FEBRUARY CENTS POPULAR ELECTRO ICS BUILD ELECTRIC-GUITAR ELECTRONIC ;111J 1-Ji I ;I NIXIE® DECADE DCU FOR $15.00 BUILD "OMNI-8" SURROUND-SOUND SPEAKER SYSTEM THE GREAT ELECTRON-PEDANTIC PROJECT lAIL ARTHUR CUSHEN'sWORLD TRIP PHOTO ALBUM DISTORTION-FREE VOICE-OPERATED EECH 11.111711;1a TWO-TONE ALARM SIGNAL INJICTOR t91474 IC Experimenter's NO-BOUNCE PUSHBUTTON Corner 100 Z STANDARD 5HLt REGISTER 'W A R C 0 ;'ircligues www.americanradiohistory.com ;;;:10 Discover the ease and excitement of learning Electronics with programmed equipment you trn at home with NRI, you train When NRI sends you with your hands as well as your head. You learn the WHY of Electronics, Communica- tions, TV -Radio the NRI pioneering "3- Dimensional" way. NRI training is the result of more than half a century of simplifying, organizing, dramatizing subject matter, and providing personal services unique for a home study school. 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Text for text, kit for kit, dollar for dollar -you get more for your money from NRI. www.americanradiohistory.com POPO LAR VOLUME 32 NUMBER 2 FEBRUARY, 1970 WORLD'S LARGEST -SELLING ELECTRONICS MAGAZINE FEATURE ARTICLES BUILD THE TWO -WAY "WAVERLY" ALARM 29 Don Lancaster ricer meaner s corner LSI GIVES SEMICONDUCTORS A "TRIP" 32 Vic Bell True -io /se quiz BUILD NUMERIC GLOW TUBE DCU 33 Don Lancaster Icw -cc_" N nie reoccut THE GREAT ELECTRON-PEDANTIC PROJECT 48 Carl Kohler ce mputer tc Ues bock NASA TO LAUNCH AUSTRALIS-OSCAR -5 52 THE THUMPA -THUMPA BOX 53 John S. Simonton, Jr. .. _m crux^ cccc.Vpcnirre ^1 ONE SECOND METRONOME TIMER 58 A. A. Mangieri BAMBOO MISSIONARY BROADCASTER 61 John Kimberley Fc' Ens' E- _ccccs :- OMNI -EIGHT SPEAKER SYSTEM 69 David B. Weems FIRST PERSON DX'ING 74 Arthur Cushen ENGINEERING -LEVEL OPPORTUNITIES FOR YOU 76 Alexander W. Burawa BUILD THE VOXOR 81 Robert A. Hirschfeld THE STEREO SCENE 85 Charles H. Dodson Magnetic lape hure e uoh cure THE PRODUCT GALLERY 93 IM6 Equipment Ccb,net Kedmen Screw -Holding Screwdrivers Sharpening Heathkit Co/or TV Allied Horn Bond Receiver A -2.516 TWO -WAY REACTIONS 97 G. H. Reese, KCN6990 AMATEUR RADIO 99 Herb S. Brier, W9EGQ SHORT -WAVE LISTENING 101 Hank Bennett, W2PNA SOLID STATE L04 Lou Garner DEPARTMENTS LETTERS FROM OUR READERS 8 OUT OF TUNE 13 Psychedelic I (September 1969) Experimenters' Loser (December 1969) ELECTRONICS LIBRARY 14 READER SERVICE PAGES 15, 115 NEW PRODUCTS 22 POPULAR ELECTRONICS is indexed This month's cConover photo by in the Readers' Guide rad Studio in Periodical Literature Copyright © 1970 by ZIFFDAVIS PUBLISHING COMPANY. An rights reserved. POPULAR ELECTRONICS, February 1970, Volume 32, Surber 2, Published monthly at One Park Ave., New Yo k, S.Y. 10016. Oue year subscription 'Ohr for U.S., C.S. Possessions and Canada, Ó6.0(): all other countries, $7.itp. second class postage paid at Arne 1 ork. V.1. and at additional mailing offices. Authorized as second class mail by the Post Olhbe Department, Ott eea. Canada and for payment of postage in cash. Subscription sereice and Forms 3579: Portland Place, Boulder, Colorado 80302. Editorial offices lot o,wrnocript contributions, reader inquiries, etc.: One Park Ave:, Seer York, N.Y. 10016. 4 CIRCLE NO. 7 ON READER SERVICE PAGE -* www.americanradiohistory.com What a Beauty, What a Build And Bog!!!! What Performance! The 176 is the up-top CB base antenna for on-top people .. from C/P Corporati Division, The Shakespeare Co., P. 0. Box 5207, Columbia, S. C. 29205 www.americanradiohistory.com In ONE Educational Program Earn BOTH Your POPULAR ELECTRONICS LICENSE LAWRENCE SPORN F.C.C. Publisher OLIVER P. FERR LL And Your Editor LESLIE SOLOMON Technical Editor JOHN R. RIGGS Managing Editor A. S. E. E. EDWARD I. BUXBAUM (Associate in Science in Electronics Engineering) Art Director ALEXANDER W. BURAWA Associate Editor ANDRE DUZANT Technical Illustrator PATTI MORGAN DEGREE Assistant Editor JUDITH L. HOGAN Editorial Assistant H. BENNETT, WZPNA Orantfjam %fjooY of Jngílleeríng H. 5. BRIER, W9EGQ L. E. GARNER, JR. bas tOnttrrtD On G. H. REESE, KCN6990 Contributing Ed ol. ,: RICHARD J. HALPERN j",otjn Poe Advertising Manager ROBERT UR tlle Degree of Marketing Manager MARGARET DANIELLO g66o[Íate in $titnrt in 6!lettrouits Qngilietring Advertising Service Mar tiger FURMAN H. HEBB bat .s tb rigar n. mM, ryraam. anat., an loan... MrrN rp, efrl.m. Group Vice Presider 0.4 upa0 An Yen n.ur0lp ta Yrpml a0wmvra.n a,n rrinmmrnOmmn M Ipt Elerlronies and Photos,. phio ZIFF -DAVIS PUBLISHING COMPANY UM, a ta Ya.l.n Ia. .Q - r..l 10 _02- Editorial and Executive Offices Ore Park Avenue, New York, New York 10016 fuse. 212 679-720C Midwestern Office Boa 307 North Michigan Avenue, Chicago, Illinois 60601 312 726 -0892 Midwestern Advertising Manager, JAMES WEAKLEY The home -study program which accomplishes both of Western Office l these objectives is the Grantham Associate -Degree Pro- 9025 Wilshire Boulevard, Beverly Hills, California 90211 213 CRestview 4 -0265; BRcdshaw 2 -1161 gram in Electronics Engineering. This educational pro- Western Advertising Manager. BUD DEAN gram consists of a total of 370 correspondence lessons, Japan: James Yogi followed by a two -week period of review and evaluation Ishikawa Mansion, #4, Sakuragaoka at the School. The prerequisite for enrollment is high Shibuya -ku, Tokyo, 462- 2911 -3 school graduation (or equivalent) and at least one full Circulation Office Portland Place, Boulder, Colorado 80302 year of experience as an electronics technician. Upon completion of the first 160 correspondence lessons, you William Ziff, Presicent are prepared for your first class FCC license and radar, W. Bradford Briggs, Executive Vice President Hershel B. Sarbin, Senior Vice President endorsement. Then, upon completion of the remainder Stanley R. Greenfield, Senior Vice President of the program, you are awarded the ASEE Degree. Philip Sine, Financial Vice President S. Mills, Jr., Vice President, Grantham School of Engineering is accredited by the Walter Circulation Phillip T. Heffernan, Vice President, Marketing Accrediting Commission of the National Home Study Frank Pomerantz, Vice President, Creative Services Council, is approved under the G.I. Bill, and is author- Arthur W. Butzow, Vice President, Production ized under the laws of the State of California to grant Edward D. Muhlfeld, Vice President, Aviation Division academic degrees. Irwin Robinson, Vice President, Travel Division George Morrissey, Vice President Grantham School of Engineering Sydney H.