11 48784 $2.50 U.S. $2.95 CANADA FEBRUARY 1 ?88 THE MAGAZINE FOR THE ELECTRONICS ACTIVIST! The _ )0. Power Play ON ! Two power supplies in one 410 OFF NE ; case with digital readout G for voltage or current. SIDEC um.- NI PIS1110 ERI 11.11 UI/. 711KIS2 PIP :Ia 11 U.rr Isles (OPIMI (On 25717 2101111 1,1t.. INt PICT SPL I I/N/ MII71 kort .,Ad EDITOR p1 177721 11151111101 1.lrt tOt1 L«l;l lit NERI MI 7175 Atli SPL 7772 LONG AL? 191577 A. UTILITIES PRINT mP 1117 17511y~r1 t SERIAI MT N IT,11. bytes ..r1 Put your home computer SPELL Vol 22172 455768 19t.. fetal STARVI I17 112 TIOVE-1 11 IIIIS ...Niel 1. ... 1 .K/TREE YEK 725152 11 3M TIMIIIY011 Ldlri1 in We cover . LETTERS overdrive! POI /PIOC 11.,1.1 - 0111 041 22711 ÈUQIOIE REPLIES 1:16.. GOV.. ACTION the most powerful PERSONAL Ente cow I TYP. I C... =PMdEwa MI ht. I T. - SHIERS ,r packages available. - C rat 110. C. - OUI, Auno - 11(0115 Plus - INDUCTANCE BRIDGE 11.1 V1[ Unknown Ls to Henrys (..1_.u1..I01l.I lrt 1.. Set 11J V1. S..<1.1 Prut fete 0.01 T1 .r.M..l Doi On /rot. (.M ti01 it Prr..ltuY.N lee .. IF". WIND WITCHER .r <t1. <.y.l4l. pot. Tl.. 0.01 1..1yI.M 1!... ..I.tN .1t1 t011 ..1 011ry ,01 r1 .<1.,t .Y 1r 01 11 It tinkles without motion Ir (.L. 2747,1,11 15,27113,01 27,/Y21M4 274141,1 27,71444 DISH POSITIONER 27045,144 2704(711,1 1111 r TVRO remote move -it plans w.1I.,r4 .r.. 111111011 I 1r T. 14.. 1[S(1 1.01 1.1 I ,TINT <1.... I.tr..n.t 11 I I.r 1t 01 t.11.1 III. try 11101 V 1.4.. I... AUDIO SWITCHBOX ( (... Ws 1 - 1 - 11. 11M 0 - I- Wale /Ile 1-MI.<I... 5 inputs -5 outputs 1-rl.lnle ELt.rrd. 5-b.1nn. 1 lbw lil. -01lwW W -Lrl.i 1 - Iambs ...1 - 11 P.11, l- Ley /Wale - Ts= l..., 02 l- NNW diesel P -Ltl.tl -IN.,I.. / - - Lut t.. .. ..1w..a. ..les IJ.r 1- It.m hie 1111[-.1111 1lY I - S,..l - Ll.r. T - TN 111t ,11..w 1, 1- Fete Ills M1.<.t... _+GERNSBACK t. INAtr.1 111t .111 .ns. 44...a .r.t. 4117 71896 48784 8 nformatìon radio is on the air. Before you hear about Hear Your Hometown Like it on your old radio, hear it You've Never Heard it Before. live on your Just turn it on. As easy to use new Inform- as your AM/FM radio. Instantly, ant Information Radio. you're tuned into real life adven- Whether its an all- points- tures. One touch control lets you bulletin from the State Police, emergency frequencies, select and hold police, fire and the dispatcher for the city's Fire as well as NOAA weather in- emergency broadcasts so you don't Department, an ambulance racing formation channels in all 50 miss a single minute of the action. to the hospital or a National Weath- states. All pre- programmed. This Hear the amazing Information er Service report, the new Inform- new Information Radio utilizes a Radio today. Take it home and be ant from Regency makes you a principle similar to the seek a part of the action tonight!! part of all the action... instantly. and scan feature found on expensive AM/FM radios. Breakthrough Technology. Your information radio l scans Instant Information. the public service .11VT 1 ORM.RNI channels in the area, locates BY REGENCY Informant Information Radio the active signals, locks in and uses a revolutionary new technol- broadcasts all the information Information Radio ogy that allows you to constantly right to you. With revolutionary for Real Life monitor your police, fire and TURBO -SCAN speed! Adventure CIRCLE 10 ON FREE INFORMATION CARD ahn cs Volume 5, No. 2 FEBRUARY 1988 CONSTRUCTION 26 Remote TVRO Dish Positioner -puts the focal point of your satellite dish where you want it for maximum signal strength 31 Maxwell Inductance Bridge -determine the exact value of inductance with this project 35 Power Play -put this power supply on your workbench, and you'll need no other! 4- 40 Wind Witcher- Listen to mother nature's gentle song with this hot -wire sensor electronic chime NRO Dish Positioner-page 26 43 5 x 5 Audio Switch Box -eliminate the rat's nest of interconnecting wires hidden behind your stereo equipment 111j,_,Litate' FEATURES 59 Identifying Unmarked or Obscurely Marked Logic Chips -make use of those otherwise useless logic devices 65 Getting Your FCC Radio -telephone License -what you need to know to Maxwell Inductance Bridge-page 31 legally get your own license 69 E -Z Math -Scientific Notation and Unit Conversions: clearing up milli, micro, kilo, Meg, etc. with powers aim. ,. J .. - 11 I l J ll HANDS -ON REPORTS 4---1-____:),4:i.: 34 Date Calculation Software -gives the day of the week that a particular Power Play-page 35 date has fallen, or will fall, on 49 Utility Software -Utilities are what make newcomers to personal computing appear like old hackers 61 Bytesize Calc -an on- screen calculator for those times when all the frills aren't needed SPECIAL COLUMNS 74 Ellis On Antique Radio -Firing up the Crosley 50 76 Circuit Circus- Produce the most -basic building -block circuits from inexpensive op -amps Wind Witcher-fie 40 78 Carr On Ham Radio -Why's my dial all scrunched up while yours isn't? 80 Friedman On Computers -lt takes no space to tick away the time 84 Wels' Think Tank -What to do with number two? 87 Saxon On Scanners -A scanner with a flair for the weather 88 Jensen On DX'ing -Say goodbye to that 1987 calendar DEPARTMENTS x 5 Audio Switch Box -page 43 2 Editorial -The HOE PC give -away; the votes have been tallied and the winner rewarded 4 Letter Box -where readers get involved and make things happen 8 New Product Showcase -where you'll find stocking -stuffers for the technically oriented 17 Bookshelf -take a look what's new in easy -to -read electronic reference and data books 37 FactCards -the component data and applications at your fingertips 63 Free Information Card -why waste time ?; let the manufacturer clue you in Saxon On Scanners-page 87 1 L Volume 5, No. 2 The Magazine for the Electronics Activist! February 1988 Larry Steckler, EHF. CET Editor -In -Chief 8 Publisher Art Kleiman, editorial director Julian S. Martin, KA2GUN, editor Robert A. Young, associate editor The winner is.... Herb Friedman, W2ZLF. associate editor ...Walter W. Schopp of Livermore, John J. Yacono, associate editor California for his construction article Brian C. Fenton, associate editor Carl Laron, WB' SLR. associate editor "Digi -lyzer IC Tester" that appeared in Byron G. Wels, is2AVB, associate editor the August, 1987 issue of Hands -on M. Harvey Gernsback, contributing editor Electronics. The Digi -lyzer offers Doris Kelly, assistant editor rapid IC checking of most logic -type Teri Scaduto, editorial assistant IC's available to the experimenter. Schopp's Digi-Iyzer Ruby M. Yee, production director Karen S. Tucker, production manager For those of you who do not recall, I ran a contest for the best Robert A. W. Lowndes, editorial article published in this magazine in 1987. The prize is an IBM associate compatible computer, which we have shipped to the winner and Marcella Amoroso, production assistant he is probably playing with it now. Jacqueline P. Cheeseboro, circulation director Arline R. Fishman, advertising director Lets do it again.... BUSINESS AND EDITORIAL OFFICES Gernsback Publications. Inc. ...and offer another computer. Why a computer? You have seen 500 -B BI -County Boulevard the advertisements, especially those on television, that say that Farmingdale, NY 11735. 516 293 -3000 report writing for is school and office simpler and has improved President: Larry Steckler the potential of the individual using a computer. This is also true Vice -president: Cathy Steckler for the professional and amateur writer. Word processing pro- grams, spelling checkers, thesaurus, and other writing aids such NATIONAL ADVERTISING SALES (For Advertising Inquiries Only) as simple desk -top publishing programs are must items for Joe Shere MIDWEST/PACIFIC writers today. 1507 Bonnie Doone Terrace Corona Del Mar. CA 92625 714 760 -8697 So get busy.... The Paths Group ...and start producing those exciting manuscripts about features 310 Madison Ave. Suite 1804 and projects that are related to our exciting hobby. The topics New York. NY 10017 712- 953 -2121 come easy. For example, there are topics on shortwave listening, project building, scientific developments, amateur radio, com- puters and software, scanners, television, satellites, odd -ball .,omposition by Cover photography by Mates Graphics Herb Friedman semiconductors....I could go on and on. But, if I do, and go beyond this editorial page, I'll be entering the contest. AIA ') Start writing today.... ® Hanson Electronics, (ISSN 0703.29881 Published monthly by ...and I'll Gernsback Publications. Inc 500-B Bi-County Boulevard. Farm maybe be announcing your name next year in the tngdale. NY 11735 Second-Class postage paid at Farmingdale, NY and at additional mailing offices One-year. twelve issues subscrip- February issue. You can make it so if you begin today! bon rate U S and possessions $28 00 Canada $33 00. all other countries $35 50 Subscription orders payable to U S funds only International Postal Money Order or check drawn on a U S bank U S single copy pone $2 50 c 1988 by Gernsback Publications.