several TTL and CMOS Schmitt triggers gate inverts the logic 1 to a logic 0, the These switching points are called trip are available. One low-cost TTL IC is the second gate inverts the 0 to a 1, and the or threshold points. The region between 7413 dual Schmitt trigger. You can buy LED turns on. them is called the hysteresis zone. Fig. 2 this 14 -pin DIP for less than 50 cents Now let's connect the wiper of R1 to shows how the hysteresis zone looks (only a quarter per trigger!)

R2. When R1 is adjusted so that R2 is at when the circuit's response is plotted on Recently, I used one of these handy or near ground, the logic state at the in- a graph. The hysteresis of a Schmitt trig- chips to perform two completely different put to the first gate is logic 0. Therefore, ger is important because it prevents un- the LED turns off. wanted oscillation. If the two switching As RI's wiper approaches the positive points were identical, the circuit would supply, an increasingly positive voltage tend to oscillate when the input was at or is applied to the input of gate 1. The out- near the switching voltage. put of this gate will switch from 1 to 0 You can build the circuit in Fig. 1 on a when the input voltage exceeds the logic solderless prototyping breadboard in a 1 threshold. However, R3 provides a minute or two to observe its operation. t cc

Fig. 3. Connecting one of the two triggers in the 7413 as an oscillator to provide pulses. Fig. 1. A basic two -inverter operations in a digital controller circuit. Schmitt trigger. One of the Schmitt triggers was con- nected as a variable frequency oscillator to provide a clock for the controller cir- cuit. The other was used as a threshold buffer for a phototransistor at the input of the controller. Let's look at both these 74100 NANG GA'TE VER5/ON applications.

82 POPULAR ELECTRONICS

AmericanRadioHistory.Com Schmitt Trigger Oscillator. Fig. 3 ou TPUT shows how to connect one of the two SCNM/TT Fig. 5. How a Schmitt trigger Schmitt triggers in the 7413 as an oscil- TR/GGR cleans up an erratic waveform. lator that provides a reasonably stable source of pulses with fast rise and fall times. The frequency of oscillation and the pulse width are determined by R1 Other Applications. After a little ex- Schmitt trigger in some monostable mul- and Cl. With the values shown, the perimentation, you will be able to come tivibrator applications. Finally, be sure to pulses have an amplitude of 2 volts, a up with Schmitt trigger circuits of your experiment with Schmitt trigger IC's, width of 25 microseconds, and a rise own. For starters, try a bounceless such as the 7414 TTL chip with six time of less than 100 nanoseconds. The pushbutton. Or build a sine -to -square Schmitt triggers, and the 4093 and 4584 oscillation frequency can be varied from wave converter. You can also try using a CMOS Schmitt triggers. O a low of 70 Hz to a high of about 300 kHz by adjusting R1. Increasing C1 to 100 microfarads will Cramped reduce the frequency of oscillation to a few Hertz, making the circuit useful as a for Antenna light flasher or visual logic indicator. For the latter application, remove the con- SAVE! space? w. nection to pin 1 and replace it with a suit- 43.4- MONEY TIME FREIGHT able probe. When the probe is floating or QUALITY STEREO EQUIPMENT connected to +Vcc, the LED will flash. AT LOWEST PRICES. When it's connected to ground, the LED 1 I lc jh REQUEST FOR QUOTA- will glow continuously. YOUR :.,,, TION RETURNED SAME DAY. FACTORY SEALED CARTONS- Schmitt Trigger Threshold Buff- GUARANTEED AND INSURED. The McKAY DYMEK DA 100. er. Using the other half of the 7413 as a The DA 100 is a compact, wide dynamic SAVE ON NAME BRANDS LIKE: threshold buffer for a phototransistor is range, broadband, untuned, omni-direc- tional receiving antenna covering the illustrated in Fig. 4. Assume the light PIONEER SANSUI frequency range of 50 kHz to 30 MHz. KENWOOD DYNACO The exterior module, a small weather-proof SONY SHURE box with a 56 inch (142 cm) whip delivers MARANTZ KOSS the signal to the power supply unit through a supplied 50' coaxial cable. AND MORE THAN 50 OTHERS The power supply locates near your BUY THE MODERN WAY general coverage receiver and attaches BY MAIL-FROM with a supplied patch cord. The DA 100 antenna is small, but will equal or outperform a 100' long wire antenna, and is priced within reach of everyone! Output Impedance - Attenuator Switch provided to match receiver input requirements and prevent overload. Q/-IJNY NPN P1/0ToT/Z9/S/57O1Z Order factory Direct. Call toll free today! Minkaudio Money Back guarantee. Rent/Own Plan Fig. 4. Using half of a 7413 available. Specs and details on request. 12 East Delaware Nationwide 800/854-7769 as a threshold buffer tlllE5 COl for a phototransistor. Chicago, Illinois 60611 California 800/472-1783 McKay Dymek Co. 312-664-0020 reaching phototransistor Q1 varies in in- l 111 South College Ave. Claremont CA 91711 tensity or flickers. When the light level at NO. 30 ON FREE INFORMATION CARD Q1 is high, the phototransistor turns on CIRCLE CIRCLE NO. 23 ON FREE INFORMATION CARD and provides a low resistance path from To: Billboard Publications the input of the Schmitt trigger to 2160 Patterson Street, World Radio TV Cincinnati, Ohio 45214 ground. Thus the trigger switches high. Please me copy -NMI,. send When Q1 is dark, its resistance is high Handbook 1978 '''';_%1 (copies) of the WORLD RADIO TV and the low resistance path to +Vcc HANDBOOK 1978 @ $11.95. A check Reference!1~ or money order is enclosed, including An Indispensable through R1 forces the output of thé applicable sales tax in the states of for a Working Anyone With I Schmitt trigger low. Incidentally, these NY, OH, MA, CA, TN, NJ. understand Interest in International. that if I am not satisfied with my pur- switching conditions are reversed from chase, I may return the book(s) within Radio and TV 10 days for full credit or refund. those of the two -gate Schmitt trigger in The most complete and authoritative guide to broad- Fig. 1 because the outputs of the 7413 Name stations around the world, the are inverted. casting and television new WRTV HANDBOOK 1978 features names and Address The net result of all this is that the addresses (by country) of stations and officials, pro- Schmitt trigger cleans up erratic signals gram data (including frequencies, wave lengths, call City and converts them into more easily signs), a special editorial section-and much, much State Zip processed pulses. Fig. 5 illustrates this more-for only $11.95. Order your copy today for a FREE 10 -DAY EXAMINATION. Signature graphically. 2198 83 FEBRUARY 1978 CIRCLE NO. 53 ON FREE INFORMATION CARD

AmericanRadioHistory.Com AUDIO RFI Q. My stereo cóntains no tuner, but Hobby Scene/ , the ham who lives up the street comes ín loud and clear. The signal is not affected by the volume control. How can I stop this?-David Sluiter, Grand Haven, MI. are experiencing audio rectifica- By John McVeigh A. You tion. That is, the r -f signal is being picked However, there is one caveat that up by a wire (probably the speaker Have a problem or question on circuitry, compo- must be mentioned. If you slow down leads) and introduced to the circuitry Send it to the Hobby nents, parts availability, etc? too much, you will damage past the volume control. It is POPULAR ELECTRONICS, One Park the motor somewhere Scene Editor, an Ave., New York, N.Y. 10016. Though all letters can't it-unless it is impedance -protected. then detected or demodulated into be answered individually, those with wide interest Unless the motor is turning fast enough, audio signal by a diode, transistor junc- will be published. it won't develop a sufficient back emf. tion, or possibly even a poor metal -to - This will result in excessive current metal connection. Once the signal is de- through the motor windings and reduced modulated, it is amplified alohg with the MOTOR SPEED CONTROL motor life. program material you are listening to I vary the speed of a single - Q. Can and delivered to the speakers. ac motor by using a variable speed r-f signal can also enter via the Crudington, Ell- The resistor?-George power cable, path cords, or in severe sinore, MD. 12 -VOLT POWER SUPPLIES with slowing A. I once experimented Q. Why do most "12 -volt" power sup- noise) of an ac down the speed (and plies and battery chargers actually by inserting various cooling fan motor have an output of 14 volts?-David resistors in series with one side of fixed W. Kraeuter, Washington, PA. 450 ohms at the ac line. I finally selected EARTH line -powered dc supplies are GROUND 20 watts to obtain an optimum combina- A. These output so cases can be picked up directly by wir- Of course, I generally rated at 13.8 volts tion of quiet and air moving. preamp if the closely simulate the output ing within the amplifier or could have used a rheostat to find this that they can auto en- components are not completely shield- it with a fixed of an alternator driven by an value, and then replaced can be consecutively gine. The alternator output (nominally ed. Signal leads resistor. r -f entry higher than that unplugged to determine the Another way of varying the motor's 13.8 volts) is somewhat (12 volts) so that the alter- path. is to use a conventional SCR or of the battery speed I the speaker current through the bat- In your case, suspect triac controller, such as that shown on p. nator can force negative, thus leads. Disconnect them, but monitor the 1977 Radio Amateur's Hand- tery from positive to 544 of the output through headphones. used with charging it. If the alternator output were amplifier book. This controller can be cable to reduce the same potential as the battery'out- Wrap up the headphone fixed speed drills to get the benefit of at install action would occur. its length. If the RFI has stopped, variable speed. put, no charging 0.001-1.A.F disc ceramic capacitors from each side of the speaker outputs to the filter rolls off at 18 dB/octave and will chassis and ground the chassis as provide cutoff frequencies between SCRATCH FILTER shown here. If the RFI persists, remove 6000 and 15,000 Hz. The setting of the the line cord from the wall socket. If the Q. I need a scratch filter to attenuate -ohm potentiometer determines 25,000 RFI stops immediately, that's how it's the surface noise on my old 78 -rpm the exact cutdff frequency. A dual op getting in. You can prevent this by in- records.-H.A. Dobson, Orangeburg, amp such as a 747 can be used. Two 9 - stalling a 'brute force' line filter. If it fades SC. volt batteries can be used as a power away as the capacitors discharge, the r -f a source. You can insert the filter between A. Try the circuit shown here. It is con- is entering via another route. the system's preamp and power amplifi- tinuously variable passive filter with op In cases where the volume control af- the preamp's tape monitor loop. amp buffers at the input and output. The er or in fects the interference, the signal is en- tering at an earlier stage. Remove one input patch cord at a time until the r -f stops to determine the r -f entry point. Shielding the patch cord with a ground- ed copper braid, or installing small by- pass capacitors, ferrite beads, or r -f chokes at the appropriate input jacks. By all means notify the ham that you are experiencing RFI. Although he is not obligated to help you, he often will coop- erate by setting up a series of test trans- missions and by giving you some techni- cal advice.

POPULAR ELECTRONICS 84

AmericanRadioHistory.Com Technical Details. A block diagram of the transceiver is shown in Fig. 1. In- put signals are applied to the receiver mixer via individual double -tuned cir- Product cuits (using toroid-wound inductors) for each band. At the mixer, the input sig- nals are heterodyned with a crystal -con- Test Reports trolled local -oscillator signal of 9, 12.5, 9, 16, 23, or 23.5 MHz to produce an i -f between 5.0 to 5.5 MHz over the respec- tive bands of 3.5 to 4.0 MHz, 7.0 to 7.5 TEN-TEC CENTURY/21 HAM CW TRANSCEIVER MHz 14.0 to 14.5 MHz, 21.0 to 21.5 MHz, and 28.5 to 29.0 MHz. The differ- Sophisticated, solid-state transceiver for the Novice. ence frequencies are used for the lower two bands, while the sum mixtures of the frequencies are used for the latter four bands. The mixer uses a balanced four -diode design that minimizes unwanted outputs 6 from the input signal and the local oscil- lator. It also has superior signal -handling capabilities. The r -f gain control is a po- tentiometer that functions as a variable a attenuator in the antenna circuit. The output from the mixer passes through a 5.0 -to 5.5 -MHz bandpass filter to a second mixer where it is hetero- dyned with a 5.0- to 5.5 -MHz varia- ble -frequency oscillator (vfo) signal, pro- THE Ten-Tec Century/21 solid-state stant OSY with broadband r -f circuits on ducing an audio=frequency beat note. CW transceiver is specifically de- receive and transmit to eliminate retun- This mixer operates as a product detec- signed with the Novice in mind. Even so, ing; class -AB power amplifier with in- tor, with the vfo acting as a beat -fre- it has features normally found only in dividual low-pass filters for each band to quency oscillator (bfo). more expensive and sophisticated com- minimize harmonics and TVI; full break- Selectivity is obtained by audio filter- munication gear. It will not become ob- in; adjustable -level sidetone; electronic ing that eliminates beat notes beyond a solete as the Novice upgrades. In fact, it switching; automatic overload protec- specific range of frequencies. The audi- can well serve the old timer as a CW tion; transmitter input -power meter; o -frequency signal is then amplified to a transceiver and SSB receiver. transmitter zerobeating facility; internal, usable audio level. The transceiver features 70 watts of fi- regulated power supply; built-in speaker Three degrees of selectivity are pro- nal input power and full coverage of the and phone jack; crystal calibrator acces- duced as follows. The 2500 -Hz band- 80- through 20 -meter Amateur bands. sory socket; and 12 -volt dc outlets for width is obtained by shaping the re- Coverage of 15 meters and 1 -MHz seg- other accessories. sponse of a two -stage IC preamplifier. ment of the 10 -meter band is provided The transceiver measures 124/3"W x The 1000 -Hz bandwidth is obtained with by three optional plug-in crystals. It has 11 3/é"D x 5 34"H (31.4 x 29 x 14.6 cm) an active bandpass filter. And the the same linear tuning rate over each and weighs 181/2 lb (8.4 kg). The Centu- 500 -Hz bandwidth is obtained with two 500 -kHz band segment and offers a ry/21 comes with crystals for the 3.5-, additional cascaded active bandpass fil- choice of 2.5-, 1.0-, or 0.5 -kHz selectiv- 7-, and 14 -MHz bands for $289. Option- ters in the same IC. ity. Other features include r -f and audio al crystals for the 21-, 28-, and 28.5 - Ten-Tec has dubbed the receiver a gain controls; offset receiver tun ng; in- MHz bands are available at $5.00 each. "double direct -conversion" design. It is D5-8 SPKR DI -G 5.0-5.5MNt ICIA,ICIR IC2A-IC2C 01, IC3 similar to a single -conversion super- I.0-0.5 kHz heterodyne but with selectivity obtained FILTERS L.

ANTENNA eliminates the i -f and applies the signal LOW- PASS directly to the product detector. The dis- FILTERS advantage of this approach is that the operating range of the vfo/bfo must be shifted for each band. It therefore must Fig. 1. Block diagram shows "double -direct conversion"design of transceiver. often function at high frequencies,

FEBRUARY 1978 85

AmericanRadioHistory.Com where stability problems are aggravat- range. Sensitivity for a given S/N also beat from signals greater than 100 µV or ed. Also, it is very difficult to produce a depends on the selectivity being used, at higher audio frequencies with signals direct conversion receiver with a con- with the best figures obtained at the greater than 300 µV, heavy clipping and stant, linear tuning rate on each band. 500-Hz bandwidth. Using this setting, distortion occurred. This is probably due The vfo/bfo in the Ten-Tec Transceiv- we measured between 0.4 and 1.1 µV to a lack of agc, which allows overload- er is a permeability -tuned oscillator sensitivity for 10dB (S + N)/N, depend- ing at the product detector or the audio (pto). It is adusted by varying its fre- ing on the band and section of band set preamplifiers, which precede the volume quency -determining inductance with a up. For 1.0 -kHz bandwidth, the variation control in the circuit. movable powdered -iron core instead of was 0.6 to 1.5 µV, while for the 2.5 -kHz Third -order r -f intermodulation (IM)

using a tunable capacitor. The use of an setting, it was 0.8 to 3.0 µV. products of 1 µV were produced by two inductor yields excellent tuning linearity The 6- and 60 -dB bandwidths for the equal -amplitude signals spaced 25 kHz

and enhances stability. 0.5 -kHz position were 450 Hz (550 to apart at levels 62 dB above 1 µV (-45

Offset tuning for the receiver shifts the 1000 Hz) and 3200 Hz (300 to 3500 Hz). dBm or 1300 µV). The 1 -dB desensitiza- frequency approximately ±5 kHz. It is al- For the 1.0 -kHz setting, they were 975 tion of a desired signal occurred with an ways active in receive. When transmit- Hz (425 to 1400 Hz) and 7300 Hz (100 undesired signal displaced 25 kHz at a

ting, it is automatically disengaged to 7400 Hz). For the 2.5 -kHz position, level 75 dB above 1 µV (-32 dBm or whenever the key is pressed or the they were 2100 Hz (250 to 2350 Hz) and 5600 µV). transmitter's zerobeating feature is be- 12,400 Hz (100 to 12,500 Hz). The over- The output power from the transmitter ing used. all response in each case is indicated in averaged 40 watts in the CW portion of The transmitter signal is generated by parentheses and plotted on the graph in the 3.5 -MHz band, 39 watts on 40 me- premixing the output from the vfo with Fig. 2. ters, 35 watts on 20, and 36 watts on 15 the signal from the crystal oscillator. The R -f images from signals at frequen- and 10 meters. Maximum input power sum or difference frequency as required cies equal to that of the vfo plus that of was 70 watts on the two lower bands for each band is selected at the output of the local oscillator crystals appeared and 60 to 65 watts on the three higher the IC premixer by individual fixed, dou- when the 3.5- and 7 -MHz bands were bands. ble -tuned circuits that are switched in for used. The same was true on the higher Oscilloscope observations of the key- each band. A low-level r -f driver feeds a bands at the vfo minus the local oscilla- ing waveform indicated fairly steep rise push-pull class -AB power -output stage. tor crystal frequencies. Image rejection and fall times, with a slight rounding off Fixed bifilar- and trifilar-wound toroid in- on the 3.5-, 7.0-, 14-, 21-, and 28.5 -MHz at the crest of the leading edge. No over- ductors provide broadband operation bands averaged 90, 60, 40, 45, and 45 shoot was noted. Audibly, keying was a

over the entire frequency range. No re- dB, respectively. The 5.0 -to -5.5 -MHz i -f bit on the hard side but soft enough to tuning is required when going from band signal rejection figures averaged nomi- hold down key clicks. By spectrum to band. nally 50, 45, 70, 60, and 80 dB. analyzer measurements, the key clicks Separate two -section low-pass filters We located internal tweets at approxi- were 55 dB down at ± 3 kHz from the for each band are switched into the sig- mately 3596, 14405, and 21,335 kHz carrier frequency and more than 60 dB nal path to the antenna to provide at- that were equivalent to signal inputs of down at greater than ±5 kHz using both tenuation of harmonics and other spuri- 0.7, 0.7, and 3.2 µV, respectively. low- and high-speed keying. ous signals. The filters are in the anten- The maximum audio sine -wave output The full break-in (05K) worked excel- na line in both transmit and receive. into 8 ohms was 1 watt at 2.5% THD at lently. There were no delays, missed Keying is accomplished through di- 1000 Hz. However, with a low -frequency first dots, or shortened first dashes rect -coupled transistor stages that re- move the cutoff bias from the high-level !! 1,1 _ _ _ _ .. . . ._ - _ - _ driver and power -amplifier stages. Si- :_:::i:::m_i' : _ rwa _ rrni ai:._ly::I Q E multaneously, the side -tone oscillator is activated, the front end of the receiver is 1111011d.limi disabled, and the antenna is disconnect- _. r ru ed from the receiver a Il.I_-I ' input by PIN di- u r_ _r_w F.i üFüi 'I ode electronic switch. i: l An r -f drive control permits adjustment of . the output level of the transmitter mix - Is NNiG®_ s,iY i er and is used to set the transmitter input !_k1w 1111M power up to the maximum tolerable by 9 , the final transistors. Beyond this point, :wi 11®®i__IE_rrr._l w_ excessive current is drawn from the volt- 3' age regulator and a current limiter im- 1111111.112150111I_I0_0sHE mediately shuts down the regulator - H and ao11_I .T: removes power from the transceiver. O The power switch must then be recycled EN to place the transceiver in operation 50 MEN u_® . again after the shutdown. - _;lr-.-:i{'; E..-:-:r_.,Lr:, . _': _. . 1r :- , r r NMI r - Laboratory Measurements. Both 60 _ t-i r- k 0 4 5 12 13 14 the overall gain and the sensitivity peak up somewhat near the center of each Fig. 2. Response curves of the active audto fi ters in the Century/21.

86 POPULAR ELECTRONICS

AmericanRadioHistory.Com Use Quick -Wedge to fasten leads, wire in panelights, which occur with keyed vox (semi - Since the transceiver has no agc sys- break -in systems). The sidetone, which tem, when you tune to a very strong sig- connect test equipment, is not quite pure sine wave (most side - nal after listening to moderate -strength install components tones aren't) had a nominal frequency of signals, your ears will be blasted until 450 Hz. A unique twist here is that a you turn down the r -f or audio gain con- slight but audibly undetectable delay is trol. Additionally, over -loading with sig- built into the sidetone system to elimi- nals greater in strength than 100 to 300 r nate key clicks at the speaker and also µV can be eliminated by turning down at the headphones. the r -f gain. .Tr"91~:Z,1 Starting at an ambient temperature of Zerobeating the transmitter to the re- 944,',f-Py 80° F (27° C), the frequency of the tran- ceived signal is accomplished by press- I&3a'.ilt9éu; .. sceiver drifted 100 Hz after the first 30 ing a button on the control panel and si- minutes of operation and averaged 200 multaneously adjusting the tuning dial Hz/hour for (5,2 thereafter. zerobeat with the signal. The receiv- : ° , er can then be shifted for á desirable 1. User Comment. The Century/21 is beat note while using the receiver's off- . L housed in a textured, black vinyl -fin- set tuning control without affecting the ...... ished, two-piece aluminum cabinet. transmitter frequency. As mentioned ,.. ..i...... Snap-up/down wire bales at the front of earlier, this control can be used to shift . e ai ..' the enclosure allow the transceiver to be the signal to either side of zero beat, de- They do all that ordinary tilted up or placed horizontally. The tun- pending on which results in the least ad- screwdrivers do, PLUS they ing knob is large and has a fingertip re- jacent -signal interference. hold and start the screw cess for high-speed operation. About 17 Transmitter tune-up is accomplished revolutions of the tuning knob are re- by pressing a panel button and trimming quired to cover the entire 500 -kHz tun- the drive control for an indication in the 17 sizes ing. The operation of the tuning system 60 -to -70 -watt black area on the power - QUICIFUIEDCE is very smooth and exhibits no detect- input meter. Advancing the setting Screw -holding screwdrivers able backlash. beyond this point cuts the power to the Unconditionally guaranteed. The tuning dial is back -lighted, with transceiver as explained previously. At BUY A SET TODAY calibrations in 5 -kHz increments that are first this may provide you with a surprise, See your dealer or write to: Kedman Company, P.O. Box 25667, spaced about Vs" (3.2 mm) apart on the thinking that you've blown a fuse or Salt Lake City, Utah 84125 dial. Because sum- and difference -mix- damaged the unit. CIRCLE NO 28 ON FREE INFORMATION CARD ing is employed on different bands, the The transmitter is designed to work tuning calibrations go counterclockwise into 50-to -75 -ohm impedances. If the on 3.5 and 7 MHz and clockwise on 14, load is badly mismatched, automatic n .:;pvanitio 21, and 28 MHz. This may be a bit con- shutoff may occur below the 60 -watt in- : 0 ` fusing at first, but the confusion rapidly put point. In some cases, particularly Pte'tO° ce ,. Eléctronics disappears with familiarity. The calibra- where a random -length antenna is used, ryt tion accuracy was within 2 kHz when set a matching coupler might be required, to the nearest 100 -kHz point. tuning it up with a low drive level while . S ecialist Single sideband reception is very using an SWR indicator at the output of in elec- .o h _ Combine your interest Opportu- t easy to obtain with the Century/21, al- the transmitter. Otherwise, no r -f circuit tronics with the Great Good Pay in Avion.iat though it is somewhat more difficult to retuning is required for either the trans- sities tune in SSB signals with this transceiver mitter or the receiver when moving from Learn how you can train-in 12 months- than it is with transceivers equipped with one band to another or when changing to repair, maintain and sideband filters. frequency within a given band. Only the calibrate sophisticated electronic navigation, Direct conversion, such as is made at drive control may have to be reset when control, environmental the product detector in the Century/21, you return to transmitting. and communications sys- aims now used in modern can produce an audio image. Therefore, The built-in speaker is bottom -facing. x aircraft. if the receiver is tuned for an audio beat Even so, this arrangement appears to Now Spartan, world's largest vocational school from a desired signal lower than the os- present no hindrance to the path of the of aviation, offers specialized training in Avion- ics ... the science of electronics as used in cillator frequency, a beat may also ap- sound, especially when the transceiver the field of aviation. Train where thousands of pear from an adjacent signal on the up- is in pilots have won their wings . .. where thous- its tilted -up position. ands of top people in the field of per side of the oscillator frequency. Nev- The Century/21 has much to offer, technical aviation got their train- ing. Train at Spartan, America's ertheless, if this should cause interfer- making it a good investment for the No. 1 School of Aviation. ence, it can usually be eliminated or present and the future with reference to Send for FREE FACTS ... including "Aviation Career Kit" with colorful minimized by tuning for the desired sig- CW operation. Although its power rating brochure and full information about all courses . avionics, mechanics nal on the other side of zerobeat. If the of 70 watts input is less than the new _E. '. and pilot training. No obligation! transmitter is set to zerobeat with the de- Novice regulations permit, it is more rSPARTAN SCHOOL OF AERONAUTICS, Dept.PD0181 sired signal, the above procedure can than sufficient for plenty of state -side I International Airport, 8820 E. Pine St., Tulsa, OK 74151 l be performed using the receiver's offset and DX QSO's, as we experienced even Rush me free Aviation Career Kit with full I No obligation. tuning to dodge QRM. We found that with simple antennas. information. this procedure could produce dramatic it NAM F AGE_ results. CIRCLE Net 104 ON FREE INFORMATION CARD ADDRESS

1978 STATE ZIP FEBRUARY LCITY J CIRCLE NO. 50 ON FREE INFORMATION CARD

AmericanRadioHistory.Com The New Heathkit Catalog has everything from Personal

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r

The Digital Electronic Scale with laboratory -type precision Unique and functional truly describe the new Digi-Scale electronic "weighing machine". Big, Learn all about the Microprocessor bright LED's show your weight with more precision than nor- mal scales. and there are no springs or weights to compro- with this new Self -Instruction Course mise performance. Unlike cheaper digital scales, this one Our EE -3401 Microprocessor Course ($89.95) is your key to uses a precision strain gauge for the utmost in accuracy. learning about microprocessors. Features Heath's famous The digital readout may be mounted on the wall or just individualized learning techniques to provide you with a about anywhere. thorough background in microprocessor operation, inter- GD-1186, only $99.95 facing and programming. Accompanying software and hard- ware experiments provide "hands-on" experience with the companion ET -3400 6800 Microprocessor -based trainer Low-Cost Starter Series ($189.95). Test Bench ..°} ;a_ These five starter instruments e are an economical low cost II way to your first bench. They're ' emm . - ti intended for (but not limited to) the beginner and you'll be sur- C? 4SSS'SSSS #j ,k" prised at the features and per- m formance these new instru- ments have to offer! There's Build this new Stereo Hi -Fi Receiver the IG-5280 RF Oscillator with for top performance and value 320 kHz to 220 MHz frequency r range, the IM -5284 high perfor- Experience the subtle shadings of the symphony, cool jazz, mance multimeter that reads and the driving beat of rock all with this stereo performer volts, ohms and DC current, the from Heath. 35 watts, minimum RMS, per channel into 8 IT -5283 Signal Tracer for RF, ohms with less than 0.1% total harmonic distortion from AF and logic tracing, the IB- 20-20.000 Hz. The AR -1429 is perfect for the budget con- 5281 RCL Bridge for design scious stereo buff who requires a high quality system. It and experimentation and the has all the features of a high-priced receiver and the per- á IG-5282 Audio Oscillator with formance too. Phono hum and noise are -65 dB. FM sen- a 10 Hz to 100 kHz frequency sitivity is 1.8 µV. Has provision for optional Dolby' FM range. And to power the 5280 module. AR -1429, only $319.95 series, you can build the IPA - 5280 -1 power supply. Only $37.95 each, $24.95 for the power supply.

.. Heathkit/Dana Elec- tnDO rOf pp, 't U ' I- tronic Speed Control RESUME -I° spad BY Fits Most Cars ¡ 11111 1 `' Long distance drivers will really appreciate the CS - 1048. It makes the most of fa- mous Dana Corp. technology Super-Value Digital Alarm Clock and a crystal clear Heath in- A perfect kit for the first time kitbuilder. This super -accurate struction manual for easy in- timepiece has an attractive blue four -digit display that dims stallation. Electronically main- automatically according to ambient light. It also has the tains your auto's speed uphill features you need in a clock; 24 -hour "smart" alarm, snooze or downhill. switch, alarm -on indicator and power failure indicator. CS -1048, only $64.95 GC -1107, only $27.95

Read more about these and nearly 400 other unique and exciting kit products - all in the big, NEW, Heathkit Catalog.

88 POPULAR ELECTRONICS

AmericanRadioHistory.Com AVAILABLE LOCALLY IN THESE MARKETS ARIZONA: Phoenix, 85017, 2727 W. Indian School Entertainment to Personal Computing Rd., Phone: 602-279-6247; CALIFORNIA: Anaheim, 92805, 330 E. Ball Rd., Phone: 714-776-9420; El Cerrito, 94530, 6000 Potrero Ave., Phone: 415-236- 8870; Los Angeles, 90007, 2309 S. Flower St Phone: 213-749-0261; Pomona, 91767, 1555 Orange H8 Computer Grove Ave. N., Phone: 714-623-3543; Redwood City, 94063, 2001 Middlefield Rd., Phone: 415-365- . t 8155; Sacramento, 95825, 1860 Fulton Ave., Phone: 916-486-1575; San Diego (La Mesa, 92041), 8363 saxti~ Center Dr., Phone: 714-461-0110; San Jose (Camp- bell, 95008), 2350 S. Bascom Ave., Phone: 408- H11 Computer 377-8920; Woodland Hills, 91364, 22504 Ventura Blvd., Phone: 213-883-0531; COLORADO: Denver, 80212, 5940 W. 38th Ave., Phone: 303-422-3408; CONNECTICUT: Hartford (Avon, 06001), 395 W. $ Assembled Main St. (Rte. 44), Phone: 203-678-0323; FLORIDA: Miami (Hialeah, 33012), 4705 W. 16th Ave., Phone: LA36 DEC 305-823-2280; Tampa, 33614, 4019 West Hills- borough Ave., Phone: 813-886-2541; GEORGIA: II Writer Atlanta, 30342, 5285 Roswell Rd., Phone: 404-252- 4341; ILLINOIS: Chicago, 60645, 3462-66 W. De- von Ave., Phone: 312-583-3920; Chicago (Downers Grove, 60515), 224 Ogden Ave., Phone: 312-852- 1304; INDIANA: Indianapolis, 46220, 2112 E. 62nd St., Phone: 317-257-4321; KANSAS: Kansas City H10 Paper Tape (Mission, 66202), 5960 Lamar Ave., Phone: 913- H9 Video Reader/Punch 362-4486; KENTUCKY: Louisville, 40243, 12401 Shelbyville Rd., Phone: 502-245-7811; LOUISIANA: Terminal re~.~1 New Orleans (Kenner, 70062), 1900 Veterans r. .3 ruMs Memorial Hwy., Phone: 504-722-6321; MARYLAND: °19.M+Zod i:;.u>.!a»`.s:ss 21234, R>N .. Baltimore, 1713 E. Joppa Rd., Phone: 301- 7a7%"flR7" MOOR 1111.-,.lr.iw 661-4446; Rockville, 20852, 5542 Nicholson Lane, A Phone: 301-881-5420; MASSACHUSETTS: Boston (Peabody, 01960), 242 Andover St., Phone: 617- 531-9330; Boston (Wellesley, 02181), 165 Wor- Complete "Total Concept" Personal Computer Systems and cester Ave. (Rt. 9 just west of Rt. 128), Phone: 617-237-1510; MICHIGAN: Detroit, 48219, 18645 Systems Software: Economy, power and service backup from W. Eight Mile Rd., Phone: 313-535-6480; E. De- troit, 48021, 18149 E. Eight Mile Rd., Phone: 313- a single source! 772-9416; MINNESOTA: Minneapolis (Hopkins, Heathkit and System Soft- Heathkit Peripheral Devices follow the 55343), 101 Shady Oak Rd., Phone: 612-938-6371; Computers MISSOURI: St. Louis (Bridgeton), Our H9 63044, 3794 ware are designed for complete con- same total concept philosophy. McKelvey Rd., Phone: 314-291-1850; NEBRASKA: tinuity from top to bottom. The 8080A 12" CRT ASCII Video Terminal has all Omaha, 68134, 9207 Maple St., Phone: 402-391- based H8 computer is a good example. standard serial interfaces, auto scroll- 2071: NEW JERSEY: Fair Lawn, 07410, 35-07 It features a front panel ROM monitor ing, erase mode, long and short form Broadway (Rte. 4), Phone: 201-791-6935; Ocean, program readout, 8 -bit operation, a and plot mode displays and ASCII 67 - 07712, 1013 State Hwy. 35, Phone: 201-775-1231; heavy duty power supply and a host of key keyboard for just $530. If you need NEW YORK: Buffalo (Amherst, 14226), 3476 Sheri- other user benefits. Like all Heathkit hard copy, the LA36 DEC Writer II is dan Dr., Phone: 716-835-3090; Jericho, Long Is- Computers, it's easily expanded. In- perfect. Fully compatible with the H8 land, 11753, 15 Jericho Turnpike, Phone: 516-334- 8181; Rochester, 14623, 937 Jefferson Rd., Phone: H11, has a cludes BASIC, assembler, editor and and this incredible terminal 716-244-5470; White Plains (North White Plains, 7 debug software for only $375. 7 x dot matrix print head, selectable 10603), 7 Reservoir Rd., Phone: 914-761-7690; Our most sophisticated computer, the 10, 15 and 30 CPS print speeds, half or OHIO: Cincinnati (Woodlawn, 45215), 1^133 H11, utilizes the famous DEC LSI-11 full duplex operation and much more Springfield Pike, Phone: 513-771-885^; Cleveland. 44129, 5444 Pearl CPU for 16 -bit operation. Has a 4096 x for a low $1495. Our low cost mass Rd., Phone: 216-886-2590; Col- 16 read/write MOS semiconductor storage peripheral is the H10 Paper umbus, 43229, 2500 Morse Rd., Phone: 614-475- 7200; Toledo, 43615, 48 S. Byrne Rd., Phone: 419- memory and 38 high speed data, ad- Tape Reader/Punch. Precise ratchet/ solenoid drive, 50 CPS max read rate, 537-1887; PENNSYLVANIA: Philadelphia, 19149, dress, control and synchronization 6318 Roosevelt Blvd., Phone: 215-288-0180; 10 CPS max punch rate and the fea- Frazer lines. Executes and includes the pow- (Chester Co.), 19355, 630 Lancaster Pike (Rt. 30), erful 400+ PDP-11 /40 instruction set. tures of similar units that cost far more Phone: 215-647-5555; Pittsburgh, 15235, 3482 Wm. It also includes a complete software than $350. Penn Hwy., Phone: 412-824-3564; RHODE ISLAND: package for only $1295. Providence (Warwick, 02886), 558 Greenwich Ave., Phone: 401-738-5150; TEXAS: Dallas, 75201, 2715 Ross Ave., Phone: 214-826-4053; Houston, Get of the'latest 77027, 3705 Westheimer, Phone: 713-623-2090; your copy VIRGINIA: Alexandria, 22303, 6201 Richmond Hwy., Phone: 703-765-5515; Norfolk (Virginia HEATHKIT CATALOG Beach, 23455), 1055 Independence Blvd., Phone: 804-460.0997; WASHINGTON: Seattle, 98121, 2221 Nearly 400 exciting Third Ave., Phone: 206-682-2172; WISCONSIN: Milwaukee, 53216, 5215 W. Fond du Lac, Phone: electronic kits 414-873-8250.

HEATH Iiifafa~fati lafa fa fa fa fa fa r Heath Company, Dept. 010-380 MAIL COUPON TODAY Schlumberger Benton Harbor, Michigan 49022 1 or bring it in person to any of the 50 Heathkit Electronic Centers Please send me my FREE Heathkit Catalog.

(Units of Schlumberger Products 1 I am not on your mailing list. 1 Corporation) listed at right, 1 where Heathkit products are Name 1 displayed, sold and serviced. 1 (Retail prices on some products ca=3 á) Address may be slightly higher.) Prices are mall order net F.O.B., \City State 1 Benton Harbor, Michigan. Prices and specifications subject to change without notice. GX-340 Zip 1 Heath Company, Dept. 010-380 L mm Illa ~~ ~MI MIall allIRE =ItD- J CIRCLE NO. 5 ON FREE INFORMATION CARD FEBRUARY 1978 91

AmericanRadioHistory.Com 567 works fine here) in the receiver. Each tone detector can then control its own power socket. Bits Although the transmitter and tone Computer are turned on manually in the generator original circuit, an address decoder or some other form of digital signal can be used to turn on the different tones (and transmitter) from a computer. Speaking of using the ac line to carry digital remote control information, Ener- By Leslie Solomon gy Technology, Inc., 1601 South Main St., Las Cruces, NM 88001 (Tel: MUSIC GENERATORS AND OTHER ITEMS 505-526-3358) has just announced their Coby 1 system. This stand-alone remote control uses an 8085 processor and fea- AS THE hobby computer field keeps of filters to create different sounds, tures solid-state 7 -segment readouts to growing, many "noncomputer" peri- we've emulated some really strange indicate the time, date, and number of pherals are starting to appear. The latest "synthesizer" sounds. the remote unit being programmed. It of these is the music generator. has 24 keys to provide complete pro- Several music systems are now being Remote Control. Not long ago, we remote gramming, review, and control. Each offered on the market. We have discussed a simple tone -system master control can direct the activity of "played" some of them-the most re- control that could be used over existing was fol- 100 remotes. Each remote can be cent being the $24.50 Music System power lines. This, as you know, turned on or off at any time and date, in from Software Technology, Box 5260, lowed by the Intelligent Remote Con- cycles as short as a second or as long San Mateo, CA 94492 (Tel: troller features in our December 1977 as 100 hours. Each control contains 2k 415-349-8080). This system has a four - and January 1978 issues. of RAM, 2k of ROM, the 8085 processor, octave range and can produce three There is still one area of concern, how- a power cell and firmware operating sys- notes simultaneously. The hardware is ever. What do you do when there is no The power cell backup keeps the very simple. A small S-100 bus board common ac line between the controller tem. memory up during power fail- mounts three resistors and two capaci- and the remote device to be controlled? clock and when moving the system. tors; the output drives an audio system. We encountered this problem recently. ures or requires no knowledge The bulk of the Music System is soft- A little investigation led us to the Neil Programming West- of computers or computer languages. ware, which comes ín cassette form with Henson Co., 1 Elmwood Lane, The remotes are available in three basic 1200 -baud CUTS on one side and 300- port, CT 06880 (Tel: 203-226-4482). styles: standard 117 volts for conven- baud KC format on the other. This firm sells a small handheld trans- tional lights and appliances; standard The computer requires 2k of RAM to mitter that's powered by a conventional - wall -switch replacement; and 220 volts support the music language and to play 9-volt battery and operates in the 300 for high -power systems. The controls any of the six classical pieces (mostly MHz band. The associated receiver can for $399 and each remote (10-A Bach) provided on the cassette. The be located 100 ft away from the trans- sell models) is $40 each. software includes a multifile editor that mitter and still have reliable control. As supports the standard 8080 source file purchased, the system (Model AT -100 CRT Monitors. Many computer en- structure, subroutines required to drive Remote Control Switch at $39.95) has thusiasts have "real" CRT monitors, but the hardware, and a high-level music only one controlled power socket. an even larger group uses a convention- language having a one -pass compiler Since the transmitted signal is a tone, TV receiver and some type of r -f mod- located anywhere in memory. and the receiver uses tone demodula- al of ulator to inject a signal into the antenna All standard musical notation is sup- tion, it is not difficult to install a couple terminals. ported, including key signatures, time extra tone generators in the transmitter Recently, we had an opportunity to try signatures, clef notation, note values and some companion tone filters (the from whole notes to 1/64th notes, rests, dotted notes, triplets, staccato, articula- tion, and accidentals. There is also a full repeat support with the capability for WICKIR 1 °° second endings and refrains and the ca- YFM WOWS _I l pability of transposing keys. 1 1 1f1 1 I_1 1~ ,4"."'. I Interestingly, you do not have to be a III I-1 I_I wha musician to learn how to score music (your own or from sheet music). And, if r you are a musician, you do not have to ,r,.. ..-. be a computer expert to use the system. It is that easy. How does the Music System sound? With the original board, about the clos- est we can get is a reed -organ. How- remote control information. ever, experimenting with various forms The Coby 1 Control has 24 keys to provide POPULAR ELECTRONICS 92

AmericanRadioHistory.Com - - . i=1 v Credit Card Orders I Call Toll Free Discover Air 800-323-2272 out the Super Mod -2 ($29.95 plus $1 The Beautiful Way To Sleep /11'2' III. Residents Call postage/handling) from M & R Enter- - t,r , , . 312.595-0461 prises, Box 61011, Sunnyvale, CA 94088. The package comes as a built The and tested modulator and r -f section Original Velveteen tuned to channel 3, a 60 -dB antenna iso- lation switch, and the necessary video and r -f coaxial cables. Power require- ments are 6 to 12 volts dc at 2 mA. The r -f output is 800 microvolts into 75 ohms. The modulator is dc coupled and will ac- cept a 0 -to -2 -volt video signal. Input The World's Most Comfortable Mattress With Independent Air Coil Support impedance is 2.2 kilohms. The power SUPER SALESAVEUPTO25%S 95 The AIR COIL BED has become synonomous with the most revolu- King Size Now Just and video cables are equipped with fer- tionary and luxurious way to spend a third of your life. You are emia Imw ~ MallNM89 ~ , . ° gently but firmly supported by 100% air instead of metal springs rite rings to reduce the level of extrane- and stuffing. Many chiropractors agree the structured Air Coil Bed rase send me the following red velveteen finished Air Bed(s). If not satisfied I can return In 10 days for a prompt refund. has unprecedented orthopedic value as a permanent mattress. ous signals that produce chromatic Lightweight...Sensual...Adjusts to your comfort. The Air Bed is an Originally Now Only "worms" on the screen. experience in rest or play unmatched by any other support strut- I O King (Item 1314)' $119.95 $89.95 ture. It takes the seasickness, immobility, and weight out of O Queen (Item 1360) SB9.95 $69.95 waterbeds. Yet, it gives you the same "give and take" sensation. We tested Super Mod using the chro- Full (Item 1354) $19.95 $59.95 _ Two people can sleep on a full, queen or king size bed virtually un- p Twin (Item 1339) $59.95 $44.95 disturbed by the other's movements. This is because the air coil ma output from our computer driving a Add $4.95 per bed for shipping and handling.' construction . with multiple controlled air chambers supports Illinois Residents conventional color -TV receiver. your body evenly and independently. add 5% sales tax. Despite I O Air Pumps $29.95 ea. AC(Item 0004) 0 DC(Item 0005) Store it on a shelf, take it camping, use it in your van, boat, sum- O Check or M.O. enclosed Charge my Credit Card the fact that we live in a very strong TV ' mer home, on a floor or in a frame. Sunbathe and float on it. All Please Bank Americard Diners Club Carte Blanche ' 8" high standard sizes:Twin-39"x74", Double -54"x74", Queen- O O signal -strength area, the modulator per- 60"x80", King -74"x80". Inflates in minutes with any air pump or O Master Charge American Express formed well. The ' cannister vacuum (Adapter included). Durable 20 gauge poly vinyl Credii Card No quite viewed image cleans with soap and water. Repair kit included. 1 year manufac- Master Charge No. tap Date was stable, and the modulation and ' turer's warranty. High Powered Air Pumps. AC pump operates from standard electrical outlet. DC pump operates from auto' Name sync were excellent. Modulation level cigarette lighter. $29.95 each. Do not be confused by inferior Address This s the original, can be adjusted via an on -board level permanent, red ivelvetee a rbed, once priced as high as $119.95. ^' State Zip control. Flipping the 60 -dB switch allows Because of recent direct -from- m Signature manufacturer arrangements, we Pe m-o3z Call Toll Free: the TV receiver to operate in its normal have been able to eliminate all Contemporary B00323-2272 mode. (Note: FCC rules require that middleman costs and pass O' marketing Inc. Illinois Call A Permanent Bed Jl significant savings directly to you. Maple 6,,,, e,,,.,..n..o1.6om6 312-595-046 1 modulators and/or isolation switches be ° M -M ~II A II~ CIRCLE NO. 9 ON FREE INFORMATION CARD approved together with the equipment with which it is to be used.) HOBBYISTS !`ENGINÉERS! TECHNICIANSI! STUDENTS!' New Hardware Things. Databyte Write and run machine language programs at home, display video graphics Inc., Box 14, 7433 Hubbard Ave., Mid- on your TV set and design microprocessor circuits the very first night dleton, WI 53562 (Tel: 608-831-7666) - even if you've never used a computer recently introduced their 24 -channel log- - before! SPECIFICATIONS ic analyzer for the S-100 bus having ELF II features an RCA RCA COSMAC microprocessor/mini- 256 -by -24 data 10 COSMAC COS/MOS 8 -bit sets, -MHz clock, and microprocessor address- computer TTL logic level inputs. It can be used to able to 64k bytes with DMA. interrupt, 16 regis- A THOUGHTFUL GIFT disassemble a program exactly as it was ters, ALU 256 byte RAM, FOR ANYONE WHO MUST full hex keyboard, two 11 STAY UP TO DATE IN executed, with triggering display format- digit hex output display, ' COMPUTERS AND 5 slot plug-in expansion L ELECTRONICS' ting and operational modes controlled bus. stable crystal clock by the user input device. The trigger for timing purposes and a - double -sided plated p. word is 16 bits; and the readout, on a through PC board plus RCA 1861 video IC to dis- ELF" CRT terminal, is in binary or hex. It has play any segment of mem- =' SEND TODAY 9995 ory on a video monitor or 7 post -trigger, pre -trigger, or any trigger TV screen. N ETRONICS R&D LTD., Dept. PE -2 333 Litchfield within 256 points. The monitor requires Road, New Milford, CT 06776 Phone (203) 354-9375 USE ELF II FOR ... Yes! I want to nut programs at controllers, etc. (soon to be GAMES home and have enclosed: available as kits). Manual in- Play interactive keyboard games, $99.95 plus $3 p&h for RCA eludes instructions for assembly, games with analog inputs, games COSMAC ELF II kit. Featured testing, programming, video in POPULAR utilizing your TV set for a video ELECTRONICS. graphics and games plus how display! Includes all components plus you can get ELF II User's Club everything need GRAPHICS you to write bulletins. Kit can be assembled and run machine language pro- in a single evening and you'll Create pictures, designs, alpha-, grams plus the new Pixie chip still have time to run programs, numerics and fabulous animated that lets you display video including games, video graphics, effects on your TV screen for graphics on your TV screen. De- controllers, etc., before going to hour after hour of family fun! signed to give engineers practice bed! $4.95 for 1.5 amp 6.3 CIRCUIT DESIGN in computer programming and VAC power supply, required for Design circuits using a micro- microprocessor circuit design, ELF II kit. $5.00 for RCA processor. Use ELF II as a ELF II is also perfect for college 1802 User's Manual. counter, alarm system, lock, and college -bound students (who I want mine wired and tested controller, thermostat, timer, must understand computers for with the power any transformer and telephone dialer, etc. The pos- engineering, scientific or RCA 1802 User's Manual for sibilities are infinite! business career). Easy instruc- $149.95 plus $3 p&h. Coming Soon! tions get you started right away, Conn. res, add sales tax. Exclusive Netronics Plug -In even if you've never used a com- Program Debugger and monitor puter before! NAME As your need for computing allows visual display of any ADDRESS program on a clock pulse by power grows, five card expan- clock pulse basis to help you sion bus (less connectors) allows CITY learn programming f -a -s-11 4k memory expansion, program de- Data byte analyzer, probe memory Cassette I/O D to bugger/monitor, cassette I/O, A STATE 7IP , to D and D to A Send info ` A to D Controller plugIns. converters, on other kits! assemblies and tape monitor. ` PROM, ASCII keyboard inputs, Dealer Inquiries Invited Available now -J FEBRUARY 1978 CIRCLE NO. 31 ON FREE INFORMATION CARD 93

AmericanRadioHistory.Com character set, ASCII/baudot operation 4k of the user's memory. The kit price is (20- and 60-mA loops), full cursor con- $495; assembled, $595. Included are trol, an on -board power supply, and a three probe assemblies, system monitor modified RS232 serial port. It can also on paper tape, and a comprehensive in- be used as a stand-alone terminal. struction manual. Video output is 1.5 volts into 75 ohms. At If making S-100 prototype boards is this writing, kit price is $135, partial kit part of your hobby, then you should take (Mostek 3870 processor, character gen- a look at what E & L Instruments, Inc., erator, crystal, pc board, and documen- 61 First St., Derby, CT 06418 (Tel: tation) $79. Assembled and tested, the 203-735-8774) has to offer. Their latest mounts price is $179. entry is an S-100 board that S-100 board for prototyping three E & L Breadboarding (the solder - mounts E & L breadboards. CO CPU. Polaris Computer Systems, less variety) and other sockets around the board. There is also a 22 -lead edge 3311 Richmond Suite 200, Houston, TX connector on the top for interfacing. 77006 (Tel: 713-527-0348) offers a Each board is equipped with a +5-, and Morse code to S-100 bus interface ELECT RON ±12 -volt regulators as well as pads for board. The input connects to the com- obtaining unregulated voltages. Price is munications receiver through the head- $75 per board. Another firm making S-100 prototy-

ping boards is Sargents Dist. Co., 4209 St.405121 Knoxville, Lakewood, CA 90713. This Over 2,000,000 In Stock board has space for four regulators and IMMEDIATE DELIVERY can accommodate 14-, 16-, 18-, 24-, and 40 -pin wire -wrap sockets. Maximum INDUSTRIAL density is 48 sockets. Price is $25. the COMMERCIAL For all you SS50 (SWTP) fans, 9 '1 .1J HOME Personal Computing Co., 3321 Towar- Dallas, TX 75234 (Tel: ENTERTAINMENT wood, 214-620-2776) is now making available Sargents' prototype S-100 RECEIVING two sizes of prototype boards for the uses sockets for Wire Wrap. TRANSMITTING SS50 bus-I/O or memory sizes. The cards can be used with Wire -Wrap or phone jack and to the computer through OBSOLETE & wiring pencil, and Molex -type edge con- a parallel port. Provisions for audio and Hard -To -Get nectors are used. Memory -size boards visual sync are available. The software Numbers are $19.95 and the I/O size is $9.95 adjusts for variations in the transmis- (both postpaid). This company also has sions between 5 and 60 wpm. Final out- an ACI-33 Cassette Interface for the put is to an SIO port for display on a Call or Write TODAY for kit, SS50 system, or for use with any RS232 printer or CRT. Price is $95 for the As- Your Own Stock List output port that also supplies +5 and object program, and documentation. 12 volts. Price is $59.95 assembled. sembled and tested price is $145. BROADWAY ELECTRONICS Xitex, Box 20887, Dallas, TX 75220 548 Broadway,New York, N.Y. (Tel: 214-350-5291) has released its Software Doings. It looks like a lot of that people are jumping on the SWTP SS50 Phone: -(212); 925-6004 Model SCT-100 Video Terminal plugs into the S-100 bus. The display bus these days. Technical Systems IN Telex: 12-7016 features 64 characters by 16 lines, 128 Consultants, Box 2574, W. Lafayette, 47906 (Tel: 317-742-7509) is now mak- CIRCLE NO. 6 ON FREE INFORMATION CARD ing available its TSC Multi -User System, Only $5.95 each, 3 for $15.50 in any combination enabling four terminals to simultaneous- pÚELU%E of titles, including all postage and handling charges. U.S.A. add $1 per case. , Outside ly use one SWTP 6800 -based machine, AMERICAN M`4ZSSG CHARGE YOUR ORDER TO YOUR The EXPRESS, VISA, MASTER CHARGE all running separate programs. CA OR DINERS CLUB ACCOUNT. In board plugs into a memory slot and no Popular Electlnnics, P.O. Box 278, required. Pratt Station, Brooklyn, N.Y. 11205 machine modifications are Please send the Magazine Cases indicated below: When installed, simply load up the BA- l°` PE -65 TITLE QUANTITY SIC cassette and go! Suggested retail £``dPOPULAR a price is $129.95; including the pc board, CHECK: All Black [.f Maroon Back, Black Sides s_.f ELECTRONICS IC diagnostics, and I] ENCLOSED IS $ PE -28 all parts, sockets, CHARGE: VISA Master Charge documentation. The BASIC is on cas- . -- Express Diners Club American The ideal way to save your valuable copies, keep Exp Date There are two versions of 8k BA- them well protected and make it easy for you to Account : sette. refer to any issue at any time. Both decorative and Master Charge Interbank version name) SIC for the TSC system. One attractive enough to enhance the decor of any room, (4 numbers over your Constructed of each case holds a full year's copies. Signature supports AC -30 Cassette Interfaces- reinforced fiberboard, these durable cases are The Print Name the second covered in a rich -textured leatherette. gold one for each user-while Address embossed back adds to its elegance and makes State Zip supports the Southwest Techni- each case a welcome addition to your bookshelf City version FL, IL, MI, M0, NY STATE, or cabinet. Residents of CA, CO, O DC and TX add applicable sales tax. cal Mini -Floppy. Cases are available for your favorite magazines. POPULAR ELECTRONICS 94

AmericanRadioHistory.ComWM each line during assembly. The program, with source and documentation, is available for $45 on KIM cassette or on paper tape, and as a hard -copy object listing for $35. Write: Mi- cro Software Specialists, Inc., 303 Place, Suite 40, 3301 E. Pioneer Pkwy., Arlington, TX 76010.

Enhancement for PT Software Pack- age #1. Software Package 0.5 adds several features to Processor Technology Software

Package #1 (itself available from Processor Technology or Tarbell). New features added include automatic inspection of line numbers, Software line -number re -ordering, multiple -section as- Why Sol sembly from program source code files on tape, octal as well as hex assembly, extensi- Should be Sources - ble command table, new pseudo -operands (including ASCII text entry), global symbol ta- ble, and Tarbell/Dajen tape driver. The pack- your Small 8080 FORTRAN. FORTRAN -80 is a com- age may also be loaded in 6k PROM. Basic piler for 8080 and Z-80 systems. Includes hardware requirements are 8080 or Z-80, with Computer most features of ANSI standard FORTRAN 12k memory. Source code and explanation X3.9-1966, except for double precision and are $14.95; with object code on paper tape, complex data types. Versions now available $19.95; with object code on Tarbell cassette, Choice. for MITS DOS, CP/M and ISIS II floppy -disk $24.95. Write: Objective Design, Inc., Box operating systems. The system also includes 20325, Tallahassee, FL 32304. Sol -20 Terminal Computers are some non -ANSI features, such as logical vari- complete. You don't spend an ables, logical DO loops, extra penny for necessary interfaces. mixed -mode arith- BASIC Games. Enigmas -1, a book of metic, hex constants, logic operations on inte- computer games from the B. Erickson cata- Sol computer systems start at 51350 ger data, and read/write end -of -file or error log, is available for $8. Games included are in kit form. conditions. FORTRAN -80 can compile sever- "Gone Fishing," "Concentration" (for two We've done the software job. Only al hundred statements per minute in one pass, players), "Craps," "Slot -Machine," "Star - Processor Technology offers a fully and usually needs less than 16k memory. A ship," "Sherlock Holmes" and "Tank Attack." implemented disk operating system for relocating assembler and loader are included. The programs have been written to run under small Manuals computers: PTDOS. Our high available for $15 ($20 with relocating Altair 4k or 8k and most other BASIC compi- loader); the level languages include Extended program itself, with documenta- lers and interpreters. They range in length tion, is $500. Write: BASIC, FORTRAN* FOCAL, PILOT* Microsoft, 300 San Mateo, from 93 lines and 1397 characters to 241 N.E., and Assembler. Suite 819, Albuquerque, NM 87108. lines, 3315 characters. The games are also You available as separate listings ($3-$4). Write: can expand the Sol to handle business. engineering and research 6800 BASIC B. Erickson, Box 11099, Chicago, IL 60611. Trainer. Your computer can problems. Today's Sol can handle 65,536 teach you BASIC with "Learn BASIC" soft- bytes of memory and operate with ware. There are three packages of 4 lessons a three megabyte on-line disk memory. each, with lesson plans to coach and prompt SC/MP Assembler. A line -by-line assem- you through BASIC commands and program- bler for the SC/MP is available as a 4k firm- S-100 bus compatibility means you can ming techniques. Part I, on fundamental com- ware package. The SUPAK kit includes as- use a big group of standard peripherals. mands, requires SWTP BASIC Version 1.02, sembler, paper -tape line editor, and tape - Sol systems are conservatively rated. a copy of which is provided, to run in 12k; punch programs. $300. Write: National Semi- They won't quit on you. With over 5,000 Parts II and III run in Version 2.0, available at conductor, 2900 Semiconductor Dr., Santa in the field, we know the track record Clara CA 95051 (Att: Hashmukh Patel). extra cost. The last 3 of the 12 lessons also for reliable performance is outstanding. cover the MIKBUG operating system. Learn We back Sol with the best docu- BASIC is available on AC -30 cassette for 8080 -to -Z-80 Program Converter. mentation in the industry plus a factory $14.95 per part and on Smoke -Signal disc for Standard Intel 8080 assembly -language support team to give you caring $17.95; all three lessons together, on cas- statements can be converted. to equivalent sette or disc are $39.95. SWTP BASIC 2.0 counsel by phone or letter. What's more, Z-80 statements with a new FORTRAN pro- can be purchased at the same time for $9.95 on site maintenance and service folks gram designed tó run on any FORTRAN - on cassette. Write: Computerware Software are located in over 50 cities throughout speaking computer, regardless of word Systems, 830 First St., Encinitas, CA 92024. the U.S. and Canada. length. All required mnemonics and reserved So when names are provided for, and all required syn- you are shopping for a small 6502 Assembler/Editor. This assem- tax conversions are performed. Other fea- computer, see your Sol dealer last. bler/text editor for the 6502 processor and tures include detection and flagging of certain Then you can take your Sol with you! others in the family resides in less than 21/2k 8080 input -statement errors, control of Z-80 For more information, please address of memory. Assembler is a one -pass type output field formatting and output listing con- Processor Technology Corporation. with file, source symbol table and object code trols. Program is $300 when purchased sepa- Box I , 7100 Johnson Industrial Drive, resident in memory for greater speed (but rately ($50 with kticrotéc's Z-80 cross assem- Pleasanton, CA 94566. (415) 829-2600. with resulting limitations on source file size). bler) including source program on cards, mag- *available soon Other features include an error message that netic tape or paper tape and user's manual. flags out -of -range branches and a routine Write: Microtec, Box 69337, Sunnyvale, CA that prints the object code and source data on 94088. ProcessorTechnology CIRCLE NO. 39 ON FREE INFORMATION CARO FEBRUARY 1978 95

AmericanRadioHistory.Com Why you should buy a dígítal mulrimeter from the leader in dígítal multímeters.

If you're shopping for your first multi - times better than most analog meters_ meter, or moving up to digital from Also, the 8020A's digital performance What price to pay. analog, there are a few things you means things like 26 ranges and seven should know. functions. And the tougher your home First, look at more than price. You'll projects get, the more you need the find, for instance, that the new Fluke 8020A's full -range versatility and ac- 8020A DMM offers features' you won't curacy. The 8020A has it; analog meters find on other DMMs at any price. And don't. it's only $169.* Second, quality pays. Fluke is recog- If you're a pro. nized as the leading maker of multi - You already know Fluke. And you meters (among other things) with a probably own a benchtop-model multi - 30 -year heritage of quality, excellence meter. and value that pays off for you in the Now consider the 8020A: smaller in 8020A. size, but just as big in capability. Like Third, don't under -buy. You may think 2000 -count resolution and high -low that a precision 31/2 -digit digital multi - power ohms. Autozero and autopolarity. meter is too much instrument for you And the 8020A has 3 -way protection right now. But considering our rapidly against overvoltage, overcurrent and changing technology, you're going to transients to 6000V! need digital yesterday. If you're just beginning, Nanosíemens? $1.69.* go dígítal. Conductance To Resistance Conversion _. Of course, you can pay more. Or less. to . S= In fact, you could pay almost as much for equally compact but more simplistic C meters, and get far less versatility. And, 100 the 8020A gives you the `plus' of custom á CMOS LSI chip design, and a minimum number of parts (47 in all). All parts 1,000 fC . and service available at more than 100 Fluke service centers, worldwide. Guar- anteed, for a full year. 10,000 0.1 1 10 100 Rugged. Reliable. Inexpensive to own and to 9V Conductance (nS) nanosiemens ' operate; a simple battery assures continuous use for up to 200 Beginner or pro, you'll find the meter hours. you now have can't measure nanosie- mens. So what? With the 8020A con- Where to buy. ductance function, you can measure Call (800) 426-0361 toll free. Give the equivalent of 10,000 megohms in us your chargecard number and we'll nanosiemens. Like capacitor, circuit ship one to you the same day. Or, we'll board and insulation leakage. And, you tell you the location of the closest can check transistor gain with a simple, Fluke office or distributor for a per- ._ ' homemade adapter. Only with the 8020A, sonal hands-on feel for the best DMM Why not analog? Because the 8020A a 13 -oz. heavyweight that goes where value going. has 0.25% dc accuracy, and that's ten you go, with confidence. *U.S. price only Fluke 8020A DMM for Home Electronics Experts: $169 FLUKE

CIRCLE NO. 58 ON FREE INFORMATION CARO

96 POPULAR ELECTRONICS

AmericanRadioHistory.Com receiver can hear the world. They offer full coverage of 80 through 15 Meters, as well as the 28.0 -to -28.5- and 28.5 - to -29.0 -MHz segments of 10 Meters. Amateur Ac power supplies are built-in, and ex- ternal battery operation is also possible. A matching station speaker, Model HS -1661, is available for $19.95 in kit Radio form. With these radios, all you need are an antenna and a telegraph key to be ready to send and receive Morse code over the airwaves. THE IDEAL NOVICE HAM SHACK Key vs. Keyer. Both the Heath Com- WHETHER you've earned your Nov- one package-the Century/21 trans- pany (Benton Harbor, MI 49022) and ice license though independent ceiver. For $289, you get 70 watts of Ten-Tec offer electronic keyers priced at study or an organized training class, you transmitter input power -enough to pro- $49.95 and $29.00, respectively, as ac- might not know how to get on the air ject signals to the far reaches of the cessories for their Novice transmitting once your ticket arrives. After some on - globe-and a sensitive direct -conver- gear. To use these keyers, you push the -air experience, it's easy to look back sion receiver. The Century/21 offers op- their built-in paddles from side to side. and see what should have been done in eration on all frequencies in the 80-, This causes the electronic circuitry in- setting up a radio station. But with a little 40-, and 20 -Meter bands. Optional plug- side to generate Morse dots and dashes planning beforeheand, you can avoid in crystals give full coverage of 15 Me- of proper durations. Alternatively, you many commonly made mistakes. Here ters and the 28.0 -to -28.5- and 28.5 - can produce Morse code with a are some important factors the newly li- to -29.0 -MHz segments of 10 Meters. "straight" or manual key as telegraphers censed amateur must consider. Among the transceiver's features (de- have done for a century. scribed fully on page 85) are full If you first learned to send code with a Choosing Equipment. There are break-in keying, broadbanded transmit- straight key, you should stay with one several routes available to you when it's ter circuitry with VSWR and overload during your first on -the -air sessions. Lat- time to acquire your first rig. You can protection, receiver offset tuning, built-in er, when your code speed has in- either buy new, factory -made equip- speaker and adjustable sidetone, linear creased, you can switch to a mechanical ment, buy and assemble kits, build a crystal -mixed, permeability tuned vfo, "bug" or an electronic keyer. (Mechani- home-brew station, or purchase used and switchable (50C. 1000, or 2500 Hz) cal bugs create dots, but you must make amateur or military surplus gear. Your selectivity. Separate controls are provid- the dashes.) But you should be able to choice should be influenced by, among ed for r -f and a -f gain. The use of a Class copy perfectly and send with a straight other things, your technical knowledge, AB, push-pull final amplifier aids in the key at a rate of at least 10 wpm before mechanical ability, and budget. suppression of TVI-causing harmonics, you make the change. During the rush of excitement when as does the insertion of individual low- you first get on the air, what you need pass filters in the antenna line by the Skywires. With a rig on your shack's most is reliable equipment to ensure BAND switch. The optional, plug-in Mod- operating table and a key at hand, you'll many hours of pleasant operating. If you el 276 Century Calibrator, priced at $29, definitely need an antenna. Amateurs are not an experienced kit builder, you provides marker signals at either 100 - use many different antenna designs. A might have problems assembling, trou- or 25-kHz intervals across the dial. complete discussion of antennas would bleshooting, and aligning complex ama- The transceiver's circuitry is totally easily fill a book-and then some. So we teur equipment. Used equipment- solid-state, using transistors, diodes, can only mention the most common unless it has been reconditioned-might and integrated circuits. It has no old- types in passing. For details, refer to the need tinkering that requires test equip- fashioned tubes that eat up input power Radio Amateur's Handbook, the ARRL ment and technical knowledge. Of and produce a lot of waste heat. Al- Antenna Book, or one of the many other course, factory -fresh gear can simply be though the Century/21 can be used to publications on this topic. connected to an antenna and a power send CW signals only, it receives CW Most Novices start with the easy -to - source and then used on the air. But and SSB transmission. Thus, you can build dipole. It's a wire antenna split in new amateur equipment might be listen to the phone bands as an incen- the middle and cut to one-half wave- beyond your reach financially. In any tive to upgrade. length at the operating frequency. The event, you shouldn't make any equip- Many hams prefer separate transmit- dipole is fed at the center with coaxial ment decisions without assessing your ters and receivers over all -in -one trans- cable (either directly, or for symmetry, own resources, both financial and tech- ceivers because "separates" offer more through a balun transformer) or bal- nical. You shóuld also not make any operating flexibility. The new Heathkit anced transmission line. The dipole, un- moves without first seeking the advice of twins for Novices form a good begin- less it is used with an antenna tuner, can an experienced radio amateur. ner's station. The HR -1680 receiver and only be easily matched to modern trans- the HX-1675 transmitter, costing $199 mitters on the band for which it is cut. New Novice Gear. Ten-Tec, Inc. each, are exciting packages, look alike, There is one exception to this rule-a (Sevierville, TN 37862), a well-known and offer high levels of performance. fair match is obtained if the dipole is manufacturer of ham equipment, has in- The transmitter runs 75 watts input, and used on odd multiples of the band for troduced a complete Novice station in the double -conversion superheterodyne which ít ís cut. This means that a 40- FEBRUARY 1978 97

AmericanRadioHistory.Com Meter dipole will also offer a fair match (or live in an apartment whose landlord ground level, the use of radial wires and to coax on 15 Meters. If you want to op- frowns on such installations), consider ground rods improves radiation efficien- erate on the 80-, 40-, 15- and 10 -Meter the end -fed long wire. It's simply a piece cy. When mounting the antenna above Novide bands, you'll need three sepa- of wire as long as possible, fed at one ground, radials are a must. rate dipoles. For economy's sake, you end and worked against ground. A long The most .efficient multi -band antenna can use one feedline. There will be wire an odd (1,3,5 . . .) multiple of one - devised to date is the Zepp. It is similar some interaction between the dipoles, quarter wavelength can be' connected to dipole in that it is center fed. However, and some trimming might be required. directly to the "hot" side of the transmit- it is made as long as possible. and does A dipole can be installed so that the ter output jack. A good earth ground is not have to be cut for any specific wave- antenna wire and feedline form a "T" by essential to long-wire efficiency. Use a length. Balanced transmission line such stringing the wire between two trees, heavy copper wire, and run it from the as TV twinlead or open wire line is used poles, etc. Alterhatively, you can mount transmitter chasis to the grounding point to feed the Zepp. Flat -top or inverted the antenna with one high support at the as directly as possible. Like any other vee configurations are suitable. center so that an "inverted vee' is antenna, the long wire should be as high In some buildings, "cliff dwellers" are formed. The inverted vee has two ad- and as in the clear as possible. prohibited from putting up any external vantages over the flat -top dipole. Be- Another antenna popular with Novices antennas. That doesn't mean that they cause of its shape, the inverted vee re- is the vertical. It consists of a quarter - can't get on the air. I operate every day quires less real estate for mounting pur- wavelength radiator working against with 50 feet (15.2 m) of what was for- poses. A full-size 80 -Meter Novice di- earth ground or an artificial ground merly loudspeaker wire run around my pole is about 126 feet (38.4 m) long- plane. The vertical is omnidirectional, apartment. Because the antenna length not including the length of end support has a low angle of radiation, and pro- is not tuned for resonance on any ama- ropes. In contrast, .an 80 -Meter Novice vides a fair to good match for direct coax teur band, an antenna matchbox is inverted vee whose center is 40 feet feed. Multiband verticals made of alumi- used. Alternately called an antenna tun- (12.2 m) high and whose ends are near num tubing are very common. They usu- er, matchbox, or transmatch, it is a cir- ground level requires a horizontal run of ally use trap circuits to electrically di- cuit that allows the transmitter to see the only 100 feet. Also, the vee generally vbrce or connect lengths of tubing so 50-ohm unbalanced (coaxial) output that has a lower angle of radiation than the that an electrical quarter wavelength ex- it is happiest working into. dipole at a given mounting height, mak- ists on each band. A good ground is A transmatch is a very handy device ing it more effective in DX work. necessary if the vertical is to work effi- to have, because it performs several If you can't physically put up a dipole ciently. If the antenna is mounted at useful functions simultaneously. As just mentioned, it allows the transmitter to see a proper load impedance. ------fifes--w-----I Some transmatch designs can sub- - stantially attenuate harmonic radiation. 1 The leading niTE I A transmatch also prevents strong, out - 1 magazine of -band signals such as those radiated in the personal ?? , 1 inaLl= E by local AM broadcast stations from reaching the receiver and causing 1 computer field cross -modulation problems. If you are

1 BYTE is the magazine for the creative home computer using a Zepp antenna or. an indoor or experimenter. BYTE tells you everything you want to outdoor random -length long wire, a tran- 1 know about personal computers, including how to con- smatch is a must. struct and program your own system. 1 Many transmatch designs have been Home computers are now practical and affordable. Low published in amateur radio magazines 1 cost peripherals,have resulted in more hardware and soft- ware, more applications than you could imagine. BYTE for home -brewers. Commercial units are 1 brings it all to you. Every issue filled with stimulating, timely also available. MFJ Enterprises (Box articles by professionals, computer scientists and serious 494, Mississippi State, MS 39762) offers 1 amateurs. two antenna tuners of interest to the 1 All in the coupon today. Read your first copy of BYTE; if it's Novice. The Model MFJ-16010, priced everything you expected, honor our invoice. If it isn't, just 0111~ . 111111111Pw. at $39.95, allows the user to load á ran- 1 write "CANCEL" across the invoice and mail back. You won't rs MEP" be billed, and the copy is yours. a dom -length, end -fed wire on 160 1 Allow 6 to 8 weeks for processing. l through 10 Meters at up to 200 watts r -f 1 © Byte Publications, Inc. 1977 power output. The Model MFJ-16010ST 1 BYTE Subscription Dept. 7328 P.O. Box 590 Martinsville. NJ 08836 1 is a very flexible antenna tuner that cov- PLEASE ENTER MY SUBSCRIPTION FOR: The Small Systems Journal 1 ers 160 through 10 Meters, and can be One year $15 (12 issues) Two years $27 E Three years $39 1 1 Check enclosed (entitles you to 13 issues for price of 12) used with coax, end -fed wire, or bal- Bill Visa/BankAmericard ' Master me Bill Charge Bill 1 anced feeders. It can handle 200 watts

I I I I I I I I 1 1 1 1 1 Card Number I 1 Expiration Date 1 of r -f output power and costs $69.95. Signature Name (please print) 1 1 Address To use your antenna tuner effectively City . State/Country Code 1 or to trim a dipole or end -fed wire for res- 1 FOREIGN RATES (Please remit in U.S. Funds) onance, you should have an SWR meter Canada or Mexico $17.50 - One year E Two years $32 E Three years $46.50 1 1 Europe $25 - One year (Air delivered) or directional wattmeter. Either one will 1 All other countries except above $25 - One year (Surface delivery) 1 give you an indication of how well the Air delivery available on request antenna is matched to the feedline or if

CIRCLE NO. 59 ON FREE INFORMATION CARD 98 POPULAR ELECTRONICS

AmericanRadioHistory.Com the transmatch is properly adjusted. A directional wattmeter will also tell you how much r -f power your transmitter is producing. SWR meters can only give Mt Intrish CATALOG you a relative indication of r -f output and are less accurate than directional watt- and FM DIRECTORY meters, but are much less expensive. Get all the newest and latest information on the new McIntosh Sol- id State equipment in the McIntosh catalog. In addition you will receive an FM station directory that covers all of North America. Accessories. There are several items you should have to complete your shack. A 24 -hour clock is a must. Hams use what is now called Coordinated Uni- ..141, II WI f: II 1E fl flF ü tlI 15 -III versal Time (UTC), the time broadcast _ - a- ü 73.. 14° rl omiA by National Bureau of Standards sta- . .,,.. .,. tions WWV and WWVH. However, many . old timers refer to its predecessor, Greenwich Mean Time (GMT or Z). Uni- versal time is on a 24 -hour basis, so the day runs from 0000 to 2359. MX 113 You should keep your station log in FM/FM STEREO - AM TUNER AND PREAMPLIFIER Universal time. Although the Federal Er.s : I Communications Commission (FCC) no McIntosh Laboratory, Inc. longer has strict logging requirements, I East Side Station P.O. Box 96 Binghamton, N.Y. 13904 you'll want to follow the best amateur Dept. PE tradition. Purchase an ARRL logbook

(American Radio Relay League, 225 I NAME Main St., Newington, CT 061 11) for 50 e ADDRESS to keep track of your radio contacts. CITY STATE ZIP While you're at it, get a map of the U. S. showing the call areas and a map of the If you are in a hurry for your catalog please send the coupon to McIntosh. world showing ham call -letter prefixes. For non riish service send the Reader Service Card to the magazine. INFORMATION CARD It's also wise to have a telephone CIRCLE NO. 29 ON FREE nearby. If you have a radio, why do you need a telephone? Well, the landline, as hams call it, will bring quick help from a "Our whole family fellow operator if you're having problems when you first go on the air. Sometimes helped assemble difficulties crop up and sound advice based on experience is required. Also, this wonderful traffic handling (carrying messages for nonhams) is a big part of amateur radio. Schober Organ... When you get a message for someone in your town who is not a ham, the tele- phone in your shack will allow you to de- now we all play it!' liver the radiogram immediately. r To complete your shack, start to as- Talk about real family fun! We all to buy Schober Kits a component at a time, semble a small ham radio library. There worked together, for a few hours almost to spread costs out. Or we could have had Almost too soon, Schober two-year time payments! will be many occasions when a quick every day. our Organ was finished. Our keen -eyed daugh- Families like ours have been building reference is needed. You'll already have ter sorted resistors. Mom soldered transis- Schober Organs for 20 years. How about the ARRL Manual for studying for ham tor sockets, although she'd never soldered your family? You can have all the details, And it hearts good without cost or obligation. Just send the tickets. Add to that the ARRL Radio anything before. did our to see the care with which our son -he's coupon for the fascinating Schober color

Amateur's Handbook, the current edition only 12 -installed the transistors. Me? I was catalog (or enclose $1 for a 12 -inch LP of the Callbook, and any listings you can the quality control inspector-they let me record that lets you hear as well as see do the final wiring. And when it came time Schober quality). Clip the coupon right find of Q signals, radiogram message to finish the beautiful walnut cabinet the now-and mail it TODAY! codes, and other ham lingo. easy Schober way, we all worked at it! If you build your first ham shack Now, we gather around our Schober Organ every evening to play and sing to- The Organ Corp., Dept. PE -76 around these items, you won't have to than the .WAQpf/ gether. Some of us play better 43 West 61st Street, New York, N.Y. 10023 add to it for a long time. You'll be on the others, but we're all learning -with the help O Please send me Schober Organ Catalog. of the easy Schober Organ playing courses. air with ease and style. When you pass O Enclosed please find $1.00 for 12-inch L.P. I might add that I'm especially pleased with record of Schober Organ music your Technican exam, you can add a all the money we saved. Our completed transceiver for 2 Meters. And when you Schober Organ compares favorably with a "ready-made" one costing twice as much! NAME get the General ticket, all you'll need is a (The five models range from $650 to $2860.) ADDRESS microphone and an SSB transmitter for And we didn't even need to pay the whole CITY STATE ZIP voice operation on the low bands. O amount all at once, because we weré able

NO. 45 FREE INFORMATION CARD FEBRUARY 1978 CIRCLE ON 99

AmericanRadioHistory.Com Your Home for Quality Kits, Projects and Components Toll -Free -Wats Line -80C-631-7485. Open Saturdays In New Jersey Call (201) 964-5206

WESTINGHOUSE TUBE Multi -Range Digital i -° Voltmeter Kit $29.95 SPECIAL Oto+.2 Volts DC-Oto+2 Volts DC BOXED AND BRANDED Latest 6GH8A $1.60 technology DVM chip set High Noise Rejection 6LQ6/6JE6C 4.00 Non Critical Comp. Send for Free Hobbi House Catalog 6DW4B/6CL3 2.00 Accuracy to within .001 969 BALL AVE., UNION, N.J. 07083 3A3C 2.50 6HM5/6HA5 2.00 Contains - P.C. Boards; 4 -large .50 Fair- 6FQ7/6CG7 1.60 child Readouts; Display Drivers; Op - Amps; 6LB6 4.00 Inverter; all electronic comp. lowest prices 6GF7A 2.50 Switches, Pots; Complete instructions 6BK4C/6EL4A 4.00 and specs. o ...._-s MA1003 8FQ7/8CG7 Also includes Set/Precision Resistors for MOBILE 2.00 CLOCK 6JS6C 4.00 increasing Voltage to 200 Volts. MODULE (National) 12GN7A/12HG7 Requirements: Power Supply w/+5V, S1 3.00 ,j 895 complete 6GJ7/ECF801 2.00 +15V and -15V. Attaches directly to 9-12V Battery. Automatic 17JZ8 2.00 Multi -Meter Kit, $49.95 Nighttime Dimming. Fluorescent Display 5GH8A 2.50 complete with Power Supply gives Color Choice (Red, Blue, Green or Yellow) when used w/corresponding Color High Power Transistors 2/$1.00 2N 3055 NPN (ITT TO 3 Filter. Includes - Module, Switches, & Filter. Case) AC/DC Wall Plug ALUMINUM CASE DTS 410 NPN (GE TO 3 Case) equiv. to Adaptor -Charger WITH FILTER. ECG 162 $1.00 (switches included with clock kit). In Silver. 120 volt input/6VDC 130 MA output. Bronze, Black and Gold. Filter colors - red. Sound Actuated Switch $.85 1000 MFD 30 Volt Electrolytic blue, green, or yellow. $5.75 Capacitor Axial 6 Ft. Line Cords 6 for $1.00 Leads 5 for $1.00 Big Bright - 5" LED Alarm Clock 6 Digit AC or DC or Elapsed Timer Kit NEW KIT SPECIALS $19.95 Complete Electronic Dice $15. ea. Code Practice Oscillator $10. PC Board Drilled and silk screened (includes Xtal LED's arranged as dice. Each press of Practice Morse code with this battery Time Base Circuitry) ... 5375 Nat. Clock Chip and the toss switch generates a rancom operated (not included) compact port- Fairchild Displays ... includes EVERY part re- roll of the dice. Operates on 9 volt able code generator. Emits a loud quired for clock and all options except Cabinet and battery (not included). Case and as- pleasant tone. Case and assembly in- Crystal Time Base components if desired. sembly instructions included. structions included. Brightness Control 24 Alarm with snooze Freeze feat on every mode 12 Hr 60 Hz Electronic Coin Toss / Transistor & Semi -Conductor Decision oper. Field Tested over 1 yr. 0.60 Min Maker $5.95 Tester $18.99 Elapsed Timer Generates a statistically random "coin Use to check a wide range of bi-polar Complete Instructions - Schematics, picto- toss" for those difficult decisions re- transistors either in or out of circuit. rials, layouts quiring an unbiased guess. Great fun Designed for dynamic testing for both Options - XTAL Time Base Components, testing your ESP too. Battery oper- NPN and PNP types. Attractive case ated (not $2.95 when purchased with clock. Wood included). Case and assem- and assembly instructions included. bly Clock Cabinet, $4 with clock purchase. instructions included. Transistor Curve Tracer $41.95 T.V. Scrambler $12.99 Adapts to your scope to form a Complete Clock Kit $9.95 transis- Use to remotely blank out T.V. set tor tester that generates a family of 4 DIGIT 12/24 HOUR during commercials or while answer- characteristic curves to give you Includes: PC Board, 5316 Clock Chip, all ing phone. Can also be used as a high semi -conductor information not and Power components Supply. frequency oscillator. Battery operated otherwise obtainable (beta, leakage Displays hours and minutes ... Switch to (not included). Case and assembly in- current, forward resistance, etc.). Will minutes and seconds . .. AM -PM Indicator structions included. test both signal and power devices. ... Elapsed Timer ... Fluorescent Display Case and assembly instructions. F -M Transmitter Options: If alarm function desired add $2.50 $13.99 Portable battery operated F -M (includes speaker and all components) trans- TTL Power Supply $11.95 mitter enables you to broadcast cver 5 volt, 600ma., regulated power sup- Plexiglas Case Kit (red or blue) $2.00 your F -M radio. Use as a portable ply. Use to power all your TTL pro- microphone or in-house paging sys- jects. Case and assembly instructions Regulated Power Supply Kit, tem. included. $14.95 complete Audio Amplifier 2 Amp @ ± 15 and -15 volts Current Limiting $12. Signal Injector $10. 2-4 watt power amp. Use & Thermal Shutdown Protection. as a portable Useful for checking and trouble- P.A. system or Includes: Transformer remote listening de- shooting amplifiers, radios, stereos, ... Bridge Rectifier ... Fil- vice. Easy to assemble, ter Caps ... 4 -way Binding Posts battery oper- etc. Generates a 1-kHZ tone with ... Heat Sink & ated (not and Line Cord Voltage included) great tun. harmonics to 250 MHZ. Battery oper- ... Regulators ... Pass Tran- Case and sistor assembly instructions in- ated. Case and assembly instructions ... Resistors ... Diodes ... etc ... Com- cluded. plete Instructions and Circuit Diagrams. included. Motor Speed Control/ Terms and 12 VDC regulated CB Light Conditions Power Supply, Dimmer $8.99 Orders Shipped Within 24 Hours Use car CB or Stereo at home. $18.95 Adjust motor speed to suit applica-ion $5.00 Minimum Order, Complete! Not a kit! Converts 120 VAC to or use as a light dimmer control. A.C. Telephone C.O.D.'s accepted. regulated 12VDC. operated. Case and assembly instruc- 515.00 Minimum Bank Americard/ tions included. Transformer, 6.3 volts at 1.2 amps, $1.49 MasterCharge order. Add $1.00 Postage for orders under Diffused LEDs, Jumbo Red LEDs 0.2", and Neon Random Blinker $7.95 $10.00. Factory Prime, 7/$1.00, 100/$11.00 Randomly flashes six neon lamps. Outside Continental U.S. add'postage - A -C operated. Case and in- U.S. Funds. DL assembly 741 Jumbo 7 Segment Displays Com- structions included. N.J. Residents add 5% Sales Tax. ,'-- mon Annode $1.35 Money Back Guarantee.

4 e

CIRCLE NO. 21 ON FREE INFORMATION CARD POPULAR ELECTRONICS

AmericanRadioHistory.Com CARBON FILM RESISTORS 15%I HIGH QUALITY CARBON FILM NEW from FLUKE MODEL 8020A Only 0.n Mu/tiples 0/ THE FOR THE PROFESSIONAL -0(. 100 pro pee calve /Ohms/ RESISTOR KIT DMM * ; '4W .. 01.69 per 100 200 -Hr. Battery Life EZ 'hW 01.79 per 100 26 Ranges for 7 Functions .. EZ Hooks have been designed and held tested through the industry to save 2000 Count Resolution lime and money ,n Commercial electronic production and serwc,ng The 10 100 1.0K 10K 100K ON High Low Power Ohms 11 110 11K 11K 110K 1M sor ng.loeded hook attaches firmly. yet to gently ,t w.II not damage comport Aotoeero and Auto . .. trees hands y41,le nsulated a 12 120 ' 2K 12K 1200 2M ent testing Durably Constructed and fully to Polarity ea,lra 13 130 ' 3K 13K 130K 3M single con act pool assvnng the readings Meets eaacling laboratory and MOV protected to 60001/ space age compare, technology requirements AVAILABLE IN 10 RETMA 15 150 1 50 1514 150K Sri' 161( against hidden transients ` Red, black, tope. green. white, violet, brown 16 160 16K 160K 6M COLORS °ragon, yellow. 1!i 1B 180 1 BK 18K lOOk BM and overload protection or gray 20 200 2 OK 20K 200K 2 OM to 300V AC 22 220 :2K 22K 270K 2 2M Diode Test Function 24 740 7 4K 24K 240K 2.4M Conductance Function yJ M l1 27 270 2 71( 7711 270K 2 7M checks leakage resistance a1 MICRO HOOK 30 300 3.0K 30K 300K Jumper XM 30M to 10,000 meg ohms with 33 330 3 3K 33K 330K 3 3M ON Moro Rook 11 75 long HWL.17.1X3.4X1.81N.I Micro 36 3 6K 36K 3 Size ' 111111 Cl gram! IC Testing Hooks 360 3600 6. - toallots 39 390 39K 39K 3906 39M 118.0X8.6X4.5cm) permits hookups to wire Order No. Length Price 43 430 4 3K 43K 430K 4 3M Weigh, 13 oz. ONLY 8169.00 where eight an re.ecage may 206X81 12' 12" 51.80 47 470 4 7K 47K 470K 4 7M COMPLETE wino STORAGE BIN damage component 5.95 ea 204%M 24 2a" 51.80 51 510 51K 51K 510K 51M CAPACITORS SpeCdy colas ORDER P/N XM Specify color 56 560 5 61k 56K 560K 5 6M Each KIT Contains 20 Each of 42 Different 62 620 6 71( 62K 620K 6 2M FILM RESISTORS 50 VOLT CERAMIC DISC CAPACITORS 68 680 E.BK 60K 660K 6BM WATT 5% CARBON Per Package 75 750 7 56 75K 750K 7 5M $1.00 from 68 ohm XM-S MICRO HOOK SET r nslaaa, I ea red 82 820 6 214 82K 820K 8 2M 501 9/p1g 22001 B/pkg .001old 9/1kg .015old B/pkg black, blue. green to 4.7 megn6m $2490 orange. yenow, wn.le brown ...ores na gray Micro Hooka At this row 91 910 51K 916 910K 10 OM 1501 9/pkg 27001 7/pkg .001 5m18 9/0kg .02m1d 81010 Once you can al,p,n more man one ,e, 2501 9/pkg 300pf 7/pkg .0022m1d 9/Pkg .022,014 8/pkg COMPLETE SET (101 MICRO HOOKS 58.45 203819 3/1.70 265179 2/1.00 265826 4/1.20 2701 9/pkg 33001 7/pkg ,003m91 9/pkg .03010 8/13kg 2N TRANSISTORS 263823 .70 255194 .80 265827 4/1.20 4701 8/040 390y1 7/pkg .0047m10 9,pkg .039mtd 7/019 MINI HOOK 2N508A .80 2N3391A 4/1.00 253859 5/1.10 265210 7/1.05 255828 311.@ 6801 8/pkg 470pí 7/014 .005mfd 9/pkg .0470111 7/pkg 2N3392 4/1.12 255219 5/1.00 2558284 3/1.20 25918 3/L20 253860 5/1.00 100pí B/pkg 56001 7/Pkg .010Id 9/pkg Todd 6/pkg 2N930 3/.84 253393 5/1.10 25390 5/1.00 265220 5/1.00 216000 2/1.m 15001 B/p4g 6801,1 7/pkg N Jumper with X -100W 251132 3/1.05 253414 5/1.00 253904 5/1.10 255225 6/1.08 256001 2/1.C4 X100W Mini Nook 12 25' tong) 2N1613 3/-96 253416 5/1.10 5/1.00 255227 5/1.20 256002 2/1.3 combines rugged construction minia Mini Hooks 25390 2N1711 3/1.02 253417 5/1.10 25390 5/1.10 255232 4/1.28 2,6014 2/1.32 PLESSEY POLYESTER MINI -BOX CAPACITORS me size and Fmow no A Price Order No. Length 252102 3/1.20 253440 1.00 2N3957 1.50 2N5232A 4/1.00 256015 2/1.75 $1.25 Per Package te tne best nections 20417W 12" 51.70 292210 4/1.04 253442 1.80 2N408 2/1.32 255294 2/1.40 256027 2/1.00 14F0 OTT MFO OTT O OTT MFD CITY 00 arpe enoughhfor 'to mponen 20a.2aw 24" 51.70 252219 4/1.04 253563 6/ .90 25412 5/1.30 2145296 3/1.40 2N6028 2/1.20 .001 8/pkg .0068 8/pkg .039 7/019 .27 5/pkg yet e.enough lo ge, Specify ,0101, 252219A 3/1.08 253565 5/.90 25412 5/1.00 255306 3/1.02 256034 .92 es.maii .0012 8/pkg .0082 8/pkg ,047 7/pkg .77 4/pkg 1,001 c 5.80 ea 4/ .96 1.00 2522220 253567 5/ .96 25412 5/1.20 255322 2/1.40 256035 .0015 8/019 .01 8/pkg .056 7/pkg .33 4/pkg Spec./, c 263568 4/1.20 255323 2/1.40 2116037 .92 ORDER P/N X100W 252475 .60 20422 3/1.20 .0018 8/pkg .012 8/pkg .068 7/pkg .39 3/pkg COlOr 202484 4/1.20 2N3569 6/1.08 20424 5/1.10 255366 2/1.00 286076 5/1.071

1 .0022 8/pkg .015 7/pkg .082 7/pkg .47 3/pkg 252605 2/1.00 2N3638A 5/1.10 25474 6/1.08 255367 2/1.00 256099 .00 Jumper X100W Mini Hook .1 Jumper with X100W Mini 292647 .95 2N3642 5/1.00 2N4250 5/1.20 205369 4/1.04 2816101 I.(ES 0077 8/pkg .018 7/pkg 7/pkg .56 3/pkg .0033 .022 7/pkg .11 .68 to StackingBanana Plug9 Hook Order No. Length 752713 6/ .90 253643 5/1.00 254258 4/1.28 255447 4/1.20 206103 1.10 8/010 6/Pkg 2/pkg 2N2904Á 3/1.08 253645 5/1.00 254400 4/1.30 255448 4/1.20 256121 2/1.32 0039 8/pkg .027 7/pkg .15 6/pkg .62 7/pkg Order No. Length Price 201x81 32 Price 252905 3/1.02 263646 10/1.40 25440 4/1.30 255449 4/1.00 2186122 2/1.36 0017 8/014 .033 7/710 .18 5/pkg 1.0 2/010 2o1W 37 51.45 252905A 3/1.08 263694 5/1.10 25441 .30 255457 2/1.20 2116123 .68 at 51.50 0056 8/pkg Sp2o l y color r"-y11 202906 5/1.00 203702 6/1.08 25489 1.10 255448 2/ .90 206124 .90 2N2906A 5/1.05 253704 6/1.08 25491 2/110 255484 2/1.20 2116125 2/1.36 JAPANESE REPLACEMENT TRANSISTORS 2N29074 4/1.12 253705 6/1.08 25492 3/1-40 2N5811 3/1.20 206126 .84 1. 258405 2/S1.15 25C933 81,00 2SC2034 52.94 rrrsal 252924 3/ .90 203706 4/1.00 20508 4/1]0 255817 3/1.20 20.6218 2/1.28 252925 5/1.10 203707 6/1.08 255088 4/120 255818 3/1.20 206219 2/1.20 2SC538 2/5 .96 2SC1226A S .84 25072 S .79 202926 6/ .90 2N3708 5/1.00 255089 3/110 255819 2/ .90 2N'6270 3/1.16 2SC828 2/5 .96 2SC1359 2/S1.28 250313 S1.04 EXTRA LONG MINI HOOK 253053 3/1.08 253710 5/1.00 25513 6/1.08 2N5822 2/1.16 2146222 4/1.20 25C829 2/5 .96 2SC1973 .89 250325 S .89 XL 1 M,n, Hook 150 long, comb.nes all the proven 1 0l the 15100W 2N3054 .90 253771 2.40 255134 5/IDO 2145824 4/1.00 21162 3 4/1.20 250979 2/5 .96 25C1974 $3.00 35K49 52.19 au is woemake 1 wishne. ireong node sale, short test connections in 263055 1.00 253772 250 255172 5/100 255825 4/1.04 2116224 4/1.28 2SC930 7/5 96 2SC1975 53.00 4.341 sack, and nnoagn deep amine nest ots to 4 eeORDER P/N XL -1 Spec,ly color S1.30 Intersii 31/2 DIGIT (--tNON-LINEAR JUMPER, XL -1 MINI HOOK TO STACKING BANANA PLUG SYSTEMS, INC. 0 e..uesa Order No. Length 201%L 32. PANEL METER CD Sneafv color Price 52.05 PORTABLE 15 MHz COSMAC MICROPROCESSOR Integrated Circuits LCD OSCILLOSCOPE 6 /011 Op COP1821C0 32 . 8 Mane CMOS matingr t.ng Range Ram 51 75 csP18o2C0 COSMAC CPU 519.95 COP1857C0 Br. I/O Port 8.25

COP182ICO 1024 s I Static CMOS COPI856C0 1B emeeory'etorlBulhr Ram 14.15 5 50 or [00182200 056. 4 Static CMOs COPI857CO Ryóltenaralar/B,dle, am 15.50 5.50 a - # ay LED .N1 ,v ' I KIM1 MICROCOMPUTOR 'r ..,. 1 * : KIM.1-Computer Module from MOS Teebnologv. 10 RAM. 213 ROM ton KITS The MS -15 miniscope is only 2.7 o 6.4 x 7.5", and mmng system executive, complete weighs only 3 lbs. Vertical bandwidth is 15 MHz. The aud.o cassett .medal,. 15 b,d,ne gratieuled rectangular viewing area is four divisions adiw bona. I/O lines... 24 key keyboard BUILD A WORKING DPM IN 1/2 HOUR WITH high by live divisions wide. Division spacing is 0.25 and a si1-0,g., LEO dlsplay. Internal triggering, automatic and THESE COMPLETE EVALUATION KITS inches, and external Documentation-KIM1 Users Manual line synchronization modes, and a horizontal input are 6500 8.1/o.re Manual. and 6500 Pro Test these new par% for yourself wan Inters,rs low Cost provided. There are 12 vertical gain settings from gram m,ng Manual. prototypin9 kits. complete Dan A/D converter and LCD display 0.01 V to 50 V per division, and twenty one time base per the '106) or LED display (for lye 7107) Kits provide all from /as An Fully Only settings 0.1 to 0.5µs per division. optional , Assembled materials. PC for a functioning panel meter including board, I 10 ao 1 probe and a carrying case are also available. Fully Tested 0245.00 ICL7106EV (LCD) 529.95 ICL7107 (LED) 524.95 Power is provided by batteries or the 115 V, 60 Hz line.

HYBRID na2nw MS -15 MINISCOPE $289.00 SOCKETFOR? nS.Y 595 AUDIO SANKEN 41-140 CARRYING CASE 30.00 '""'el1lB to A ',OA POWER AUDIO AMPLIFIERS A., w 595 4 +s. 1 1 \.:..11 41-141 10 TO 1 PROBE 24.50 S , AMPLIFIERS 00 Mull. -purpose linear emplrl,ers 10, eomercra and Indus- . C trial applicacations DIP SOCKETS Less man 0 5e.. harmonic dnlor,lon al lull power level,

1 Iron 20 to 100.000 He 2 dB response LOW Single or span (dual) power supply. PROFILE Rugged. eompacl and lightweight packages SOLDER TIN Send Checo or Money Order to P.O. Box 2208P, Culver City. Buda -n current limiting for SI -1050G and efficient heat radiating construction. Calif. 90230. Calif. residents add 6e sales tax. Minimum Order 51000. ADD S100 to Coder and handling Master 1 24 25 19 50 UP postage SANKEN Series SI. 1000G ,1,otS TYPICAL CONNECTIONS Charge and Bankamer,card welcomed (include your Card amu 8 Pin 16 15 14 SI -1050G SPLIT ass sell-conla.ned nownr nybd nn WITH SUPPLY 14 Pin .19 18 17 number and Pop. date/. for 11,-F, ublters designed stereo. LEFT 16 Pin 21 70 .19 TELEPHONE ORDERS: Call 12131 6414064 musical ,nsu,nn enis, public address 40 Pin 62 .61 60 siemens, and Olher audio app .cations VISIT ONE OF OUR STORES CANADA. B.C. The amplifiers nave 011as,-comple ANCRONA class 8 outn111 The eacanl STANDARD TODAY flid-Chip s SOLDER DO employs transistors with GOLD ANCRONA STORES high reliability and chin nass,yaled RIGHT NOT ACCEPT MAIL OR .sower transistors with a cellenl sec TELEPHONE ORDERS andary breakdown Strength Built -,n B Pin 30 .27 .24 cur ,s provided 'or SI - 14 Pin 35 32 29 CALIFORNIA CALIFORNIA ARIZONA 1050G and gmpall devices can be over 16 Pm .38 35 .32 ANCRONA ANCRONA ANCRONA sled hem a tingle or spa dower 40 Pm 1 75 1.59 1.45 1080 Jefferson Blvd 1300 E Edinger Ave 4518 E Broardway unaniO Culver City CA 90230 Santa Ana CA 92705 Tucson. AZ 85711 12131 3M-3595 (7 141 547-8424 (602) 881-2348 SI -1010G (10W output' ... 5 6.90 WIRE WRAP 51.1020G (20W output) ... 513.95 alb GOLD OREGON GEORGIA TEXAS (Level No 31 51.10300 130W output) ...519.00 ANCRONA ANCRONA ANCRONA 1125 61.1050G 150W output) ...577.80 N E 82nd Ave 3330 Piedmont Ra NE 2649 Richmond Portland. OR 97220 Atlanta. GA 30305 Houston. TX 77098 14 Pin 39 .38 .37 (503) 254-5541 14041 261 7100 529-3489 Dala Sheet with Application Notes - 50.50 16 Pin .43 ,42 41 17131

FEBRUARY 1978 CIRCLE NO, 3 ON FREE INFORMATION CARD 101

AmericanRadioHistory.Com j 2 PLETE SAT'77- 1-'N IS QUR GUARANTEE YOUR COMPLETE SATISFACTION IS OUR GUARANTEE YOUR COMPLETE SATISFACTIC t.

O i >- E DISCOUNTS 1.1.1 W 'r '. Savings uptq .'70°f on rnajor.brand IC parts and computer kits. 'za .4 7400 .11 74100 28 7401 .13 74107 .28 7402 .13 74XX 74109 .22 7403 .13 7441 .70 74121 .29 7404 .15 7442 .37 74122 38 7405 .13 7443 .59 74123 48 7406 .16 7444 .59 74132f. .65 5' 74L$00-TTL 7415192 .90 1702A 7407 .23 7445 .65 74141 .70 C 74L500 5 .21 741.593 .52 7415196 .80 7408 .17 7446 62 74145 .65 7415197 7409 .17 7447 .59 74150 .88 741502 .21 7415109 .36 .80 7410 .13 u: 74L$221 1.06 7448 74151 .61 741504 ".24 74L$112 .36 7411 .18 7450 .13 74153 .61 741508 5 .21 7415113 .36 7415257 .71 J412 - .13 7451 13 74154_ .95 'r 741510 .21, 7415114 .36 741.5258 .70 MEMORY 7413 .25 7453 .13 74157- .55 Z 7414 61 7454 .13 74161 .55 C °_ 74L$14 .85 . 74L5125 .46 7415266 .26 7416 - .24 7460 .14 74163 .55 " 7415283 .72 741520 .23 74L$126 .46 7417 22 7470 .26 74164- 85 ` 741521 .23 74L$132 .75 7415365 .55 7420 .13 7472 .21 74165 .90 7423 , 741522 .23 7415138 .70 7415366 .55 ..25 7473 .21 74170 1 69 Q JUST 7425 .25 741530 .23 7415139 .70 7415367 .55 7474 .27 74173 1.10 7415368 7426 .22 7475 ,45 74175 85 741532 ".30 7415151 .65 .55 7427 17 7476 .28 74175 .75 741537 .31 7415153 .66 7415386 .39 7430 .13 7479 5.00 74176 .69 7432 23 .a . 741538 .31 7418154 1.00 811595 .77 7480 .31 74177 .70 ,77 7437 .21 7481 .95 74180 .65 74L542 .60 7415157 5.62 811596 7438 811597 .77 .21 7482. .50 74181 1.75 74L547 .75 7415160 .82 7439 25 7483 .62 74190 .95 vLL '. 741548 .72 74L$161 .82 811598 .77 7440 .13 7485 .75 74191 .95 I- 741573 .35 7415162 .82 7486 .26 74192 .79 LL 741574 .35 4023 $ :16 7489 -1.75 74193- .80 7411163 .82 CMOS 7490 40 74195- 49 741575 .53 7415164 .98 SUPPORT DEVICES MEMORY 4024 .67 4001 .16 4025 16 7491 .51 74221 .86 741576 .37 7415174 .75 7492' 40 74251 1.00 4002 16 4028 .74 741586 .36 7415175 .79 6820 5.00 7493' 74365 62 1702A 4.75 4006 .99 4030 _22 7494 60 74366' ' 62 ' G . 741590 .52 7415190 .90 6850 5.00 2708 13.50 4007 .16 4035 98 7495 60 74367 .62 74L$92 .52 7415191 .90 7496 60' 74368 62 8212 3145 2716 32.95 4008 .79 4040 99 CC 4009 .37 4049 34 8214 9.50 21L02 450ns -1.25 4010 .37 4050 34 4011 4051 . 8216 3.75 21L02 250ns 1.60 .16 89 }r _o 4012 .16 4052 1.15 8224 3.75 1101 .75 4013 .29 4053 89 n KITS 8228 6.50 4014 .74 4066 .59 W. 8226 3.85 MICROPROCESSOR 4015 .74 4071 19 KITS I-...- 4016 .29 4081 .23 z -WAMECO 8238 7.95 8080A $11.95 407 .79 4082 - .23 Z-80 24.95 4018 .79 4507 39 SOLID STATE MUSIC" cc S-100 P.C. Boards 4019 .23 4510 1.05 Z -80A 34.95 MB9 STATIC PROM/RAM Isr 8K RAM 28.00 4020 .84 Kit Less Memory 72.00 Z-80 CPU 28.00 6800 ' 16.50 4021 .89 1- 4022 .89 VB1A VIDEO INTERFACE 12 -Slot Mother Kit 129.95 II Board 33.00 Bare Board - 25.95 0 ITHACA AUDIO 27 )8 Special 102 PARR ELL I/O " S-100 P.C. Boards 'And Kludge 8K RAM 28.00 Buy 10 Kit "449.95 Z Z-80 CPU 28.00 Bare Board 25.95 Q -get 1 SOLID STATE MUSIC free 104 2+2 I/0 X3.4 S-100 Kits & Bare Boards Kit .. 139.95 < MB -3 2K/4K EPROM SB-1 MUSIC u1 Uses 1702A EPROMS Price: $13.50 each SYNTHESIZER with .I Kit -w/o EPROMS 59.95 REGULATORS Kit MB -4 4K STATIC RAM Software 174.95 LM 301H .35 ' LM 32OK-18 1.75 MT -1 Kit 95.00 LM 301AH .38 450µs Full Specjficatión Part' 1- Bare Board 25.95 LM 301AM .30 'LM 320K-24 1.75' 15 -Slot Mother LM 304H 1.00 LM 320T-5 1.10 ' ¡Li' MB6A 8K STATIC RAM Board 139.95 LM $ 305H .60 LM 358M .99 I LM, 309H '1.10 LM 320T-12 1.10 . XB-1 EXTENDER Kit $179.95 LM 307M .30 LM 379M 3.99 BOARD LM 309K - .99 2 Bare Board 25.95 LM 30811 1.00 LM 380M .99 LM 320T-15 1.10 Bare Board 8.99 ú MB7 16K STATIC RAM LM 308AH .95 LM 380N .75 LM 320H-5- 1.19 LM 340K-5 .85 SSM 8080 MONITOR V1 LM 308N 1.00 LM 381N 1.79 LM 320H-6 = 1.19 -LM Kit 435.00 LM 311M 340K-8 1.35 ON 2-2708 47.00 .90 LM 386N .99 ILM .1= Bare Board 25.95 LM 311N .85 LM 387N .69 320H-8 1.19 LM 340K-12 '.85. ON 8-1702A 47.00 LM 3I1H .90 LM 3900N .40 LM 320H-12 1.19, LM 340K-15 .85 _ MB8 8K/16K EPROM LM 312H 1.25 D LM 555M .39 LM 320H-15 1.19 LM 340K-18 1.35 } ° Uses 2708's LM 317H 3.45 1M 556N .88 LM 317K 3.70 LM LM320H-18 ,1.19 LM340K-24 .85 . Kit Less EPROMs 75.95 567M. 1.25 ui LM 318M 1.15 LM 723N .49 LM 320H-24 1.19 LM 340T-5 .95 LM 319H 1.25 LM 741H 8 .35 LM 320K-5 LM 321H 2.02 LM 741M .19 ' LM 340T-8 .95 LM 32211 2.02 LM 747H .79 LM 320K-6 $1.75 LM 340T-12 95 LM 324N .72 LM 747N .79 LM 320K-8 '1.75 LM 340T-15 .95 - LM 325H 2.25 LM 1458M .59 LM 339N .99 LM 14558H .55 LM 320K-12 1.35 LM 340T-18 .95 LM 34311 - 2.99 LM 4250CH ,89 LM - 1.111 MN 320K-15 1.35 LM 340T-24 .95 \ ÑEW 5716 W. Manchester Ave. O Send your complete catalog, Suite #5 quickly.° 1978 Los Angeles. CA 90045 O Please send me the following, items I have listed below: IC MASTER Stock No. Qty. Price o Cash TELEPHONE ORDERS: - Over 40,000 COD Call (213) 141-4200 IC's listed. Charge My 1° - BAN KAMERICARD 2,000 M.C. t _ Over 11r VISA BAC (VISA) I pages. Updated every M' - 5. . 5 1 i 90 days. fr Postage/Handling $1.50 1. Name I Retail Value I $55.00 Address .. Satisfaction 100% Guaranteed Your Price California Residents Add 6% . City State I ,_ Zip Sales Tax I O Note: Minimum Order $10.00, 5% Discount over $100.00 = I $48.50

OUR '.GUARANTEE --YOUR COMPLETE SATISFACTION IS OUR GUARANTEE' YOUR,. COMPLETE SATISFACTION !S OURGUARANT . ° . r . .CIRCLE . NO . 2 ON FREE INFORMATION .'CARDCARD . ' 1 ' . . . AmericanRadioHistory.Com MORE THAN 20,000 DIFFERENT COMPONENTS 7400 TTL LINEAR NEW FROM NEWTONE 7400 .18 7442 1.08 74107 .49 75450BP .49 LM301H .35 LM741CH .45 7401 .21 7448 1.15 74121 .55 75451BP .39 LM307H .35 LM747 .90 Regulated Power Supply Components Kit -Contains the 7402 .21 7450 .26 74122 .49 75452BP .39 LM309K 1.25 LM748H .45 to build a fixed -voltage regulated 7404 .21 7451 .27 74123 1.05 754538P .39 LM311H .90 LM1458N .80 components needed 7405 .24 7453 .27 74125 .60 754548P .39 LM318N 1.50 N5556V 1.50 supply including: 117117V- 1 ampere Transformer, Bridge 7407 .45 7454 .41 74126 .81 75491BP .79 LM339N 1.85 NE5558 1.00 7408 .25 7460 .22 74132 3.00 75492BP .85 LM351AN .65 NE555V .60 Rectifier, 2000 uF Capacitor, and a 1 ampere LM340 7409 .25 7472 .39 74141 1.15 CA3005 1.60 LM370N 1.25 NE556 1.50 3 IC Regulator. Makes a fine "on board" supply 7410 .20 7473 .45 74150 1.10 CA3006 3.50 LM380N 1.45 UA702 .80 -terminal 7411 .30 7474 .45 74151 1.25 CA3018 1.10 LM566 2.25 UA703CH .45 or use it for breadboarding. Components only. Specify 7413 .85 7475 .80 74153 1.35 CA3018A 1.60 LM711CH .60 UA709CH .30 7416 .43 7482 1.7E 74154 1.54 CA3026 1.50 LM723H .75 UA749CH .45 5, 6, 8, 12 or 15 volts. NT525 $4.99 7417 .43 7483 1.15 74157 1.30 CA3046 .35 LM741CN .45 Pioneer 6" Speaker - 71/2 -watt, 3.2 -ohm speaker made 7420 .21 7485 1.12 74161 1.45 IC's ON THE MOVE 7422 1.50 7486 .45 74164 1.65 the way speakers should be made. Has heavy-duty treated 7425 .43 7489 2.49 74185 1.65 BBD BUCKET BRIGADE DEVICE 7427 .37 7490 .69 74166 1.70 M M 3001 19.50 M N 3002 11.70 paper cone, protected magnet housing, and a ceramic 7428 .35 7491 1.20 74174 1.95 9.45 A speaker 7430 .26 7492 .82 74175 1.95 MM3003 terminal strip marked with polarity. beautiful 7432 .31 7493 .82 74180 1.05 HALL IC:DN834 1.25 DN837 1.50 at half the price you'd expect. NT526 $2.39 Three for $6.00 7437 .47 7494 .91 74181 3.55 DN835 1.35 DN838(NEW) 7438 .40 7495 .91 74191 1.50 PC Boards MIL grade, '/,," glass -epoxy boards with 2 - 7440 .21 7496 91 74195 1.00 DIODES 0 7441 1.10 74100 1.25 74197 1.00 ZENER ounce copper on one side. to V /2 Watt, ± 10% $ 30 each 33 NT521 6"x3" S.50, NT522 6"x6" $.90' NT523 6"x8" $1.20 TTL 1 Watt, ± 10% $40 eachto33V 74L SERIES Dry Transfer Patterns for PC Boards - Includes 0.1" spaced 74L00 .33 74LSO4 .45 74LS113 .98 Voltages to 200V, and = 5% Available 74L10 .33 74LS10 .39 74LS138 1.89 IC pads, donuts, angles, and 3 -and 4 -connector pads. 1 Megohm Potentiometer Made by Claro- 74L30 .33 74LS20 .39 74LS174 2.50 225 patterns on a 2" x 71/4" sheet. NT520 $1.49 74L42 1.50 74LS51 .39 74LS386 5.50 tstat.'I diam., split, knurled shaft 1/2" Over 74L86 .69 74LS74 .65 745153 2.25 NT544 $.39 Three for $1.00 3PDT - 24 Volt DC Relay - Potter & Bromfield KUP14D15. 74LS00 .39 741.5112 .65 745387 1.95 voltages to 240 Vac. 74H00 TTL Each contact can handle 10 amperes at Coil resistance is 450 ohms. A super buy! Limited quantities. 74H00 .33 74H11 .33 74H53 .39 / 5400 SERIES VOLT.REG .33 74H20 74H55 .39 NT508 $.99 74H01 .33 5400 1.00 5475 1.50 LM340K-5 1.95 .33 74H21 .33 74H73 .59 74H04 5404 1.25 5486 1.90 LM340K-6 1.95 74H05 .35 74H30 .33 74H74 .59 Meter -One milliampere full scale, 31/2", 5410 1.00 5493 2.00 LM340K$ 1.95 5" Taunt -Band 74H10 74H40 .33 74H76 .65 .33 5426 1.25 54100 1.80 LM340K-15 1.95 scale length. Coil resistance 465 ohms. Made by Modutec 5473 1.50 54LSO4 1.00 LM340K-18 1.95 LM340K-24 1.95 for Bose. Meter scale in VUS (-20 to + 30). Meter is de- MOTOROLA LM340T0-5 1.75 signed to be mounted coil up. Complete with "smoke" MC663P 2.50 MC1460 3.95 LM340T0-6 1.75 1.60 MC1469R 2.50 RESISTORS LM340T0-8 1.75 Over-all 5118"x4". Meter face mounts in a MC666P V. Watt ±5°/. Packed 5 of any plastic cover. MC670P 1.60 MC1489 4.60 LM340T0-12 1.75 one value $ 25 meter. NT539 $4.89 MC1496 1.65 LM340T0-15 1.75 5'/8"x2318" cutout: A beautiful MC679P 2.50 '/2 Watt ± 5% Packed 5 of any MC725P 1.50 MC1510G 8.00 LM940T0-18 1.75 one value $ 30 - knob with 4.50 LM340T0-24 Aluminum Knob Solid machined aluminum MC789P 1.50 MC1514L \STANDARD RESISTANCE VALUES MC790P 1.50 MC1595L 6.25 fluted sides made for Bose. Black front -face insert, black MC817P 1.30 MC1723CL 3.60 MC836P 1.35 MC1741CG 1.20 SEE OUR AD ON JAPANESE pointer line. Fits flat 1/4" shaft, does not require set screws. MC844 1.25 MC1810P 1.25 TRANSISTORS AND IC's 8 .7 worth $1.50 NT540 $.82 2 for $1.50/ MC853P 2.25 MC3004L 2.25 high, diem. Easily MC876P 2.25 MC3007P 2.25 IN THIS ISSUE. MC1004L 1.25 MC3021L 2.15 MC1010L 1.25 MC3060L 2.65 MC1305 1.95 MC3062L 3.00 MINIMUM ORDER $5.00 MC1352P 1.55 MC4024P 2.20 All' orders odd 1.00 Postage and Handling. BOSE SPEAKERS MCI 357 1.70 MC4044P 4.80 Bose has discontinued their original 301 System.\ MC1371 1.85 MC14507CP 1.25 Canada $1.50 MC1439 2.65 MC14511CP 2.76 New -Tone purchased the speakers remaining in . 1N J. Residents odd 5%, stiles tax MC1458P .50 MC14512CP 1.70 inventory when the 301 was discontinued, and is ELECTROLYTIC CAPACITOR offering them at prices that seem impossible. C MOS 2.2MF50 Axial Leads .15 30MF25 Axial Leads .18 The speakers have been tested with the Bose Axial Leads .15 47MF25 Radial Leads .19 4001AE .29 4023AE .29 3.3MF10 as a reference and have been No Polarity .15 47MF50 Radial Leads .24 "Tone Standard" 4002AE .29 4024AE 1.50 3.3MF10 10MF25 Axial Leads .15 100MF16 Radial Leads .19 subjected to the Bose power -handling test which 4007AE .29 4025AE .35 Radial Leads .24 4010AE .58 4028AE 1.60 10MF50 Axial Leads .16 100MF25 includes both fixed and sweep -frequency testing. .20 500MF50 Axial Leads .60 4011AE .29 4029AE 2.90 10MF150 Axial Leads .18 1000MF35 Axial Leads .65 8 -Inch Woofer (Bose Part No. 102606) has a free - 4012AE .29 4030AE .65 25MF35 Axial Leads 4015AE 1.25 4037AE 4.50 air resonant frequency of 25-35 Hz., and has a 4016AE .65 4040AE 2.40 MICROPROCESSOR 1.5", 8.5 -ounce magnet. The upper tested -fre- 4018AE 1.10 4044AE 1.50 C1702A 9.95 2708 34.95 8008 19.95 4019AE .65 4049AE .75 2101 5.75 C5101-3 4.50 8080A 19.95 quency is 4000 Hz. 4020AE 1.75 4050AE .75 2102 1.75 MM5013 3.25 8224 3 -Inch Tweeter (Bose Part No. 107376) has a us for all your microprocessor needs. 4021AE 1.50 Contact free -air resonant frequency of 1200-1500 Hz., and has an upper tested -frequency of 16.5 kHz. (ÍRECTIFIERS UNIJUNCTIONS HARDWARE - SOCKETS Supplies are limited. We urge you to take ad- 70 100 Nylon Screws, Nuts and Rivets - 50 piece assortment 51.99 vantage of these prices and stock up for your For For 2N2160 .65 MU4892.50 MK 20 TO -3 Mounting Kit 5 for 6.99 future needs. 1N4001 .60 5.00 2N2646 .45 MU4893.50 NT-505 Mica and bushing. Specify 1N4002 .70 6.00 2N2647 .55 MU4894.50 TO -3, TO -66 or TO -220 10 sets for 5.99 Sorry, we have no information about the Bose 1N4003 .80 7.00 2N4851 .75 2N6027 .55 IC Socket 14-Pin DIL 5.25 each enclosures or the crossover networks; nor do 1N4004 .90 8.00 2N4852 .75 2N6028 .70 IC Socket 16 -Pin DIL 5.27 each Wire Wrap 16 -Pin OIL 5.32 each we have more specs. Bose says these data are 1 N4605 1.00 9.00 2N4870 .50 D5E37 .35 1 N4006 1.10 10.00 2N4871 .50 MU10 .35 proprietary information. \ 1N4007 1.20 11.00 MU4891.50 MÚ20 .40 8" Woofer NT541 $10.95 3" Tweeter NT542 $ 3.95 POPULAR JEDEC TYPES

(1'N34 .25 2N1540 .90 2N2712 .18 2N3394 .17 2N3856 .20 2N4402 .16 1N60 .25 2N1544 .80 2N2894 .40 2N3414 .17 2N3866 1.25 2N4403 .20 1N270 .25 2N1554 1.25 2N2903 3.30 2N3415 .18 2N3903 .16 2N4409 .20 1N914 .10 2N1560 2.80 2N2904 .25 2N3416 .19 2N3904 .16 2N4410 .16 1N4148 .25 2N1605 1.75 2N2904A .30 2N3417 .20 2N3905 .16 2N4416 .75 1S1555 .35 2N1613 .50 2N2905 .25 2N3442 1.85 2N3906 .16 2N4441 1.00 2N1711 .50 2N2905A .30 2N3553 1.50 2N3954A 3.75 2N4442 1.15 2N173 1.75 2N1907 4.10 2N2906 .25 2N3563 .20 2N3955 2.45 2N4443 1.35 2N338A 1.05 2N2102 .70 2N2906A .30 2N3565 .20 2N3957 1.25 2N4852 .55 2N404 .75 2N2160 .70 2N2907 .25 2N3638 .20 2N3958 1.20 2N5061 .30 2N443 2.50 2N2218 .25 2N2907A .30 2N3642 .20 2N4037 .60 2N5064 .50 2N508A .45 2N2218A .30 2N2913 .75 2N3643 .20 2N4093 .85 2N5130 .20 NEW-TONE 2N706 .25 2N2219 .25 2N2914 1.20 2N3645 .20 2N4124 .16 2145133 .15 2N718 .25 2N2219A .30 2N3019 1.00 2N3646 .14 2N4126 .16 2N5138 .15 2N718A .30 2N2221 .25 2N3053 .30 2N3731 3.75 2N4141 .20 2N5294 .50 2N918 .60 2N2221A .30 2N3054 .70 2N3740 1.00 2N4142 .20 2N5296 .50 ELECTRONICS 2N930 .25 2N2222 .25 2N3055 .75 2N3771 1.75 2N4143 .20 2N5306 .20 2N956 .30 2N2222A .30 2N3227 1.00 2N3772 1.90 2N4220A .45 2N5400 .40 2N1302 1.25 2N2270 .40 2N3247 3.40 2N3773 3.00 2N4234 .95 2N5401 .50 2N1305 .75 2N2369 .25 2N3250 .50 2N3819 .40 2N4400 .16 2N5457 .35 PO BOX 1738A BLOOMFIELD, N.J. 07003 2N1420 .20 2N2484 .32 2N3393 .20 2N3823 .70 2N4401 .16 2N5458 .30 I. 1HONE: (201) 748.6171, 6172, 6173 ALL PARTS GUARANTEED WRITE FOR FREE CATALOG

CIRCLE NO. 32 ON FREE INFORMATION CARD

POPULAR ELECTRONICS 103

AmericanRadioHistory.Com n II FREE 800-421-5809 o FOR ALL CUSTOMERS EXCEPT CALIF. CALL TOLL t/'JY./Y./'1lll.rOG/Y1.030/.Odr1Y.J0'.AC/'./Y'./'l_t/SOGCl.d'./''lOCYI./ -; - - - ./YY1'O0-4160 MICROCOMPUTER MISC. RAM BOARD MICROPROCESSOR.' 8080A SUPPORT DEVICES CHARACTER PROM'S OTHER COMPONENTS 8K STATIC 1702A 5.00 F.8 19.95 8212 3.95 GENERATORS NH0025CN 1.70 ASSEMBLED & TESTED 2704 15.00 Z80 25.00 8214 9.95 NH0026CN 2.50 2513 UP 6.75 2708 13.00 Z80A 35.00 8216 4.50 2513 DOWN 6.75 NBT20 3.50 CDPIBD2CD 74.95 8224 4.95 2716 38.00 2513 UP 15v1 9.95 4.50 N8T26 2.45 AM2901 22.95 8228 8.75 3601 7513 OOWN150 10.95 74367 .90 n 6502 12.95 8238 8.00 5703A0 4.00 $199.95 DM8098 .90 250ns. MCM6571 10.80 5204A0 6.00 6800 19.95 8251 12.00 1488 1.95 MCM6571A 10.80 6834 16.95 8008-1 8.75 8253 28.00 MCM6572 10.80 1489 1.95 8080A 15.95 8255 12.00 6834.1 14.95 MCM6574 14.75 825238 4.00 D3207A 2.00 450ns. $150.00 TMS-99001L 89.95 8257 25.00 MCM6565 14.75 C-3404 3.95 8259 82238 2.70 25 00 P -3408A 5.00 * WILL WORK WITH NO FRONT PANEL e 6800 SUPPORT P.4201 4.95 DYNAMIC RAMS MM5320 7.50 * FULL DOCUMENTATION 6810P 4.95 STATIC RAMS 1.24 25.99 100 6820P 1103 1.50 MM5369 1.90 * FULLY BUFFERED 8.00 21107 14501 1.50 1.40 1,25 6828P 11.25 2104 4.50 DM.8130 2.90 21L02 12501 1.95 1.80 1.50 S100 DESIGN 6834P 16.95 21078 3.75 DM8131 2.75 * 21L11 4.25 4.10 3.95 4.50 6850P 9.95 21078 DM.8831 2.50 * ADEQUATELY BYPASSED 1101A 1.49 1.29 1.10 4.00 6852P 11,95 21078-4 DM -8833 2.50 2101.1 2.95 2.75 2.60 POWER 14.95 TMS4050 4.50 DM -8835 2.50 * LOW SCHOTTKY SUPPORT IC'S 6860P 2102 1.25 1.15 1.00 TMS4060 450 6862P 17 95 SN74LS367 .90 2107-1 1.50 1.30 1.15 4096 450 6880P 2 70 SN74LS368 .90 21111 4.00 3.50 3.25 4116 4200 21121 3.00 2.80 2.69 MM5270 5 00 KIM KIT 280 SUPPORT DEVICES 2114 17.95 16.95 16.50 MM5280 600 KIM1 245.00 250ns. 3881 12.95 4200A 12.95 12.50 11.95 MCM6605 6.00 $169.95 6502 12.95. 3882 12.95 5101CE 11.95 11.25 10.25 UART'S 6520 9.00 6522 9.25 KEYBOARD AY51013A VI SUPPORT DEVICES WAVEFORM GENERATOR CHIPS 5.50 6530-002 15.95 450ns. $129.95 8038 4.00 AY5.2376 13,95 AY 5.1014A 8.95 3851 14.95 TR-1602A 6530003 15.95 MC4024 2.50 AY5.3600 13.95 5.50 6530.004 15.95 3853 14.95 TM56011 6 95 566 1.75 6530 005 15.95 v° IM 6402 10.80 BARE BOARD LATE ADDITIONS { FLOPPY DISC CONTROLLER IM.8403 10,80 USRT $25.00 17718 55.95 W/SCHEMATIC TMS 4044 $14.00 5,7350 10.95 TMS 5501 $24.95 1771 B-01 59.95 ADAPT YOUR MOTOROLA 6800 SYSTEM TO OUR 5.100 8K JADE PARALLEL/SERIAL RAM , / JADE VIDEO INTERFACE BOARD. KIT PRICE $12.95 KIT INTERFACE KIT FEATURES $124.95 KIT $89.95 s-1oo IMSAUALTAIR S-100 Bus Compatible 2 Serial Interfaces with RS232 V_100 COMPATIBLE 32 or 64 Characters per line interfaces or 1 Kansas City cassette 16 lines interface. a, Serial interfaces are crystal controlled. Graphics 1128 x 48 matrix) Selectable baud rates. Parallel & Composltive video Cassette works up to 1200 baud. JADE On board low -power memory 1 parallel port. o , Z80 -with PROVISIONS.for Powerful softer a included for KIT ursor, home, EUL, Scroll Graphics/ ONBOARD 2708 and POWER ON JUMP Character, etc. EDGE CONNECTORS Upper case lower case & Greek S-100 Altair Spacing $4.45 Black-on -white & white -on -black S-100 Imsai Spacing $4.45 $135.00 EA. (2MHZ)

MOTHER BOARD (4MHZ) 13 SLOT MOTHER BOARD w/front HE PROM SETTER $149.95 EA. panel slot WRITE and READ S-100 DESIGN EPROM FULL GROUND PLANE ON ONE SIDE BARE BOARD RC NETWORK TERMINATION ON 1702A-2708-2716 $35.00 EVERY LINE EXCEPT PWR & GRD a KLUGE AREA 5204-6834 STRONG 1/8" THICK DOUBLE SIDED Plugs Direr/1y Info your ALTAIR/IMSAI BOARD Computer Includes Main Module Board and External EPROM JADE 8080A KIT BARE BOARD $35.00 KIT $85.00 Sr.ckel Unit The EPROM Socket Unit is connected to the Com- pulerlhrough a 25 FOR S-100 Pin Connector $100.00 KIT PERSCI DISK DRIVE Programming is accomplished by the Computer Info 2000 S-100 DISK SYSTEM IMP lust Read In the Program to be Written on the COMPLETE EPROM into your Processor and let the Computer BARE BOARD Info 2000 S-100 DISK SYSTEM do the rest $35.00 (includes dual drive, power supply, case, Ilse Socket Unit to Read EPROM's Contents into intelligent controller, adapter, cables, and your Computer Software included disk monitor on EPROM) $2,650.00 VIDEO INTERFACE No External Power Supplies. Your Computer does TIJ-L It all COMPLETE SOFTWARE You will want to know about the TV -1 Video PKG.KKG DISK Doubles as an EIRht 811 Parallel I/O to Televisior Interface Kit. Manual included Dnlrvery Less thou 90 days No need to buy a separate Video Monitor if THE PROM SETTER you already own a TV set. Just connect the REAL TIME CLOCK FOR S-100 BUS TV -1 between your system video output and KIT ASSEMBLED the TV set antenna terminals - that's all there BARE BOARD $30.00 KIT $124.95 $210.00 $375.00 is to it - to convert your TV set to a Video Monitor, and at a much lower cost! PR ICE $8.95

SOROC 10120 A CAPABLE LOW $975 00 COST. APPROACH TO REMOTE VIDEO Assembled TERMINAL DISPLAY TERMINALS. Computer Products Cure. Centro' Key. Standard Price Includes Numer.c K. P.O SI.nd.rd 5351 WEST 144th STREET Lie. nd Page Ere. Standard LAWNDALE, CALIFORNIA 90260 ddrnadle Cursor Sundaid Block Mode Stolen S.Iect.ON Tr.nrnMWon 12131 679.3313 som es to 15.200 p Sl.nd.rd Cornmunlc.uon Mode: Lower Case NCI 0800 Bloc. RETAIL STORE HOURS M -F 9-7 SAT. 9-5 Intent...: Prints Interlace/ 24 Line Option W'V' RS232 F sMnelon Discounts available at quantities. Add RS232C Interlace and shipping OEM 61.25 1e5.': Non.01.,. Reed Out Screen for shipping. California residents add 6% sales talc. Protect Mud. Standard charge is us. Iba Ta6 51.00.04 on

104 POPULAR ELECTRONICS

AmericanRadioHistory.Com 6161. .1. 6161 5 '7 0 e 9 Raft MICROPROCESSOR CRYSTALS COMPU/TIME offers 7400 TTL Series

A price Pricer COMPLI/TIMIE 7400 7443 1-}0 741017 1.75 )4162 190 Real Darn Clever 1401 20 7445 05 14107 )alb] 1.40 FREQUENCY F11a0UENt T 1401 7446 145 A5 74154 150 1403 741090 80 14165 1.40 CT 100 Enhancement to users of 7447 86 I O MH! 5.95 50 MHz 4.95 1404 744049 95 15116 200 )4166 150 7405 120 1.25 7416) 4.95 IMSAI/ALTAIR 1 .20 300 18432 MHz 9.80 50688 Mhz 7406 7451 00 )4121 65 41)0 250 7407 4122 1453 .20 A5 i4172 9 75 2.0 MHz ' 5.95 Microprocessors 1409 95 ñ 7454 ,20 4123 nn I So 8.50 5185 MHz 4.95 1409 15 7460 .20 74125 55 1.10 2.097152 MHz 5100 BUS COMPATIBLE 7410 7410 40 14125 60 1u14s 1.20 5.7143 MHz 4.95 ,}5 1411 7472 4128 65 14116 I 50 41} 35 6.30 MHz 4.95 .40 7173 0 .132 I50 75117 90 TIME & CALENDAR .75 1474 90 4136 160 140 1.40 6 144 MHz 4.95 - 8.50 151 7475 70 741. .15 14181 1.00 2:4576 MHz 7516 35 14181 YO 6.40 MHz 4.95 COMPU/TIME 717e .40 74142 400 21667 MHz 8.50 CT100 $199 Kit $245 Assembled 40 )sl9 200 74144 4.00 7414 200 7420 6.5536 MHz 4.95 COAAPU only C101 $149 Kit $189 Assémbled 20 7930 69 74,45 1.10 74165 2 00 5 1422 15 1482 1.50 74147 250 14186 , OD 300 MHz 8.50 40 TIME only T102 $195 Kit $205 Assembled 7425 .]s 7483 95 74148 175 8.50 1426 30 7495 1.10 14150 100 550º 1.25 3 20 MHz 80 MHz 4.95 14]1 74191 1.12 COMPU/TIME PC Board Only 5 ]5 7'156 .40 1751 110 2 ao 3 2768 MHz 8.50 4.95 7415 +0 89 2.25 415] 110 74193 1w 100 MHz 1429 .40 95 1.20 7.90 .55 54 1.10 3 579545 MHz 1.25 1800 MHz 4.95 ,439 ,15 .91 t 10 74155 1.10 14195 1 00 7432 14196 1.10 432 4.95 MM16 iL 1492 613 74166 1.10 4.0 MHz 4.95 18 MHz '° 7433 .100 14197 150 149: 57 120 7431 1 50 4.95 Ul lizing up 10 16 2708 EPROMS 39 1494 155 )4158 1.15 98 40 MHz 20 0 MHz 4.95 7438 .35 1195 90 4159 3.60 141 9g 1 15 1439 4 MHz 4,95 77 1184 MHz 4.96 S100 Bus Computer Systems 1196 90 14160 100 194304 7497 400 161 4.95 16K 130 491520 MHz 4.95 770 MHz Memory capacity of 8K or bytes by DIP . } 160 MHz 4.95 8K boundary addressing by DIP Switch 9 9.00 49 0 MH: 4 95 0 l0 4 wait Cycles by DIP Switch T FOR PROCESSOR TECH Data output. address input lines fully buffered CMOS 14.318 $4.95 HI -grade glassepo.y with platedthru holes 61 4511 B 5o 3400 40 4050 Enos- S91d0r 051 1.10 4518 1.65 202 25 4052 1 10 4519 .9p 1.9 DIP SWITCHES 4001 25 4053 I10 4520 165 7 POSITION 1.80 FCS aSIM - 310 Digs a Display 4002 25 4025 40E0 125 4521 125 350 71 4 8 POSITION 2.00 94m .a, 1 POSITION $1.50 r , AzIwI 4006 140 4061 100 4522 75 11 4063 2.50 4527 300 4007 25 5 POSITION 1.60 9 POSITION 2.25 44Eo.a -WRAP WIRE WRAP TOOL 40E6 85 4518 1 75 SLIT -II 4008 1 5 ,1 600 4583 1.45 C 0 61149 ? 4009 4067 POSITION 2.50 ¡I CBIIT sins and opens insulation 44005.11 15 6 POSITION 1.70 10 4584 4010 4068 35 sí000./83 .1m. ; bare were 4069 35 ,11161 «8 150900 1 rem, 4011 25 44070 85 o 1.4 ,410 mo 0 40 4012 .25 SPECIAL. 110 pre -cunm4 or 4011 35 6144 Pre-W.1WD 4013 a 410 4013 35 $3.75 ea. cAmp191e «no two 100 M 500015 [F 40,4 1 25 Domes 4073 35 1.06,44.0216 WRAP CENTER 0+444+1) .0 .9. 3.84 4 4015 1.25 WIRE .28 AWG woe 4016 59 4015 5 y 25 ,M 1 5 01 WOW. 401 I 0 417 1 25 510.11,41015 HOBBY -WRAP TOOL-BW-630 , Ms4e Pilo $24.54 4018 1.15 44p17 S N } 1. , 4018 .3425 8 .4 4019 0 61.1744241, Battery Operated (Size C) 4020 1.25 4061 35 91K305 4082 35 38 MM 5 Ill 4021 1.25 )4[]}9. ID Weighs ONLY 11 Ounces 4085 I 35 AMPiugboards 8800V 4022 1 25 169.0444261 147 744.9195 419 n 4096 1.45 4023 35 K92}á 565 Wraps 30 AWG Wire onto 4099 300 C48N Universal Microcomputer? ao`5 1 00 419 4093 I Standard DIP Sockets ( 025 inch) 4075 .35 15 M74C9T.15 1100 7 Processor plugboard. use with 4098 2 50 Z:1;111,' 4026 2 25 5,; 9592. bit and sleeve 4 60 .1146165 84 M1449766 4200 Complete with built-in 5100 COmplele won heal sink 6 4021 60 5 { 0.5 4161 155 200 4029 1.25 59.1144855 M74097114 hardware 5 3 . 10 a 1,16 75 200 1200 4029 1 50 50.0441166 99 <162 75 1 4030 'fil 895 6 75 904492861 1}40 4 75 4032 1.60 C90N 132 4116 60 WIRE -WRAP KIT WK -2-W $19.95 4033 2.00 - 40`4 350 419111 80 Ibi 1.15116.414/164K95,6 1 WRAP STRIP UNWRAP ... 4035 60 4501 38 89 644HBOC9N, 84 4502 75 4038 1 60 Tool for 30 AWG um :V 4503 15 ;111;:1:1',", ]80 Wire ., W 250 1.50 4506 40,1 5 .)0 M744154Ñ 561 Roll of 50 Ft White or Blue 30 AWG Wire 4507 4042 25 00 340 4508 00 SO 1" 3 4 lengths 4043 1 20 1609. I11 pcs each 1 6 -- 75 I 71 Ad4wnnn..eSosoOpOption 4044 I 25 6,81.0616 CHANNELr preStrlpped 255 4510 00 K16)N 757 wire Automatic time and scot Mleepin0 451] .50 56 195 uM144c655M7 Balbry-tree AC operation 4.7 250 4514 75 I .61 4515 75 $11.95 ro 8 -way Rion 40413 1 00 59.47441656 461 I. DWI OD web ions 4515 )5 /14s. 049 61 o $129.95 Boo -inPro Hockey and Tennis games Easy hooko0 on any e.W or Colon TS factory warranty 111.500 29 435191 0 90 WIRE WRAP TOOL WSU-30 7443501 29 5771 300 1 741.2 29 74LS00 ]00 WRAP STRIP UNWRAP $6.96 oeu - aaL19¢M 13 0, 2 aeyn, 741:03 29 6115111 300 . r e , o cartridges 08. 0et ti 5 11 - r -517.95 1 sp9rH,11 of 2 w49m 4 25 79 1515iü 141.905 16600 o1 2 0.v 35 01.560 " Soma -war .2 °ahem 0819 - DraS ano 11 -rani 0811 - 1.'l31w751a980 DaNars Dill 14 508 .A 711573 Man Oñ514"7 5é WIRE WRAP WIRE 30 AWG Gwen 400091000áM 0814 - MaON Nome, 0820 - 12 0449161 41509 50 741574 - 41510 141.5)6 ]5 Io..Srwolns Gawn 1008.6111 10001 0922 - ~4412 PM61 25 K575 69 1415791 91 soh St 95 10005 $15.00 0417 - own 49 40 '711/1 5 14,5115L51) 50 fo 7515]51 SPECIFY COLOR White - Yellow Red - Green Blue Black 74 - 14L513 7415158 i 95 69 /1-181329 55 74LK52'í951í15 1 195 25 Ks14 N 711566 $$ 95160 D -SUB CONNECTORS 4L515 1 95 7435}1¡0 741_520 29 4i599 89 1515? 259 WIRE DISPENSER WD -30 NO. PINS PART NO. PRICE COVER PRICE a0 1593 89 - 05L5r1 h toll AWG KYNAR ware wrap wire )413M ié s9i ;isriº i SO 30 $3.45 ea. A 1:51171 1.25 ' S S6 Cuts iinte to desired length 9 " DE -9P 1.49 1: 5 56 74153025 11515 9 DE -9S 2.15 7415112 )K5115 200 . Strips 1 - of insulation 517915- Blue -Yellow -While -Red 60 .151'18 74í53i ]W 15 2.1 1 1 ° DA -15P 1.50 5,538 4511: 40 y,-- ..e, - ,1 6. 15 4 1K512} 60 K5353 DA -15S 3.10 540 lasts 81 O DIGITAL 25 DB-25P 3.00 1.50 15i540 sii: éó 616 LIQUID CRYSTAL 4 5125 151 145367 751548 25 DB25S 4.00 4 51]6 1 07 15191 8115369 51 CLOCKCALENDAR 5122 37 DE -37P 4.14 ,512 1. 2.00 4LS136 I 411123 5394 300 59 For Auto. Home. Office 37 DE -37S 6.00 01515i'ss5 74156105395 )4151Á 111 íñ131 111 ómau in 50 DD -50P 5.40 2.25 size 1242 24 8'01 50 DD -50S 8.00 ' I °USN button for seconds release for date C1oc+5 loom 66 ,666/6.«ne 4. m 0,1011 3001125 0 311ap800 vELCnO 'cll,deO 1M30nH I10 8 122 2 MODELS 19313140 35 634116416 EDGE CONNECTORS RL92111N 1.35 15 tnl ' 142]0105 LCD 0190 LM290oN DOOM, 00e1 0n 5e11 60nla1ne0 193025 5 PINS 1TPE Dat1el.e5 10, belle, loan a year NO. LM3660 250 LINEA L91901N 395 '2 1M7902N I LC0 182 u s (n 1438)5 55 300 V,,: sis em ano , D4ck 5 .50 1929039 :6578.0 DUAL 10 PIN GOL6 39114 35 160 - e - ° 20 1,7091679 1M290aN PIN GUIO .75 0845 325 I 30 DUAL IS 7030 4s 29475 LCO.101or LCO.102 DOLO 1.95 L93084N 300 a4 DUAL 22 0111 LM10xN 45 L 93046N 239 2.50 L1.930,98a9N 100 LMIO9CN 40 your choice 6161. $33.95 es 44 DUAL 22 PIN GOLD 1W 19305]6 1 50 4.95 15.171061.1 60 1932659. 25 40 DUAL 40 PIN GOLD I 15 5.00 1.54,106 1930656 100 DUAL 43 PIN GOL D(68001 r71a5 2 c Clear cloak gland for ...... $2.00 86 4.25 163110 2o0 /1161.1 1931179 1.60 50 PIN GOLO(IASAI/ALTAIR) 1.41/11619 loo DUAL 4.95 L54311N º 19.1511 15 100 DUAL 50 PIN GOLD(I21SAI/4LTAI9) 193119 151123414 SS 300 3.50 23CN 1M11i65 00 100 DUAL 50 PIN GOLDING EARSIMSAI 193119 80 SS MA1003, 12V DC CLOCK MODULE 19 125Cr1 ] 50 L93102N 70080 50 PIN TIN (.1" SPACING) 3.25 3120 2 -::710-11 100 DUAL 19 /25C51 LMN01N 30 19 J199. 300 1.1 193188 Lr4133C0 o0 49 y Built in %'TAL controlled 1M131CN 36 O 1390. 99 0 925 against EACH 19]196 151139,1 LM 1909N tima base. Protected ALTAIR/IMSAI CARD GUIDES .254 193'2111 300 9 LM )41CH 1939119 I 25 au tomotiv volt transients. 1.932111 300 35 . 11,1141016 19 32414 5 Automatic brightness con- 1933945 300 LMI416.1 164402aN 2 /5 with 0.3 green color 14,141616 O .44044.4 300 trot 1933914 99 39 CLOCK L914ICH 79 04425001 200 display. Display turnoff 1 85 49 95 1143481,4349 MMN 1M4250CN 2.00 oco.. ]50,4 100 79 with ignition "OFF" IIfD UQeb 12 N$ouI 4 95 L 9C0 1M45515N )5 O 1 M. L 358N 1 00 5 d 4 L M1<8CN Ow tICO OIAeO I P$ OA. 95 1,431010 15 15,160551 300 LM5556N 1 /5 12 a 24 Iba 50 alb Hz 4 95 163105 ] 75 09M. 1.955585 1 00 6 95 31]14 295 Dgll. moos. I EMS Woo 0413039 90 951 9 95 16131516 300 Miele Cwa P.. For UM Ma1 IMMSMI 49 1013045 I 19 1111131,19L 700 RCA Mean. 12 a 24 Mow 585 1.91305N 140 115848 SERIES O+ GWir. 3105 1 05 LM130716 85 LMl60N 1 OS ]I0N CA3013 2 15 Computer Products I 05 ]]5 1913585 CA30n 2.56 1 ,5 100 1939111 CA3035 2:48 10382N 15 1.61414N I IS WY. Wray IC SOCKETS 1914580 130 C43019 I 35 5351 WEST 144th STREET 193860 85 CA3256 43p 19361ÁN 15 1.914586 59 9144944$.4444 Tr. CA3059 3 25 101-999 IN L4236714 95 290 LAWNDALE, CALIFORNIA 90260 1-24 25-99 101488N C43060 3.25 1-24 2599 1019181 10 16]895 I 25 95 10 39 36 32 26 6 Up LM1499N t95 CA308o .85 1213) 6793313 I el IS 14 13 163695 2 14 34 33 31 29 12 I 1.914960 95 cAl0e1 16 36 34 32 30 1141 25 20 16 14 NE5:419/1,200 1M1496N g5 200 L M1556N C43062 2.00 la 70 54 40 I1N 25 20 le 16 NE5504 130 I0 75 RETAIL HOURS M -F ,5963 C43083 1.60 STORE 9-7 SAT 9-5 (1a1 2e 27 NE555V 39 25 2022 75 26 20 NE5568 1.25 14018005 1 90 CA3O86 95 1201 95 M 67 59 3e 33 30 739 NE5608 5.00 1918089 1 00 C43089 3 75 Discounts available at OEM quantities. Add 1018109 CA3130 39 $1.25 24 .96 lB 72 59 1221 36 35 34 211 14E5628 500 200 9.85658 150 191812N 400 CA3140 1 5 VI M 90 71 1747 36 35 33 269 CA3401 49 for shipping. California residents add 6% sales tax K NE5fi68 200 1918209 I 25 1 (39) 43 42 CA 74 I.4! 125 a O 367 NE5E61/0 1.75 1919309 200 .1600 314 M tit I 40 120 M 1401 éó e 5.' 493 E5670 .59 LM1845N I )5 1978 CATALOG NOW AVAILABLE

. 0 - a 9296

CIRCLE NO. 26 ON FREE INFORMATION CARO FEBRUARY 1978 105

AmericanRadioHistory.Com VI. o, ,.. T i

KNOW YOUR ALPHA FROM THETA! For greater relaxation & concentra- tion, monitor your Alpha/Theta brainwaves with audio or visual signals on Biosone II. Features of $200 -up units. Incl. 3 feedback models! 4 lb.

No. 1668AV $149.95 Ppd.

No. 71,809AV (FOR BEGINNERS) $59.95 Ppd. MAXIMIZE TV AND FM RECEPTION WITH THE MINI -ANTENNA SAVE 25% - DELUXE AM/FM WALL RADIO New 6" omni-directional antenna is unlike any in ,Free Catalog Great surplus buy saves you 25% on brand new

use today! Not a miracle "gadget" or gimmick, AM/FM Deluxe Wall Radio. Mount anywhere - den, GET UP-TO-THE-MIÑUTE this antenna acts like an infinite number of dipoles kitchen, bedroom, office, workshop. Self-cont. Philco- providing uniform response over FM, VHF/UHF. WEATHER CONDITIONS WITH Beautiful walnut and brass panel Ford radio chassis (141/ix3 13/16x3'/o") w/11 tran- Mounts inside or out with standard 11/4" hardware THIS PRECISION houses a cluster of quality wee sistors, vol. control, AM/FM hi sensitivity tuner, AFC, (not incl.) and is not affected by nearby objects or ELECTRONIC WEATHER ther instruments. Install the roof 23/" dia. speaker, 7'/2" 110V AC cord. Orig. cost people. No need to keep adjusting like "rabbit STATION transmitter with lead-in cord to $30 ea. ears." You get broad band splitter w/leads to ac- measure wind speed and direction. No. 72,275 AV Ppd. cept standard coaxial cable. Powerful performance! Barometer indicates frontal (READY TO PLAY!)... $22.50 No. 72,400 AV changes. Thermometer and hy- Ppd. 0 grometer show you temperature $29.95 and humidity. Console meas. 17x12x3". Uses "D" bast. (not incl.) SEE MUSIC --. REST YOUR MIND No. 80,218AV Ppd IN PULSATING COLOR $285.00 WITH THE EDMUND CONDITIONER 3 -Channel Color Organ Free Catalog : PROFESSIONAL SOUND lets you modulate 3 inde- ó Unique new scientific device masks pend. strings of colored fi' unwanted noise while adding rest- °oii lamps with intensity of , oV PRO ELECTRONIC SOUND CATCHER ful, interesting background sounds.. your music. "Audio light now simulates ' Parabolic mike w/183/e" transparent re- Modern electronics BS show" flashes, responds , o- flecting shield & 2 I.C.'s in amplifier soothing sounds of ocean surf, pitch! to rhythm, magnifies signals 100X over omni-direc- falling rain, and a rushing No. 42,309ÁV .50 lion mikes. Catch sounds never before waterful. 5" dia. speaker, on - (ASSEMBLED).. $18.50v Ppd heard; highest signal to noise ratio poss. oft volume controls, tone con- 51/2 Ib. trol, & 4 sound channel ad- justments. 71/2' AC cord. No. 42,336 AV No. 1649 AV (REO. (2) 9 V No.72,293A. (UNASSEMBLED)... $15.9 5 Ppd. BATT)... No. 72,293ÁV $129.95,Ppd, $299.00 Ppd. SUPER POWER FOR ANY AM RADIO SUPER QUALITY Antenna assist has pulled 10X MAGNIFIER Selñd for your FREE Ñ in station 1,000 miles off! Fi This Hastings triplet is No wires clips, grounding. :164 page Edmund possibly the most fay- Solid state. No batteries, ] ored pocket magnifier today. Full 10X color -correc- tubes, plugs. £ ted, flat -field, cemented lens system. Great for No. 72,095AV... ;Scientific Catalog jewelers, collectors, engravers, hobbyists, etc. with over 4000 bargains Mtd. in aluminum cell;- chrome -plate case. 3/:' x $19.95 Ppd. 1'/2" closed; clear lens dia. V2". II

ULTRA SELECTATENNA $24.95 Ppd. Ppd. No. 30,344AV $12.95 No. 72,147AV... V rt,.key oz.,a

0 . '

ORDER ' r '-.`. -r_ TO ORDER. PRODUCTS-

:sf{ _M 1FREE'CATALOG_= o =UrSE 'TH1S ,COUPON - L, . .. ,, _-- . . HERE _ _ .w . Please send me the following items I have EDMUND SCIENTIFIC CO. indicated below: Dept. AV03, Edscorp Bldg. No. Qty. Price EDMUND SCIENTIFIC CO. Barrington, N.J. 08007 Stock Dept. AV04, Edscorp Bldg. Barrington, New Jersey 08007 Charge My o Amer. Exp. BAC IVISAI FJ MC Interbank M Acct N Send GIANT 164 Page Catalog Card w Exp Date packed with unusual bargains. Sig. $1.00 Name N.1. esidents add 5% sales tax Handling

Address 30 DAY GUARANTEE Name You must be completely sobs. fled with any Edmund item or City return it within 30 days for Address

a full refund. _ Late Zip City State Zip

AmericanRadioHistory.Com THIS SPECIAL ONE CENT SALE IS FOR MAGAZINE ADS ONLY 1st Time Offered: It's Different! POLY' PAKS° BIGGEST % It's Inflation Fighting: New: 10 GIVEAWAY SALE! JT MAKES''CENTS'' TO EVE OUR CUSTOMERS THE BEST'BARGAINS:,

Type Each 2 for 557483 .99 1.00 557485 1.49 1.50 KITS BY POLY PAKS° TTL'S, BUY OPTE 557486 .39 .40 :3- 567488 1.95 1.96 557490 .69 .70 557491 .79 .80 AT SALE PRICE, 5147492 .45 .46 O 557493 .49 .50 .69 .70 SUPER ECONO KITS [ 557494 1 O 557495 .69 .70 1 GET 2ND FOR 557496 .69 .70 BUY 10 KITS & 557498 .69 .70 1.50 ONLY $1.98: CHOOSE 11TH FREE! 5574100 1.49 J J I 1 5574107 .39 .40 ' / .26 O 5574112 .25 e MONEY BACK GUARANTEE * AVG WT.6 OZS. 5574113 .19 .20 O 5574114 .25 .26 (Order by Cat. No., see peranthesh) Sale .50 Quantity Description SN74121 .49 KEYBOARDS, up 20 keys (2E1524) 51.98 51174123 .69 .70 10 -CALCULATOR t4 U 8 -LINE CORDS, 8 -ft. la, loin (18 w e. Plug (2E3843) 1.98 O 5574125 .59 .60 1.98 .40 30 -NEON LAMPS, NE -2 si.>le, red gle , leads (2E2613) SN74126 .39 1.98 O 5574132 1.25 1.26 3-17024 ROMS, factory fallouts, hobby, toseable (2E37291 O 5574140 ..9 1.00 D/1140 -FT SHIELD CABLE, 1 -cold, -n -shield, a22 wire, vinyl jack <3E35773 1.98 o 5574141 1.49 1.50 50 -TRANSISTOR ELECTRO'S, asstd values, uprltes, aziala (2E2747) 1.98 5674145 1.25 1.26 3 -SOUND TRIGGERS, handclap tr)ngers ser, w/amp ( 2(3625) 1.98 5574148 1.75 1.76 8 -IC SOCKETS, Incl. 4-14's and 4-15's, low prof (2E3621) 1.98 51474150 .99 1.00 15-6V TEST INDICATORS, w/lends, grain -o -wheat (2E1526) 1.98 5574151 .99 1.00 O 3-GLOW'N PANELS, 301-, 110064, glow -n -dark, green (2E3650) 1.98 Honest Abe 5N74153 .99 1.00 0 400 PARTS ON A BOARD, greatest asst on P.C. boards (2E3401> 1.98 Order 5574154 1.75 1.76 150 -METAL FILM RESISTORS, I/ veratts, color -Coded, lends (2E3413) 1.98 By Cal. 5574155 .79 .80 O 15 -JUMBO "1E05" RED, prime, lends, like 151V5054 (2E3369) 1.98 No. 2E1981 .70 o 5574156 .69 30 -MINI TRIM POTS, to 1 meg, 1 turn, 1/4W (2E3345) 1.98 Penny Sale! .99 1.00 8 Type No. 5N74157 gi 10 -VOLTAGE REGULATORS, TO -3 cave, 30911 etc. hobby (2E3330) . 1.98 .99 1.00 ...... o 5574158 -PANEL SWITCHES,SPE IA1,i ea, .slide, e, 1100a:. e(2 (054) 1.98 ñ 2 Type Each 2 for 1.25 1.26 030 Topa Each for n 5574160 I/ 2W,to metal, (2E3227) 1.98 5574161 1.25 1.26 O 40 RESISTOR SPECIAL, carbon 587400 5.19 3.20 557444 .65 .66 40-UPRIL TE values to 100 ,mí, volts11 (252232) 1.98 C 557401 .19 .20 557445 .99 1.00 5574163 1.19 1.20 1.98 1.36 5574164 .99 1.00 40 -UPRIGHT ELECTRO'S.T oastd volts, values to I1 1453226) T.'. III 557402 .35 .36 557446 1.35 150 --MOLEX SOCKETS,AL fit all ]c'a, most 2(31364) 1.98 .19 .20 0 557447 1.25 1.26 5574165 1.25 1.26 pins 11 557403 1 solder I2E) 1.98 557404 .25 .26 557448 1.35 1.36 [ 5574166 1.25 1.26 150 -TERMINAL STRIPS,LS,alie, to 8 vol¢, solder (tc. 1.25 1.26 O 10-PHOT ELECTRIC, asst COO vol.pan nkebens,trble,for etc. í 2E3057) 1.98 557405 .19 .20 0 557450 .19 .20 51174173 1.98 557406 .19 .20 0 557451 .19 .20 o 5N74174 1.49 1.50 20 --HALF ELECTRIC CELLS, CDS pancake , asst (2E3056) 51174175 .99 1.00 200 -HALF A IC lied, :,-7400 pre:, metal 3046) ... -. 1.98 557408 .21 .22 0 557453 .19 .20 1.98 5574177 .79 .80 100-NATIONAL-HBY BONANZA, rears, , romo, clocks, untested (552860) 557410 .19 .20 0 557454 .19 .20 1.98 557413 .39 .40 13 557455 .19 .20 5N74179 1.49 1.50 O 40 -HOBBY L VOL, AGE b d, untested mostly 713.2 12 (2E26) .49 .50 TORTSGE 6 TO.220 1.98 557414 .65 .66 13 557460 .19 .20 5574180 100-CAPAT BEGS hobby, m mice 557416 .29 .30 557462 .19 .20 SN74182 .69 .70 O 100-T CITORWATT RS,SPECIAL, ,oredips, etc, mica, leads (2(2735) 1.98 557417 .35 .36 557464 .19 .20 5N74190 1.49 1.50 carbon, metal, pre:, tng0 marked, leads (252735) 1.98 0 1.76 O 100-TWOWAITERS, 557420 .19 .20 0 557465 .19 .20 5574191 1.75 O -SLIDE100-POLYSTYRENEWI CAPS, asst vnluea, voltages, hi -E(2( (262729) 1.98 557470 .25 .26 O 5574192 .86 1.98 557423 .29 .30 .86 10 -SLIDE SWITCHES,TRA, spat to S, many types5(2etn. 13 557426 .25 .26 0 557471 .25 .26 5574193 .85 POWER TRANSISTORS, TO 253055 useableu e able (2(2626) 1.98 5574194 1.25 1.26 200 -PR -3 557427 .25 .26 0 557472 .25 .26 O 100 -PLASTIC RA RESISTORS, color -coded. work,.. ork, asst svaluestable (2E2609) 1.98 557430 .29 .30 0 557473 .55 .56 51474195 -0.9 .50 1.98 .75 .76 100-PLASTICISC TRANSISTORS, Tong 2, Rant values,2E259 nosily (2...... 557432 .25 .26 13 557474 .29 .30 5874197 1.98 .80 1.75 1.76 100 -DISC CAPS, note', 5750, long Inds (la S147437 .25 .26 557475 .79 5574199 200 DIPPED MYLAR CAPS, values A volt finest (2E24) 1.98 557438 .29 .30 5117476 .59 .60 5674200 5.50 5.51 ~laces, 200 -PRECISION RESISTORS, 1 Lb, 2, leads (2E2421) 1.98 0 557440 .19 .20 0 557478 .59 .60 5574251 1.75 1.76 1.98 557442 .69 .70 0 SN7480 .29 .30 S1474284 4.50 4.51 15 -VOLUME DIODE, single, 4,crdoubles, asst hafts es (2(2421 557443 .69 .70 0 557482 .39 .40 SN74285 4.25 4.26 150 -SWITCHING DIODES, ío'3148, most p mostly000aoy good (2(2415) 1.98 0700-15 400 S, mostly useable, w pop asst of obly 4151(2E2 1.98 100-IN4D00 1 amp, ail, moat pop, asst. mostly goodRood (25241]) 1.98 POP -AMPS AT PRICES RECTIFIERS, O "CENT-CIBLE" "KIT KING" $1.19 KITS - "The Eeono's" Buy ONE At Sale Price, Get 2ND For Only 1C More Order By Type No. CD BUY 5 KITS -- CHOOSE THE 6TH FREE! MONEY BACK GUARANTEE! 2 Tree Each 2 for Tvuo Each 21or Type Each for Quantity Description (order by Cat No., see paranthesls) Sale, ol O LM300H 5.49 $.50 LM374H 1.19 1.80 LM741V-N-H .29 .30 30 -RADIO -N -TV KNOBS, asst sizes, colors, ahopes (2E217) $1.19 LM301H-V .45 .46 0 LM376V .29 .30 8 LM1304 .79 .80 10-P115 PHONO PLUGS -N -JACKS, OCA style, 10 plugs, 10 jacks (2535.402) 1.19 O LM307V-N .45 .46 0 LM377N 2.25 2.26 1M1310 .99 1.00 35 -DIPPED SILVER MICA CAPS, includes rect types too, asst (2E455) 1.19 LM308V-H .79 .80 0 LM379 7.95 7.96 LM1312 1.99 2.00 DISC CAPS, use, asst values, up to (2E1219) 1.19 LM381N 1.69 1.70 LM1414V .79 .80 75 -PREFORMED for p.c. 2KV LM309K 1.79 1.80 0 10 -NE -2's WITH RESISTOR,,forT for 1el,, use, neon, loado (251222 1.19 O LM311HV .79 .80 0 LM387V 1.19 1.20 LM1458V .69 .70 LM318V 1.29 1.30 0 LM531H 1.49 1.50 0 LM1800N .99 1.00 O 12-TR HEAT SINKS, ET asa melee A. plastic ONOtnpp fin type (251832) 1.19 .66 O 12 -TRANSISTOR SOCKETS, neat styles NPN mp. types (2(1920) 1.19 LM32OH-5,12,15 1.19 1.20 LM532HN .29 .30 0 L513028H .65 1.19 11.13200-12, 15 1.19 1.20 0 1.51555V .75 .76 0 1M39005 .49 .50 Q 20-THERMISTORS, a resistor 1801 changes .vilh temp, protectal (252048) LM320T-6,15,24 1.19 1.20 0 LM558V .79 .80 LM3909V L75 1.76 40 -INSULATED RF CHOKES, resistor a ag. styles, coded (2E3203) 1.19 LM322N 1.19 1.20 0 LM5615 1.00 1.01 0 1.54195 1.95 1.96 30 -WIRE NUTS, tics, 2 bore ended together (2E3833) 1.19 LM324N 1.75 1.76 LM565N .99 1.00 0 1514250 1.19 1.20 2 -BLANK PC BOARDS, 6'a0 double aided,aided C-10 12E3824í 1.19 O LM339N 1.09 1.10 LM567V 1.95 1.96 LM75451 .39 .40 2 -BLANK PC BOARDS, x, double tided, C-10or ( 253824) 1.19 O LM340K-5, 6, 8, LM703H .49 .50 LM75453 .39 .40 3 -"OPEN FACE "ICSREADOUTS,K l doubles, s sing sags (2(2934) 1.19 12.15,18,29V 1.19 1.20 1M70411 .29 .30 0 1_5175491 .79 .80 FIBER3 -PIGGY -BACK" IC SOCKETS,2 will hold pin IC's-on slab (21 693) . . 1.19 LM340T-5, 6, 8, LM709N-H .25 .26 LM75492 .79 .80 4IBER OPTIC LITIC .IAN, 12" long high'> ends, vinyl jack í(2E3400 1.19 12, 15, 18, 24 4 -FERRITE "STIC:t" ANTENNA, T"xt/.", 1111 Scott, Fisher hl -8 e4pt (2E 3400) 1.19 1.19.59 1.-60 LM733N .79 .80 0 P4239 94 1.30 0 60 -TUBULAR CAPS, asst molded, plastic, mylar, values, volts (2E219) 1.19 .89 .90 0 PA263 1.50 1.51 LM35ON1.29LM37ONH 1.29 1.30 LM739N 55 -LOW NOISE RESISTORS, for hi-fi, metal films % % to 25V (2E220( 1.19 O 50 -POWER RESISTORS, w and, VS, s4, up 25 w sat (2E228) 1.19 O 60 -COILS AND CHOKES r'pf. ant parasitic, i-(. etc. (2E297) 1.19 PENNY SALE PRICES LISTED ARE GOOD TILL MAR. 15, 1978 75 -HALE WAT7ER5, res!stora, color -coded, carbo-film, most pop (35454) 1.19 WE RESERVE THE RIGHT TO LIMIT QUANTITIES'II"' 10 -SOLAR CHIPS, albeon, "broken ene.-gy", each 01,11, 0.50. nett mili. (2E5083) 1.19 RIEE: CHOOSE DOUBLE BONUS 1 Low Power ICs 1 ANY $1.19 ITEM, By No.I2E3667 Type No. \ OUR $25. PLUS MORE 'PENNY SALE' ITEMS! \ Order Cat. á SURPRIZE PAK FREE Sale 10 Sale Typo Sale Typo Sale GET Cat. No. Output V. Amps MI.c. Each 21or 74L500 $.32 741_5132 1.11 \ BOTHTEITEMS FREE O 2E3399 6.3V 500mn Metal encased $1.98 $1.99 Í 741502 .32 741_5138 1.24 WITH ANY 2E3814 6.3V IA Open Irame 92.49 $2.50 74L504 .35 O 741_5139 1.24 $15 TRANSFORMER 0 $1.96 ]4L508 .32 741_5151 1.2' We think, add ORDER: 1 0 2E3412 12V 300ma Open frame 51.95 25c for 741_5153 1.25 5 handling! SALE. 2 2E4400288 12V Ole`aal Iramesed \ 741510 .32 PENNY 1A 52.955 $2.96 1 74L511 .32 O 741_5155 1.25 BUY ONE AT SALE PRICE, 2E3323 24VCr 300mn Open (rama $1.95 $1.96 741513 .64 74L5í60 1.47 frame 51.96 741520 .32 7415161 1.47 2ND FOR ONLY tC MORE 2E3937 24V IA Open 51.95 \ \ O 2E2773 48Yer 2A Metal encased $2.95 $2.96 741521 .32 O 7415162 1.47 Primaries 253875 110V 300.60 Isolation $1.19 91.20 741.522 .32 O 741_5163 1.47 110VAC 1 741527 .39 741_5168 1.66 \ 741510 .32 74L5160 1.6E 1 ]41.532 .39 7415173 1.68 IN400o Epoxy Reetífíers SALE! DIP SWITCHES [ 741537 .45 O 7415174 1.0 BUY ONE AT SALE PRICE, \ 741.538 .45 741_5190 1.77 \ Miniature) Order by Cat. No. and Type No. 1 1.5 Amp] 2ND FOR ONLY le MORE! O 741542 1.19 o 741_5191 1.75 Sale 1 741.547 .99 7415192 1.75 Cat. No. Type No. Ply Sale 16 Sale \ 74L574 .49 7415193 1.76 \ Cat. No. Switches Each 2 for .89 O 2E2377 1N4001 50 10 for $.65 20 for $.66 o 2E 3668 2 9.77 5.78 .89 1.25 2E2378 154002 100 10 for .75 20 for .76 3 88 .89 1 O 741592 O 7415197 0 o 2E3669 O 741-593 .89 741_5257 1.35 - 2E2379 154003 200 10í4r .85 20í4r .86 2(3021 4 .99 1.00 400 o \ 7415109 .58 741_5266 -54 Í 2E2380 154004 10 for .99 20 for 1.00 o 2E3670 5 1.19 1.20 741_5112 .58 741_5366 .66 2E2381 1N4005 600 101,r 1.29 20 for 1.30 2E 3671 6 1.29 1.30 1 74L5113 .58 741_5368 .69 a 0 2E2382 1N4006 800 10 for 1.39 20 for 1.40 o 2E 2677 7 1.79 1.80 \ 7415114 .49 7415390. 2.95 \ 2 Epoxy Bridge Rectifiers -Amp lc sale MICROPROCESSORS! Send for your FREE PIV Sale Each 2 for PENNY SALE! BUY ONE Sale POLY PAKS CATALOG AT SALE PRICE, GET 0 50 9.59 9.60 MEMORIES D Mcó6t 524.95 2E2320á Type No. ?_ .69 .70 C-MOS 2ND FOR ONLY IC MORE 14.95 Typo Sale Types sale tos WORLD'S O 210000 .69 .7 SUPPORT! 0 é0004á" 9.95 FEATURING THE 1.19 - Full Wavel TO -5 c40e1 400 .89 -90 0 1101 O CD4000 5.29 CD4022 800 Order By Cap, No .69 CD4002 .29 O CD4023 .29 r°- 2E3459 á Type No. D 1103 1.29 Order by Cat. No. 2E1346 800 1.19 1:20 17520 CD4002 .29 CD4024 .79 1000 1.29 1.30 5.95 CD4003 1.19 CD4O25 .34 ; BEST BARGAINS and PIV 21024,1 1.69 CD4007 .29 CD4027 .69 IN ELECTRONICS oNMs O 2111 5.95 CD4003 .79 CD4028 .89 0 100 O 2112 2.49 O CD4009 .59 CD4029 1.19 ; 2708 19.95 CD4013 .59 O CD4030 .49 Terms: Add Doatane Rated: net 30 61(4200011 i ° 3/8"Sq. POTENTIOMETERS 500 3.95 C04011 .29 CD4033 1.60 Phone : Wakefield, Mass. (617) 245-3829 O 6615202 6.95 CD4012 .29 O CD4035 .99 upright -type 64 SALE! 16 2 .i 16-18 Del Carmine St., Wakefield, 1_] 2E3863 25 Tarn PENNY 665203 895 1 CD4013 .69 CD4040 1.19 Retail: 25 Turn flat, (YO. 64 21( D MM5260 CD4015 1.19 CD4041 1.25 2E3864 type 63 514 MINIMUM ORDER -$6.00 E° 2E3866 Single turn 11aí SPECTROL 81.15262 .99 ® CD4015 .49 CD4042 .88 seWd,.iyer'SKINNY-TRIMS'OBre 10K 8212 3.95 C04017 1.19 CD4046 1.79 tnlernnoe, ..s O 8216 3.95 O CD4013 1.19 O CD4049 .49 fihatf, x2007 6et any 508 O CD4013 .49 CD4066 .79 watt. Cermet construction, Choose OHMS 1008 O 8224 4.95 POLY PAKS CD4071 .29 é>' Can. 144. + D 8228 9.95 CD402) .99 O and a Order to ea 200K O CD4021 1.29 BOX 942 E and Value. 2 for 700 20 5000 8251 11.50 P.O. aNc. 0 8255 11.95 Avellabl In all $.eo50each 0 1 Meg LYNNFIELD, MA. +Avallabla In Cat. No. 353863 40íY- -

INFORMATION CARD © COPYRIGHT 1978 - POLY-PAKS INC. CIRCLE NO 38 ON FREs

FEBRUARY 1978 109

AmericanRadioHistory.Com 1111R1/0 /(11) BUG600KS 1 and It 617.00 pet Sol filf/M/ 7400N TTL Ellffp h Pelee A. Re., Dado G. lamo, w14IT1 HOBBY -WRAP TOOL-BW-630 Continuing Education Senes n4 ,s , set Irm e Iw o boobown,. on, sa m 4es41wd n team trear,000( de r ne w neta a .now ames rn w9.ar0 mí54 n 175016171110 Cm i6 SN7472N .39 SN74160N 1.25 tor.. loth mvoaorarse. 5.444 V.11 kan about. bans noma. t. Battery Operated (Size C) 5474014 .18 54747374 39 SN74161N .99 004,1 eNamww mawlnp ales, 18940 0í8w41, aleles. damaw s mu lo ele.en aeunnisivs.1594.4411m RAY .,ROM'a.,n moco. mum more. 11 SN7402N .20 54747414 .35 5N74162N 1 95 Weighs ONLY Ounces SN7403N .20 SN7475N .50 SN74163N 99 30 77 BUOB00K IIa 55.00 Wraps AWG Wire onto SN7404N .20 5N7175N .35 SN711644 99 by Pelo n. noey.0a.49. l.raen. 415111 Standard DIP Sockets (.025 inch) 51474054 .20 SN7479N 5.00 S4711654 .99 ta,r $34.95 M .urn/ w0 41wu4 you I0 th 40u4us udR1 a4 -Iha1 a0 immmnl SN7406N .35 9174804 .50 SN74166N 1.25 l0aneues not MXA. with built-in bit and sleeve 44+44 wteen dY Lennon. etc 5na 16u1 mamCmami n ,No mwn Complete 51474074 .35 5474824 .99 SN141674 3.25 surron11044 and 54 115 232Ci0e4,04 Suna,16. Pin¢aarry nmmmenaea 5474084 .20 5474834 .70 '5N14170N 2.10 10 ,M RTTY emNswl SN7409N .25 5N7485N .09 SN74172N 6.00 THE 555 TIMER APPLICATIONS 55.95 BUGBOOK III 519.00 SN7410N .20 S147485N .39 51474173N 1.50 WIRE -WRAP KIT WK -2-W SOURCEBOOK WITH EXPERIMENTS 4y Pe4r 0. Ran., 0411 0. Larsen. , I144A - 70 SN7411N SN7188N 3.50 SN74174N 1 25 A 00.04 M, 0.mn , Out .11oaw`4K aes4enw..pn ^^Kn .wwae 1a1 WRAP . STRIP . UNWRAP 5974124 .35 SN71894 .99 1N11. what 2.49 514741751. took ...you the 355 M.r n om Mw t0 use a. wa over m m4 kM ry.0700aw.MwrYs, SN7413N .69 SN7490N .45 SN74176N 19 so0 .nnul eelipn wMlnws.w plepM b4nee'na+o éóó o wer c"xmwiwswana msrnmIpn , Tool for 30 AWG Wire SN74144 ,70 SN7491N .75 5474177N 79 band n rOnemmawn tpacnel.Lieu or the none one Mooch, pwwar,on tlnmusic and around nMIGBOOA516babe Roll of 50 Ft. White or Blue 30 AWG Wire" 5474164 .35 S147492N !9 54741794 2 aoap 413903004'4 5474174 .35 9474934 .19 5N7416oN 005800K V and VI 519.00 sal 50 pcs. each 1". 2". 3" 8 4" lengths l INSTRUCTOR'S MANUAL per - 13.00 5474204 .20 54749414 .79 SN74181N 2.49 by D.de 0. 004,4. Osier n, Mg, 444auan A nth Massa, bar 44007644 a 84mk 1. II M s ountonl Harem pre-stripped wire. .39 .95 104 SN7421N SN7495N .79 SN74182N for l40,naa4 44m. of Auln 0,0P0,0n Y Nut elearmia. 6030A mempwermm 0n0Lena4nmm SN7422N .49 54749674 79 54741814 195 e4emp0e94n1011.t.a *mug lo, se... 111.411. 0Á0A An aepn0e4 app me c 44.Y1 ei.a°wam'4 104 00406 n0'np;piWn mmup $11.95 SN7423N .37 5474974 3.00 5474185N 195 OP AMP MANUAL 59.00 0084444 N 4004100 loe a anO,aa0 400 01 41740th; , uegr SN7125N 29 94741004 1.25 SN7418614 15 00 ppban el dpnlnrW amWlers 0.,r 75 e.Rn 0 "7 slop 3-1 6 4wnnry SN7426N -29 547410714 39 SN74187N 6.00 m Ma 119,9,===11=10 6 WIRE WRAP TOOL WSU-30 SN7127N 37 SN71109N .95 SN741118N 3 95 0002 í5.00 CMOS-M - DESIGNERS PRIMER S6,00 WRAP STRIP UNWRAP -55.95 5474294 .12 5N74115N 1.95 SN74190N 1,29 ANO HANDBOOK pe11 aM,Orern apug,,. A a49m ra emMrq, aW9gtq and 1.1414 SN7430N .25 64741214 ,39 5474191N 1.25 nxntN 144w9e p441771. Suns,' bass Anson a CMOSO4na1 441411 WIRE WRAP WIRE 30 AWG SN7432N .25 5N74122N .39 5N74192N - SN7437N .35 54741234 .50 54741934 89 COMPLETE MANUAL FOR DIGITAL CLOCKS by John Weiss and John Brooks 25 ft. min. $1.25 50 ft. 51.95 100 h. $2.95 100011..515.00 SN743BN .35 5N74125N .60 1 25 an0e5 lethniman or hobby's(Kiln bail[ Iheor es behind digital clocks Includes trouble shooting qul0e5 bask 547419411 SPECIFY COLOR White - - - Yellow Red - Green Blue - Black 5474394 .25 SN74126N .60 917419514 .75 Cnara6lenObAS Of clocks. soldering techniques, clock component data sheets and cOnnilutllon tips. $3.95 547413214 SN7440N .21 125 SM74196N 1 00 WIRE DISPENSER SN7411N .09 SN141364 .95 1.00 WD -30 SN74197N 125" fila. - die .190' SN7442N SN74141N 50 ft. .69 1.15 SN74198N 1.75 %0209 Red ACI11 Fed 10/51 roll 30 AWG KYNAR wire wrap wire $3.45 .75 ea. SN7443N 5N74142N 2.95 5474199N 1,75 AC209 Green ái1 %CIII 5men 411 Cuts wire to desired length 5974444 .75 54741434 3.25 5 59 647421734 40209 Orange 11 ECIII Yellow 111 Strips 1" of insulation Specify Blue-YellowWhite-Red SN7445N .75 1.79 DISCRETE LEDS - 54711401 3.00 5474251N 80209 Yenow 4,51 XCIII Orange 111 SN7446N .99 SN74145N 1.15 SN74279N 90 .201- dla .185 dla. 200" 069. .085- ma. REPLACEMENT DISPENSER SPOOLS FOR WO 30 5474174 .ẠSN71147N 2.35 SN74283N 2 25 ÁC22 Red 511 AC526 Red 541 )10556 Red 511 MY50.Red 651 SN7448N .89 91741484 2.00 014742844 6 00 Specify blue, yellow, white or red 51.98/spool 0C22 Green 411 AC526 G1wn 411 Yí556 Green 411 5974504 .25 SN711504 1.25 SN74285N 6.00 8022 Yellow 411 AC526 Yellow 411 Yellow 451 0750.060 LEO .25 54741514 .79 %C556 DIP/IC INSERTION TOOL WITH PIN 5474514 54743554 75 t '16 STRAIGHTEN %C22 Orange 441 AC528 Clear 4,51 ÁC556 orange 1 51 SN7453N 25 647415314 .59 5414366N 75 S5L-22 RI 411 KC556 Clear 751 Fat 5/1.00 Inserts both 14 and 16 pin packages. Pin Straightener SN1454N .25 SN741S4N 1.25 S47436214.15 6474599 .25 54741554 .89 SN743664 75 built into Handle. TYPE POLARITY NT PRICE SN7480N .25 SN74156N .89 SN74390N 2.25 MAN 6630 Common Mode -orange 560 125 Model INS -1416 53.49/ea. .45 DISPLAY LEDS SN7470N SN74157N .89 SN71393N 2 25 MAN 6640 Common Cailwde'orange.0.0..560 1.25 TYPE POLARITY NT PRICE MAN 6650 Common Catnode'orange .1 .560 1.25 20% Discount for 100 Combined 7400'5 MAN 6660 Common Anode.orange .560 125 HP 5082-7400 SERIES MULTI -DIGIT MAN 1 Common Ano4e.nd .270 2.95 - MAN 6680 Common Calhode'oranoe .560 1.25 10+ MAN 2 5 a 7 001 90(04 -red .300 4.95 MAN 6710 Common Anodered'D.D. .560 1.25 CMOS MAN 3 Common Calhddered .125 .39 Vs" ht. Common Cathode Red 2 S.49 .39 MAN 6730 Common 0100eled .1 .560 Digit C0400 23 004520 1 1.25 004044 .89 29 MAN 4 Common CAt5Odered .107 1.95 C04001 23 MC14562 11.50 MAN 6740 Common CalIOOe-red-O.D. 560 1.25 3-5 volts (A 5 mils/second 3 Digit .59 .49 CD4046 1.79 MAN 7 Common Anode -red .270 125 C04002 23 C04506 2.25 MAN 6750 Common 04lnodered _1 .560 1,25 7 segment Monolithic 4 Digit .69 .59 C00047 MAN 7G Common 00003 -oreen 270 1.95 1.19 2.50 MAN 676D Common Anode -red 560 125 C04006 MC14583 3.50 MAN MOO,(011ow .270 C04048 1 35 7Y Common 1.95 Dip Package 5 Digit .79 .69 C04007 25 74C00 Serles MAN 5780 Common COlnodered .560 1 25 CO4049 !9 MAN 52 Common Anode -preen .300 1,00 CDd009 ,49 71C00 39 01701 Common An0de.red .1 300 100 CD4050 !9 MAN 71 Common An0dered .30 1.25 CD4o10 .49 74032 55 01702 Lommon Camode.red 300 1.25 1.19 MAN 72 Common An0de.re0 .300 1.25 004051 01704 Common Cathode-red TV GAME CHIP SET $9.95 CD4011 74C01 75 MAN 300 1.50 1.19 74 Common Calnodered 300 1 50 - C04053 CD4012 .25 74C10 65 01707 Common 01008 Rd 300 1.50 Includes AY-3-8500.1 Chip and 2.010 mhz crystal C04056 49 MAN 81 Common Anode'yellow .300 1.00 C04013 .39 74C14 0L741 Common Anode -red .600 1.95 3 00 MAN 82 Common Anode -yellow .300 1.00 (2.010 51.95 ea/AY-3-8500-1 Chip $8.95 C04059 9.95 Anode crystal - ea.) 1 01746 - CD4014 39 74C20 65 Common -red 0I .630 1.95 CD4060 1.49 MAN 84 ' Common Cathode Yellow .300 1 00 c04015 1.19 71C3D 65 0L747 Common 0no0e.re0 .600 2 25 CD4066 .79 MAN 3520 Common Anode -orange .300 1.00 ZENERS DIODES RECTIFIERS 0040113 74C42 15 01749 Common Callmdered .1 .630 1 95 - !9 2 - C0406B 39 MAN 3630 Common Anode'orAnge -1 .300 1.35 TYPE VOLTS W PRICE TYPE VOLTS W PRICE C04017 1.19 74C73 150 01750 Common 0,1One-red 500 2.49 C04059 .45 MAN 3540 Common Cathode -orange 300 1.75 1N746 33 4005 4/1,00 144005 600 P101 AMP 1011.00 001018 .99 74C14 I 15 01335 Common Catlode.red 110 .69 MAN 1610 Common 9408,oran00 .300 I CD4070 55 100 IND70 147514 5.1 400m 4/1.00 144000 800 PP/ AMP 10/1.00 C01019 .49 74089 4 00 Common Catnode (1N2352) 250 75 C04071 .23 MAN 4610 Common Cathode -orange 400 1.00 114752 5.6 40m 411.00 114407 1000 PIV I AMP 10/1 00 C01020 1.19 FND503 Common Cathode (5N0500) 500 1.29 74C90 3.00 MAN 4710 400 1.00 40011 4/1.00 CD4072 49 Common MOOCH. .1 FN0507 14753 6.2 143500 50 20010 6/1 00 CD0021 1 39 74093 Common Anode (442510) 500 1.29 004076 .23 2.00 MAN 4730 Common Anodered .400 1,00 11475/ 6.8 1004 411,00 144148 75 105 15/1.00 5082-7300 4 % 7 631 CD4022 1.19 74C95 2.00 OIgn'RHOP .600 19.95 C04081 .23 MAN 4740 Common CAlhOne-red 400 1 00 114959 8.2 400,9 8/1.00 1N4154 35 IOm 12/1 00 004023 .23 74C107 1.25 5082.7302 1 A 7 S41 0i0it-040P 600 19 95 CD4082 23 MAN 4810 Common Anode- 1100 400 1.00 1496513 15 100m 41,00 1144305 75 25111 2011 00 C04024 .79 74C151 5082-7364 0uerrenge cnaracler I, 1) 600 15.00 C04098 2.49 2.90 MAN 6610 Common An0de'orange.D 0 580 1.25 145232 5.6 5005 26 144734 5.6 Iba 28 50827340 4 a 7 Sol. CD4025 .23 740154 .3 00 DIgnHe.adeclmal .500 22.50 MC14409 14.95 145234 6.2 Stem 28 144735 6 2 Iba 28 CD4026 2.25 74C157 MC14410 14,95 2.15 145235 6.8 500m 28 144736 6.8 I/O 28 C0A027 .59 740160 3.25 XR-2206KB Kit S19.95 OR-2206KA Kit 514.95 MC14411 14.95 RCA LINEAR 145236 7.5 501)r11 2B 1144738 82 Iba 28 CD4028 .89 740161 3.25 WAVEFGENERATORMRS TIMERS MC14419 4.95 C93013 2 15 CA3082 2.00 14156 25 404 611 00 144742 12 Iba 28 004029 1,19 74c163 3.00 1,0 51 .49 MC14506 .75 CA3023 2.56 042083 114458 150 700 6/1.00 141744 15 I. 28 CD4030 .49 740154 3.25 CÁ3035 2.48 043086 .85 %4 205 00 40 55 MC14507 .99 EXA R 111485A 160 10m 511.00 1141183 50 PIV 35 AMP 1 60 C0<035 .99 740173 75 04'22060P 5.50 KR'55:CP 185 C04508 3.95 2.60 CA3039 1.35 003049 3 144001 50 PIV I AMP 12/1.00 141164 100 PIV 35 AMP 1.70 CD4040 1.19 74CI93 2.75 093046 130 003091 3.50 %R-2207CP 3 85 MISCELLANEOUS 064060600 3 20 C04510 1,39 144002 100 PtA 1 AMP 12 100 141185 150 710 35 AMP 1 50 C04041 125 740195 2 75 LÁ3053 1.50 CA3102 2.95 %R.2211CP 56 70 A P 4 8D C04511 129 144003 200 PIV I AMP 12 1 00 141186 200 MY 35 AMP 1 00 C0/012 .99 40095 1.50 3 CA3123 2 15 DECODERS 01.13601.136STEREO1D6 2.00 PHASE LOCKED LOOPS LD4515 2.95 C03059 25 144004 400 7111 I AMP 12 1 00 141188 400 716 35 AMP 3 00 60097 1 CA3130 139 01'1310CP 53 20 64.1468 3 65 01,211 5 20 CD4518 1.29 50 063060 3 25 1 8/1310504 04.1488 003080 85 C03140 25 320 5.80 4/254 690 SCR -AND FW BRIDGE RECTIFIERS .11300P %8.1489 180 1 1M30H CA3081 230 CA34111 49 3.20 %R-56.CP 95 .80 LINEAR LM239N 1.19 %0.2567 C360 15A @ 4000 SCR 51.95 CA3600 1 75 2.99 087208 5.20 011-5001 170 11.130111 .35 .35 161340T 13 1.25 LM741LH 0380 354 @ 2000 SCR 1.95 1M30ICN .35 LM34oT-12 1.25 1/1741CN .35 IC SOLDERTAIL LOW PROFILE (TIN) SOCKETS 242328 1 NA @ 2000 SCR .50 LM302H .75 1.25 39 - LM340T-15 LM741.144 124 2549 50.100 1.28 3.49 004 980.0 126 @ 500 FW BRIDGE REC 1,95 1M30411 1.0 1.743407 15 1 25 LM747H .79 5010 6 we 5 17 15 IS 24 pm 5 38 37 MOO 9803 IDA @ 2000 FW BRIDGE REC 1.95 11.130511 ,60 LM340T-21 1,25 LM747N .79 36 11 pm 20 19 18 28 pm 15 LM307CN 35 01174811 39 x4150 041 m LM350N 1.0 16 pIn 22 21 20 36 pm 11.13031-1 1.00 1M3S1CN .65 0147484 .39 60 59 58 TRANSISTORS 18 pin 29 28 ?7 40 ñ LM308CN 160 7606 1.75 LM1303N .90 pm 63 62 61 22 pin 37 36 35 75)m103 1M309H 1.10 1M31014 1.15 LM1301N 1.19 SOLDERTAIL STANDARD (TIN) 2153701 i4l m 4.03 41 CO 14 pm 5 27 163701 Sasm 101. 101 CO 1M309K 125 LM373N 3.25 LM1305N I!0 25 24 28 pIn 5 99 90 81 16 pm 30 25 175705 La1m 1.15 27 pin 139 1 U43104 1113774 4.00 1M13074 .85 l6 26 15 551m 18 0m 15 12 LM311H .90 1.1438014 125 LM131014 3.95 40 an 1 59 T 15 1 3C 312; NIW 24 a0 49 45 12 * 1843114 90 LM380CN 1.65 4374 541 00 .99 0I511351N SOLDERTAIL STANDARD (GOLD) LM311K 7.50 LM381N 1.79 LM1114N 1.75 1113711 5 B pin 30 1113715 51m 051318014 1.50 LM382N LM1458CN .59 5 27 24 71 Dm 5 70 63 57 1.79 111771 5119 14010 35 32 29 28 ban I LM319N 1.30 NE501K 8.00 LM1496N .95 .A'' 10 100 90 1153903 541,00 16 pn 3B 35 32 36 4M11 00 1113208-5 1,35 NE510A 6.00 1M1556V 1.75 an 175 0 1 26 2113. 18 pn 52 47 43 ell 40 pin 1 m LM320K-5.2 1.35 NE5290 4.95 1112111N 1.95 175 59 1 45 3oA 1.35 NE531H LM2901N WIRE WRAP M5 L113205-12 3.0 2.95 SOCKETS (GOLD) LEVEL 003 .10013 iCO 1.35 NE536T 103053 1,50 161320.15 9.00 8 pin 0.40 .311 .35 ZT DIn .95 .85 .75 1.04 31400 01.13207.5 1.25 NE5401 6.00 01430654 .69 10 on 45 11 37 IIII' pm 24 51 05 95 85 7,1?'69 11r42 1151mII L143207.5.2 1.25 NE550N LM3904(3401)49 pin 1.30 11 39 38 37 28 Pin 40 1 25 1 10 0113207.8 1.25 NE555V .39 LM3905N .59 16 pin 43 12 36 pIn 159 130 '15 CAPACITOR 50 VOLT CERAMIC CORNER LM320112 1.25 NE560B 5.00 1M3909 1.25 18 pin 75 68 62 40 on 75 55 I40 DISC CAPACITORS 0813201-15 1.25 4E5518 5.00 1.1455554 1.85 1.9 10.19 1/13201-18 1,25 NE5628 5.0 MC5558V 1.0 50 PCS. 50.100 1.9 10.49 50.10 RESISTOR ASSORTMENTS PER ASST. 10 21 1.25 NE565H LM7525N .90 $1.75 .05 .04 33 .01ní .05 .D4 .035 114320T-24 1,75 IO OHM 22 pl .05 .04 .03 0M32361 5.95 NE565N 1.25 LM7534N .75 12 OHM 15 060 18 OHM 22 OHM .047,F .05 .01 .035 1 47 pI 05 .04 .03 LM324N 5.80 NE566CN 1,75 8038B 4.95 ASST. s ea. 27 OHM 33 OHM 39 OHM 47 0110 56 OHM 104 WATT 5w - 50 PCS. .01,4 .05 .04 .035 100 of .05 .04 03 .0220F .06 .05 .04 11433914 ,99 NE 587H 1.95 LM75450 ./9 68 OHM 82 OHM 100 OHM 120 OHM 150 OHM 220 91 05 ,04 .03 .041,E 1M340K5 1.35 NE567V 1.49 75451CN 39 .0 .05 .04 ASST. 2 5 ea. 180 OHM 220 OHM 270 OHM 330 OHM 390 OHM 104 WATT 5% - 50 PCS. 470 pI ,05 .04 ,035 . I .12 LM3406-6 1.35 1M103CN .45 75452CN .09 .075 470 100 VOLT 501.411 FILM CAPACITORS LM3401c-0 1.35 LM709H .29 75453CN .39 OHM 560 OHM 680 OHM 820 OHM 1K .0151 12 .10 .07 .022m1 .13 .11 .08 LM340512 1.35 LM709N .29 75454CN .39 ASST. 3 5 ea. 1 28 1 SK 1 86 2 28 2 70 lid WATT 5% 50 PCS. 0322 .12 .10 .07 1.35 06171014 75491CN 79 047m1 21 .17 .13 1M340K-15 .79 3 38 3.96 4 78 5 68 6 85 .0047m1 .12 .10 .07 .151 27 .23 .17 1M340K-18 1,35 LM711N .39 7549204 .89 ASST. 4 5 ea. 6 2K ION 128 ASK 18N I/4 WAR 5% 50 PCS. .01ml ,12 .10 .07 2251 33 .27 .22 0031011.24 1,35 1.6172311 .55 75494CN .89 20% DIPPED TANTALUMS CAPACITORS 1M3407.5 125 107234 .55 804194 5.95 221 27% 335 39K AlA (001101 115V .28 .23 .17 1.5/359 30 .26 .21 0034006 1.25 11.17334 1.0 RU195 3.25 ASST. 5 5 ea, 568 68K 828 FOOL 1205 1/4 WATT 5% 50 PCS. 15/35V .28 23 .17 2.2/25V 31 .27 22 1508 1805 2205 2701 3305 .221356 .28 .23 .17 317056 .31 ,27 .22 741502 .29 1.25 ASST. 6 5 ea. 3900 4708 56,131 6000 4205 114 WATT 5% 50 PCS. .33/35V 28 .23 .17 4.7/250 .32 .28 .23 47/356 711503 29 74LS00 TTL;;;;s; 1 50 28 .23 .17 6.8250 .36 .31 .25 1M 0 2M 1 569 1 8M 2 2M 71LS03 .39 741575 .69 7415160 1.95 .68135V .28 23 .17 10/250 .40 .35 .29 ASST. 7 5ea. 2.7M 33M 39M 4769 56M 1/4 WATT 54- 50PCS. 741504 .35 74L576 49 7415161 1.95 1.0/35V 2B .23 .17 15/256 .63 .50 .40 740505 .3s 740583 I.)5 7415162 1.95 ASST. BR Includes Resistor Assortments 1-7 (350 PCS.) $9.95 ea. MINIATURE ALUMINUM ELECTROLYTIC CAPACITORS 741516 .29 740585 2-19 7415163 1.95 601.1 Lead Radial Lead 741510 740588 Á7/50V .15 .03 .10 .47/250 .15 .13 .10 .29 .19 7405164 1 95 $5.08 Minimum Order - U.S. Funds Only Spec Sheets - 254 - Send 354 Stamp for 1978 Catalog 740513 741590 .89 1,01506 16 .14 ,11 .47/507 .16 .14 .11 .69 7405175 1,95 California Reoldenta - Add 6% Wen Tao Dealer Information Available 1405/4 t 75 741592 .89 7415181 3.69 3.3/500 .15 .13 .10 1.0/160 .15 .13 .10 741520 .29 741193 .89 7415190 2,49 4,77255 .16 .14 .12 1.0/256 .16 .14 .11 741526 .39 741395 1.50 74E5191 2.19 10/250 .15 .13 .10 1.0150V .16 .14 .11 10/500 .16 .11 .12 4,7/156 .13 .10 711527 .39 741596 1.89 7áL5192 2.49 1978 .15 741538 39 7405107 59 05193 2.49 Q' 22/25V .17 .15 .12 4.7250 .15 .13 .10 740530 .29 741510 59 7415194 1,89 Q P CATALOG 22/500 .24 .20 .18 4.7/506 .16 .14 .11 741532 .39 7411112 .59 7415195 1.89 47250 .19 .17 .15 10/16V .14 .12 .09 741540 79 74L5123 1-25 7105253 Ames NOW 47/106 25 .21 .19 10250 .15 .13 .10 741142 1,25 7115132 1.25 7415257 !:ELE 10256 .04 .20 .18 10/50V .16 .14 .12 741547 1.25 7415136 .59 7415260 I75 AVAILABLE 100/500 .35 .30 .28 47/501/ .24 .21 .19 741551 .29 7111138 1.25 7415219 .79 - .-_ _%..°max. __ _- 220250 .32 .28 .25 10/15V .19 .15 .14 HOWARD VE.. 741555 .29 74051i9' 1 25 7405367 . 220/500 .45 .41 .38 100250 24 .20 .18 741573 ,19 7405151 1.25 470250 '.33 .29 .27 10/500 .35 .30 28 7405360 .9999 PHONE ORDERS WELCOME - (415) 592-8097 741571 ,49 7415153 1000/160 .55 .50 45 220/16V 1.25 7405670 3.95 Advertised Prices Good Thru February .23 .17 .16 A 220/160 .70 .62 .55 470256 .31 .28 .26

110 POPULAR ELECTRONICS

AmericanRadioHistory.Com BREAD BOARD EacnxXconln535opares The Incredible cut to 14 dillerenl lengths MICROPROCESSOR COMPONENTS 1 ElJUMPER WIRE KIT'ramorms.o 80809 CPU $16.00 CDP1802 CPU $19.95 Each wire is stripped and "Pennywhistle 103e" 4.95 MC6800 . 8 Bit MPU 24.95 _ P the leads are ben, 90 tar 8212 8 Bit Input/Output 15.00 3g1511, - wry easy insertion 8214 Priority Interrupt Control 15.95 MC6820 Periph. Interface Adapter Wire length Is classified 8216 Bi-Directional Bus Driver 6.95 MC68104P1 128 x 8 Static RAM 6.00 y.: ./ br color coding. LI saU hair Generator/Dr ver 9.95 MC6830L8 1024 0 8 Bit ROM 15.00 $129.95 Kit Only _ AI Ire is solid honed 22 8224 Clock without gauge wdn PVC Insulator 8228 System Controller Bus Driver 10.95 Z80 CPU 29.95 The Pennywnrsne 103 ma capable ol recording data to and Irom audio tape The tyres came packed m RAM 5 Zeal speed requirements for the recorder and a is able la communicate directly 1101 Stalx 5 1 a and a convenient Masuc boa. CPU'S 256r' w:h another modem and terminal for telephone "hamming" communaatans JK1 ....S10.00 / kit 256x4 laic 5 9 adiuslmenis and is but pals non-preclsa, 80 BOA Super 8009 16.1x7 Olor ic' the deaf In MOaior, it Is tree ob twat 2102 1021 . 1 Start I IS readily avallabie with two rows of .025' sq. or 2650 e BIT MPL! 26 50 pans 2107 5280 4096 e Dtnwnº 1 95 Keying, IUli'dunlea (nail -duplex Mates PB085 CPU 29.95 Oda Transmlas,on Method Frequency -Sum olio. posts on patterns of .100" Obre 256 a SUM' 6 95 selectable). SOCKET SP'S :489 16e4 Sutra 2 49 Maximum Data Rate 300 Baud centers and shielded receptacles. 2504 rata Dynamo 0 3 95 I 8101 256 4 Static 5.95 ASynes0000us Serial (elum to martslever reguued . Oda Formal Probe access holes in back. Choice 2518 He. 32 90 00 S 9.11 7: Slarc 6 95 between each cnaraeterl. JUMPER 2519 40 sir 00 of 6" or 18" length. see 8599 ia Stara 9 Receive Channel Frequencies --.2025 Ha for spars. 2225 HE 105 mark 2522 Dual 132 Be S5R 2.95 21L02/91102 102: . 1 Suter 2 25 Transmit Channel Frequencies Satoh seleclab'x Low (norma4 1070 space, Part No. No. of Contacts Length Price 2524 512 Dynamic 1.95 :4200 256 , I Slaw 695 1210 mark. No . 025 space. 2225 mart. 924003-188 26 18' S 5.38 ea. 2525 1024 Dynamo 3.00 93421 109 . Receive Sensitivity -46 dam accousileally Coupled. 2527 Dual 256 311 395 4.78 I t 924003-06R 26 6" ea. IMM5262 2x a Ovnamic TIoe 00 Transmit Level -ts ohm nam rnal Adiuslable from -6 abm 2529 Dun 512 311 00 ea. UPD41412104)46 DynarnK 18 PM 5.95 IC -20 deco 924005-188 40 18" 8.27 2532 Guar 80 en 3 95 PROMS Receive Frequency Tolerance Frequency reference automatically aaiusls to 924005-06R 40 6" 7.33 ea. 2533 1024 Sute 5 95 1702, 20 8 Fames 5 9 95 for operation between 1800 w and 2400 Ha Edo 6 95 allow 50 18" 10.31 ea. 3341 tames 14 924006.188 5203 711,8 95 Data Interlace EIA R5 -232C or 20 ma current loop (receiver 15 731.5 670 16. 1 Reg 3 95 appal 924006-06R 50 6" 9.15 ea. 82523 32e8 Open C 500 oeralsolated and non-colarl users 825123 37e thole s00 Power Requirement 120 VAC. single phase, 10 Walls. Solder to PC boards for instant At -5.1013 306 Ban 55.95 95 745287 1024 Physical All components mount on a single 5- sy 9- ROM'S 3 95 "JUMPER plug-in access via socket -connector 160, 256.4 East onntd Urtult board All components ioduded 2513121401 Chal Ger .upper case 5 9.95 (2/08 8K -prt m 1019 to align jumpers. .025- sq. posts. Choice Pegwres a YOM, Audio OscnlaroF Frequency Coonte, anmor 05uilOaaope 251313021) Char Gen Mower case 9.95 31 95 straight right angle. 2116 16K Eomm HEADERS of or 2516 Char Gen 10 95 6301.1 1024 pState BomarO 3 49 Part No. No. of Posts Angle Price MM5230 2048 CH (512 a 4 on 256 e 81 1.95 6330 I 256 Open Collector Bipolar 11 NEW! BULB -ENERGY SAVER 923863-R 26 straight 51.28 ea. CLOCK CHIPS BULB -ENERGY SAVERS used for years by SPECIAL REQUESTED ITEMS MA15309 5995 _ 923873.8 26 right angle 1.52 ea. sr major moustnal users now available for FCM3817 55 go 11C90 19.95 7205 19 95 9368 3.95 MM5311 )8 - - 40 1.94 ea. home or office use. Bulb Savers can cut 923865-R straight 0,3,85001 8.95 40033 3.95 ICM7045 2495 LOO 10/19t 25.00/ill MM5312 49595 923875.8 40 right angle 2.30 ea. Ay -59100 17,50 8720 750 IC117207 7.50 951390 11.95 5,9515314 495 A :' electrical bills by as much as 3%. MC3061P 923866-R 50 straight 2.36 ea. AY -5921x7 1a.% 8797 2.00 1CM7208 22.00 3.50 5405315 5 95 BULB -SAVERS lengthens light Me by: AYó-9500 496 H00155 7.95 ICM7209 7.50 MC4016 (744161 7.50 005318 9 95 Acting "shock 923876.8 50 right angle 2.82 ea. F) 1. as an electncal ab- 1350 MK50240 17.50 MC1408L7 B.95 2 AY -52376 rags MCe.6571 005309 95 sorber", turns the bulb on slowly, ellminat 75 MC140813 9374 1.95 MCM6574 13.50 050026CH 3 9.95 MUSEUM 995 10.50 Bulb lasts 3 or Inp the "thermal shock". Bulb irte increases 825115 25,00 MCM6575 13.50 TIL308 C77001 595 INTRA-CONNECTOR more Imes longer 300 percent. Fin Standard Socket 2. Banishes Current "Surges". Cushions Provides both straight and right angle functions. Mates PARATRONICS O vats to 200 wars line voltage surges when other loads cut IIII with standard .10" x .10" dual row connectors (i.e. 3m, Ainsley. Featured on February's Front Cover of Popular Electronics 10+ power line.51.50 etc.) Permits quick testing of inaccessible lines. BES -1 1-9 Logic Analyzer Kit Model 100A Model 10 ea. 1.25 ea. 3. Reduces Energy Consumption Pan No.: 922576-26 No. at contacts: 26 Price 56.90 ea. Model 100A III - DIGITAL STOPWATCH INTRA-SWITCH . Bright 6 Dqn LED Display $229.00/kit . limes to 59 minutes 59 59 seconds Permits instant line -by-line switching for diagnostic or OA Model 1o0A assembled 6295.00 Crystal Controlled Time Base testing. Switches actuated with pencil or probe tip. Mates with Analyzes any type of digital system . Three Stopwatches In One Times Singe Event - Sent 6 Taylor standard .10" a .10" dual -row connectors. Low profile design. Checks data rates ie excess of 8 s Sitea5".215 a 90' Ole ounxsl Switch buttons recessed to eliminate accidental switching. million words per second T Uses 3 Denote Cells applications are: Pan IS No. Price ea. TTL. CMOS. DTL, RTL. .Sore No.: -26 of contacts: 26 $13.80 Trouble shoot Troubleshooting microprocessor Kit - 539.95 Schottky and MOS families add-ess. instruction, and data flow Assembled Displays 16 logic states up to &digits wide - 549.95 Examine contents of ROMS _ CRYSTALS Ar See ones and zeros displayed on your Heavy Duty Carry Case $5.95 THESE FREQUENCIES ONLY -1- Truing operation of control logic CRT, octal or hexadecimal format Polio. - Frequency Case/Style Polos Checking counter and shift - Tests circuits order actual operating conditions Stop Watch Chip Only (7205) S19.95 CerA 0.000 MHz 11C33i8 55.95 register operation CY2A 2 000 MHz HC33'U 55.95 Easy to assemble -comes with step-by-step construction Monitoring I 0 sequences 1C72.01 2 010 MHz HC33/U 51.951 manual which includes 80 pages on logic analyzer operation. DPM KIT Verifying proper system operations II 31/2DIGIT 4 000 CY3A MHz HC18 U 54 95 (Model 100A Manual - $4.95) during testing CY7A 5.000 MHz HC18 0 94 95 2 CYr2b t0 000 MHa HC18 U 54 95 PARATRONICS TRIGGER EXPANDER - Model 10 Model 10 Kit -5229.00 07144 14 31818 MHz HG18U 54.95 Model ID Assembled - 5295.00 Adds 16 add6anal Ala. Provides digitalg delayand 4qualification of Input does Base/Idol 69.95 o'tu CY19A 18.000 MHz HC18 U $4.95 - and 24 -bit tugger word. -Connects direct to Model 1009 for integrated unit). Model to manual sess CY22A 20 000 MHz 11C78 U $4:95 - et - 04108 32.000 MHz HC113.a 54.95 a126y 3 a -Digit Portable DMM =0= CONNECTORS Overload Proteaed 100 MHz 8 -Digit Counter 3- high .60 Drsptay 20 11a-100 MHa: Range . Rout oower souses.l.e. PRINTED CIRCUIT EDGE -CARD Battery ar AC operaran .6- LED Dispay batteries, 110 or 2205 pale New Bipolar Unit Auto Polarity .156 Spacing -Tin -Double Read -Out Auto lacing Cryslal.eontrolled Ilmebase charger 12V with auto Auto Zeroing Low Power Hoy. Iva. 0.1 ohm resolution Bifurcated Contacts Fits .054 to .070 P.C. Cards Fully Automata lighter adapter and external - .5r' LED Single IC Unit 15/30 PINS (Soldef Eyelet) 51.95 Overange reading Penable - c0molerely 71-104 power supply 0 meg %tout imoenaence sell.cont med PINS Eyelet) S2.49 MAX -100 18/36 (Solder DC Amery i . rypcal sue-1.75x 738' $134.95 Model KB500 DPM Kit $49.00 22 44 PINS (Solder Eyelet) S2.95 Ranges: DC Voltage h0 -1000V/ X 5.63 Voltage Model 311D -5C -5V Power Kit $17.50 50/100 PINS (Wire Wrap) 55.95 AC 0.1000V I' Frees Response 50-400 132 50/100A (.too so0ctnq( PINS (Wire Wrap) $6.95 OC/AC Currant 0-000m0 JE700 CLOCK Resistance 0.00 meg ohm 25 PIN -D SUBMINATURE (RS232) IL The JE 11x1 is a tow cost dlgi,l clock Dul Sue 64 x - Y nigh red. I 7: 5 3144 b very guaiily un4 Ire uml DB25P PLUG $3.25 Me, a sommated w In,, Case path dr Model 2800 Accessories: 2, DB25S SOCKET S4.95 ACCESSORIES FOR MAX 100: mensions 0.6 l moves a AC Adapter BC -28 $9.00 a, s MAN72man woMness readout. and Inc $99.95 Mobile Charger Eliminator Rechargeable MM531a dock 050 Comes with test use power from can battery Model 100 - 592 53.95 -. 17 or 211óu 680-.759 201 Mads operalag enamel Batteries BP -26 20.00 Charger/Eliminator HEAT SINKS and spare fuse Carrying Case LC -28 7.50 use 110 V AC Model 100 CAI 59.95 KIT ONLY - 115 VAC $16 8 95 205-CB eryllium Copper w -black finish for TO -5 S 25 291-.368 Aluminum for TO -220 Transistors & CONTINENTAL SPECIALTIES PROTO CLIPS HEXADECIMAL Regulators S .25 PROTO BOARD 6 Other CS Prato Boards 14 PIN $4.50 ENCODER 19 -KEY PAD 680-.75A Black Anodized Aluminum for TO -3 $1.60 515.95 PB100 - 4.5" x 6" $ 19.95 16 PIN 4.75 1.0 Dude 4 Black Anodized Aluminum predrilled - long X 4'- wide) PB101 - 5.8" x 4.5" 29.95 24 PIN 8.50 (6" ABCDEF mounting holes for TO -3 444 x 1 e/a x 2" $1.75 40 - PB102-7"x4.5" 39.95 PIN 13.75 Shift Key oC0tJS PB103 - x 6" 59.95 Kits (cannot he snioped Pia air) j , 9" DESIGN MATES 2 Optional Keys Etching 51 PB104 - 9.5" x 8" 79.95 32 X A-1- P C Ertl Materials K11 529.95 ea. DM1 - Circuit Designer r`v PB203 a x enough for 5 wood boards a e/ - 9.75 644 214 80.00 $10.95 each 1 ' -1:5 $69.95 Kil PB203A - 9.75 x 614 x 23/4 129.95 27 X A-1- hence emrcud S 9.95 ea. DM2 - Function Generator Comalele al omy oca warm "Pon Plugbaards - 0"°"" P''' $74.95 6 5 5. 5 x 1 16 Epoxy grass S 6.95 ea 63 KEY KEYBOARD 3662 LOGIC MONITOR DM3 - RC Bridge P.Paneme.44 PC tabsspaced 1%- $29.95 $84.95 $74.95 Mating conneao. for 014550. - ea for DTL, HTL. TEL or CMOS Devices 22/44 S 2.95 lnis keyboard !enures 63 Oren - _ 22 pm double readout ill type wholes cured SPS7 keys. unattached to . . 5 1.595 590 irice2 50 . . 8800V un ersal Microcomputer Processor S19.95 ea CMG QT PROTO STRIPS b .,aer any tend o, P C B A very solo T59B bus sing 250 plugboard -E puny Glass complele molded piaslic 13 4 base - I'i . ie 45 6910re1001I' Ta75 0 tono with hemsink mounting m-595 JIIrY awls roe, aomnatans and hardware t i . Tdli;iE4i41ad:r!g33.e 7478 bus strip 25 {e1Xf'0 B -99W 1109165 Eraode Chlp(encodes 16 Keys) 57.95 es. 5 313 x 10 X 1/16 cooper clad 7355 350 850 ' C7 -59B 45-5-2376 Encoder emo 'encodes 88 Kern) 514.95 ee, .091411: 1.355 MA sino 2 00 iN11501191kLkiI9E9r71ti1y9W T.185 100 a 75 1/16 VECTOR BOARD 13r 47s :A./a:1'0110' 1Jlllii'52191b Y9'ii901ygB91E1 07125 120 175 44011/4--- D 1 Cale Snclne P.PaRern Pure - 01.175 07.85 80 325 PROBE van No L w 1-9 10 up - T 0115 JE803 9.1" or75 70 300 IirC Probe is which rs ld loe most PHENOLIC 64P44 062xxsP 4 50 6 50 1.72 1.54 r111+9ift0finl Dr.355 -re logre a and oar " 4.50 H9R991W69411p Experimento, 300 $ 9.95 xdespensaa in UMW wing logic fa 16915a4 062000P 17.00 3.69 3.32 OT IS nu CU05 derwe5 tM " Tll 411111 a EPDXY 64744 062WE 4.50 fi 50 2 07 1.86 e..i.01.358 Experimentos 600 $10.95 oil it ow",1 55i weds ta ourate directly on lar me WWI uoei GLASS 534P44 062,E .50 8.50 256 2.31 rest drawing a scan, 10 ma ma. it uses a MANS 169Paa 062wE 4 50 17 00 5.04 4.53 $5.00 Minimum Order - U.S. Furds Only Spec Sheets - 25e - Send 35e Stamp for 1978 Catalog mdeale loe by 169P61 062WE B.50 17.00 9 23 8,26 eadoul lo any o, loe owmgstates California Residents - Add 6% Steles Tax Dealer Information Available the 60069 GLASS 169P44 062wEC1 4.50 17.00 6.80 8.12 synods Olt IILOWI :uisesEI.P Mon lreguenryou%sea to 45 MHa COPPER CLAD 1978 teseoad ran delco $9$ 95 Per Kit cant rte used an MOS levels or cacuit damage CATALOG INSTRUMENT/ 'es"" printed circuit board ON/ CLOCK CASE ames T°L 5V 14 Supply AVAILABLE Inlecnon molded Inn. -ELECTRONICS This is a standard pal power supply 55, 09 Ire well mown raqutaiar IC to provele a solid 1 AMP or current at 5 Complete with red bezel. I 103095 1021-A HOWARD AVE., SAN CARLOS, CA. 94070 wits We Icy to make things easy Mr you by providing 495" x 4 x 1-9/16. you need in including the Nrdware PHONE ORDERS WELCOME - (415) 592-8097 everything one package $3.95 ea.'. Advertised Prices Good Tbru February °' 0n15 $9.95 Per Kit /

CIRCLE NO. 27 ON FREE INFORMATION CARO

FEBRUARY 1978 111

AmericanRadioHistory.Com Money back guarantee. NO COD'S. Texas residents add 5% sales tax. Add 5% of order for (All prices subject to change Radió postage and handling. Orders under $15.00 add 75 cents. Foreign orders add 20% for postage. without prior notice.) For your convenience, call your Bank Americard or Master Charge orders in on our Toll Free P.O. Box 38323P HutP Watts Line: 1-800-527-2304. Texas residents call collect: 1-214-271-8423. Dallas, Texas 75238 POWER SUPPLY 60 Base VARIABLE This model will power a 5 watt tran- Hz. Crystal Time UNSCRAMBLER sistorized Radio KIT NO. 1 ONLY CB for Digital Clocks Continuously variable from 5V to $10.95 20V $4.50 $19.95 Excellent regule Iron up to V, Amp

. KR includes all components Dolled libergless P.C. Board LOOK AT THIS SPECIAL Buy 2 for $8. Case included A. 60 Hz output with accuracy comparable to a digital 4400 Mid of filtering FROM RADIO HUT watch. One hour assembly B. Directly interfaces with all MOS clock chips. Plugs Into earphone or external Power Supply Kit: 5V1 amp reg. C. Super low power consumption ma type./ speaker of any Scanner or Monitor. Line regulation .005% 11.5 VARIABLE POWER SUPPLY D Uses latest MOS 17 stage divider IC. Guaranteed to unscramble any Load regulation 50mV E. Eliminates forever the problem of AC line glitches.. 1085 call. KIT NO. 2 Kit includes components. PC board, F. Perfect for cars, boats, campers, or even for portable Easily tuned transformer, fuse and pilot light. Line clocks at ham field days. Full instruction Included Same as above but with a 1 Amp oul- cord not Included. G Small pul, also with case size, can be used in existing enclosures. Drilled nbergiess P.C. Board ONLY 513.95 KIT INCLUDES CRYSTAL, DIVIDER IC, P.C. BOARD One Hour Assembly Only $6.50 PLUS ALL NECESSARY PARTS 8. SPECS. Punched Case

MA 1003 CAR CLOCK FROM NATIONAL $ 17.95 ALSO, THIS MONTH ONLY, INCLUDES SPECS. AND 3 SWITCHES. . FREE EDGE CONNECTOR.

'7400 TTL DIGITAL CIRCUITS .. ITT HIGH LEVEL LOGJC HOUSE .1 TTL Í0's ` CRYSTALS

7400 .,1. 7430 '13 7480 .31 74153 .61 301 Dual 5 Input NAND Gate .15 7400 1011.00 Please specify 7437 611.00 300 KHz 51.50 7401 .13' 7432 .23 7481 .55 74154 .98 302 Quad 2 Input Buller open collector .18 7604 1011.00 7438 6/1.00 3.57945 1.25 7402 .13 7433 .26 7482 57 74155 .89 303 Ouad 2 Input NAND Buffer .15 7408 10/1.00 Ina/ you 74141 3/1.00 7403 ' .13 ' 7437 .23 7483 .67 74156 89 311 Master Slave F/F .16 7420 10/1.00 are ordering 74153 3/1.00 7404 .15 7a38 .23 7485 .89 74157 .55 312. Dual JK Flip Flop .18 House Number TTL. 74L04 .29 7440 .13 7489 1.25 74160 .55 321 Quad 2 Input NAND Gate .18 , 74504 .44 7641 .76 7490 .65 74161 .65 322 Dual 5 Input NAND Gate .15 7405 13 7442 .47 7691 .61 74163 .65 323 Quad 2 Input NAND Gate .18 COUNTER AND CLOCK CHIPS 7406 .16 7443 .59 7492 .43 74164 .85 324 Quad 2 Input NAND Gate .18 MK50252 7407 .16 7444 .59 7493 .43 74165 .89 325 Dual 2 Dual 3 Input NAND Gate .13 Clock Chip 54.99 MM5316 7408 .19 7446 .68 7494 .67 74174 .85 326 Dual 2 Dual 3 Input NAND Gate Clock Chip 3.75 .13 MK50250 7409 .19 7447 .68 7695 .67 74175 .85 331 Dual 5 Input Expander .13 Alarm Clock 3.75 7410. .13 MK50380 Alarm CKES 7448 .71 7496 .67 74180 .67 332 Hex Inverter .18 Chip 2.95 y0 1C 7411 .18 FCM7010 Direct Drive Clock 4.95 P714 S1 yy0 7450 .13 74100 .30 74181 1.93 333 Hex Inverter .18 Chip 18 Op MK5005 4 7412 .26 7451 .13 74104 .49 74182 .68 Hex Inverter .18 Digit Counter wlLatch 8.50 5. pCHP 7413 334 MK5002 6Digit Counter .37' 7453 .13 74107 .26 74191 .98 335 Hex Inverter .18 8.95 ENP1-O°C. IC 7416 MK50395 6 12.95 .15 7454 .13 74109 .31 74192 .79 342 Dual One Shot Multivibrator .25 Digit UP/Dewn Counter 'NNE (CL 7420 .13 7460 .19. MK50397 6 Digit Elapsed Timer 8.95 74121 .29 74193 81 343 Dual 4 Bit Comparator .22 ' 7421 .13 CT5005 Calculator Chip w/ Specs 2.25 7470 .27 .74123 .48 74194 .81 370 Quad D Flip Flop .22 7423 .25 7472 .25 MK5021 Cal. Chip wing. rt. 2.50 74132 .99 74195 .69 371 Decode Counter .30 7425 .29 7473 .29 74136 .99 9316 .85 372 Ouad Ripple Counter 39 7426 .24 7474 .29 745138 1.95 9601 3/51 380 BCE to Decimal Decoder ,39 7a27 .19 SOCKETS - 7475 74141 .75 ' TRANSISTORS .47 9104 .35 381 BCD to Decimal Decoder .39 7a29 .. .26 7476 .31 74151 .61 8 Pin Low Profile .20 TRANSISTORS ITT MOS TO LED DRIVERS 14 Pin Low Profile .22 INTERSIL DUAL 16 Pin Low Profile .25 Originally Cost 53. each 74L500 LOW POWER SCHOTTKY Profile TT 501 1tp 18 Pin Low .30 Similar to 2N913 17 502 HexH Digit Dr. .49 28 Pin Low Profile .69 .74eoousand5eve o1 2 Per Pack 2/21 7411S0Ó .21 47411547 .73 7415136 .37 74L5258 .71 TT 503 Quad Seg. Dr. .49 40 Pin Low profile .89 741302 .21 74LS51 .26 7416138 .71 7415260 .26 Ti' 506 Hex Digit Dr. .49 0, . parts 74L503 .26 .21 741.554 7415139 .71 74L5266 .26 TT 5088 Digit Dr. .49 741504 .28 74L555 7415145 1.00 7415279 .55 1`+ .26 TT 509 8 Seg. Dr. .49 toese Pa'.tne. GENERAL PURPOSE POWER TRAN. 741505 .28 7415151 .70 741673 .35 7415290 .75 TT 511 Quad Seg. Dr. .55 100.1. P's 74L508 .21 74LS153 2N 2905 PNP 4/51 115W2000 NPN .95 741574 .35 .70 7415293 .61 TT 514 8 Digit Dr. .59 741509 .28 74LS76 .49 7415155 .69 7415295 .95 2N 390a NPN 8/51 TIP 29 (EP967) NPN 4/51 741510 .21. 741.583 .73 7415156 .70 741.5298 .95 2N 3906 PNP 8151 TIP 30 )EP929) PNP 4/51 741.511 .21 741085 1.35 7415157 .75 7416365 .55 TTL SPECIAL! 2N 3392 Pre -Amp 25/51 TIP 31 P.C. Leads NPN 5151 4400 NPN 741613 .45 '741_586 .36 7415158 .71 7413366 .55 2N 10151 MJE 2370 3/51 741514 99 741590 .55 7415160 .85 7416367 .55 9002/7400 10/1.00 2N 4402 PNP 10151 2N 3055 .75 741515 .26 741592 .55 7415161 .85 741-S368 .55 900317410 1011.00 EN 2222 NPN 8151 TN 2021 By RCA .95 series v. 741020. .24 741593 .55 741.5162 .85 7415390 1.75 9004/7420 10/1.00 EN 2907 PNP 8151 FET TIS 75 HOUSES 5/51 741521 .28 IcoT 7415109 .38 741_5163 .85 74LS393 1.45 9006/7460 611.00 line 741522 .28 7415112 .38 74LS164 1.49 7415670 2.30 9007/7430 10/1.00 Pt PM Pin tot CAPACITORS 74L526 .32 7415113 .38 74L5168 .85 7415192 .95 9009/7440 10/1.00 741.627 .32 7415114 .38 7413169 .85 741_5193 .95 9016/7404 8/1.00 ELECTROLYTIC 74LS30 .26 7415.122 .49 7415170 1.69 741_5194 .95 9024/74109 3/1.00 co 1 stn 74L532 .32 7415124 .99 7415173 1.10 741_5195 .85 9300174195 3/1.00 74b1e AXIAL TYPE RADIAL TYPE 741537 '..32 7415125 .47 74L5174 1.00 741.5196 .85 20MFD 250V 5151 47 MFD 35V PC Leads10151 741538 .32 74L5126 .47 74L5175 .81 7415197 .85 35 MFD 25V 15/51 68 MFD 25V PC Leads 8151 741540 .26 7415132 .79 '74L5190 .95 7415251 .85 200 MFD 25V 5/51 330 MFD 50V PC Leads 5151 741542 .65 7415133 .35 741_5191 .95 7415253 .81 DTL. - 470 MFD 35V 4151 470 MFD 16V 4/51 741_5257 .71 470 MFD 16V 4151 1000 MFD 35V PC Leads 6151 500 MFD 35V 5/51 932 Dual 4 Input Buffer 8151 2000 MFD 16V 3151 150 PFD MICA 5% 10/51 74H 'SERIES TTL 934 Dual5 Input NAND Gate 10151 941 One Shol Multivibrator 5/51 945JKFIF 8/51 COMPUTER GRADE 74H00 .18 74H21' .29 74H53 .29 74H73 .39 946 Quad 11 Input Gate NANDINOR 8/51 1,900 MFD 35VJVDC (Mini/ 31S2 68 PFd 50V 680 PFd 500 74H05 29 74H40 .29 74H61 .25 74H74 .39 948 JK'F/F 8/51 8,000 MFD 15VJVDC 95 cents each 100 PFd 100V .001 Fd 74H20 29 74H50 .20 74H72 .45 10151 33.000 MFD 40WVDC 54.00 Each 150PFd 50V .002MFd 50V 951 One Shot Multivibrator 5/$1 220 PFd 50V .01 MFd 200V 1800 (see 934 above) 10151 330 PFd 50V .02 MEd 200V CMOS 1806 Quad'2 Input NAND Gate 10/51 TANTALUM .001 UFd500V 3.3 PF 500V 9093 Dual JK F II F 8151 .0015 UFd500V 4.7 PF 5000 .F 9094 Dual JK F/F 8IS1 1 MFD20 VVVDCPC Leads 15151 .005 UFS500V 8.2 PF 500V CD400 .19 CD4017 .95 CD4040 1.00 CD4071 .19 9097 Dual JK F/F 8/51 3.3 MFD35 VJVDC PC Leads 8151 100PF 500V CD4001 .19 CD4018 .95 C04041 .69 C04081 .19 9099 Dual JK F/F 8/51 4.7 MFD10 VJVDC PC Leads 5/51 CD4002 .19 CD4019 .19 CDa042 .69 CD4507 .35 9109 Hex Inverter 7151 10 MFD20 WVDC PC Leads 8151 PC Leads 25/89 cents No Mix CD4006 1.20 C04020 .97 CD4043 .60 CD4508 2.80 9110 Hex Inverter 7151 33 MFDIO WI/DC 6151 CD4007 .19 CD4021 .97 CD4044 .60 CD4510 1.00 9112 Hex Inverter 7/51 22 ÚF10 10151 Long Leads 25189 cents No Mix CD4009 .47 CD4022 .97 CD4046 1.39 CD4512 1.10 9601 One Shot 3151 CD4010 .39 CD4023 .19 CD4047 1.50 CD4516 .79 9930 Dual 4 Input Ext. NAND 8/51 CD4011 .19 CD4024 .75 CD4049 .35 CD4518 1.10 9932 Quad 2 Input NAND Buffer 8151 - 'RTL's BY FAIRCHILD CD4012 .29 CD4025 .19 CD4050 .39 CD4520 .69 9945 RS FIF 8101 CD4013 .32 CD4027 .39 CD4051 1.19 CD4528 .85 9946 Quad 2 Input NAND 81$1 The most popular digital IC's ever CDa01 a .78 CD4028 .85 CD4053 1.19 74CO2 .45 9949 Quad 2 Input NAND 8151 produced. Very hard to lindl Ca4015 .78 CD4029 .99 CD4056 1.15 7aC04 .32 9951 Monostable Multivibrator 8151 UL DUAL 2INPUT NOR .99 CD4016 .72 CD4030 .35 CD4066 .78 74C107 .79 9962 Triple 3 Input NAND 8151 UL923 JK FLIP FLOP 51.19 VOLTAGE REGULATORS

7805 Pos 5V1 Amp .99 7818 Pos. 18V1 Amp .99 723 VOLTAGE REGULATORS ^e MOTOROLA VOLTAGE REGULATOR 7806 Pos 6V 1 Amp 7824 Pos. 24V 1 Amp .99 .99 Output voltages variable from 2 volts to 37 volts. MC1469R. TO -66. 9 lead package for 3lo 30V out- 7808 Pos 1 7905 Neg. 1 Amp 1.10 8V Amp .99 5V A very versatile and popular device. -14 PIN DIP. puts. Provides 600 MA direct output or more by 7812 Pos 12V 1 Amp .99 7912 Neg. 12V 1 Amp 1.10 69c using an external power transistor. Regular cata- 7815 Pos. '15V 1 Amp .99 7915 Neg. 15V 1 Amp 1.10 log price - 54.00 each! With specs. 51.95 each

. BRIDGE. RECTIFIERS DIODES

1 Amp 200V filS1 IN 4002 1 Amp 100 PIV 40/51 ZENER DIODES HOUSE S ZENER SWITCHING DIODES 1 Amp 50V 5.90 IN 40041 Amp 400V 15IS1 N 746 3.3 V 400M 4/51 4.7 V 500 MW 10/51 IN 4148/IN914 Long Leads20l51 6 Amp 50V 1.10 IN 4007 1 Amp 1000 V 10/$1 N 752 5.6 V 400M 4/51 9. V 5110MW 10151 IN 4148/IN914 Cut Leads 40151 10 Ars1p 50V 1.25 N 1958 8.2 V 400M 4151 10 V 1 Watt 8151 IN 4148/IN914 PC Leads 100151 25 Amp 50Vr 1.39 GERMANIUM DIODES N 5259 39 V 500M 10/51 15 V 5:10 MW 10/51 IN 54A 8151 N 5271 100 V 500M10/51 22V 5'Watt 6/51 IN 270 10151 N 5280 180V 500M10/51 LINEARS 1 709 Operational Amplifier .25 LM 308 Operational Amplifier .95 LM 377 Dual 2W Amplifier 1.85 NE 567 Tone Decoder 1.25 710 Diffnrenllal Comparators .40 LM 3096 5V Lamp Regulator 1.49 LM 3900 Quad Op-Ampllle, .40 1458 Dual Op-Ampllfler .55 711 Dual Differential Comp. .35 LM 710 Voltage Comparator .25 LM 761 Operational Amplifier .25 75491 Quad Segment Driver .35 712 Half Adder .25 LM 311 Voltage Comparator .85 LM 748 Operational Amplifier .25 75492 Hex Digit Driver .35 749 Stereo Pre -Amp by Fairchild 2151 LM 318 Operational Amplllier 1.15 NE 553 Ouad Timer 1.95 3043 IF Amplifier .75 LM 301 Operational Amplifier .30 LM 723 Voltage Comparator .69 NE 555 Timer .40 8038 . Voltage Cont. Osc. 3.95 LM 307 Operational Amplifier .30 LM 324 Quad Operational Amplifier NE 556 Dual Timer .95

RADIO HUT 1.800-527-23021 VISA P. 0. Box 38323 Dallas, Texas 75238 Use Our Toll Free Watts Line For Master Charge and BankAmericard Orders

CIRCLE NO. 42 ON FREE INFORMATION CARD

AmericanRadioHistory.Com AN EMPIRE IND. CO. S. D. SALES CO. VISA D P.O. BOX 28810 DALLAS, TEXAS 75228 ORDER BY PHONE CALL TOLL FREE 1-800-527-3460 S.D. SALES NEW EXPANDO RAM KIT 8K FOR $151.00 EXPANDABLE EPROM BOARD INTERFACE CAPABILITY 16K or 32K EPROM $49.95 w/out EPROM Control, data and address in- 2708's for 16K of 32K FOR $475.00 on puts utilizes low power Allows' you to use either Schottky devices. Eprom or 2716's for 32K of Eprom. MEMORY CAPACITY POWER REQUIREMENTS MEMORY ADDRESSING + 400MA DC MEMORY WRITE 8V UC KIT FEATURES: . DC PROTECTION +18VDC400MA -18VDC 30MA DC Mos- 1. All address lines & data lines buffered. 8K, 16K, 24K, 32K using regulation is provid- MK4115 with 8K bound- on board tek ed. On board (invisible) refresh 2. Quality plated through P.C. Board, in- aries and protection. Utilizes is with no wart states switches. PC board comes provided cluding solder mask and silk screen. DIP 41.- or cycle stealing required. with sockets for 32K operation. now being accepted. e MEMORY ACCESS TIME 3. Selectable wait states. Orders IS 375ns. Allow 6 to 8 weeks for delivery. #14.401.:141 Memory Cycle Time is 500ns. 4. On board regulation provided. Buy an S100 compatible 8K Ram Board and upgrade the same Board to a maximum of 5. All sockets provided w/ board. 32K in steps of 8K at your option by merely purchasing more ram chips from S.D. 450ns 2708's AT $11.95 Sales! At a guaranteed price - Look at the features we have built into the board. WE CAN SUPPLY PRICES START AT $151. FOR 8K RAM KIT WHEN PURCHASED WITH BOARD. Add $108.00 for each additional 8K Ram Z-80 CPU BOARD KIT - $139. 8K LOW POWER RAM - $159.95 4K LOW POWER RAM KIT CHECK THE ADVANCED FEATURES OF OUR Z-80 Fully assembled and tested. '. Fully Buffered - on board regulated - IR CPU BOARD: Expanded set of 158 instructions, 8080A Not a kit. Imsal - Altair - reduced power consumption utilizing operation from a single 5VDC power S-100 Buss compatible, uses a software capability, low power 21L02 - 1 50Ons RAMS - supply; always stops on an M1 state, true sync generated low power static 21L02-500ns Sockets provided for all IC's. Quality a on card (a real plus feature!), dynamic refresh and NMI fully buffered on bcard regulat- plated through PC board. 'Add $10. for available, either 2MHZ or 4MHZ operation, quality double ed, quality plated through PC 250ns RAM operation. sided plated through PC board; parts plus sockets priced board, including solder mask. 8 for all IC's. 'Add $10 extra for Z -80A chip which allows pos. dip switches for address Works - $79.95 9 4MHZ operation. Z-80 chip with Manual - $39.95 select. The Whole s MUSICAL HORN Jumbo LED Car Clock Kit DIGITAL LED READOUT One tune supplied with each kit. Additional tunes - $6.95 FEATURES: THERMOMETER - $29.95 each. Special tunes available. Standard tunes now available: - A. Bowmar Jumbo .5 inch LED array. Dixie - Eyes of Texas - On Wisconsin - Yankee Doodle B. MOSTEK - 50250 - Super clock chip. Dandy - Notre Dame - Pink Panther - Aggie War Song - C. On board precision crystal time base. Features: Litronix dual 112" displays. Anchors Away - Never on Sunday - Yellow Rose of Texas - D. 12 or 24 hour Real Time format. Uses Silicoarx LD131 single chip CMOS Deep in the Heart of Texas - Boomer Sooner - Bridge over E. Perfect for cars, boats, vans, etc. AID converter. Kit includes all neces- River Kwai. F. PC board and all parts (less case) inc. sary parts (except case); AC line cord CAR & BOAT KIT HOME KIT Special Design Alarm option - 01.50 and power supply included. 0-149' F. $34.95 $26.90 Case $3.50 AC XFMR - $1.50 $16.95 5 Digit Countdown Utility 6 Digit General Purpose or 6 DIGIT ALARM CLOCK KIT Darkroom Timer Kit Computer Timer Kit - $29.95 Features: Large LED 112" displays Features: Litronix dual 1/2" displays, Mostek oper. from 0.1 sec. to 59 min. Features: Large LED 112" displays, Mostek 50250 super clock chip, single I.C. segment 59.99 sec. 5A -115V. Relay Included to 50397 counter dlsplayldriver, counts up to driver, SCR digit drivers. Kit includes all ne- control appliances. Operates on 115V 59 minutes, 59.99 seconds with crystal con- on parts (except case). Xfmr optional. AC. Displays can be turned off for total trolled 1/100 second accuracy, operates cessary darkness while coun,ing. All necessary 115V AC or 12V DC supply. All necessary Eliminate the hassle. parts included. $44.95 parts included. Special design case $3.75. AC XFMR - $1.50 Case $3.50 Special design case $3.75. Bowmar 4 Digit LED Readout Array NEW COMPETITION CHESS TIME KIT Low Cost Cassette Full 1/2" Litronix Jumbo Dual WITH TWO INDEPENDENT FIVE DIGIT Digit LED Displays 1/2" LED DISPLAYS Interface Kit 4 JUMBO .50" DIGITS ON ONE STICK! The timers can be used in- $14.95 -Su.ww,wlwwu/- WITH COLONS & AM/PM INDICATOR dependently or coupled. set to 59 The timer can be Features: K.C. standard 2400/1200 Hz, 300 Baud, TTL, I/O $3.95 seconds at 0.1 minutes 59.9 compatible, phase lock loop, 22 pin connector. Feeds serial data DL 722 - C.C. DL 728 - C.C. includes all $79.95 intervals. Kit via microprocessors I/O ports and from cassette tape recorder. DL 721 8 C.A. DL 727 - C.A. parts and an at- necessary $14.95 99c $1.29 tractive woodgrain case. Complete Kit MICROPROCESSOR FLAT PACK TRIMMER POTS IC ASSORT. ELECTRICAL COIL CHIPS THERMISTORS TANTALUM CAPS 2 TRANSISTOR MK. 20K. 25K 350 RAM'S FLAT PACK 5400 13T TYPE C AUDIO OHM. Mini for PC 8212 I/0 port 1 MFD. 20VDC. MEPCO - NEW/ SERIES. SPECIAL 10T TYPE tararas. 8214-PIC 12.95 8111.50 1.5K OHM P.C. LEADS BUY FROM ITT. am/. WlSpecs. 4 21L02.50ONS YOUR CHOICE YOUR CHOICE 8216 - Non Invert Bus 95 8/15.95 5/$1.00 15ior 51.00 20 Auorled 61st 4 95 21L02-25ONS 12/51 10/51. 8224 - Clock Gen 2114-4K 14.95 Devices for 51.00 8226 - Invert Bus 3 95 1101A- 256 8/54.00 PIO for Z-80 14.95 1103-1K 35 CTC for Z-80 14.95 MK4115-8K 15.45 8228 Sys. Controller 8 20 74S 200 - 256 3 95 8251 Prog. comm. Interface 10.95 SILICON 8255 Prog. perp. interface 13.50 DISC CAPS BALUM STANDARD COILS AUTO COIL NEW CAMBIOS RECTIFIER 8820 Dual Line Recr 1 75 TRANF. Speclell FOR BYPASS Used in TV Tuners Use in TV Sets. 1.2 JACKS 8830 Dual Line Dr 1 75 1N4007 1 AMP CPU'S .01 MFD-100 Can be rewound un 5% and 1.5 un Ideal for the wiper. PART a 450-4352 2513 Char. Gen 750 17100 PIV W V OC. PC leads. for Ham freq. 10%. Your choice. Gold Plated 8838 Quad Bus. Rem'Re 200 includes manual 12151 PRIME UNITS Z-80 29.95 401$1. 6151 12/51 50/51 74LS138N-.1l8 decoder 99 Z Includes manual 34.95 10/51. -80A 8797 -Hex Tri-State Buffer 1 25 8080A CPU 8 BIT 11.95 1488/1489 RS232 1 50 8008 CPU BIT 695 * * TR 1602B Uart 3 95 Photocell Asst. RESISTOR We bought almost PLASTIC READ. Special! ASST. 200K from a big US OUT FILTERS DISC CAP P C. LEAD DIODES 1 Watt. PROMS mtg. Three product TTL ASSORTMENT 22 Ohm. PC leads. Al least 1N4149I1N914 Originally used In 10%. families: ma 1. Contains a high Carbon Comp. 10 different values; 1702A-1K-1.5us 395 or 10/35. desk top calcula- Handy value. Paral. -100/52.70 Z-80 PROGRAMMING medium and s dual for yield of usable pans. includes .001. .01, - 450ns tors. Perlecl use 10110 1714002 -IA 2708 - 8K Intel 14.95 photocells. Perfect make low Ohm- .05 plus other stan- with LED and other 50/51.50 resistors. - 100 PIV MANUAL 5204 - 4K 7 l age Dower 95 all Ilght sensi- type readouts. dard values. 825129-1K 250 tive applications. Help? We bought 60/61.00 40/51.00 AMBER -tiler 51. 100.000 pieces! 2708S 8 8K signetics 650ns 9 95 * 12/51.00 * * * 251or51. IN DEPTH DETAIL OF JOY STICKS THE Z-80 CPU COUNTER CHIPS MICRO -DIP $1.95 MICRO -COMPUTER MK503976 Digit elapsed timer .... 8.95 MICA TRIMMER New - Series 2300 FOUR 100 K -OHMS STANDARD MK50250 Alarm clock 499 PC 402 Miniature The Wo Id's Smallest ANT. TER. 1.5-20 P.F. POTS for Ant. Hook- MK50380 Alarm chip 2.95 Coded BCD Dual -In -Line U,r04 P.C. Mount up on all TV Sets. S.D. Sales Special MK50396 6 digit up/ down counter 12.95 Switch! PC Mount 4/51 Ideal for 1211 MK5002 4 digit counter 8.95 2300 02G BCD 1.2-4-8 $9.95 MK5021 - sq. root 2.50 Cal. chip 2300 12G BCD 1-2-4-8 electronic Compliment games $3.95 'Choose $1. Free Merchandise From Asterisk Items on each $15 order! ADD Texas Residents Call Collect: NO COD's. TEXAS RESIDENTS CALL IN YOUR BANKAMER- 5% SALES TAX. ADD 5% OF ORDER I CARD (VISA) OR MASTER 214/271-0022 rams - 60 Day FOR POSTAGE & HANDLING . OR- CHARGE ORDER IN ON OUR DERS UNDER $10. ADD 75c HAND CONTINENTAL TOLL FREE 1-800-527-3460 Hack OraraNteei LING.FOREIGN ORDERS - U. S. WATTS LINE: DEALER INQUIRIES INVITED! »mg FUNDS ONLY!

CIRCLE NO. 43 ON FREE INFORMATION CARD AmericanRadioHistory.Com R'`'`' -:it

DIGI-KEY .TOLL^ Ct7,]: CORPORATION -800-3Q6-51 Components i. Qualitv Electronic FREE MINNESOTA RESIDENTS 218-681-6674 = DON'T FORGET OUR l.c.'s RESISTORS TRANSISTORS CAPACITORS DIODES I.C. SOCKETS & PINS SWITCHES DISCOUNTS WHEN COMPARING PRICES CLOCK MODULES OPTOELECTRONICS BREAD BOADING & TESTING DEVICES DRAFTING SUPPLIES DATA BOOKS HEAT SINKS WIRE TOOLS ... AND MORE ... WRITE FOR FREE CATALOG MICROPROCESSORS LED DIGITS AND LAMPS DATA :re INTEGRATED CIRCUITS 011 DATA BOOK, 592 P. NAT. SEMI 9101 B 64.00 `- 80804 8-811 CPU, 1 USEC CYCLE 512.95 smgb Dy6, CC R 5.1.38 LINEAR DATA BK, 957 P. NAT. SEMI. 90118 54.00 f6p0p 4 D 74198 1 d9 7415261 2.00 LF357N 1.20 8212 8-811 I/O PORT 5 3.95 S' CMOS DATA BK. 77 EDIT, 555 P, NAT. SEMI 90128 53.00 TTL NON/ e" Seale Oq6, CC. 4.0.. 1.Js POWER 74199 1.49 7415266 39 1013741 .76 8216 BI-DIRECTIONAL BUS DRIVER 5 4.25 TRANSISTORS, 151 P. NAT. SEMI 90138 53.00 '. d" 5.94 D9n. CA. Red.. 2.50 74221 .86 7415273 1.28 1.M301AN .44 0ENteco6000?35 MEMORY DATA BK 597 P. NAT. SEMI 90148 8214 CLOCK GENERATOR S 3.95 amJ 53.00 7400 .21 FND813 3" 5494 raga. CA. Red . 74251 1.09 7415279 .61 LM307N 64 M05/151 DATA BK 713 P. NAT. SEMI. 90158 54.00 .21 8218 SYSTEM CONTROLLER 5 604374 3" Dint Dram. CC. Red. 2.50 - 7401 7415283 6.95 74279 .55 .79 1M308N 1.00 NS INTERFACE DATA BK, 464 P. NAT. 90168 400 .21 8251 ÚT4 3" 00l D'cn, ((. Red . 2.002.20 54. , -7402 7415290 .65 LM309K 1.80 COMMUNICATIONS INTERFACE 512.95 7403 .11 74298 .94 656184 S" Owl D96s CA. Red.. 2.00 VOLTAGE REG. Be, 128 P. NAT. SEMI. 90178 53. a ' 7415293 .65 1M311N .90 8255 PERIPHERAL INTERFACE 51195 656581 7404 .71 74365 67 S" Duel 096, CA. Red:: 2.00 LIN. APPLIC. BK. VOL. I, 432 P. NAT. SEMI 90188 54.00 . 7415295 1.12 1M3171 17024 2K EPROM NSNPBI CC Red 7405 .21 74366 .67 3.00 1156.8) S 6.95 T Dml D9n, 0.00 LIN, APPLIC. BK. VOL. 2, 746 P. NAT. SEMI 90198 54,00 7415298 1.30 TT DId lamp 74367 .67 LM317MP 1.90 2708 BK EPROM (08.8/ 529.50 14g+fit 9n, J.00 AUDIO HANDBOOK. 196 P. NAT. SEMI 90708 54.00 7406 25 7415365 1.1 1J NHSOv óe DFM 74368 .67 .67 LM318N 2.70 8080A MICRO. SYS. DESIGN MAN, NAT. 30208 7407 .25 2102-1 111 RAM 500 NS 5 1.79 - - Mtg. MSc 41.80710 .10.00/100 SEMI 55.00 ,- 7415366 .67 LM320MP-5 1.30 SC/MP MICRO. APP. HANDBK, NAT 7408 .21 SC/MP 5 VOLT SC/MP CPU 5 9.95 851.5054 Angle Red SEMI 90228 55.00 741500 7415367 .67 1M320MP4 1.30 mononf*' DI Norm* 1.1.. lamp 7409 .21 ram IlMe31.80/10 P16.00/100 SPECIAIfUNCTION DATA B0, NAT. SEMI 90238 53.00 7415368 .67 1M320MPE 1.30 2650 MICROPROCESSOR 1.25 MH-2 CLOCK 40 DLL 524.95 , 7410 .21 741500 .28 CMOS L.C.'S, 278 P, SOLID STATE SCIENT 90308 53.00 7415377 1.50 1M320MP-9 1 30 .d ; 7411 .21 741501 SIGNETICS ANALOG MANUAL. P .28 7415386 .39 LM320MP-121.30 I.C. 5% CARBON FILM RESISTORS I 637 9031B 55.95 7412 .21 74/501 .28 SOCKETS 7415395 1.74 LM320MP-151.30 X 'h WATT RESISTOR ASSORTMENTS 7413 .25 741503 .28 8 PIN SOLDER.. .17 1.60/10 14.50/C 8080A 7413670 2.34 LM320MP-181.30 MICROPROCESSOR BOOKS 7414 .89 741504 14 PIN SOLDER. .20 1.90/10 07.00/C .29 811595 .77 LM320MP-181 30 . 7416 .25 741505 .29 16 PIN SOLDER. .22 2.10/10 18.75/C ADAM OSBORNE 811596 .77 LM320M8241.30 . 7417 .25 741508 .19 18 PIN SOLDER. .29 CHIP 85125`--- -59.90 NDISCOU .A811/ 811597 .77 1M323K 7.50 2.75/10 24.50/C 7420 .21 741509 .29 20 PIN SOLDER. 30 AN INTRODUCTION TO MICROCOMPUTERS, 811398 .77 LM324N .72 2.85/10 25.25/C R5225,Y. m'i1 +m 0 59.90 VOl I 7421 .25 PIN A iivr ..,. 741510 .28 22 SOLDER. .33 3.15/10 27.5/C SET BASIC CONCEPTS 90008 -ND S 7.50 LM325N 2.70 V WATT RESISTOR ASSORTMENTSa 7423 .35 741511 .28 INTEK4ACL 24 PIN SOLDER. .38 3.65/10 32.25/C AN INTRODUCTION TO MICROCOMPUTERS, VOL. II LM326N 2.70 ONE EACH 8080A, memo LS 7425 .35 741512 .28 SOME REAL PRODUCTS 8093 .40 LM327N 2.70 90018 -ND 515.00 tl 7416 .25 741313 .47 40 PIN SOLDER. .63 600/10 53.50/C 8212, 8224 8094 .40 LM339N 1.15 BOB0 PROGRAMMING FOR LOGIC DESIGN 90028 -ND 5 7.50 7427 .33 741514 1.02 8 PIN W -W ... .24 2.30/10 20.50/C clod 8095 1M3407-5 1.25 8228 R5150t'4ii.ü,áyi.: "59,90 6800 PROGRAMMING FOR LOGIC DESIGN 90038 -ND 5 7.50 P . 7428 .28 741515 .28 .67 14 PIN W.W... .26 250/10 22.00/C 8096 .67 1M34014 1.25 PLUS . 7430 .21 741520 .28 16 PIN W -W... .30 2.85/10 25.50/[ R5250M.m.iitl v.2 w. e ,eermi $9.90 8097 .67 1M3401-0 1.25 7432 .25 741521 .28 18 PIN W -W... .60 5.70/10 51.00/C SIXTEEN 2102-1's 8098 LM340T-10 1.25 . 7433 30 741522 .28 .67 20 PIN W -W... .70 6.65/10 5,11119211 1M340T-12 1.25 59.50/C ALL FOR a5=.6' : rAl;pJ - 7437 .25 741516 .33 75450 .88 - TV BishopGraphics CMOS 22 PIN W.W... .84 8.00/10 71.50/[ 006 COOKBOOK 21398 -ND 5 9.45 , 7438 75451 .61 LM2401-15 115 .25 741327 .33 THE 810 CMOS WALICHART 21399ND 5 2.80 75452 .61 1.913400-113 1.25 .r...-111111111191 ' 7439 .50 741318 .33 TB PIN W.W...L2 10.00/10 FET CIRCUITS 4.70 75453 1.M3400-24 1,25 95.20/iá49.95 21439-9D 5 7440 .21 741330 .28 .61 IC 40 PIN W.W 1.36 12,50110115.00 Cl TIMER COOKBOOK 21416 -ND S 9.42 75454 .61 LM341 P.5 .98 ... .e4.. 7442 .53 741537 .33 d. It PRINCIPLES& APPLIC. 161341P4 .98 ^ .__ m141 OF INVERT. d CONY 21454.ND 5 7.55 A 7445 .70 741533 .33 75491 .81 ."';"1"'"":v Ia6S.64 12.50 MOLEX I.C. SOCKET PINS ABC'S OF CAPACITORS (2ND EDIT.) 20849 -ND S 4.04 7446 .70 741.537 .33 75492 84 1M341PE .98 LM341 P.10 .85/C 8.20/M 38.20/5M 275.00/50M ABC'S OF INTEGRATED CIRCUITS 20813.ND 5 3.33 7447 .70 741538 .33 75493 1.09 .98 LM341 P.12 ABC'S OF RESISTANCE & RESISTORS 21126 -ND 5 3.75 7448 .70 741540 .28 75494 1.19 .98 CLOCK MODULES 191341P-15 ABC'S OF VOLTAGE -DEPENDENT RESISTORS 20771 -ND 5 3.09 7450 21 741542 .67 MC1488N .90 .98 PLESSEY SAMPLER 1.91341P-1E1 T. MÁ1002 oM .1010 cone, clod modules by 11.1nol S.n4«duster e. ACT IVE.FILTER COOKBOOK 21168 -ND 514.20 7451 .21 741347 .79 MC1489N .90 .98 METALIZED POLYESTER CAPACITORS fully accemNsd ore rated cods using a 4 Malt LED dopby ISM on M05 7453 LM341 P-74 .98 AN ASSORTMENT OF COLLECTED BASIC CIRCUITS 20784.90 5 5.23 .11 741548 .77 and c.wn on 1te somebrad. Smyly conxe meddles oN our sp,oI« LM34814 1.60 HOW TO DESIGN & USE MULTIVIBRATORS 21043.ND S 3.75 7454 .21 741551 28 300 CAPS 18 VALUES 526.00 mnsform« one two tea, a Iuly functioning dock. HOW TO IC . USE LOGIC ELEMENTS 7460 .21 LM349N 1.60 21081 -ND 5 4.70 741554 .28 4000 118 161/005 clod nodule is a fully assembled add nn.4 la clock LM35eN bur IC OP.AMP COOKBOOK 20969-9D 512.30 7470 .30 741555 .28 4001 .23 :781 MINIBOX METALIZED POLYESTER CAPACITORS using a high briBw. p.en flouno. display and crystal time bam nnki9 LM1310N LED CIRCUITS AND PROJECTS 7472 30 741573 .39 4007 .23 it perfect for e. 6oai or other somebb us. If djenly from 12 21006.90 S 4.99 7473 LM1800N 1.25/10 10.00/e DC so , Mne Wean M05 DIGITAL IC'S 71299.90 5 6.18 .30 741574 .39 4006 133 '94 .001 ..14 1.15/10 9.00/C .033..15 colt. n ned.M Curyo .he., w,6 LM1801N PRACTICAL SOLID-STATE CIRCUIT DESIGN 2101 BND S 'i 7474 .30 741574 .39 4007 .23 .0022 .14 1.15/10 9.00/C .047 ..15 1.25/10 10.00/C rams.. for sen6N M t 6.18 LM1812N ¿. RC CIRCUITS 7475 .49 741375 .53 4008 .79 .14 1.15/10 9.00/C .068 .35 1.25/10 10.00/C 21332-91) 5 4.70 LM1830N 0033 Moor Module 7476 74(576 4009 .44 1.30 1 1.35/10 11.0000 MA1002A .5- LED 12 AMP. Clod ....'10.50 REGULATED POWER SUPPLIES 20844 -ND S J2 .39 700 .0047 .14 1.15/10 9.00/C ...17 5.23 7480 4010 .44 LM1889N .22 RTL COOKBOOK .70 741378 .39 ,71/ 9.00/C ...23 1.85/10 15.00/C MA1002A SET Mode, e%e tmn.ta^ner L swdc6.e '13.95 20715 -ND S 5.46 7483 4011 LM2111N 1:75 TRANSKTOR SPECIFICATIONS .70 741503 79 .23 1.15/10 9.00/C MAN. 1606 E0.) . 21335 -ND S 6.60 1M29079 ,50 .0..iñ .47 MA1002C S" LED 24 Hw Clod Module 010.50 7485 89 741585 .49 4012 .23 ...36 3.00/10 24 00/C TRANSISTOR SUBSITUTION HDBK ED.) 21333 -ND S 4.70 LM2917N .072 ..15 1.25/10 10.00/C (161H - 7486 .28 741596 .39 4013 .40 1.50 ABC'S OF FET'S MA1002C SET Module onmmfann« 4 swnoS., . '13.95 20789 -ND S 2.80 7489 2.19 741590 .57 4014 .96 1M3089N 1.30 . ELECTROLYTIC CAPACITORS ABC'S OF TRANSISTORS (3RD ED.) 71146 -NO S 4.04 7490 .44 741592 .57 4015 .96 LM3900N .88. MA1003 12 Volt C con wan .weo., '24.95 ABC'S OF ZENER DIODES 21045 -ND 5 3.75 ..7491 70 741593 .57 4016 LM3900N .88 AMP. VALUE RADIAL LEADS AXIAL LEADS MA1010A e1- 110120w, Con0.4,0.. '13.00 FET PRINCIPLES, EXPER.. & PROJECTS 12901 21167 -ND S 8.08 .,7492 .44 741395 .B8 4017 1.05n0 LM3905N 1.40 08 .65/10 LINEAR IC PRINC., E%PER. & PROJECTS 21019.90 S 8.50 5.41/C .11 .90/10 7.65/C MA1010A SET Module. immlmme 4 Womb. . '16.45 < 7493 .44 74L596 .88 4018 1.05 LM390N .60 47/509 MICROMINIATURE LM3911N 1.50 08 .65/10 5.41/C .11 .90/10 7.65/C ELECTRONICS 20582 -ND S 5.46 7494 .70 7415107 .39 4019 .13 MA1010C H" 000 N Omer Clock Module '13.00 2.7/509 08 .65/10 5.41 /C .12 .90/10 7.82/C SEMICONDUCTOR REPLACEMENT GUIDE 21092 -ND 5 3.75 7495 .70 7415109 .39 4020 1.14 MC1456V 1.00 3.3/50V 08 .65/10 5.41/C .121.00/10 MA1010C SET 004464 wrtmmmnn..6 twin., '16.45 TRANSISTOR FUNDAMENTALS A CAREFULLY PLANNED 7496 .70 7415117 .39 4021 1.14 MC1458V 53. 8.31/C - 4.7/35V 08 .65/10 PROGRAMMED COURSE IN SEMICONDUCTOR THEORY 74100 1.28 7415113 .39 4022 .96 MC1496N .70 5.11/C .12 95/10 7.91/C 4.7/SOV 08 .6B/10 5.75/C .12 1.00/10 ANO CIRCUITRY: 74107 .30 7415114 .39 4023 .23 MC3302P 1,15 8.31/C 10/168 VOL. 1 -BASIC SEMICOND. PRINC. 74109 7415125 .49 4024 84 NE536T 2.50 08 .65/10 5.41/C .I1 .90/10 7.65/C R CIRC. 20641 -ND 4.99 .33 10/25V 74116 1.26 7415126 .49 4025 .23 NE5401 2.04 08 .65/10 5.66/C .121.00/10 8.31/C VOL. 1-8ASIC TRANSISTOR CIRCUITS 20642. ND 4.99 10/355 09 .70/10 .13 VOL. 3 -ELECTRONIC 74121 .35 74E5132 .81 4026 1.68 NE555V .4888 6.17/C 1.10/10 8.94/C EQUIP. CIRCUITS 20643.90 4.99 10/50V 10 .75/10 4 74121 .44 7415136 .39 4027 .40 NE556A . 6.58/C .14 1.15/10 9.56/C VOL. -DIGITAL d SPECIAL CIRCUITS 20644.90 4.99 72068 08 .67/10 4 74123 .61 7415138 .73 4028 .89 8E5509 2.40 5.66/C .17 1.00/10 8.30/C VOLUME SET 20645.90 18.53 74125 .40 7415139 .73 4079 1.14 NE550N 2.50 22/259 09 .70/10 6.09/( .13 1.05/10 8.74/C TRANSISTOR-TRANSISTORLOGIC 20967 ND6.17 74126 .40 7415151 .75 4030 .23 9E5609 2.50 22/359 11 .65/10 7.29/C .15 1.19/10 9.98/C TUBE SUBSTITUTION HOOK 90980/0.1 21225 -NO 2.14 74128 .48 74E5153 .75 4033 1.51 NE5618 2.50 n6Vn/509 12 C .17 1.32/10 11.22/C SPECIAL TWINCPAK TUBEUBE SUB. PACKAGE 21227.90 3,80 74132 .70 7415154 1.10 4034 3.50 NE561B 2.50 09 .75/10 6.90/C .12 1.00/10 8.48/C SOLID-STATE COMPONENTS 21099.90 3.75 33/25V 74141 .88 7415155 .75 4035 1.14 NE565A 1.25 10 .81/10 750/C .14 1.15/10 9.56/C SOLID-STATE IGNITION SYSTEMS 20010-90 4.70 33/35V 13 74145 .70 .75 4040 1.14 NE566V 1.28 1.05/10 9.65/C .17 1.34/10 11.23/C SOLID-STATE POWER SUPPLIES & COPIO 20310 -ND 3.33 NE5678 33/50V 14 1.13/10 10.41/C .19 1.52/10 12.89/C 74147 1.63 7115157 .75 4041 .79 1.36 TRANSISTOR AUDIO AMPLIFIERS 20838 -ND 5.62 UA709CV .44 47/105 09 .71/10 6.57/C .13 1.04510 9.50/C 74148 1 30 7415156 .75 4042 .79 TIE COOKBOOK 21035 -ND 8.50 74150 1.16 7413160 1.02 4043 .70 UA710CA .44 47/16V 10 81/10 7.47/C .14 1.15/10 956/C 47/75V USER'S GUIDE TO TTL 21080 ND 2.38 74151 .70 7413161 1.02 4044 .70 UA711CA .53 131.05/10 9.65/C .17 1.30/10 11.22/C TV TYPEWRITER 47/35V COOKBOOK 21313 -ND 9.45 7413163 1.02 4046 1 0471304 .60 14 1.13/1010.41/C .19 1.51/10 12.89/C 74153 .65 86 UNDERSTANDING CMOS I.0 'S 21129-90 4.70 74154 1.03 7413164 1.02 4049 .40 UA733CA .75 47/500 15 1.21/10 11.16/C .21 1.71/10 04.55/C UNDERSTANDING IC OPERATIONAL AMPLIF 20855.ND 7415168 1.14 4050 .40 1.1741CV .44 100/108 10 .77/10 658/C .14 1.13/10 9.56/C 3.75 74155 .70 UNDERSTANDING OSCILLATORS 20837.ND 4.70 74156 .70 7413160 1.14 4051 1.26 1.1474704 .70 100/108 11 .85/10 7.28/C .17 1.30/10 11.22/C UNIQUE IC OP.AMP APPLICATIONS 21163.ND 4.70 74157 70 7413170 1.73 4052 1.26 1.1474e04 .49 100/258 131.10/10 9,15/C .20 1.55/10 13.30/C HOW TO BUY 6115E MINI d MICROCOMPUTERS 21351 -ND 9.45 74160 .88 7413173 1.34 4053 1.26 UA7805CU 1.25 100/358 17 1.41/10 11.85/( .25 1.93/10 16.50/C HOW TO PROGRAM MICROCOMPUTERS 74161 .88 7413174 1.06 4060 158 047806C0 1.25 100/50V 21 1.71/10 14.55/C .29 2.30/10 19.70/C 1459.N 8.50 MICROCOMPUTER PRIMER 21404-NDD 7.55 74162 .88 7413175 .84 4066 79 UA7BOBCU 1.25 220/100 13 1.08/10 9.15/C 18 1 42n01.55/1013.02.20/C00/C THE 80804 800800K, MICROCOMPUTER 74163 .B8 7415181 2.50 4071 .23 UA7812CU 1.25 170/168 15 1.16/10 9.86/C . 74164 .96 7413190 1.18 4072 .23 847812C0 1.25 220/250 21 1.71/101455/C .29 2.35/10 19.96/C INTERFACING & PROGRAMMING 21147-90 9.45 74165 1.15 7415191 1.18 4073 .23 UA7815CU 1.25 120/350 .. ., 25 2.03/10 17.26/C .35 2.79/10 23.70/C COMPUTER DICTIONARY (260 EDIT.) 20943 -ND 8.50 74166 1.15 7413192 .98 4075 23 UA7918CU 1.25 130/661, 79 2.35/10 19.96/C .40 3.23/10 27.44/C COMPUTER DICE. G HANDBOOK 12ND EDIT ) 20850 -ND 18.53 ' 74170 2.64 7415193 1.06 4081 .23 330/66 14 1,12/10 9.50/C .19 1.48/10 13.71/C COMPUTERS & PROGRAMMING GUIDE FOR 2,474174 .98 7415194 .88 4082 .23 UA78LOSACZ .40 330/10V 15 1.16/10 9,83/C .21 1.64/10 15.13/C ENGIN 20950 ND12.70 74175 .93 74E5195 .86 4502 .79 UA78106ACZ d0 330/16V 21 1.66/10 11.14/( .31 2.45/10 22.70/C 74176 .79 7413196 .86 4510 1.14 UA781.08AC2 .40 330/258 23 1.86/10 15.79/C .38 3.07/10 28.38/C 1/2 WATT ZENER DIOD- ES I HARDWARE . 74177 .79 74E5197 .86 4511 1.05 UA7BL1o6CZ .40 330/35V 33 2.66/10 2/.59/C .43 343/10 31.68/C 74180 .70 7415197 .86 4514 280 UA7BL12ACZ .40 330/60SOV 54 4.30/10 39.73/C .60 4.81/10 44.45/C -.15 1 30/10 11.00/C 2-56 1/4 SCREW ... 99/C 74180 .70 7415221 1.06 4515 UA7BL15ACZ .40 470/ 15 280 1.21/10 11.16/C .20 1.64/10 15.13/C 2-56 1/2 SCREW... .99/C - 74181 2.15 7413240 1.90 4516 123 047811BACZ .40 470/100 21 1.71/10 14.55/C .31 2.45/10 22.70/C 195226B 3.38 1957418 129 4-40 1/4 SCREW... .55/C _ 74182 .79 7415241 1.90 4518 1.14 UA78I24AC2 .40 470/168 23 1.81/10 05.39/( .33 2.66/10 24.59/C 1145227E1 3.6V 1952438 139 4.40 1/2 SCREW... " 74184 7415242 1.70 470/25V .60/C 1.15 4520 1.14 UA7905CU 1.70 29 2.35/10 19.96/C .43 3.43/10 31.68/C 1952280 3.9V 1952448 148 6.32 1/4 SCREW....65/C 74185 2.19 7415243 1.70 4527 1.68 1.70 470/358 41 - 047906(0 3.27/10 30.26/C .47 3.78/10 34.99/C 1 N52798 4.3V 1652458 150 6.32 1/2 SCREW . .. .75/C 74109 3.50 7415244.1.70 4528 .89 UA7908CU 1.70 470/50V 4.30/10 . 54 39.73/C .75 6.03/10 55.80/C 1952300 4.78 1952468 16V 8-32 3/8 SCREW... .90/C .s 74190 1.23 7413247 .79 4585 1 UA790CU 1.70 1000/6V 23 22 1.90/10 16.50/C .35 2.76/10 25.54/C 195231B 0.IV 1952470 17V 8-325/8 SCREW... .99/C . 74191 1.23 7415248 .79 74(00 23 UA7912CU 1.70 1000/109 24 1.96/10 16.62/C 38 3.07/100 28.38/C 1 N52328 5.6V 1952488 188 2-56 HEX NUT 55/C - 74192 .88 7415249 .79 UA7915CU 1.70 1000/160 19 19.96/C .43 235/10 3.43/10 31.68/C 1N5233B 6.0V 1N52498 19V 4.40 HEX NUT 55/C 74193 .88 7415251 .84 UA7918CU 1.70 1000/25V 42 3.33/10 18.17/C .68 5.47/10 50.13/C 19523413 6.2V 1852508 203 6-32 HEX NUT 60/C - 74194 .08 7413253 .84 CA3046 .75 1/47924(0 1.70 1000/353 60 4.81/10 44.45/C .75 50 6.03/10 55.81/C 1 N52358 6.80 1952519 22V 8-32 HEX NUT 60/C 74195 .88 7415257 .75 'A3086 2200/60 36 286/10 26Á8/C .43 4.83/10 44.45/C .76 MISC IC 1952368 750 1952528 24V NO 2 IOCKWASHER 85/C . 74196 .88 7415258 .75 LF351N 7200/10V 42 3.33/10 28 5 27/C .60 /10 44.45/C MÁ1003. '24.95 185237E1 8.29 0952538 25V NO 4 LOCKWASHER 45/C 74197 88 7465260 .34 19356N 1.20 MM531/N 3. 21170/161/ 4.30/10 54 36 58/C .685.4a2/1050.13K .^+`^"11`sp 91501 IN52388 8.7V 1852548 27V NO 6 LOCKWASHER 45/C 1852398 9.1V 1N52550 28V NO 8 LOCKWASHER 45/C 010.1( ay 1N574013 100 1652569 309 NSUPER QC ALITY Stocks DOUBLE DIGIT DISCOUNTS SAVE YOU EVEN MORE[ 1N5741B I_IV 1652578 33V FRLE CATALOG SUPER PRICES VOLUME DISCOUNT A I SILICON TRANSISTORS t°P"°° HANDLING CHARGE 104C00N .25 74(154N 2.901 HANDLING VOLUME MPS918 16 1.55/10 13.60/C 130.00/M MPS930 16 - 74CO2N .25 74C1579 1.90- SILICON DIODES ' All items except those with catalog 1.55/10 13.60/C 130.00/7 - 74(04N .17 74C160N 1.18 CHARGES' numbers ending with the suffix -ND may DISCOUNT MP52222A 16 1.55/10 13.60/C 130.00/61 164001 .64/10 5.50/C MPS2369A 16 1.55/10 13.60/C 130.00/M - 74C08N .25 74C161N 1.18 be combined for discount. First -total $ 164502 .66/lo z.bo/e $ 0.00.5 4.99.... Add $2.00 0,00.5 MPS1907A 16 1.55/10 13.60/C 130.00/M "74CION .25 74C162N 24.99. .... NET 1.1B 5.80/C items MPS3393 16 1.55/10 13.60/C 130.00/M "074(14N .90 1.18' $ 5.00.$24.99:... Add 50.75 I 74C1639 ÍN44Ó4 :7óñó vs C volume discount6le dddt ihis :tb. $ 25.00-$ 99.99. Less MPS3393 16 1.55/10 13.60/C 130.00/M - 74C70N .25 74C164N 1.10 1114005 87/io 1 $ 25.00-$49.99... Add $0.50 total the ncndiSCWntable items. Add' $ . MPS3394 16 155/10 13.60/C 130.00/M 74(309 .25 74C165N 1.10 100.00.5499.99 less 15% á 1114006 .90/10 7.75/, is total. MPS3395 16 1.55/10 13.60/C 130.00/M 74C32N .25 74(173N S 50.00.$99.99... Add the handling ,hone. This your 1.30 .90/10 8.60/[ 50.25 $ 500.00-5999.99 . Less 20% 61853563 16 135/10 13.60/C 130.00/91 .98 cost. We pale all shipping and insurance , 74C42N 74C174N 1.16 119400794141 .40'10 3.so/c 5100.00 Up .,.. No Charge Up Less 25% MP53565 16 155/10 13.60/C 130.00/M . 74C489 1.28 74C1759 1.16 i to addresses in the U.S.A. and Canada. $1000.00 i .... MP53636A 16 1.55/10 13.60/C 130.00/M 1 74C73N .72 74[1926 1.38 14753640 16 1.55/10 13.60/C 130.00/M 74[746 .48 74[1936 1.38 FREE CATALOG . Orders Accepted by Phone or Moil MP536/1 16 135/10 13.60/C 130.00/M . 74(766 .77 74C195N 1.10 { MPS3643 16 13.60/C 130.00/M 'um dEANXAMlA1C4Ra MostorCharge Bonk-Amerlcard COD Check Money Order made/ line 1.55/10 . 74C83111.38 74C221N 1.90 293904 16 1.55/10 13.60/C 130.00/81 74(856 1.38 .48 SPST .15 1.25/10® 10.00/C iff==ffl P.O. 'Boe 677, Thief River Falls, Minn. 56701 (218) 681-6670 . 80(959 283906 16 135/10 13.60/C 130.00/M SPDT .19 1.70/10 13.00/C 740369 .40 BOCOON .48 294124 16 1.55/10 1360/C 130.00/M DPDT23 200/10 19.00/4 - 740909 .98 80097N .48 294126 16 1.55/10 13.60/C 130.00/61 ' 74(939 .98 B0C9BN .48 5D VOLT DISCS, 2N4401 16 135/10 13.60/C 130.00/61 »- 74C939 1.10 74(901 N .48 294403 16 1.55/10 13.60/C 130.00/M ' w 100 PE 40/10 74C107N .70 74(9026 .48 3.50 "+!d i7 284410 16 1.55/10 13.60/C 130 COMA - 220 PF 40/10 , 74C1508 2.90 1.78 3.SDK s~ 2115087 16 1.55/10 13.60/C 130.00/M : 174(9099 * 470 PF 40/10 . 2401519 1.00 74(9289 7.80 3.50/0 DIGI-KEY 2850139 16 1.55/10 13.60/C 130.03/M .001 OF 40/10 3.50/C 285210 16 1.55/10 13.60/C 130.00/61 .0022 ilirilinag.111 UF 40 10 3.50/C . - Wilija] CORPORATION 293055 99 9.20/10 85.00 C 800.00/M UF 40/10 3.50/C " 20 go PVC.. 2.50/100' 10.00 500' '0047 MPFI 02 36 3.35/10 30.60/C 300.00/M .01 OF 45/10 3.65/[ - 48 o121 g9 PVC.. 2.80/100' 11.25 500' .022 2"5457 4.50/10 41.00/C 400.00/61 OF . 50/10 4.00/C MPSA13 . 24 go PVC.. 2.10/100' 8.50 S00' 047 Quality Electronic Components 28 2.60/10 24.00/C 230.00/M OF . 70/10 5.60/C 85.00/C00 26 go PVC.. 2.10/100' 8.50,500' .1 OF ....1 35/10 11.50/C P.O. Box 677 Thief River Falls, MN 56701 (218) 681-6674 e - TPI2G 9999 9.20/00 800.oiM .4...... r. 114 CIRCLE N0. 12 ON FREE INFORMATION CARO POPULAR ELECTRONICS

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want to know - I Corp Let us know 8 weeks in advance so that you Z1p I won't miss a single issue of POPULAR need to know ELECTRONICS. I State label where indicated and print 33 Attach old NEW ADDRESS HERE 0218 about .. . new address in space provided. Also include your mailing label whenever you write con- cerning your subscription. It helps us serve Name o CB -HAM - SWL - you promptly. please print Apt Write to: P.O. Box 2774, Boulder. CO 80322 Address MARINE RADIO - giving the blowing information: my subscription City DETECTORS Change address only Extend RADAR ENTER NEW SUBSCRIPTION State Zip Payment enclosed o 1 year $12.00 Additional postage on foreign orders: add 53 a year for Canada, $5 (1 extra BONUS issue) in the all -new 1978 Allow 30-60 clays for a year 'or all other countries outside the U.S. and its possessions. delivery. Bill me later Cash only on foreign orders, payable in U.S. currency. COMMUNICATIONS

HANDBOOK at P.O. Box 4430C Santa Clara, CA 95054 [; (408) 988-1640 Same day shipment. First line parts only. Factory tested. Guaranteed money back. Quality IC's and other components at factory prices.

INTEGRATED CIRCUITS 0w510 15, 5:. C1.027 I 51 19M1003 4 r/ casle º Po1np., 5m P51o1 11 O i.on 74153oN .55 ]M340r.15 tc coto, ,1 CorSí1 s 25 2 25 151 e05 wN Ir rasux 39 ]+pl.le I capo, zl cwwó 00.oa ELECTRONICS 50 úsrs ,'0 7.O,x 9 1l53lN ]0 1.1401 ). 10 CDC. I 0 Ca561 e 91102A 2'd 19 raise,N 35 LYa3x 50 cor001 11 co.,,, 0 r4 Np1 6 s D rrtslsx r L9YOro s 0+008 m cwm9, ] o 6s s nCOp }e qM50100 9.A U Í<1oN 1 14L59pN se l 371 50 00.009 e9 rt .tYMf00 03 .5 005,1003 141.11 63 74159]M SI lY]19 42 0w010 39 t4cw ll 115d 5341 97SISrORiM..1159. 1.09 CO Correo rl 1ae10 n 116571A 6q 14e0N 11 7oLs95x 100900 d 10 per 00pe 03 1000 PC, type 15 60 C04011 11 74014 1 10 roer, 1 39 ,a151070 11UI 25. Y9114025 350 p.< p«1 1+C10 51 OLMC113 NJON }e r.15111x n 103e5 60 Cw011 IfiN 100 per type 015 5 pet type fi75 II6 1e ru1N 50 1 L 2009 0 Cwo,. 7,30 Ne25n 11 LSp3N MMs]11 1,6N 69 74LSytN 72 LM] 00 c.o., 96 rolar 195 11e rn J50 )4 74074 75 14915017 «,pe 1tr WA 63 1451360 15 LM3231191 50 c0401e 36 N 25156 MM5313 S,d KEVloeR05v^x,0º5xeyoo.re.Srvñ*QºfiM95 /a48x 69 7,L5151. 67 0473314 67 tor011 94 74076 I 40 1ry 1 d 9 m:rt 1495 O n15155M 67 úÁad 35 Corae 10090 R 55,J 3 55 w,m Ascn Á45Jx I: ºs 4NN ri ALs157N 67 4e n cw019 óe 4Cv rliúvii 4.d iro! Ie so 64to Mm6N,aófnw,w, ro15N 4 .91 LMI4hVx 62 COUt0 , 2 740;54 3 00 pM95 i 90 CLOCK MODULES t9 51630 MM5),e eE LEpS ronce Y ia1516JN .96 LMr e7 1 ri PI^ M, CO O7' z14 m,. Prv9 9s rA,Ñ cc u 3º MESSSV e1 Áóe 3 3nw Á,163N 7 i0joyyÑ coto, ,] eno so 4 350 ,11 x101,10 Radio, and Radar Detec-' 16 20 58 IM31MM, s5 2n Wp Listening, Marine NF146A Cwop 1 2 14x x,}K t'191 1er3 300 50 NVCl+00m. ]95 0l]a CC 1: :1 rl 150 e 21 0 a, 1,95M7 11 r; 1,,,,.- L0]11NM r0 Cor069 Iro 2.ver,om. 3n o,ronmSaR CA 3o0Im Is 40 ñ n io1o1N7 tors plus product buying guides for each 1 9oN Iy v" cwoe ein 310 75 cc smIºo nnm i32 n,znTxe 15oLp.oº w5 1x, 2oºnuew, coMPurlRepARoms n1º,x é; 113,e 15 8r2, 1ti..,.. MNr 5s en 00 0L7+r>5ll WCC 60E 19s o-^ IS 19 2SM "úós 60 00arro . to 7:1101r:3., 1 specialty complete with specifications, n,vN ü lM]2a.5 I r0 r IÑ 95 Ol>50 CC 600 95 21 le - p2}1N 155 IOe COaUn 1 MICROPROCfSSOP. CC 1 ro 1M113x.5 fi.95 Á9 b 9o.m xn 50 {N0359 1+nex I6s 0 CorOn r' éT56125 1 óe00 2 LM32w 12 1 35 n 0.r0 and prices. Whatever your radio 7.365x fi5 15105 C04071 ?I 90 1 photos, 3,OM.15 I]5 ei91 4 lpen, wn 9u 505v 50 i1°Á0'r i.105Ó01iió 1{-1 soo ' m f ''''*°"°°°'.'ú01 é u°p Ill: 5109 1 7+366N 66 13e01.s 1.60 ri ii 9195 169 Áe01 n>D6SSÜMM7 50160E1'R0M'6o.re.n.0.'00M5500BxOeo0e02 Coe. eoln ss 500a0,6115 you're an old hand or n361N L132p1 e 150 eHºtcx ,. alar M.I. ri 16x IMY oaarO.rt 00 3 or0, 9u6eN 6o specialty-whether 1aºsx ss cwo,e OMOLMEMURVRAYIn4 sl4 nEsaonl LM3201n2 I14 e 2 ro so Ole. sl.r flop," DIY KII sóós m a9x 6waM80 ,5494CN !9 COarn 21 5,01 I .50 e116 !e5 I 75 ' i n64 this vital how-to IalSOM ri LM]ro1.es I fi0 M1r. SD 4o,rnN Moe .n W,,,..0,1,1=1,..,I Puorneml just getting started o COMVF1rER Ca061 n 1t00.e 1 Be 425, - 1 5 SOG°Ua"1fluorescent 1.15025 LMh°0x n I7009 2 ºs Cw116 110 110y.a 4 95 e27I jy CONx[[TOPS plGlrel 1NfRMOMF7ER 34s50 1 1alSaÑ 003395 I v Mn OD 55 ro10, 23 0o ca,9p 12 .eQ . ur0ox m+v9., guide will help you get greater value, p5 M Ox -5 9.0 6255 en. xgM 2 P9rt ]9 Í7504 Ca507 i m i1á10. i o 6255 . ,00 Rm - º 42` 2JCr M.+n.ie,m wrx : J,p1°'°, ar I+LSÓ6N 0l00.1 1 10 or o eop. V!w r 9 mv, Dp0 º ri Cor501 , 2' ál,.i v 1e420U 695 -e c«ne at,Y noenWO ra1 39 out of every minute you ,1515 a06n1 I 10 ury lu0 C1rx Pnor«,Ix greater enjoyment ri , 00 61.116 oÁ W COP1p10 IDr5 ia15,], ap o t0 110011 º 50 1 a0 sr 15118 e 11 5 61PMI 0C c+Mwar u«, e""°"'" I o0 1 coor4f10 IS LSPIefi1 ñ iñit7i 151a 90 iM34p..1, 111x 6900 a M1 spend with your equipment. 004515 ) 52 11102.1 190 fi!]C I. 00 3.r390, 1t Orn nlsld 15 110 CMOS meu°, } 7' 2 x.Dp e"ne" 50 6e50 00 9613006 ó,6a, T 14,52211 LMacT.1 I,0 C0.H001 f.r mi°, SV oown+uOON 23100 LMSIfi I p2 MMSnV02 5 9 0542 }r. 50 243055 42 9uuueur u1 SY.95 7aL520N Á1 10a 1.12 1 10 Cor000 6 RESERVE YOUR COPY Sinclair 31/2 Digit Multimeter 60 Hz Crystal Time Base Paratronics 100A Logic

Batt. oper. 1 mV and .1 NA resolution. Re- . Kit $4.75 Converts digital clocks ' Analyzer Kit $199.00 NOW AT THE sistance to 20 meg. 19/. accuracy. Small, 1 from AC line frequency to crystal time Converts an oscilloscope into a digital portable, completely assem. in case. 1 yr. base. Outstanding accuracy. Kit includes: tester and analyzer. Trace computer pro- s, Best value ever! $59.95 PC MM5369, crystal, resistors. PRE -PUBLICATION guarantee. p board, gram flow, monitor I/O sequences. etc. capacitors and trimmer. Trouble shoot all digital, CMOS and MOS Not a Cheap Clock Kit $14.95 families. 128 bit truth table (8 by 16 bits). New Cosmac Soper 14ELF" PRICE OF $1.95 Includes everything except case. 2 -PC Complete with case, parts and instructs. RCA CMOS expandable microcomputer boards. 6-.50" LED Displays. 5314 clock Model 10 Trigger Expander Kit expands This offer is available to readers of POP- w/HEX keypad input and video output for Model 100A to 24 bits 5229.00. Model o chip, transformer, all components and Just turn an and start loading ULAR ELECTRONICS only. Regular news- full instructions. Same clock kit with .80' graphics. 150 Bus Grabber Kit S369.00, a one program using the resident monitor is mail order $3. Save displays. $21.95 your board logic analyzer for S-100 bus appli- stand price $2.50; ROM. Pushbutton selection of all four the convenience of hav- on cations. Instant access to 56 S-100 bus money and enjoy CPU modes. LED indicators at current ° signals. Complete kit with all parts and ing the 1978 COMMUNICATIONS HAND- ' Digital Temperature Meter Kit CPU mode and four CPU state. Single instructs. Indoor and outdoor. Automatically BOOK mailed to you from first -off-the -press step op. for program debug. Built in pwr. -R k ' switches back and forth. Beautiful. 50" supply, 256 Bytes of RAM, audio amp. & , published. LED readouts. Nothing like it available. 2.5 MHz Frequency Counter copies when spkr- Detailed assy. man. w/PC board 8s Needs no additional parts for complete. Kit Complete kit less case 537.50 parts. Comp. Kit $106.95 Custom full operation. Will measure -100° to - all cab.: front panel 19.75 30 MHz Frequency Counter +200°F, air or liquid. Very accurate. hardwood drilled PRE -PUBLICATION RESERVATION' FORM Complete instructions. $39.95 ' Nicad Battery Backup Kit w/all parts 4.95 Kit Complete kit less case $47.75 Fully wired and tested in cabinet 151.70 ' Prescafer Kit to 350 MHz $19.95 1 HANDBOOK, P.O. Box COMMUNICATIONS for info. 278, Pratt Station, Brooklyn, N.Y. 11205 1802 software xchng club: write Clock Calendar Kit $19.95 Stopwatch Kit $26,95 Enclosed is $1.95' (outside U.S.A, $2.50) for CT7015 direct drive chip displays date - RCA Cosmac VIP Kit 275.00 ° Full six digit battery operated. 2-5 volts. the 1978 COMMUNICATIONS HANDBOOK. to and time on .6" LEDS with AM -PM indi- o Video computer with games anc graphics. 3.2768 MHz crystal accuracy. Times to ' be mailed to me in March, 1978 when cator. Alarm/doze feature includes buz- 59 min.. 59 sec., 991/100 sec. Times std., published. zer. Complete with all parts, power supply Original Cosmic "ELF' kit split and Taylor. 7205 chip, all compo- 'Residents of CA, CO, FL, IL, MI, MO, NY and instructions, less case. Full instruc. White or with PC board, monitor, power supply nents minus case. TX tax. r - STATE, DC and add applicable PE -28 ' plus all parts and instructs. $89.50 black plexiglass case. 55.00 1977 IC Update Master 14.95 Print Name Board only - Manual Auto Clock Kit $15.95 Final 1977 closeout S15.00 while they 41/2 Digit DMM kit $85.00 DC clock with 4-,50" displays. Uses MA -1012 module with alarm - Address last. 1978 Master available late Jan. 1978 li Volts-ohms-milliameter accuracy -±1 National $30.00. Complete IC data selector, 1234 count. Ranges: Volts -2. 20, 200. Ohms option. Includes light dimmer, crystal City, pg. master ref. guide, 17,000 cross ref- -2K, 2meg, 20 meg. Ma-2CD, 2000. timebase PC boards. Fully regulated, comp. instructs. Add $3.95 for beautiful erences. Free update for 1977. Domestic o .4' display. Variable update rate. Comp. dark gray case- Best value anywhere. State Zip postage $2.00. Foreign $6.00 w/parts, PC boards,lastructs-, he case. TERMS: $5.00 min. order U.S. Funds. Calif residents add 8% tax. FREE.' Send for Our copy of our NEW,1978 BankAmericard and Master Charge accepted. , QUEST CATALOG. Include 240stamp,, FEBRUARY 1978 Shipping charges will be added on charge cads.

CIRCLE NO al ON FREE INFORMATION CARD AmericanRadioHistory.Com SHOP;iOUR NEARBY RADIO SHACK FOR'QUALITY PARTS AT -LOW PRICES! Top quality devices, fully functional, carefully Inspected. Guaranteed manufacturer's quality control procedures. These are not rejects, not to meet all specifications, both electrically and mechanically. All are fallouts, not seconds. In fact, there are none better on the market! made by well known American manufacturers, and all have to pass Count on Radio Shack for the finest quality electronic parts.

TTL Digital ICs Resistor and Capacitor Packs I Tantalum Capacitors

First Quality +10 Maximum capacity in smallest size. Low ti 16v , Made, by ESR, highly stable electrical characteris- ` National r tics and low leakage. Radial leads. Semiconductor 44~4 0, and . 6'42P Motorola -_ Cat. No. µF Each Cat. No. µF Each Resistor and capacitor kits in handy plastic 272-1401 0.1 390 272-1407 2.2 45C Type storage boxes you Cat. No. ONLY can use over and over again. Stock up! 272-1402 0.22 391 272-1408 3.3 456 7400 276-1801 350 'h Watt, 10% Tolerance Resistors. 271-601 Pkg. of 350/9.95 a. 272-1403 0.33 39C 272-1409 4.7 490 7402 276-1811 396 '/4 272-1404 390 f 7404 Watt, 5% Tolerance Resistors. 271-602 Pkg. of 350/9.95 r, 0.47 272-1410 6.8 490 276-1802 350 272-1405 -p 7406 276-1821 490 5OWVDC Ceramic Disc Capacitors. 272-601 Pkg. of 175/9.95 0.68 390 272-1411 10.0 496 7410 276-1807 390 35WVDC Radial Lead Capacitors. 272-602 Pkg. at 35/9.95 272-1406 1.0 390 7413 276-1815 790 35WVDC Axial Lead Capacitors. 272-603 Pkg. of 36/9.95 Nos. 1401-1408, 35WVDC: 1409-1411, 16WVDC. 7420 276-1809 390 7427 276-1823 490 7432 276-1824 490 7441 276-1804 990 7447 276-1805 990 PC Board Accessories Build an 7448 276-1816 990 LED = 7451 276-1825 390 7473 276-1803 490 Digital Clock 7474 276-1818 490 7475 276.1806 790 7476 276-1813 596 7485 276-1826 1.19 7486 276-1827 49C 7490 276-1808 790 7492 276-1819 690 _1 - I i I_.;' 74123 276-1817 990 i_ - . i_t t - ° 74145 276-1828 1.19 I _ 74150 276-1829 1.39 _cáéd4P.rt.ira7irT7.rr:,. e' 74154 276-1834 1.29 74192 276-1831 1.19 74193 276-1820 1.19 8 -piece photographic PC board processing kit - fastest, 74194 276-1832 1.19 easiest way to produce perfect printed circuit projects. 12iiR LED Clock Module. Just add a transformer and switches for a 74196 276-1833 1.29 276-1560 12.95 complete clock with 0.5' LED display. 277-1001 14.95 - Etch -Resist Marking Pen. 276-1530 1.19 Transformer for above. 120VAC 60 Hz. 273-1520 3.99 Etchant Solution. 276-1535 1.89 SPOT Miniature Pushbutton Switch. 275-1547 5/1.99 PC Board Assortment. 276-1573 1.98 Display Case. 1t3/,ax37/ex47/,e". 270-285 3.95 - CHAOS ICs

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Type Cat. No. ONLY Ir Yir'1 -44yr1r í 'MT 111: 74C00 276-2301 490 74CO2 276-2302 490 74C04 276-2303 490 74C08 276-2305 490 Digits Size Drive Cat. No. ONLY Digits Size Drive Cat. No. ONLY 74C74 276-2310 890 El I 0.6" Anod. 276-056 m 1 74C76 276-2312 2.99 0.3" Anod. 276.1210 4/6.99 896 1 El 0.6" Cath. 276-066 2.99 18 1 0.3" 74C90 276-2315 1.49 Cath. 276-1211 4/6.99 OE 1 0.3" Anod. 276-053 1.99 ® 4 0.5" 6 -Amp Full-Wave Bridge Rectifier. 50 Ply. 74C192 276-2321 1.69 Anod. 276-1201 6.95 o OE 1 0.3" Cath. 276-062 1.99 ®4 276-1180 74C193 276-2322 1.69 0.5" Cath. 276-1202 6.95 1 99 50V 3 -Amp 4601 276-2401 490 Power Rectifier. 300-A surge. 4011 ° 276-1141 Pkg. 2/690 276-2411 490 Electrolytic 4013 276.2413 896 Capacitors 3300 uF at 35V. 272-1021 4017 276-2417 1.49 2 99 IC 5000 µF at 35v. 272-1022 4020 276-2420 1.49 Accessories 3 49 Heavy -Duty All for 120VAC, 4027 276-2427 896 Transformers. 60 Hz 4049 276-2449 690 Cat. No. Volts Current Size Each 4050 276-2450 696 273-1512 CT 4511 276-2447 1.69 25.2 2A 28x21/462' 1.99 273-1513 12 4518 276-2490 1.49 5A 462x214" 8.95 273-1514 18 CT 4A 4x2x2/5 8.95 Q ?L1 © Low -Profile DIP Sockets Silicon Solar Cells Pins Cat. No. Price

Linear ICs O Bus Strip. 276-173 1 99 8 276.1995 2/590 O Experimenter Socket. 276-172 9 95 14 276-1999 2/890 16 By National Semiconductor © OIP Switch. 275-1301 1 99 276.1998 2/890 28 276-1997 Ea. and Motorola first quality a DIP Header. 276-1980 1 29 890 - © Right Angle 16 -Pin Socket. 276-1985 40 276-1996 Ea. 990 ... 1.49 Type Cat. No. ONLY IIII',IIIIII. 301CN 276-017 490 324N 276-1711 1.49 Computer 339N 276-1712 1.49 Chips Produce Power from Light! 386CN 276-1731 990 fy 2cmx4cm. 0.5V at 100mA. 276-120 2 99 555CN 276-1723 796 2cmx2cm. 0.5V at 60mA. 276-128 1 99 556CN 276-1728 1.39 566CN 276-1724 1.69 7 ^ li 567CN 276-1721 1.99 723CN 276-1740 690 I c 741CN 276-007' 490 1 + (nú Clock 741H 276-010 490 U The CPU and Memory IC's 3900N 276-1713 996 N7. Chips 3909N 276-1705 996 you need for building your 3911N 276-1706 1.99 Ir ???rJ own personal computer. 4558CN 276-038 790 ! 75491 276-1701 998 75492 276-1702 996 8080A Microprocessor. An 8 -bit Na- 2102 Static RAM. 1024 -word by 50252. 12 -hour clock, 24 -hour alarm chip. With 7805 . 276-1770 1.29 tional Semiconductor chip in a one bit read/write memory. Under full specifications. 276-1751 6 99 7812 276-1771 1.29 40-pin DIP. 100% Prime. 600 7815 276-1772 1.29 nS access time. 7001. 12 -hour calendar alarm clock IC. With all 276-2510 17.95 276-2501 2 49 Ea. or 8/14.95 data. 276-1756 10.95

WHY WAIT FOR MAIL ORDER DELIVERY? IN STOCK NOW AT OUR STORE NEAR YOU! ° adze Prices may vary at individual stores and dealers iÑióki A TANDY COMPANY FORT WORTH, TEXAS 76102 116 OVER 6000 LOCATIONS IN NINE COUNTRIES

AmericanRadioHistory.Com .11:4 a-@bF8bFB6FBd,FB&FB&FB&FB&FBbFB&FB&FB&FB&FB&FB&F ... 9 _ SPECIAL Jumbo LED'S LINEAR SPECIALS m KEY TO MAGNETIC - 0 a z green -yellow LM301 mini dip .20 K-.. m LM308 TO -5 .65 TAPE DATA RECORDER ' _._u SALE amber- clear 160 ea. r i O LM311 mini dip .65 Singer/Pertec 4301 - 7 data recorder . LED'S with display station, keyboard, 7 track O ZENER DIODE -400MW LM340T 6V .89 MAN 72 .99 .89 magnetic data recorder, controller, etc. 3.6V 5.1V 6.6V 15V LM565 dip Ñ Units are used, and were in good run- - 1.09 4.7V 10V NSN 74R .99 LM567 mini dip removed service. 5.5V $ .1 5 EA. ping order when from .99 LM747 dip .50 n DL702 Sold "AS IS". tapes not included, ship- 8/$1-00 ANY MIX 1 ND 359'.59 LM1458 mini dip .50 peel via truck, freight collect - customer Now Only pays all shipping. Data package avail- ,49155,, M V I OB CA3046 dip .75 $189.99! 1 able. Shipped via truck, Sh. Wt. 200 Lb. r TTL BARGAINS 6/51.00 Md. 4301.7 -$21-8v8B- ALSO: Md. 4325 LINE PRINTER 7416 5 .19 CALCULATOR KI Complete Data Package . $28.50. Singer helical serial line printer. 30 CPS, 7420 .13 SIGNAL DIODES-400Mw LITRONICX 1502 MEMORY OTHER SINGER SYSTEMS: Work Sta- 132 char./line. "AS IS", no data yet .. 7432 .19 tions, Badge Reader/Entrance Station. Sh. Wt. 150 Lbs. (shipped via truck). 7437 .19 201$1.00 etc. All from B&F - send for catalog! 75F70441 5248.88 7440 .13 SHIFT o 7442 .29 REGISTERS (ÁIC. KIT ONLY $7.95 SPEAKER SYSTEMS KIT 7460 .13 251051.75 ADAPTER -60H, 53.95 Z 8&F does it again! New speakers and 7495 .59 enclosures; includes 8" woofers, 4" 74141 .68 2511 1.95 °1-,1`.: dome tweeters, enclosures (21e12x8"), 74145 .59 2518 2.50 2708 5314 6 DIGIT grill cloth, crossover networks, damping, 74151 .59 2522 1.95 FULL SPEED EROM CLOCK CHIP hardware and instructions. A complete 74165 .79 2532 2.29 $10.95 CIAI-! kit with quality at low B&F 2. S components 5016 89 1702A P . . . sells $198 if Now OnIY prices this system for 4 10 3 - N M` bought ready -to -go. Now you can afford MM 5330 .. f'? 256 BIT RAM pair quality sound! Oty. Ltd., Sh. Wt. 45 Lb. 4V1 DIGIT DVM LOGIC $ 4.95 4.75 559.951 S. TRI-STATE; 7 Z U 70283 ~pan, 9 MAN 3M Save $100!.. 12 kits for $599.00 CALCULATOR 8080A, 8008 CABINETS Only: Sh Wt. 30 Lb. DISPLAY ON PC BOARD $16.95 DART I E I 70870197 $25.00/pair Ó LD110, LD111 A 1á1013A z 99 4 ¢J MORE SPEAKER KITS AVAILABLE . 011.11 A 111Y)sVrNrI:M $6.95 as SEND FOR FREE :,! TV HOCKEY/ I CATALOG! MM5369 Divider mDIP 2.49 SI, ' 24.75 f Crystal 3.58 MHZ color TV 1.75 513 ri) 1.95 82S23 i 1_-i _ SOCCER GAME Crvstel 7 010 MHZ HARACTER GEN 'COMPUTER/TV 256 BIT PROM 64,8,5 ASCII 4 games in 1, Joystick controls, LED ELECTRONIC DOOR CHIME KIT scoring, Novice/Expert. Features hockey INTERFACE $2.95 $6.95 o mode in which player retains & shoots Neat,complete checked -out video mod. WITH TI TMS 1000 .J puck while stick -handling up & down ice. ulator permits signals from video games MICROPROCESSORCHIP KEYBOARD 4 2 -dimensional play. 115VAC. Wt. 5 Lbs & microprocessors to the antenna term- PROGRAMMED TO PLAY 20 KEYS N.$22800a inals of your TV set. VV/data, not a kit! it 7HU70284. $17.50! 24 DIFFERENT TUNES 2 SLIDE Sil v With 12 ft. cord for your input. 2 Lbs. S .99 8ZU80015 .. %12.88 ea... 6 for $69.98 $39.50 sxterIsl-si.w CB POWER SUPPLY KIT Salislaclion guaranteed. Shipment hill he made postage prepaid within 3 days Irpm 115VAC in, 10 to 24 VDC, 2A, out. B&F ENTERPRISES receipt of order. Payment may be made with personal check, charge card (include Reg., includes PC board & all parts, you number and exp. dale), or mones order. Phone Orders - Bola and M/C card or C.O.D add your own case! Sh. Wt. 10 Lbs. Dept. P-2 Add 51.00 to caber shipping and handling if order is Ieu than 510.00. ó ea 3 for $43.33 6C60498...514.88 .. In< lade shipping expense for shipped our of or 119 FOSTER STREET C4ilornia residents add sales tax. orders LOGIC Power Supply KIT: 5V, 'IA PEABODY, MA. 01960 U.S. and Canada approx. Ia... of order. reEecuyuLOCAVAILAeLF ONREOUEFT o 5 volts, 1 amp, regulated. No case, all O ELECTRONICS UNLIMITED other parts supplied. Sh. Wt. 3 Lbs. INTERNATIONAL (617) 531-5774 93924 USA $15.00 for 3 VILLAGE SQUARE, P.O. 30X 449, CARMEL VALLEY, CA w 7C70267... $6.00 ea... SURPLUS REIGNS SUPREME TELEPHONE 408 659.3171 r - O :1WHEREPOSTAGE: Please add postage I BLF8LFBLFB4.FBbF86F`BaxBLFBLFB6FBb FBbFBbF CIRCLE NO. 25 ON FREE INFORMATION CARD CIRCLE NO. 4 ON FREE INFORMATION CARD

OWEST- PRICES ONT. PRIME ' GUARANTEED TTL . IC s AND BRAND SYMBOL. NO RETESTS COMPARING OUR PRICES THIS MONTH YOU WILL FIND ICC HAS AGAIN OFFF.RED TIIE ORIGINAL MANUFACTURER'S FULL MARKING ICC. IN OUR VOLUME DISCOUNT LOWEST POSSIBLE PRICES ON PRIME TTL ICa,. OUR HUGE PURCIIASING POWER TO FUNCTIONAL ONL1S, OR FALLOUTS AT ADDITION, MIX 1OUR REQUIREMENTS EVEN GREATER EXPORT TO OUR INTERNATIONAL CUSTOMERS ALLOWS US TO OFFER TIIE LOWEST SCHEDULE ALLOWS YOU TO ALl. Fob POSSIBLE PRICES AND PASS ON THE SAVINGS TO YOU. AS ALWAYS, OF COURSE., WE SAVI\GS. GUARANTEE EVERY IC PURCHASED FROM US TO BE OF PRIME QUALITY AND WITII VOI.UAIE DISCOUNT SCIIEDULE , 1.90 7470 27 74166 .... .95 74LS09... .23 7415139.. .70 7415386 .. .36 745257.. 1.15 74C161 ... 1.90 7472 24 74167..,.3.20 741510 ... .21 7415151.. .65 7415390 .. 1.65 74S258 , .. 1,15 74C162 ... 7400 TTL 1.90 Merchandise Total Discount 7473 24 74170 1.85 741511 ... .21 7415152.. .65 7415393 .. 1 35 745280... 2.25 740163...... S 000$ 9.99 NET 1.10 741512 .27 7415153 .. .66 7415490 .. 1.10 745287 ...320 74C164 ... 2.95 7400 .... $ .14 7474 24 74173 ...... $ 1006S 24.99 LESS5% .85 741513 .40 7415154 .. 1.00 7415670 .. 2.29 74S289 ... 3.55 74C165 ... 2.95 7401 15 7475 45 74174 ...... S 25.005 99.99 LESS 10% .62 745300 1 60 74C173 ... 1.60 7402 15 7476 29 74175 .... .75 741514 ... .85 7415155.. ... S 10000249999 LESS 15% .. .62 74S305 1.90 74C174,,, 1.95 7403 15 7480 31 74176 .... .69 741515 ... .26 7415156 ... S 500.0O5999.99 LESS 20% 74500 In 1.95 7404 16 7482 50 74177 .... .70 741520 ... .23 7415 157 .62 745310... 2 85 74C175 ... $100000 and Up LESS 25% 1 05 74C192 ... 2.00 7405 16 7483 54 74178 .. , . 1.20 741521 ... .23 7415158.. .70 74500...5 .35 745312 ... .82 74S313 1.55 74C193 2.25 . .35 ... 7406 24 7485 80 74179.. , , 1.20 74LS22 .. .23 741_5160.. 74502 ...... 7407 24 7486 27 74180.... .65 741526 ... .31 7415161.. .82 74503 .... 35 745316 ...2.80 74C195 ... 2.25 STANDARD SHIPPING CHARGES 745341 4 10 74C200 8.25 . ... , 74SO4 .36 7408 17 7489 1 75 74181 .. 1.75 74LS27.. .26 7415162 .. .82 ...... 2.00 7409 17 7490 40 74182 .... .75 741530... .23 7415163.. .82 74505 .... .36 74S342 ... 1.20 74C221 ... If your merchandise total is between: 74S343 4 95 740901... .96 S 000-S 4.99 add 0200 7410 15 7491 51 74184 .. , , 1.75 74LS32 ... .30 7415164.. .98 74510 .... .35 ... add 51.00 7411 18 7492 40 74185 ..,.1.75 741537 ... .31 74LS168.. .83 74511 .... .38 745346 ...1.25 74C902 ... .96 S 5.0052499 .38 74S362 ... 2.15 74C903 ... .96 S 2906249.99 add $075 7412 20 7493 40 74188 . 2.80 741538 ... .31 7415169.. .83 74515 .... S 500059999 add 50.50 7413 25 7494 60 74190 .... .95 741540 ... .26 74LS 170.. 1.60 74520 .... .35 74S387 ... 4.70 74C904 ... .96 74C905 6.60 $10000 and Up NO CHARGE 7414 55 7495 60 74191 .... .95 741542... .60 7415173 .. 1.00 74S22 .... .36 ... .80 741547 .75 7415174 .. .75 74530 .... .27 74C906 ... .96 7416 22 7496 60 74192 ...... 74C00 TTL The above charges include shipping via 7415175.. .79 74S32 .50 740907... .96 7417 22 7497 245 74193 .... .80 741548... .72 .... First Class Mail or UPS (your choice). 74C 908... 2.10 7420 ' 15 74107 .29 74194 .... .80 741551... .25 7415181 ..2.50 74540 .... .35 74C00 .27 and insurance on ah domestic shipments 3.95 7421 17 74109.... .32 74195 .... .49 74LS54 .. .25 7415190 .90 74S51 .... .17 74CO2.... .27 74C909 ... 7423 25 74121 .... .29 74196 .... .73 741555 ... .25 7415191 .. .90 74564 .... .38 74C04.... .29 740910...6.60 .29 74C914 ... 1.90 7425 25 74122 .... .35 74197 .... .73 741573 ... .35 7415192.. .90 74565 .... .38 74C08.... SPECIAL SNIPPING CHARGES 2.20 7426 22 74123 .... .39 74198 .... 1.30 741574 ... .35 7415193 .. .90 74574 .... .58 74C10.... .27 74C918 ...

. . . . 1.50 74C925 9.25 7427 19 74125 .... 37 74199 ....1.30 741576 ... .37 7415194.. .85 745112 ... .58 74C14 ... COO $1.00 -additional 7430 15 74126 .... .38 74251 .... 1.00 741578 ... .36 7415195.. .50 745113 ... .58 74C20.... .27 740926...925 Air Mail SI.00-additional 74C927 9.25 7432 23 74132 .... .65 74279 .... .49 74LS83 ... .75 7415196.. .80 745114 ... .58 74C30.... -27 ... Postal Insurance 51.00 -additional .75 .35 74C928 .. .9.25 Delivery $1.25 -additional 7437 21 74141 .... .70 74283 ... . 1.00 741585 ... 1.30 7415197.. .80 745132 ... 74C32.... Special 7438 21 74145 .... .65 74290 .... .59 741586 ... .36 7415221 .. 1.05 745133 ... .38 74C42 . . . , 1.50

. . .80 . . . 1.95 7439 25 74147 .... 1.50 74293 .... .57 741590 . . .50 7415251.. 74S134 ... .38 74C48 .49 .75 7440 15 74148 .... 1.15 74298 .... .92 74LS92 . . . .50 7415253.. .80 745135 ... 74C73 .... INTERNATIONAL 7441 70 74150 .... .79 74365 .... .62 741593 ... .50 7415257.. .70 74S138 ... .77 74C74 .... .65 7442 38 74151 .... .59 74366 .... .62 741595 . . . .85 7415258.. .70 745139 ...1.50 74C76.... .95 COMPONENTS, 7443 55 74152 .... .59 74367 .... .62 .74LS107 .. .35 7415259 .. 1.60 745140... .47 74C83 .... 1.50 7444 55 74153 .... .60 74368 .... .62 7415109.. .35 7415260 .34 745151 ...1.25 74C85 . . . . 1.20 7415112.. .35 7415266 .26 745153 ... 2.10 74C86 .... 1.45 CORPORATION''-`.` 7445 55 74154 .... .95 -. n }., 7446 62 74155 .65 74L5113.. .35 7415279 .52 745157 ... .75 74C89....3.95 .... LL 7447 57 74156 .... .65 74LS114.. .35 7415283 .72 745158 ... 1.25 74C90 . . . . 1.10 1.50 74C93 1.10 7448 60 74157 .... .59 74L500 .. S .21 74LS123.. .90 7415290 60 745174 ...... 7450 15 74160 .... .79 74LS01... .27 7415125.. .46 74LS295 .90 745175 ... 1.45 74C95 . . . . 1.30 P.O.BOX 1837 7451 15 74161 .... .79 74LS02... .21 74LS126.. .46 7415298 .90 745189 ... 2.75 74C107... .80 7453 15 74162 .... .79 741503 ... .21 7415132.. .72 74LS365 .52 745194 ... 1.75 74C151 ...2.75 COLUMBIA,MO. 65201

...... 34 7415366 .52 745200. 3.25 74C154 2.70 7454 15 74163 .... .79 741504 . .24 74LS133.. 745206 ...3.75 74C157 . . . 200 OPEN SATURDAYS 7459 15 74164 .... .79 741505 . . . .24 74LS136.. .35 7415367 .52 (314)-874-1150 7460 15 74165 .... .90 741508 ... .23 74LS138.. .70 7415368 .52 74S253 ... .95 74C160... 1.30

CIRCLE NO. 24 ON FREE INFORMATION CARD

AmericanRadioHistory.Com . --ercr^r1rY .:.. . I , ` . memories: TM ECONORAM II 74LSTTL. This 8K X 8 static memory board has been the 74LS00....$0.30 74LS139....1.15

, choice of thousands of computerists who use the 74LS01 0 30 741.S151....0.95 S-100 buss. Two independent 4K blocks, buffers, 741502 0 30 74LS155....1.38

a tri -state outs, handles DMA devices...and lots 74LSO4 0 33 741.5157....0.95 more. Kit form $135.00 741.S08 0 36 74LS160....1.40 Assembled, tested, 1 year warranty $155.00 74LS10 0 30 74LS161....1.40 Special! 3 kits (24K of memory) 3/S375.00 74LS11 0 36 74LS162....1.40 741512 0 33 74LS163....I.40

741514 1 38 74LS168....1.87 ECONORAM 111 TN 741515 0 30 74LS169....1.87 Finally...an 8K X 8 dynamic that really works, 74LS20 0 30 741.S173....1.65 no matter what buss S-100 machine you use Exclu- 74LS21 0 33 74LS174....1.25 sive timing process eliminates the traditional 741.822 0 33 7415175....1.15 problems associated timing with dynamics. 74LS26 0 43 741.5240....1.88 Zero wait states, as two h configured separate 74LS27 0 36 74LS257....1.25 blocks for versatility. a kit Not ---assembled, 74LS30 0 30 741.5258....1.25 tested, 1 year warranty $149.00 74LS32 0 38 74LS266....0.53 IpW 74LS37 0 45 74LS283....1.20 741.S38 0 45 741.S365/ r-Liv -, ) ECON 74LS42 0 98 80LS95....0.75 Now you can give your Heath Company 118 some- thing to remember...I2K of reliable static memo- 74LS47 1 00 741.5366/ 74LS48 ry, for the same price as Heath's 8K board. Same 0 98 801595....0.75 YOU'RE READING 74LS74 0 50 7415367/ Find of features, and performance, you've come to 74LS75 68 expect from products carrying the ECONORAM name. 0 801597....0.75 74LS76 0 50 74LS368/ Kit form $235.00 POPULAR F1fCIflONNS. 741586 0 50 801.S98....0.75 That already says a lot about you.That SPECIAL 111 --- ;" phone 112 74LS109....0.50 741.5386....0.55 SPECIAL --Cable ties you're fascinated by the diversity of elec- jacks. Mono, closed Can accomodate bundles 741.S125....0.63 81LS95 1 13

74LS126....0.63 1 ' circuit. Switchcraft of wire or cable from 81LS96 13 tronics. Everything from microcomputers at less than the price 1/16" to 3/4" in dia- 741.S132....1.25 81LS97 1 13 to audio. from construction projects to of imports!! 10/ $3.00 meter. 100/$2.95 '4LS138....1.10 811598 1 13 ham radio. Who knows what area of TERMS: Please allow up to 5% for ship- electronics will catch your interest next'! " ping; excess refunded. Californians add That's tax. COD orders accepted with street why you read P. E. To keep in address for UPS. For VISA" or Master- touch with all -that's new and best in the charge"orders ($15 min) call our 24 hr. many worlds of consumer electronics. desk at (415) 562- 0636. Prices good DG® through cover month of magazine. BILL GODBOUT ELECTRONICS FREE FLYER: Send for it, be surprised. BOX 2355, OAKLAND AIRPORT, CA 94614 Popular Electronics

CIRCLE NO. 19 ON FREE INFORMATION CARD

TTL LOW POWER SCHOTTKY PLASTIC DUAL -IN -LINE I.C. CMOS CMOS TEXAS INSTRUMENTS I.C. SOCKETS SN/41SOON 17 SN741591N 99 SN/415191N 175 SN/41 5.1:'/N 7 55 CD4010BE .35 CD4060BE 99 (Low Profile Solder Ta111 SN/41S01N 17 SN741597N fiq SN/41519.'N 95 SN/41 5.15'N .1S CD4011BE .15 CD40668E 55 Unit SN14L502N 17 SN741593EIN 60 SN7415193N 95 SN7415353N 150 Unit CD4012BE .15 CD4068BE 21 , $N741S03N 17 5N74LS95AN 99 SN141S194AN 99 SN7415365N 65 Description Price Description Price CD40138E .28 .21 5N74LSO4N 17 SN741596N 1 45 SN741S195AN 75 SN7415366N 65 CE40698E 8 Pin DIL (C840802) .15 22 Pin DIL (C842202) .34 SN74LSOSN 19 SN7415107N 19 SN741S191iN 175 SN/41 :i36/ N 65 CD4014BE .69 CD4070BE 21 14 Pin DIL (C841402) .18 24 Pin DIL (C842402) .34 SN74LS08N 19 SN74L5109N 19 SN741519/N 125 5N/41S368N 65 CD4015BE .69 CD4071BE 21 16 Pin DIL (841602) .19 28 Pin DIL (842802) 5N74L509N .45 .70 SN741S112N 39 SN/41570/N 1800 SN7415373N 1 75 CD4016BE .28 CD4072BE 25 18 Pin DIL (841802) .29 40 Pin DIL (C844002) 65 5N74LSION 17 SN7415113N 44 5N7415'ORN 1800 5N741S374N 75 CD4017BE .68 CD40738E .25 20 Pin DIL (C842002) .35 _ 5N/41S11N 19 5N74LS114N 44 SN7415'14N 1395 SN74153/5N 77 CD4018BE .74 CD4075BE .25 SN741517N 73 SN7415177N 79 SN/41 571',N 1595 SN74153//N 17', SN741513N 55 SN741S123N 99 SN/415771N 25 5N74151/BN 37 CD4019BE .35 CD4076BE .89 VOLTAGE REGULATORS

SN/41514N 99 I 5N7415124N SO SN 741 S:'4IlN 95 SN/4153/9N 1411 CD40208E .78 CD4078BE .21 LM300H .79 Voltage Regulator SN74L515N 21 SN7415125N 65 5N14LS741N 95 SN74L538IN 365 C04021eE .79 .21 CD40818E LM304H .79 Precision Voltage Negative Regulator 5N741520N 19 SN74LS126N 65 SN/41 S7 47N 95 SN7415386N 57 CD40228E .79 CD4082BE 25 LM305H .79 Positive 5N/41521N .21 SN741S132N Voltage Regulator 99 SN/415743N 95 SN 74l I 5390N 9R CD4023BE .15 CD4085BE 69 71 LM309H .79 5 Volt Positive Regulator TO5 SN74L527N SN74L5133N 79 SN/415744N 95 5N7415393N I SO SNI4L526N 29 45 CD4024BE .59 CD4086BE 69 LM309K SN74L5136N 5N/4L5747N 75 SN7415395N I 8o 1.45 5 Volt Positive Regulator T03 CD40258E .15 95 SN74152/N 25 SN7415138N 79 SN7415748N 95 SN/415396N 70 CE45028E LM323K 5.60 3 Amp 5 Volt Regulator SN74L528N 27 5N7415139N 79 CD40268E 1.29 SN741S749N 30 SN/415398N 7 /5 CD4507BE .38 LM376N-8 MiniDip .99 Positive Voltage Regulator 25 mA SNI41530N 71 SN741S145N 99 SN/41S7,IN 75 5N/41 5199N 1611 CD4027BE .37 CD4510BE .95 (Plastic) SN/41 537N 25 SN/41S1411N 765 5N/415:151N 75 5N/4154?4N 4 ',11 CD40288E 64 CD4511BE I .00 LM723CH SN/41531N 79 SN/415151N 65 SN/41S75/N 40 .48 Voltage Regulator (Adjustable) SN/415445N I ?5 CD4029BE .69 CD45128E .65 SN74LS3/N .29 LM723CN-I4 .44 Voltage Regulator (Adjustable) SN7415153N 65 5N/415258N 95 SN141544/N I 25 SN74L538N .29 CD4030BE .35 CD45148E 1.95 SN7415155N 1 75 SN7415759N 45 SN741S490N 195 SG3501AT 3.60 Plus/Minus 5V Dual Tracking Regulator. 1.50 SN74L540N 23 SN74LS156N 12S SN7415760N 29 SN74L5668N 95 CD4033BE CD45158E 1.95 SG3524J 7.25 Switching Regulator Converter SN74L547N 69 SN741S157N 65 SN7415761N CD4034BE 2 85 79 50 SN7415669N 95 CD4516BE SG4501T 1.80 Plus/Minus 15V Dual Tracking SN741547N 99 SN741S15RN 99 SN/41S766N 5141.11 39 567ON ?/n CD4035BE .85 CD45I8BE 79 Regulator SN/41 548N 99 SN/415160N 95 SN/4152/3N 65 CD4040BE .79 CD4519BE 65 RC4I94TK SN141549N 99 5N/415161N 95 5N7415?/9N 3.95 Variable Dual Tracking Regulator Plus, ° 69 CD4041BE .65 CD45208E 75 SN74LS51N 71 SN741S167N 95 5N/41 5780N 75 Minus 35V Plus/Minus 9.5V CD4042BE 57 99 5N741554N 71 5N741 5161N 95 SN/4IS':111N ,5n CD45228E RC4I95T 2.35 Fixed Plus/Minus 15V Dual Tracking 71 CD40438f 44 99 SN/41S55N SN/41':I64N 50 5N/41',:'II IN 111 04526131 Regulator TO5

,.19/4156 IN I 511 SN/41 5165N 45 5N/41 (:I)404413E 44 1 CD452/BE 50 RC4195TK 3.15 Fixed Plus/Minus I5V Dual Tracking SN/41S/.1N 39 SN/41 5166N 45 CMOS SN/41 S:I IN 'll CD40468E 1.50 CD45288E 95 Regulator T066 SN/41514N 35 SN7415168N 95 SN/AIS?95AN /0 CD40008E I5 CD40478E 2.50 CD4531BE .95 TL497CN 1.98 Switching Voltage Regulator mA . SN/4LS75N 49 SN7415169N 95 SN74LS298N 70 500 CD4001BE .15 CD4049BE .33 CD4539BE 1.15 SN7415/6N 39 SN74L5170N 50 SN7415799N 70 Adjustable Output CD4002BE .15 CD4050BE .33 CD4555BE 69 SN741578N 39 SN74L5173N 50 5N741.5314N 1395 78H05KC 6.35 5 Amp 5 Volt Positive Regulator 103 CD4006BE .95 C04051BE .74 CD4556BE 69 SN74LS83AN 1 75 SN74L51/4N 75 5N/41S315N IS95 7800 Series .79 Positive Voltage Regulators (Plastic) SN741585N 119 SN7415175N 75 51,17415324N CD4007BE 15 CD4052BE .85 CD458IBE 1.98 150 1 Amp SN/415R6N 35 SN74ISIRIN 7/5 SN74153?5N 7 55 CD400881 .74 CD40538E .74 89 CD45828E T0-220 / LM340T 5, 6. 8, 12, 15, 18, 24 Volts 5N741S90N 65 SN741S190N 1 75 SN741S1:6N 755 CD4009BE 35 1.29 1.25 CD4055BE CD4585BE 78M00 Series 1.39 Positive Voltage Regulator 'I, Amp TO -5 / LM340H 5, 6, 8, 12, 15, 18, 24 Volts

' o e n y .. o t.' 4 .. Our new comprehensive 1977/1978 Catalogue, list- ing complete descriptions, illustrations and special P.O. BOX 1035 FRAMINGHAM; MASSACHUSETTS 01701 monolithic pricing on over Telephone Orders & Enquiries (617) 879-0077 In Crudak, 2 Location.. 111,(1(10 items, 5651 Ferris St. 44 Feeken Dr -Unit 25 MINIMUM ORDER $10.00 * ADD $2.00 TO COVER now atail- 1 is n, I 11Inatt n,.m., gn n.p,mnrt ~Arbil, Quebec Risxdale, Ontario Comoro nn a US Rank n,a'1 n POSTAGE & HANDLING * Canad,an customers add /0% able on request. A^r'can Poyly Monty O,ot, Tel. (514) 735-6425 Tel. (416) 675-3311 In, duly and handing MI ,eoe'a, and p,ovinr.al taxes Pu.,

CIRCLE N0. 2 ON FREE INFORMATION CARO 118 POPULAR ELECTRONICS AmericanRadioHistory.Com RCA Radiola 82. Schematic and source of tubes. Heathklt tion manual. Robert Hoffmeister, 514 Esther St., N. Tona- FM -3A. Owner's and assembly manual. Mike Miller, 20211 N. wanda, NY 14120. Operation Assist Ballston Ave., Scotia, NY 12302. N you need information on outdated or rare Censo #71556 oscilloscope. Operating manual and servic- ing information. D. Samek, 31-06 38 St., Astoria, NY 11103. equipment -a schematic. parts list. etc -another reader PR -10 tape deck. Source for drive belts needed. Re- might be able to assist Simply send a postcard to Opera- alistic Patrolman 4 portable radio schematic. Bill Stottlemy- ASSISI POPULAR tion ELECTRONICS / Park Ave . New York A, TN er, Box Trezevant, 38258. manual. M. Toman, NY 10016 For those who can help rearlets. please re- Roberts 770X tape recorder. Service 7143 Georgia Ave., N.W., Washington, D.C. 20012. spond directly to them They II appreciate it (Only those Military oscilloscope, Model OS62B/USM50. Schematic dia- items regarding equipment not available from normal gram and parts. G.M. Durrence, 1587 Coralwood Ct., De- Tektronix sources are published Tektroddx dual -trace oscilloscope, Model 535. catur, GA 30033. plug-in unit 53/54C, Model 535. Beckman/Berkeley Uni- versal EPUT and Timer, model 7360W. Robert T. Kintz, 104 Instruments, LS -5 ruby laser system. Any technical Trion Council Rock Ave., Rochester, NY 14610. information. Hajdrowski, 965 Cambridge Lane, Crystal Lake, IL 60014. Farnsworth CRT -F10 -WC, BT 57 battery radio, serial No. Neathlclt Model EV-3 or EVW-3 Impscope. Operating In- F22520. Service information and plans for suitable ac power struction, manuals, and schematics. Doug Marston, 263 RT-380 (18 S-4) Autotune transceiver. Man- Collins surplus supply. G.W. Brown, Box 3543, Burlington NC 27215. Saddle Lane. Grants Pass, OR 97526. ual, schematic, conversion information. Chris Bobbitt,. WDNA Radio, CPO 381, Berea, KY 40404. Superior Instruments Co. Model #TV -50 Genometer. Pyramid, CRA-2 capacitor resistor analyzer. Schematic. Schematic and service manual. Robert D. Lansky, 137 Wa- Harvey -Wells Bandmaster Z-Match radio gear unit. Instruc- Hugher. memoscope Model 105A. Need source of high -volt- terman Ave., Coldwater, MI 49036.

- I Lafayette Model HE -15 AC, CB. Schematic and operator's manual. Ron Brunson, 16191. Azales Way, Los Gatos, CA 95030. ABOUT YOUR SUBSCRIPTION Lafayette Micro -P450 uhf mobile monitor receiver. Sche- matic and operation manual. L.A. Freel, 4725 Lane Ave. S., Jacksonville, FL 32210. Your subscription to POPULAR ELECTRONICS is maintained on one of the world's most modern, effi- cient computer systems, and if you're like 99% of our subscribers, you'll never have any reason to Orundig Model 5490. Schematics. John F. Pane, R.D. #1, complain about your subscription service. Mason Rd., Baden, PA 15005. We have found that when complaints do arise, the majority of them occur because people have writ- differently at different times. For example, if your subscription were listed National HRO-50, 60. Need coils, calibrator, original ten their names or addresses were to renew it as "Bill Jones, Ce- speaker. George Saunders, 28821 Portsmouth Dr., Sun under "William Jones, Cedar Lane, Middletown, Arizona," and you in- City, CA 92381. dar Lane, Middletown, Arizona," our computer would think that two separate subscriptions were volved, and it would start sending you two copies of POPULAR ELECTRONICS each month. Other exam- VÍvitar Model RC -730 stereo cassette recorder/AM/FM ra- ples of combinations of names that would confuse the computer would include: John Henry Smith and dio. Schematic. R.V. Powell, 2202 Villa Dr., Greensboro, NC Henry Smith; and Mrs. Joseph Jones and Mary Jorres. Minor differences in addresses can also lead to 27403. difficulties. For example, to the computer, 100 Second St. is not the same as 100 2nd St. when you write us about your subscription, be sure to enclose the mailing label from the Revere open -reel tape recorder Model T-1100. Schemat- So, please, as they appear on the mailing ics, instruction manual, parts information. Paul Goldwhite, cover of the magazine -or else copy your name and address exactly CI) request much 1704 Oak St., So. Pasadena, CA 91030. label. This will greatly reduce any chance of error, and we will be able to service your more quickly. \IA Carvin Bass Master solid state bass guitar amplifier. Sche- matic and parts list. R. Davis. 107 Spicer Avenue, Apt #1, CD Groton, CT 06340. PRINTED CIRCUIT BOARD TRANSISTOR SPECIALS ull Wave Bridges 266233 NPN RF POWER, 5 1.95 Halllcrafters Model SX105. Need schematic and service PR 2A 6A 25A 4th 8 6u, SINGLE SIDED EPDXY BOARD MRF-8004 a CB RF Transistor NPN S 1.50 manual. Reno, NY 1/16'' IhIEL, unetclleo 5.60 ea. 5/52.601 1.30 Bill Bond, 52111 Elko Street, 89512. 2'43772 NPN 5. Ti) 3 . S 1.00 100 200 .75 t.25 2.00 OIODÉ IR $8.95 2N1546 PNP GE 10.3 S .75 7 WATT L065'LASER 400 95 1.50 3.00 254908 PNP S. TO 3 5 I (q Aerovox - L -C Checker, Model No. 97. Schematic and in- 2N3820PFET 5 .45 2N6056 NPN 5. TO 3 J.,,h,19K,n 5 170 600 1.20 1.75 4.00 .45 struction manual. Edward W. Kremm, 1592 Sheridan Rd., 2N 5457 N FET 5 21,5086 PNP S. T0 97 4 S 100 2N 2646 5 .45 San Bernardino, CA 92407. ER 900 TRIGGER DIODES 4/$1.00 7144e98 PNP T0 66 5 60 SANKEN AUDIO POWER AMPS 25 6028 PROG VJT 5 .65 76404 PUP [,E r 0 5 5 5 1 O(1 5, 10100 10 WATTS. 5 680 2N39t9 NPN 5,TO3R' S 150 Si 1020020 WATTS . S13.10 MINIATURE MULTI -TURN TRIM POTS Frlden Model EC1114, 14 -digit desk calculator. Schematic NS'SA 13 NPN 5. TO 97 3 5 1 00 S, 1050 G so WATTS 525.90 100. 500. 1K, 26, 5K. 10K, 506, 100K, 2113767 NPN Si T066 S 70 or service manual. Robert Miller, Rt. 1, Anadarko, OK 73005. 200K. 500K 1 Men. $.75 each 3/52.00 100 7N2222NPN5.TOIB 55 TANTULUM CAPACITORS ' VERIPAx PC BOARD 7513055 NPN 5. TO 3 S .5o Hallicrafters Model S-22R shortwave receiver. Schematic Tb,5 board Is a 1/16" Angie sided paper 263904 NPN 5. T097 5 5 t 00 22UF 35V 55100 6BuP 35V 45100 epoxy boar0, 41R" 0 61/í' DRILLED and 100 47UF 35V 5 51 00 10UF 10V $ .25 ETCHED whie6 4.111 hold up to 21 single 14 55 and alignment information. Joseph A. Zolnik, 73 Plumb Ave., 68UF 35V 551 00 22UF 25V S 40 pen IC's or 8. 16, or L51 DIP IC's with bus- 265296 NPN 5, TO 220 S 50 lUF 00 Meriden, CT 06450. ses for power supply connector. 34.00 216109 PNP S.TO720 9 55 35V 551 15UF 35V 3/51.00 7 2 UF 70V5 51 00 1 00 30uF 6v 5,'S1.00 RED, YELLOW. GREEN or M114641.00 '114:16J8 PNP 5, 5 S 3 3U 35V 45100 47U6 '20V S .35 or LARGE 15V G.E. radio Model L-640 superhet receiver. Schematic any 1L51MCT-2 s IC SERIES 4.7UF 5/51.00 68 UF 15V S .50 available information. Howard E. Colbert, 810 South 21 St., MOLEX PINS100/$1.00.75TTL 7400- .16 7430- .16 )4490- .45 74163-. .80 1000/38.00 7401 .16 7432- .25 7491- .fi5 )4164- .95 7415 SERIES LINEAR CIRCUITS St. Joseph, MO 64507. MC6860 MODEM CHIP $9.95 .24 7492- 43 7402- .16 7437- 14165-1.05 15125 65 L 75 7436- .24 7493- .45 7áI)0-2.25 147500 26 101 . 7403 .r6 815126 65 SiliconPowsrRectilNrs 7404 20 7440- .16 7494- .70 74173-1.35 503 26 301 744 29 4L5102 30 Halllcrafters Model SX110 shortwave receiver. Schematic PRV lA 3A 174 504 125A 7405- .20 .70 :495- .65 74174_ ,95 741 26 M301 7406- .25 71-7442- .52 7496- 6 74175.. .90 ,41.504 78 7415136 39 LYI 308 75 100 06 14 30 3 /0 and operating manual. HP1AC Camilo Castillo, Box 6-583, 7407- 25 )445- .05 74107- 28 74176 .75 746505 28 1aL5138 LM 3rr 75 35 1 15 4 1 700 07 .70 25 lá08- .20 7446- .70 7e121- .33 14117- 75 7á1508 28 1aL5139 72 LM318 20 El 1á122- .a8 7a180 .65 Dorado, Panama. 400 n9 75 50 140 650 09- .20 7447- .65 L509 26 7á15151 98 319 95 16 7a4B- 123- .40 74181-2.00 11 70 180 lá10- .70 5153 93 CM 1 OS 6LA 3o 850 4125- .40 74190-1.20 41.510 26 324 7411- .20 7450- .15 a1s155 2 00 339 0 800 IS 35 90 2 JO 1050 7412- .20 7472- .32 74126- .40 14191-1.20 14L511 26 LM Pentron Model PR -65 stereo Aristocrat IV or Pentron Presi- 741513 50 7465156 95 LM 358 I 40 1000 20 45 1 10 2 75 1250 7413- .39 7473- .32 74150-1.10 4192- .83 /465157 I IS 7416- .85 7474- .32 74151- .65 74193- .83 746515 28 98 M 3)0 dent open -reel. Schematics. Jerry Harris, 1928 South 3, analog 74L5160 SAD 1024.0 RED CON 1024 stage 7416- .25 7475 45 14153- .65 74194_ ,85 74L520 26 02 LM 37/ 2 50 eq,ster. 18 95 Avenue, Maywood, IL 60153. "806601 Brigade".mat )417- .25 6 .30 e155-1.00 74195- 85 4L521 26 74,5161 02 95 7420- 16 7480 45 70 74196- .86 41522 26 741.5162 02 M 381 25 15, IN 4148 1169147 51.00 7425- 15 1483- 70 7415)- .65 74279- 8) 741526 33 74,5163 02 M 502 125 2708.86 EPROM (450 ns7 510.95 7426- .25 7485- 87 74161- .85 75491- .50 laLS168 10 Patterson Model PR -15 communication receiver. Schemat- RE6 3 1.95 74L527 33 LM 537 2 50 2522 STATIC SHIFT 7427- .25 7486 30 4,5169 10 ics and service manual, E.W. Clede, 6811 Spring Forest, 2513 CHARACTER GEN 3 6 15 )áL530 26 LM553 2 50 2518 HEX 32 BIT SR 3 3.50 SILICON SOLAR CELLS 532 33 aL5170 72 555 39 TM54050NL-4K cys RAM 5 .95 741.5173 39 San Antonio, TX. 4.50 2%" diameter .40 at 500 ma 54.00 161537 37 5203-216 EPROM $ 538 37 /4L5174 05 NE540L 1 )5 01 RAM (450 a5) $ 1.19 2102.1 1024 LED READOUTS 4LSad 74,5175 22 560 00 aL542 ú 7815190 565 95 Nova-Tech Pilot Pal three -band direction finder radio. Sche- MK4000P 1.95 END 359eC 4' S 50 DL 704 3CC S 95 5280 4K DYNAMIC RAM 3 4.75 14154) 79 74i 5191 50 566 1 25 FND70CC .4 S 55 MAN7 3" C A S .95 matic and available parts source. Martin DerOvanseian, 725 1702A UV PROM 3 3.95 " 141551 76 al 5192 75 567 1 30 FND503CC 5" S 85 N5333tl,9. S.75 5204.4 K PROM 310.95 v,a 74L554 26 7435193 l5 103 90 Opa-Locka Blvd., Opa-Locka, FL 33054. FND510CA 5" S 85 Iq]C.A .6"y 62523 3 pL 51.95 95 95 25 709 25 $ 6.95 7aL580 AY -5-1013 UART 747573 40 7415196 99 710 35 DATA CASSETTES '/2 hr. 51.25 40 815197 99 )41C4.V 31 MTA P'DPDT Off ...... $ 1.85 /aLS/4 Peterson Scanner, Model HL -44. Schematic and/or service 206 Center 1aL5271 25 747 65 MSD 206 P.DPDT Center Off 44 Pm Solder Tad .156" Spacing 52.20 74L576 40 manual. Edward H. Yocher, 772 Rustic La., Cheshire, CT Lever 54,1015 1.85 74L 590 B9 74,525/ 35 LM 1310 250 41.592 as /AL 52531 '8 1456 95 124, F1GMT WIRE MM53876A with FCS8024 readouts This new Na 06401. DIP SOCKETS 830 raLS279 1458 50 CONDUCTOF WRAP bond clock chip will dire. rly drive a ED displays. 15 9 PIN - 22 24 PIN 40 81'11'5'10'9 4385 7415365 66 CA3046 SPECTOA 290E Four .8" 6181, readout) supplied 510.95 )41.5366 66 49 FLAT CABLE 14,16 25 28PIN 50 SINGLE 7441.51 I? 43 8900 Inc., Model 214 ratiometer. Ratiometer and 7415368 3 90 Transformers, 10'/51 'fi PIN 28 40 PIN 60 15113 4] 66 038CC MCM 65716 7 .9 uppe. 6.19,6e, /4L5390 1./A791r5 - 1 95 plug 400, 1000 Hz. Krankkala, 7335 IOW/513.50' SPIN30 1m/3 Loo I /4L5114 43 1 95 ins for 60, Donald . ese cnaraeer gen . .. 51075 Greensboro St., Goleta, CA 93017. REGULATORS 309K 5 .95 34016-12, 15 TRIACS SCR'S 723 S .50 24 V CTS 206 8 e,9hr pos,llon ,I,p swatch .... S 1 90 320K-5 or 340T.5.6, PRV IA t0A 25A 1.5A 6A 35A Regal -Eye TV camera and video monitor. Schematic and 154 3110 15,18 or 24V 51.10 CTS -206 4 lour Dos,Uon dip swatch ....57.75 1.30 1 3201-5,15 or 78MG or 79 .. 51.35 100 .40 70 .40 50 20 parts supply. Donald H. Palmer, 3620 Woodchase #24, 24V 41.15 ALTO MINIATUNE TOGGLE SWITCHES 200 70 I 10 1.75 60 .70 1 60 Houston, TX 77042. RS232 DB 25P male 52.95 MTA 106 SPOT 5105 400 I 10 1 60 2 60 1.00 1 20 2 20 CONNECTORS 013 255 female 53.50 MTA 206 OPO7 ...... 51.45 600 1 70 2.30 3.60 1.50 3 00 Dumont Labs, Inc. oscilloscope Type 224-A. Operating manual schematics. Leonard G. Falba, 38 Bryson Rd., and Terms: FOB Cambridge, Maas Send 25! for our catalog featuring SOLID STATE SALES New Castle, PA 16101. Send Clack Of Money Order. Transistors and Rectifiers P.O. BOX 74A Include Pottage, Minimum 145 Hampshire St., CambridgeMass. Order $5.00, COB'S t20.00 MASS.02143 TEL.1617) 542-7053 FEBRUARY 1978 SOMERVILLE,

CIRCLE N0. 48 ON FREE INFORMATION CARO

AmericanRadioHistory.Com Pushbutton

AM AUTO RADIO age transformer. Mike Kelley, 2131 N. Southport, Chicago, `r Mounts In Or IL 60614. 99 Under -Dash Popular Electronics & Volume Dumont Model 208-B, (ref. #DD -1789-C-2). Schematic, op- AU -580 Tone eration manual or supplier. D. Thorson, WB9YSE, 3365 Car- ADVERTISERS INDEX NiCad Rechargeable "AA" Cell dinal Dr., Brookfield, WI 53005. READER Í PEN-LITE BATTERY Radio City Products tube and set tester. Model 802NA. SERVICE NO. ADVERTISER PAGE NO. S 1.2 Volt Current tube chart and address of company Charles BA -341 McNeely, 1999 Redstone Dr., Fairborn, OH 45324. - Famous 1 A P Products Incorporated 79 J/ EA. Manufacturer Maroon Electronics Corp., Westem Union facsimile 2 Active Electronic Sales Corp 118 preamplifier Model 6575. Technical manual and schematic. 3 Ancrona Corp 101 Volume Controls, Pkg. of 12 Assorted. VC -274 590 Jeffrey K. White, Box 767, Athens, OH 45701. Audio Technica U.S., Inc 64 Hardware 1 Lb. Assorted. HW-076. 506 4 B & F Capacitors, Low Voltage Elect 50 Pc. CD -407 250 Nihon Handotal Co. Ltd., Nippan frequency counter model Enterprises 117 57 B&K Precision, Product Terminal Strips, Solder Type, 40 Assorted. XM-501 696 FC-3A with prescaler. Schematic and specifications. J E. of Dynascan 124 6 Broadway Electronics 94 Resistors, 100 Assorted Carton. RR -017 196 James, AM- Radio Op., VE7BCJ, 1187 West 23 St., North Vancouver, B.C. V7P 2H2. Burstein-Applebee Co 69 2" PM Speaker, 8-10 Ohm. 2 for 1.00. SS -295 796 59 Byte 98 Cassette Tape, Pkg. of 3-30 Minute. TA -879 796 Hallicrafters Model SX-62-A shortwave receiver. Schemat- 40 Minute. TA -907 490 CREI, Capitol Radio Engineering 8 -Track Tape, ic. Paul S. La Follette, 229 Amesbury Circle, Sun City Cen- Institute 70, 71, 72, 73 Earphones, 8 Ohm, Less Cord. Pkg. of 4. PH -405 496 ter, FL 33570. Cleveland Institute of Singer 12 Digit MOS Calculator Chip With Data. XM-635 1.79 Electronics, Inc 22, 23, 24, 25 UHF Varactor Tuner With Data Sheet XM-676 1 49 Ballantine Model 305 A -peak volt meter. Tektronix 180-S1 time mark generator. Manuals 7 Cobra, Product of Ceramic Capacitors, Pkg. of 100. CC -211 100 or ány information. Clyde N. Dynascan Smith, 11 Brown St., Reynoldsville, PA 15851. SECOND COVER RED LED, 2 Volt 10mA. Pkg. of 5. Pt -233 59c 10 Computer Depot, Inc 6 LCD 31/2 Digit Display. XM-371 2 79 9 93 Midwest Radio Corp. Model 816, series 16, serial No. Contemporary Marketing Inc. 709 High Gain OP AMP. RE -131 , 790 11 Continental 2 8163781. Any information and schematic. Enc L. Dreher, Specialties Corporation Slide Switches, 10 Assorted. SW -836 69t 838 Lois Ave., Sunnyvale, CA 94087. 54 Cooper Group, The 28 Deluxe Stereo Headphones. PH -460 299 12 Digi-Key Corporation 114 Precision Instruments Model 640 tube tester. Operating Famous Brand Stereo Receiver With Built-In 8 -Track Tape In- 13 Digital Group, The 31 Player. RA -598 69.00 structions and data for modern tube types, socket and adapt- er data. Kevin Lovingood, 9 Peachtree Circle, Columbia, SC 14 Ni -Cad Battery Pack (2 "AA" Size Cells). BA -359 250 EICO 68 29206. Edmund Scientific Co 106 Ni -Cad Battery Pack (3 "AA" Size Cells). BA -327 350 16 Electronics Book Club . 7 Ni -Cad Battery 1.2 Volt at 1.5 Amp/Hr. BA -348 1 75 Hallicrafters Model S -40B. Schematic, parts list, and other 17 Electronics Book Service 11 Ni -Cad Battery 1.2 Volt at Amp/Hr. BA-349 225 Information. Tim Mooney, 11 Cornell Dr., Delran, NJ 08075. 18 Empire Scientific Corp 14 Mallory Duracell Photo Type PX-825. BA -323 50 Cassette Laplel Mike, 3.5mm Plug. MM -114 100 Motorola 800 factory converter-12DC-146 MHz FM. Sche- 58 Fluke 96 matic and alignment data. J.H. McCune, 5617 Moravin Rd., 3" Recording Tape, Pkg. of 5 (125' to 300'). TA -928 100 19 118 Baltimore, MD 21206. Godbout Elecs., Bill Slidemoust For Auto Stereo or CB. AU -149 1 99 20 Grantham College of Engineering 68 .6 to 12 Volt DC Converter, 6V. Acc. On 12V. Batt. AU -297 . 4 99 Tektronix Model 513D oscilloscope. Schematic, operating 5 650 RPM Motor, 51/2" Shaft, 120V. AC. MO -265 100 Heath Company 88, 89, 90, 91 and maintenance manual. Frank Tattersall, 118 West St., 21 Hobbi House 100 9.6VDC Motor, 4 Step Shaft. MO -365 1 00 Milford, MA 01757. 22 Hobby World 102 4000 RPM 117V. AC/DC Motor. MO -395 129 18 RPM Geared Motor,120VAC. MO-409 159 RCA Manufacturing Co., Rider Channelist. Operating man- IMSAI Manufacturing Corporation 35 TV Tuner Motor, 14 RPM,120VAC. MO -392 159 ual. Nova Tech Pilot II lour -band receiver. Maintenance arid 30 Illinois Audio 83 tuning 3" Fan and 120VAC Motor. MO-416 2 49 alignment manual. W.L. Fenska Lot 27, 4729 Palm 24 International Components Corp 117 Beach Blvd., Fort Myers, FL 33905. 25 International 31/2" Digit 1-C Display. XM-371 3 75 Electronics Unlimited 117 Sperry 9 Digit Display, 180VDC. XM-643 100 Accurate Instrument Co. Model 257 tube tester. Operating 56 JS&A National Sales Group 1 RED LED, Pkg. of 5. Pt -233 69 instructions, tube chart and wiring diagram. Hower J. Kacz- 26 Jade Computer Products 104, 105 20 Key Calculator Keyboard. XM-339 1 50 marek, 565 McHenry Ave., Crystal Lake, IL 60014. 27 James Electronics 110, 111

TI Desk Calculator Keyboard. XM-523 1 00 28 Kedman Company 87 Solder Type Terminal Strips, Pkg. of 40. XM-501 100 Knight signal generator Model KG -696. Schematic and op- eration manual. John Roark, Coruus Millington, Assorted Knobs, Kit of 25. KN-030 696 3216 Loop, 29 McIntosh Laboratory Inc 99 TN 38053. .3" 7 Seg. L.E.D. Comm. Anode, Green. XM-341 1 39 23 McKay Dymek Co 83

.3" 7 Seg. L.E.D. Comm. Anode, Red. XM-370 1 39 Radio Shack 277-110 5 range DMM project board. Sche- NRI Schools 16, 17, 18, 19 .3" 7 Sed. LE.D. Comm. Anode, Yellow. XM-342 199 matics, parts list, instructions. Kevin Deitrich, 8118 8th Street National Technical 100 MFD. Elect Capacitor, 50 VDC. CC -216 990 West, Rock Island, IL 61201. Schools 36, 37, 38, 39 12K Ohm Globar Resistor. RS -241 590 31 Netronics R & D Ltd 93 Mini Poly -Styrene Caps. 500 pf. a 125V. Pkg. of 5. CC -234 59t Lafayette Model HE -10 series (A.B.C.) tube-type CB trans- 32 New -Tone Electronics 103 ceiver. Schematic and repairable unit. C. Pryson, 4909 Get- Mini Poly -Styrene Caps.1000 pf. I 125V. Pkg. 5. CC -235 . 596 tysburg Rd., Knoxville, TN 37921. 33 OK Machine & Tool Corporation ...50, 51 12 Digit Calculator IC Chip, Data Incl. XM-330 149 34 Olson Electronics 120 Speaker, 8 Ohms. SP -471 149 2" Waterproof Carnegie AM -FM 8 -track stereo console, Model 35 Optoelectronics 10 t 80-40-20 MFD 150V. Elect. Cap. CC -144 590 #V6S039-R. Schematic. Marvin Kosmal, 1931 Palmgrove, 36 PAIA Electronics, Inc 69 100-150 MFD t150 -50V Elect. Cap. CC -213 596 Pomona, CA 91767. 37 Page Digital Electronics 81 Buzzer, 11/2" Diameter: XM-756 596 3VDC 38 Poly Paks 109 Wire Terminal Lug, 50 Pcs. Solderless. XM-735 99t Hemmarlund HO 145A. Schematic and alignment data. E. Lee Tolson, 135 Manistee Ave., Panama 39 Processor Technology Co 95 100mA. Selenium Rect.130VAC. RE -117 390 City Beach, FL 32407. 40 Professional Aids Co 81 Output Transistor, 256474, to -66. TR-141 129 55 Professional Aids Co 81 8 -Track Tape Deck Chassis, Includes Pre -Amp. 117VAC., lust Precision VTVM series EV-10. Schematics, manuals, any 41 Quest Electronics 115 Add Cables. RA -604 900 information. Filbert Katz, 3311 Susan Dr., San Bruno, CA Telechron Digital Clock. 117VAC. SW-853 399 94066. 42 Radio Hut 112

20,000 MFD. 30VDC Capacitor, Computer Grade. CD -478 . 2.00 Radio Shack 116, THIRD COVER Helllcrartera Model 600 MFD-360V. Photo Flash Capacitor. CD -415 900 S -40B receiver. Schematic or any avail- 43 S. D. Sales Co 113 able service Information. Richard Nehrbass, USS SC 44 Sabtronics (CGN-37), FPO New York, NY 09501. International Inc FOURTH COVER electronics 45 Schober Organ Corp. The 99 Hallicrafters 260 S. Forge St. Model S -38C. Manual and schematic. John M. 46 Scientific Audio Electronics, Inc 34 Dept. 1-8 Akron, Ohio 44327 Ray, 306 Simone, Carson City, NV 89701. 47 Shure Brothers Inc 57 Sinclair Radionics, Inc 9 Brother Model 5 862 -function calculator. Need schematic 48 Solid State Sales 119 NAME and green gaseous 9 -digit display tube, or plans to convert to 49 Southwest Technical Products Corp 40 ADDRESS red LED display. B.S. Bridges, Box 41, Boiling Springs, NC 50 Spartan School of Aeronautics 87 STATE ZIP 28017. CITY 51 Stanton Magnetics, Inc 5 Qty. Stk. # Description Price Ea. Total Grundig Majestic Musical Instrument #7018. Need source 52 U.S. Pioneer Electronics .12,13 for fuse. Mark Hamilton, 944 Wyndsor Dr., Hixson, TN 37343. 53 Watson Gutphil 83 CLASSIFIED ADVERTISING ....121, 122, 123 1 Dumont 322-A 2 -beam oscilloscope. Schematics, manual Postage S needed. I. Graham, 3065 Uplands Rd., Victoria, B.C., Cana- da V8R 6B3.

POPULAR ELECTRONICS CIRCLE NO. 34 ON FREE INFORMATION CARO

AmericanRadioHistory.Com Electronics assiHe iecv REGULAR CLASSIFIED: COMMERCIAL RATE: For firms or individuals offering commercial products or services, $2.40 per word. Minimum order $36.00. EX- PAND -AD® CLASSIFIED RATE: $3.60 per word. Minimum order $54.00. Frequency discount; 5% for 6 months; 10% for 12 months paid in advance. PERSONAL RATE: For individuals with a personal item to buy or sell, $1.40 per word. No minimum! DISPLAY CLASSIFIED: 1" by 1 column (2-1/4" wide), $280.00. 2" by 1 col- inquire. umn, $560.00. 311 by 1 column, $840.00. Advertiser to supply film positives. For frequency rates, please advertis- GENERAL INFORMATION: Ad copy must be typewritten or clearly printed. Payment must accompany copy except when ads are placed by accredited MUST supply ing agencies. First word in all ads set in caps. All copy subject to publisher's approval. All advertisers using Post Office Boxes in their addresses the of publisher with permanent address and telephone number before ad can be run. Advertisements will not be published which advertise or promote use devices for the surreptitious interception of communications. Ads are not acknowledged. They will appear in first issue to go to press after closing date. Closing to Classified Advertising, POPULAR Date: 1st of the 2nd month preceding cover date (for example, March issue closes January 1st), Send order and remittance ELECTRONICS, One Park Avenue, New York, New York 10016, Attention: Hal Cymes.

TTL. DTI, CMOS, Tnnunpn BUILD STEREO SPEAKERS us so 8O%6 OFF on LEDs, SRs, RAM[, o. Linean, FOR SALE AND Calculator chips 8 clock chip. WITH JUST GLUE STAPLES. We're not in the electron. business. We ugwrea this inventor,/ m Payment of a debt. Over 8100,000 M merchandw whim well sell ,Save up to 50% of the cost of ready -built cheap raise the money that was owed us. A wide selection of components for everyoneresounding promptly t this ad. But FREE! Bargain LED's, readouts, fiber op- speakers by assembling Speakerlab kits. , there a morel Catalog-I-C.'s, e of a prtI.e. w tics, calculators parts & kits, semiconductors, parts. Poly We've done the design, carpentry and To geta flyer listing our [ompleteo nventory, write^ wiring, leaving you only the actual in- GOODWORKERS, Boa 900Dept. Pt, Felton, CA 95018 Paks, Box 942PE, Lynnfield, Mass. 01940. Or, Tor superfast action. calf o ring machine it (0081 335.7213. Call stallation of the speaker drivers. 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Send SASE for FREE INFO. CFR drivers that are some of the best in the industry. cuits and Bluffton, Ohio 45817. Send for our free 52 -page catalog. It's practically a Associztes, POB F, Newton, NH 03858. RADIO-T.V. Tubes cents each. Send for free catalog. manual on speaker building and acoustics. -36 MAKE PROFESSIONAL QUALITY PC boards with silk- Cornell, 4213 University, San Diego, Calif. 92105. screen techniques. Complete information, $4.95 postpaid. AMATEUR SCIENTISTS, Electronics Experimenters, eekerla TerraTronic Research, Box 513FP, Quincy, III. 62301. Dept. PE 4.G 5500 35th N.E., Seattle, WA 98105 Science Fair Students...Construction plans -Complete, GOLDMINE OF PARTS, POWERFUL POWER SUPPLY, including drawings, schematics, parts list with prices and BUILD AND SAVE. TELEPHONES, TELEVISION, DETEC- DOCUMENTATION, in complete CARTRIVISION electronic sources...Robot Man Psychedelic shows Lasers - - - TIVE, BROADCAST Electronics. We sell construction assembly. Perfect for MICROPROCESSOR and all elec- Emotion/Lie Detector Touch Tone Dial Quadraphonic - - with Engineering Service. Speakerphones, An- tronic applications. $24.95 total. Master Charge, Bank- Adapter Transistorized Ignition Burglar Alarm plans an - - - swering Machines, Carphones, Phonevision, Dialers, Color Americard. Free Brochure. MADISON ELECTRONICS, IN- Sound Meter...over 60 items. Send 50 cents coin (no TV Converters, VTR, Games, $25 TV Camera, Electron CORPORATED, 369, Madison, Alabama 35758. SATISFAC- stamps) for complete catalog. Technical Writers Group, Microscope, Special Effects Generator, Time Base Correc- TION GUARANTEED. Box 5994, University Station, Raleigh, N.C. 27607. in Inte- tor, Chrome Key. Engineering Courses Telephone. MUSIC- CMOS Envelope Generator- Attack - Fallback - METERS -Surplus, new, used, panel or portable. Send for PLUS MUCH grated Circuits, Detective Electronics. Sustain - Decay: Versatile - Highest quality - Inexpensive. list. Hanchett, Box 5577, Riverside, CA 92507. MORE. NEW Super Hobby Catalog PLUS year's subscrip- Plans $2.50. POE, 18578 Haskins, Chagrin Falls, Ohio ROTARY SWITCH 4P11P 5/$5: 6P11P 5/$7.25. Dip Switch tion to Electronic News Letter, $1.00. Don Britton Enter- 44022. prises, 6200 Wilshire Blvd., Los Angeles, Calif. 90048. 10-SPST 10/$15. Transformers 12.2V CT -6A plus 8.5V -5A NEW PERIODIC TABLE OF ELEMENTS. Atomic physics $6.95. 24V -5A $5.95. 10' RG58C/U 12/$10. Fertiks, 5249 "D", NAME BRAND Test Equipment. Up to 50% discount. Free breakthrough now reveals precise atomic models of each Philadelphia, PA 19120. catalog. Salen Electronics, Box 82, Skokie, Illinois 60076. element. Striking wall chart, $3.00. Circlon, 29500 Green - SOUND SYNTHESIZER KITS -Surf $12.95, Wind $12.95. SURPLUS COMPONENTS, Communication and test equip- river Gorge, Enumclaw, WA 98022. Wind Chimes $17.95, Musical Accessories, many more. ment. Illustrated catalog 25 cents. E. French. P.O. Box 249. Catalog free. PAIA Electronics, Box J14359, Oklahoma Aurora, Illinois 60505. Build The Artisan Electronic Organ.... City, OK 73114. CB RADIOS, monitors, crystals, CD ignitions. Southland, The 20th century successor to the classic pipe HEAR POLICE / FIRE Dispatchers! Catalog shows ex- Box 3591-B. Baytown, Texas 77520. Kits feature modular construction, clusive directories of "confidential" channels, scanners. organ. Send postage stamp. Communications, Box 56 -PE, Corn- TELEPHONES UNLIMITED, Equipment, Supplies, with logic controlled stops and RAM Pre -Set mack, N.V. 11725. All types, Regular, Keyed, Modular. Catalog 50 Memory System. Be an ar-tisan. Write for UNSCRAMBLERS: Fits any scanner or monitor, easily ad- cents. Box 1147E, San Diego, California 92112. our free brochure. AOK Manufacturing, Inc. justs to all scrambled frequencies. Only 4" square $29.95, WA 98028. RESISTORS 1/4W, 1/2W - 1.7 cents each. P.O. Box 445, Kenmore, fully guaranteed. Dealer inquiries welcomed. PDO CARBON FILM FREE sample / specifications. Other components. COMPO- Box North Little Rock, Arkansas 72115. Electronics, 841, York, NENTS CENTER, Box 295, W. Islip, New 11795. MAKE YOUR PLANS COME TRUE by using electronic kit of POLICE/Fire scanners, large stock scanner crys- PROFESSIONAL UNSCRAMBLERS - several models that Touch Switch, Patrol Car Siren, Sound Switch, Singing tals, antennas. Harvey Park Radio, Box 19224, fit any scanner. Free information. Capri Electronics, 8753T Bird. Each Kit $5.00 ppd. QMC, P.O. Box 4816, Irvine, Cali- Windom, St. Louis, MO 63114. fornia 92716. Denver, CO 80219. TELETYPE EQUIPMENT for sale for beginners and exper- UNSCRAMBLE CODED MESSAGES from Police, TRANSISTORS FOR CB REPAIR, IC's and diodes. ienced computer enthusiast. Teletype machines, parts, Fire and Medical Channels. Same day service. TV audio repairs. 2SC799 - $3.00, 2SC1306 - supplies. Catalogue $1.00 to: ATLANTIC SALES. 3730 Satisfaction guaranteed. Don Nobles Electronics, $2.95, 2SC1307 $3.85, TA7205 $3.50, Nautilus Ave., Brooklyn, NY 11224. Tel: (212) 372-0349. - - B&D WHOLESALE C.B., Scanners, Antennas, Catalog 25 cents. Inc., Rt. 7, Box 265B, Hot Springs, Arkansas more. Free catalog and transistor. Enterpr- Crystals: Special cut, $4,95, Monitor $3.95. Send make, 71901. (501) 623-6027. izes, Box 32, Mt. Jewett, PA 16740. model, frequency. G. Enterprises, Box 461P, Clearfield, UT UNSCRAMBLER KIT: Tunes all scramble frequencies, may 84015. most scanners. 2-3/4 X 2-1/4 X 1/2. $19.95. Facto- BUILD YOUR OWN' TV, ' CAMERA! be built-in YOU WILL SAVE BIG MONEY! Surplus, Clearouts, Idea! home & business ry built Code -Breaker. $29.95. Free Catalog: KRYSTAL Bankruptcy, Inventory, Deals. Catalog 51 (redeemable). ET - for KITS, Box 445, Bentonville, Ark. 72712. (501) 273-5340. - TNE ECONOMICAL ANSWER TO NOME- MOB - COA Electronics, Box 741, Montreal, H3C 2V2. U.S. Inqui- 'tie. TONING OF NURSERIES, ENTRANCES, PROJECTION TV MANUFACTURERS CLOSEOUT. Lens ries. ORIYEWAYS... BUSINESS and INDUSTRIAL - -'~ t SURVEILLANCE...ITV...AMATEUR TV PLUS quality 3 element F3.2 lens - covers 10" through 17" Nicads, HUNDREDS OF OTHER APPLICATIONS. $100 w/mounting flange, FREE CATALOG. Flash Tubes, Kits, Calculators, MODEL 0 - KIT FORM SIBS' diagonal receiver - screen AT-IA SERIES Digital Watch Modules, Ultrasonics, Strobes, LEDS, Trans- ASSEMBLED 5175. SOLID-STATE. WORKS OII 52"x40' Kodak Ektalite $175 each. All Brand New. Com- 1 NIT 528.95.. istors, IC's, Unique Components. Chaney's. Box 27038, ANY TY SET. OPTIONAL SOUND plete instructions included. Gemini Systems, 156 Andover r I PHONE or WRITE for Wain. Dial 402-981.3771 Denver, Colorado 80227. t.t" j Drive, Valparaiso. Indiana 48383. (219) 464-2060. 1301 BROADWAY ATV Research DAKOTA city, NE. 68731 SURPLUS INVENTORY - Telephone Cable Fault Finding -. ORGAN KITS Bridges. For aerial or buried cables = tests ground faults, USED TEST EQUIPMENT -Tektronix, HP, GP Write: PTI, shorts, etc. Eight units available - brand new still in boxes. KEYBOARDS Box 8699, White Bear Lake, MN 55110. Phone: (612) $350. each or all 8 for $2,400.00. Butler National Corp., 8246 THE ULTIMATE IN DESIGN 429-2975. Nieman Road, Lenexa, Kansas 66214. AND SOUND WEATHER MAP RECORDERS: Copy Satellite SCANNERS, BEARCAT 210 or Regency Touch Demo Record & Brochure $1.00 WurlltOer reproductions Photographs, National -Local Weather Maps. Learn $239.95, crystals two-way radios. Free catalog. 11 DEVTRONIX ORGAN PRODUCTS, Dept. C How! $1.00. Atlantic Sales, 3730 Nautilus Ave., Guilderland Comm., Box 591 Guilderland, N.Y. II,1 95129 5872 Amapola Dr. San Jose, CA Brooklyn, N.Y. 11224. Tel: (212) 372.0349. 12084. 121 FEBRUARY 1978

AmericanRadioHistory.Com GOLDMINE OF ELECTRONIC SCHEMATICS. 201 QUALITY KITS, over 7,000 schematics. $1 (retundablekfor . Dynamite Schematics. Send for Free Schematic List and illustrated catalog. Tek-Devices, Box 19154c, Honolulu, HI Special Schematics - Formulas List. Spacetech, Box 182, 96817. TELEPHONES & PARTS Gillette, N.J. 07933. PLANS light seeking robot, whistle controlled BREAKERLESS ELECTRONIC ignition: Auburn Spark - - TELEPHONES AND PARTS. Free catalog. Write: Surplus plugs, Synthetic Lubricants, Wheel Stabilizers. Information robot, A/D converter, D/A converter, listing of Saving Center, P.O. Box 117, Waymart, PA 26 cents. Anderson Engineering, Epsom, N.H. 03234. 18472. parts suppliers. $4 for for one, $2 each additional PLANS for Telephone Answering device. Three dollars plus NEW ELECTRONICS PARTS. Stamp brings free catalog. one. ARC Enterprises, RD No. 2, Box 89, self-addressed stamped envelope to: Polaris, Box 1414, Nudata Electronics, N. Emerson Street, Mt. Prospect, IL Valalie, 104 Palestine, Texas 75801. 60056. New York 12184. BUILD YOUR OWN UFO detector with complete easy to fol- SUN -TRACKING SENSORS low plans. Three designs, $3.00 postpaid. UFO Alert, P.O. WANTED Box 1741, Owensboro, KY 42301. Do you have a solar collector or device that needs to be pointed at the sun during the daylight hours? TESLA COIL 40" SPARKS! Plans $7.50. Information 75 - GOLD, Sun -Track systems are a family of active solar cents. Huntington Electronics. Box 2009-P, Huntington, Silver, Platinum, Mercury wanted. Highest prices sensors tracking requiring 12-15VDC that provide Conn. 06484. paid by refinery. Ores assayed. Free circular. Mercury Ter- control signals to a reversible drive motor. Models minal, Norwood, MA 02062. available for all types of collectors including point focusing. From $50. Send 256 for catalog to ORIGINAL HOME COMPUTER Game Programs. Top dollar l ENERGY APPLICATIONS, ROUTE 5, BOX 383A, BUILD YOUR paid. Free info. Vernon Brown, 2110 North Second, Cabot, 1i OWN RUTHERFORDTON, NC 28139 ~~Me(704) 287-2195. Ark. 72023. NAME BRAND TEST EQUIPMENT at discount prices. 72 SYMPHONY page catalogue free. Write: Dept. PE. North American Elec- TUBES tronics, 1468 West 25th Street, Cleveland, OH 44113. PJ OF SOUND! 100 WATTS from Hybrid I.C. into 4 ohms, .2% Ws fun and easy-takes just minutes RADIO & T.V. Tubes -36 cents each. Send for free $20.95. Hybrid Power Co., 52 Huntsbridge Road, o day! Complete kits for organs, Catalog. Cornell, 4213 University, San Diego, Calif. 92105.

pianos, . strings, rhythms Yonkers, New York 10704. amplifiers, TUBES receiving, factory boxed, low prices, free price list. synthesizers. Also Transleteronic, Inc., 1365 39th Street, Brooklyn, N.Y. AUDIBLE TRANSDUCER only .020 thick by 1.365 diameter. factory assembled. 104 -page 11218A, Telephone: 212-633-2800. Operates on 5-24 v.d.c. Produces piercing 2.9 KHz tone, at catalog $2.00 up to 80 Db, yet draws only 5ma on 9 volts. Use for keyers, TUBES: "Oldies", Latest. Supplies, components, sche- signaling devices, etc. Transducer & Data $1.50, include 50 matics. Catalog Free (stamp appreciated). Steinmetz, 7519 - cents postage and handling. Campbell Laboratories, 1180 ®WERE' PE Maplewood, Hammond, Ind. 46324. Viers' Electronics, Inc., "G" Fountain Way, Anaheim, Calif. 92806. TUBES, free low priced list. Specializing types. Dept. ZD, Box 5318, obsolete CANADA'S BEST TJ, Inc., Box 43, Bradley Beach, N.J. 07720. PRICES, IC's, Semiconductors, electron- Lancaster, PA176D2. ic parts, etc. 1st Quality Only. Free Catalog. C.M. Electron- ique, C.P FREE BARGAIN CATALOG, Industrial, Ham, Re- 95 Longueuil, Quebec, Canada J4K 4X8. U.S. In- NEGATIVE ion generator. Complete plans - $10.00. (Fas- quiries. cinating details-$1.00). Golden Enterprises, Box 1282 -PE, ceiving Tubes. Send Stamp. Astral, P.O.B. 707 Glendale, Arizona 85311. FREE BARGAIN CATALOG, IC's, Semiconductors, pet, Linden, N.J. 07036. Crystals. Send Stamp. Astral, P.O.B. 707 pes, HIGH FIDELITY Linden, N.J. 07036. TAPE AND RECORDERS

DIAMOND NEEDLES and Stereo Cartridges at Discount PLANS AND KITS 8 -TRACK and CASSETTE BELTS money back prices for Shure, Pickering, Stanton, Empire, Grado and - guarantee. Long wearing. Free Catalog $3 minimum ADC. Send for free catalog. LYLE CARTRIDGES, Dept. P, - order. PRB Corp., Box 176, Whitewater, Wisconsin 53190. Box 69, Kensington Station, Brooklyn, New York For 11218. (800) 558-9572 except WI. Fast Service call Toll Free 800-221-0906. TAPE HEAD CLEANER. 8 oz. - $2.30. Includes postage AMAZING ELECTRONIC and handling. ri. Write: "Cleaner", Box 176, Whitewater, WI PRODUCTS ALARMS 53190. LASERS SUPER POWERED, RIFLE, PISTOL POCKET SEE IN DARK PYRO. RECERTIFIED VIDEO TAPE 1/2 standard reels or 90 Cartri- TECHNICAL DEBUGGING UNCRAMBLERS GIANT TESLA STUNWAND TV ' vision on reel DISRUPTER ENERGY PRODUCING, SCIENTIFIC DETECTION, ELECTRIFYING, - -' supply $8.00, $80/12. 9200' bulk reel $17.00. CHEMICAL, ULTRASONIC, CO, AEAO, AUTO AND MECH DEVICES. HUNDREDS. Cartrivision tapes Larry Terry P O 61411 Sunnyvale CA MORE ALL NEW PLUS INFO UNITO PARTS SERVICE. Be 94086. un$imifvd rglar.Smoke INFORMATION RECORDS CATALOG fl Box 626 lord Jetted P2. Amherst. N.N. 03031 -TAPES! Discounts to 73%; all labels; no pur- Catalog chase obligations; newsletter; discount dividend certifi- cates; 100% guarantees. Free details. Discount Music Club, FREE KIT Catalog contains Test and Experimen- Billions of dollars lost annually due 650 Main St., Dept 5-0278, New Rochelle, New York, lock N.Y. 10801. ter's Equipment. Dage Scientific Instruments, Box to of protective warning alarms. 1054P, Livermore, CA 94550. FREE CATALOG Shows you how to ás GOVERNMENT SURPLUS protect your home, business TIGER SST and person. Wholesale MANUALS for Govt Surplus radios, test sets, scopes. List SIMP LI-KIT prices. Do-it-yourself. Free 50 cents (coin). Books, 7218 Roaring Drive, Washington, D.C. 20021. engineering service. GOVERNMENT SURPLUS. Buy in your Area. How, where. Btizrdex Seetúrity Co. Send $2.00. Surplus, 30177 -PE Headquarters Building, tg- Washington, D.C. 20014. FOR Box 82802 PE 028 Lincoln, Ne. 68501 GOV'T SURPLUS - buy direct from gov't. Complete info plus application form $2.00. Info -Capsule A-1, P.O. Box THE DO-IT-YOURSELFER 151, Shelocta, PA 15774. a high DON'T PURCHASE alarm equipment before getting our quality CD Electronic JEEPS $59.30! CARS $33.50! 200,000 ITEMSI NOW' free value packed catalog. Sasco, 5619-C St. John, Kansas - - - - GOVERNMENT SURPLUS Most COMPREHENSIVE Ignition System in kit form. City, MO 64123. (816) 483-4612. - Contains all components and solder to DIRECTORY AVAILABLE tells how, where to buy- YOUR build complete Solid -State Electronic QUALITY BURGLAR/FIRE ALARM equipment at discount AREA - $2.00 - MONEYBACK GUARANTEE - Govern- CD Ignition System for your car. As- prices. Catalog 50 cents. Steffens, Box 624C, Cranford, N.J. ment Information Services, Department GE -10, Box 99249, sembly requires less than 3 hours. 07016. San Francisco, California 94109 (433 California). Increases MPG 15% Eliminates 4 of 5 tune-ups Increases horsepower 15% Instant starting, any 'NSECRET NEW INVENTIONS -7 Plugs and Points last weather EMPLOYMENT OPPORTUNITIES PROTECTION VEHICLES 50,000 miles Dual system switch FOR & HOMES I Are you afraid of being RAPED, ROBBED OR ASSAULTED? The BACK UP I Fits 12 only volt neg. ground... Only $21.95 postpaid ALARM SYSTEM will let you know before you enter your house if it is SAFE or I NOT SAFE. If CAR is stolen, CAR can be LOCATED. LEARN HOW a BIG. ELECTRONICS/AVIONICS EMPLOYMENT OPPORTUN- Star Corporation can be corrected in most existing silent alarm systems Sent P.O. today. ITIES. Report on jobs now open. Details FREE. Aviation Box 1727 Grand Junction, Colorado 81501 IFAULT Check or Money $15.00 Order, 6% Tax Calif. PRINT name and address & we Employment Information Service, Box 240E, Northport, send you a CONFIDENTIAL BACK UP ALARM REPORT, Plans included I New Iwillon how to make your own FOOLPROOF Alarm System for your own, person York 11768. al, individual needs and protection. ELECTRONICS LAB TECH. Familiar construct test POPU- MIXERS-Preamps-Speakers, Top Quality FOWLER ALARMS, P.O. Box 64466, Los Angeles, Calif. 90064 LAR ELECTRONICS projects. IM EC, 96-18 43 Ave., Corona, Kits-Plans--Parts. Send 25 cents for catalog. RIO M - - -is1=10Fowler Alarms 1917 NI = me - N.Y. 11368. (212) 651-8900. Audio Design & Engineering Co., P.O. Box 154, GET THE JOB YOU WANT! Send $1.00 for simple techni- Lee, Mass. 01238. (413) 243.1333. RUBBER STAMPS ques. JOBS, 4188 Brittany Drive, Ellicott City, Maryland 21043. FIVE LASER PLANS - $8.00; Welding -Burning INDEPENDENT THINKER: You can become an Alternate RUBBER STAMPS, BUSINESS CARDS. Many new prod- Laser plans $9.00. Catalog $2.00. Solaser, PE Energy Systems Designer. Prestigious new field. Informa- - ucts. Catalog. Jackson's, Dept. K, Brownsville Rd., Mt. Ver- tion Package Boone, 178, Box 1005, $2.00. Valmont Enterprises, Box 186, Claremont, California 91711. non, Ill. 62864. North Carolina 28607.

122 POPULAR ELECTRONICS

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It Engineering Inc., 61 N. Pineapple Ave., Sarasota, FL 33577 HOME ENTERTAINMENT FILMS has important Marketing Information, a special Tidewater Trail, Fredericksburg, VA 22401. "Invention Record Form" and a Directory of 1001 and 2402 Corporations Seeking New Products. 1977 TESTS -ANSWERS for FCC First Class BE A PREFERRED SPORTLITE CUSTOMER ... send In money now! Best variety of Super 8 & 16mm sound RAYMOND LEE ORGANIZATION License. Plus "Self -Study Ability Test." Proven! your 230 Park Avenue North.New York,NY 10017 and Super 8 silent films in U.S.A. Order these catalogs: Moneyback Guarantee. "FREE" BRO- for new At no cost or obligation, please rush $9.95. $0.85 for 64-pg Columbia illustrated catalog; $0.95 4 each my FREE "Inventor's Kit No. A.112 " CHURE. Command, Box 26348-P, San Francisco Universal 8 -color 8 & 16 sound/silent catalog; $0.35 for Sportlite order forms or Universal 8 film list. Place an 94126. order for films & get put on our mailing list so you'll be first Name LEARN LANDSCAPING AT HOME. Start profitable busi- to know about our special sales. SPORTLITE FILMS. Address ness or hobby. Free booklet. Lifetime Career Schools. Elect -2, 20 North Wacker Drive, Chicago, IL 60606. Dept. A-430, 2251 Barry Avenue, Los Angeles. California city State Z p 90064. BOOKS AND MAGAZINES Phone No Area Code ELECTRONICS instruction cassettes. Send only $7.99. Sor- ry, no COD's. Hoskins, Box 403, Caldwell, N.J. 07006. FREE PAMPHLET: "Tips on Marketing Your Invention", BY MAIL. Free details. OSI, 323 S. FREE prophet Elijah before Christ. Wonderful from an experienced fee -based invention service company. UNIVERSITY DEGREE book coming 804, Chicago, IL 60606. Megiddo Mission, Dept. 64, 481 Thurston Write: United States Inventors Service Company, Dept. T. Franklin, Suite bible evidence. Rd., Rocnester, N.Y. 14619. 1435 G Street NW, Washington DC 20005. MIAMI, FLORIDA,R.E.T.S. ELECTRONIC SCHOOL - FCC Prep, Med. Electronics, R & TV Servicing, Electronic POPULAR ELECTRONICS INDEXES For 1976 now avail- Engineering Technology. 17-1/2 Mos. A.S. Degree able. Prepared in cooperation with the Editors of "P/E," DO-IT-YOURSELF (Specialized). Information Write: R.E.T.S.. 1 NE 19 St., this index contains hundreds of references to product Miami, Fla. 33132. vests, construction projects, circuit tips and theory and is an essential companion to your magazine collection. 1976 MODULAR TELEPHONES now available. Sets and com- PASS YOUR FCC EXAMS. New Tests by noted Author and Edition, '51.50 per copy. All editions from 1972 onward still compatible with Western Electric concept. Cata- Teacher. 500 Questions Second Class, 511.95; 200 First ponents, available at the same price. Add 5.25 per order for postage Box 1147W, San Diego, California 92112. Class, $7.95; 100 Radar, $4.95; Postpaid. Save, all three, log 50 cents. and handling, $.50 per copy, foreign orders. 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AmericanRadioHistory.Com Now you can save money and get the counter you want - Afrequency counter applications. All have been should deliver all the per- immediately conceived as cost-effective formance you expected when you placed the answers to frequency measurement needs in order. If the counter is a B&K-PRECISION communications, lab, field and plant applica- you'll be getting that plus some equally impor- tions. Every B&K-PRECISION counter fea- tant benefits-a price that you can easily tures: autoranging, liberal input overload afford and off -the-shelf delivery. protection, a minimum of 1Hz resolution, conservative specifications, and easy -to -read B&K-PRECISION has engineered a line of full - feature frequency counters to suit most LED displays.

MODEL 1850 520MHz guaranteed; MODEL 1801 600MHz typical 40MHz guaranteed; Period measurement 60MHz typical capability Reliable discrete TTL logic .y

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MODEL 1820 80MHz guaranteed; 100MHz typical Period, event and time measurements

At the top end of our line is the new Model At only $120, the 1827 portable frequency 1850, very conservatively rated at 520MHz. counter is slightly larger than a pocket Features include: TCXO time base... Period calculator. 30MHz guaranteed; 50MHz typical measurements from 5Hz to 1MHz... Leading . Battery saver for all -day field use ... Full zero suppression...Bright .43" LED display... range of optional accessories available. Gate times from 10 ms to 10 seconds...$450. The 1801 is a rugged frequency counter The 1820 Universal Counter is one of the most designed for production line and mainte- versatile counters available at any price. nance applications. Readings to 40MHz guar- Frequency measurement typically extends be- anteed; 60MHz typical ... Easy to use and yond 100MHz...Period measurements from read...Wide range input eliminates the need 5Hz to 1MHz . . . Period average, auto and for level adjustments...$200. manual positions Elapsed ... time measure- Isn't it time you stopped features ments to 9999.99 seconds (plus overflow)... sacrificing and performance for price? See your local Totalizes event counts to 999999 (plus over- flow)... $260. distributor for immediate delivery. DYNASCAN IMPRECISION'PREC/S/ON ' CORPORATION 6460 W. Cortland Avenue, Chicago, IL 60635 312/889-9087 In Canada: Atlas Electronics, Ontario International Sales: Empire Exporters, Inc., 270 Newtown Road, Plainview. L.I.. NY 11803

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Make perfectionist recordings for car or home!

The Realistic" TR-802 record/play deck is a double value for people who like to listen to A unique combination 8 -track stereo at home and on the road. Use it features... to make standard topes for your car's player, of then switch on the Dolby* noise reduction system for -quality recordings you can enjoy PAUSE

at home. Either way, you'll build up a custom DOLBY NR tape library at a fraction of the cost of pre-recorded material! Connect the TR-802 to your stereo system Simple pushbutton Pause button for pre- and tape directly off the air, copy records, or Dolby system for setting record levels make live recordings using the mike inputs. making and playing and editing tapes as Dolby gives you reduced hiss, superior treble noise -free tapes you make them and extended loud -to -soft range. Stereo 8 -track TtEALICSi1G never sounded so good! TIMER The TR-802 is strong on convenience, too. Two record/play modes: Auto -Stop after each 0 program and at end of program -4. Three playback -only modes: repeat, i program continuous -play, and Auto -Stop. Five push- Large dual VU meters Resettoble digital timer button function controls. glow red during record, shows tape time used in orange during play minutes and seconds So get the 8 -track deck with a difference - by Realistic! Just 179.95. "'Dolby" is o rrodemork of Dolby Laboratories. Inc. r ` SOLD ONLY WHERE YOU SEE THIS SIGN: FREE! New'78 Catalog Come in for your free copy

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AmericanRadioHistory.Com Chances are, someone you know just bought a professional 31/2 digit DMM kit for less than 70.

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Thousands of people have already bought the Sabtronics Model 2000. .. for two main reasons. First, its incredible accuracy, range and professional features. And second, the incredibly low price of $69.95. People everywhere appreciate.this bench/portable multi - meter. They depend on its basic DCV accuracy of 0.1% ±1 digit, its readings to ±1999 and its five functions giving' 28 ranges, overload protection arid 100% overrange. The 2000 is automatically appealing to hobbyist and professional alike. With automatic overrange indication, automatic polarity, even automatic zeroing. Best of all, its easy to assemble. All the parts you'll need, including the high -impact case, come right along with the clear, step-by-step instructions. The result is a professional quality 31/2 digit DMM that you could have paid a lot more than $69.95 for .. possibly receiving a lot less. But this one's from Sabtrohrics, specialists in digital technology. ,., Maybe you should order yours before you turn the page. Made in U.S.A. sabtronws ffis INTERNATIONAL INC P.O. Box 64683 'Dallas. Texas 75206 (214)369-7310

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