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CIRCLE 159 ON READER SERVICE CARD

THETEAM J ANUARY 1996ISSUE *424

El Supremo

AmateurWayne Green W2NSDIl

Associate PublisherF. I. MariOn ®

Radio TodayNitty Grittv SluffJoyce Sawtelle

Victor t .apuszynsjo TABLE OF CONTENTSContributing Culpri ll

FEATURES8 ,. BroWll WB8ELK DEPARTMENTSMike 8ryctl WB8VG E

Joseph E. Carr K4lPV 9 TheSP-l 0"SenlorSpider"Transceiver · WA8TXT

MiChael Geier KB t UMJim Gray Wt xun te Low Cost Swltetllng POWBI" Supply For HF Transceivers - A05X 73 Ad Index

90 1995 Annual IndexChuck Hough lOfl W B61GP 18 Simple Mobile Protoction • K8KWD KB1UM 59 Ask KlboomDr. Marc Leavey WA3AJR n Bar1ef 'n' BuyAndy MacAllister WASZIB 22 GoIng Public • WB2JNA K4IPV 90 Carr'. eon--Dave Miller NZ9E WA5ZIB 55 -Joe Moell KOOV 24 Tesla! • W8AHB WB2MGP 62 Hams 'Mth Oass

Carole Perry WB2MGPNZ9E 50 Hem to Ham

30 TelephOIlEl Fla5her • W6ZZB KOOV 52 Homing InJeffrey Sloman N t EWO W2NSOIl 4 Never Say Die

32 Free Electricity • WB8VGE 35 New Products

Advertising Sales W1 XU .. --Frances Hyvarinen .. Kill Your tm..1ellluce • WB2Wl~ WB8VGE 64 aRP

Roger SmithWA3AJR .. RTTY'-

WQ5GNR 79 Special Events603-924-()()58 79 U_800-274-7373 REVIEWSFax: 603·924-8613

38 Add-On 2 Meter Receiver Selectivity • WA4BLC Radio Fun sectionCIrculation W2NSOIl " Welcome Newcomers

Linda Coughlan 41 Oak Hills OHR-400 4 Band OAP Kit • AC4HF CommunicationsK20AW .. Simplified Pin 1

Helen Senechal «eazcc .. Une Wtage MonItor«eazoc " RF ......

Ol tl Entry & Other St uff Two lTI8tEw SSBISat8Ili1e-, W861«JA 64 loops

Norman Manon

Business OfficeOn the cover: The photo shows the QTH of Dick Sparling N2KEY on Chautauqua l ake, Bemus Point, NY,

Editorial · Advertising - Circulationseeooaoc - Product Reviews73 Amateur RadiO Today Magazine70 Route 202NPeterborough NH 03458-11 07603-924..Q058Fax: 603-924·6613

Reprints; $3 per article Feedblck; Any ctrcutt work s better wit h feedbac k, so p lease take the time to repo rt on how much you like ,Back issues: $5 each hate. o r don 't care one way or rne othe r abcut me artic les and COlumns in this issue. G ~ g reat! , 0 ~ okay. and

U ~ ugh. The G's and O's wi ll be co ntinued, Enough U's and iI's Silent Keysvill e. Hey. this is yourPlinted n the USA by communications medium. so don't just sit there sc ratching your ...er .. .head. FYI: Feedback ·number· is meQuad Graphics page number on which the art icle or column starts as shown in me index ,

Manuscripts: Contribu tions f"possible pubhcaticn ". ~"

73 Amsteur Rad io Today (ISSN 1052-2522 ) is published monthly by 73 MagaZine , 70 N202, Peterboroughwelcome. We'll do the best we can NH 03459 ·1 107. The entir e co ntents 0 1995 by 73 Magaz ine. No part 01 th is publi cation may be reproducedto return anything you request, but wnnout wr itten perm iss ion 01 the publi sher. which is not all that d iUicult to gel. The subscripti on rate is : onewe assume no responsibility for year $24.97, two yea rs $44 .97; Canada : one year $34.21 . two years $57.75, including postage and 7% GST.

~" o- damage. Payment f" Foreign postage: $1 9 surface, $42 airma il addit iona l per ye ar , payable in US tuoes on a US bank. SecondSUbmitted articles will be made cla ss postage is paid at Pe terborough. NH. and at addit iOnal mailing offices . Canadian second c lass ma ilupon pub.cation. Please submitboth a disk and a hard copy 01 regi str ation 111 791 0 1. Canadian GS T registration ,,25393314. Microlilm edition : Unive rsi ty Microfi lm, Ann

your article (tBM or Mac formats) , Arbor Ml 46 106. POSTM ASTE R: Send ad dress changes to 73 Amafeir Radio Today. 70 N202 , Peterbo rough

caretouy checked drawings and NH 03456- 1107.schematics, and the clearest bestlocussed and lighted photos you Contrlct: Merely exposing this page to your eyeballs ccnsnuures a lIegally binding contract between you andcan manage. ..-tow to write for 73· pubtnsner Green wherein you have agreed 10 get out of tha t rut you 've been in, to shape up and pul someguidelines ." available 00

adventure into your lile. Th us you will . in 1996 . open at least one new ham horizon , such as getting act ive onrequest. US Citizens must includetheir Social Sec\JriIy number wrth packet or gel set up and sta n making sate llil e contac ts. Furt her, you will c ccu mem mrs aevennne With a log

submitted manuscripts so we can and se nd a copy 10 publisher Green. and g ive a tatk on your adventure to your iocat ham clUb, plus wnte a

submit it to you know who. piece l or the ham c lub newsleller.

73 Ama/eur Radio Today. January 1996 3

N"",b« , on your FINd"-"/{ a rd

Wayne Green W2NSOIl

NEUER SRV 0 IE

IfYou ' re So Smart•••

A note from I'U2M pP explainsIhal they have three licen se classesin Brazil. C lass C requires no code,C lass B requires 5 wpm code . Cl assA is 10 wpm. To be more det ai led.the Cl ass B test sends 125 charac tersin fi ve minutes and calls for a mini ­mum of 87 characters 10 be copiedcorreclly. Thc Class A is double thai.Thai sure bealS our 20 wpm hurd le.

Brazilian Licenses

Pirate Of

Recently I wrote about a possiblebusiness opportu nity for hams in set­ling up iow-po....ered F!>1 trans mit­ters for private parties ... 1ll1·d like tobe able to listen 10 their own musicaround their nome. A chap in Berte­ley has been carrying this to ex­tremes ....ith his Free Radio Bedeley(FRB). Steve Dunifer sraned outwith a 5-wall rig and a IO-foot an ­tcnna. broadcasting three hours Sun­day nights on an unu sed n t chan­ne l. The FCC natu rally got after him,assessing hi m a S20,OOO fi ne .Dun ifcr fou ght back with lawyers.demanding to gel copies of the re­pon s ofinte rference. wh ich the FCChad cited in their com plaint.

When the FCC could producenothing, D umfcr began making andse lling micro-power FM tranvnut­ling kits. with the result lhal severa lhundred similar stations are now inoperation around the count ry, Then,when a federal judge refused 10 back

the FCC on constitu tional grounds,he took FRB full- time from a penna­nenl loca tion , broadcasting 24 hou rsa day. complete with a call -in phonenumber and ru nning about -W ....ans.

Canada allows unlicensed micro­power F!>-I stations. but monitorsthe m 10 make sure lht:y don' t inte r­fere ...ith commercial stanons. Andin Japan unl icensed n l stationswith up to 10 ....aus are permitted.....ith communi ty s tations popping upall over the country. Companies suchas Teac and Sony are sell ing micro­power FM station kits which includeeverything needed. even a C D player,

O kay. as a ham you are a commu­nicalions npcn . Well. you' re sup-­~ 10 be . That's what you'~'e

conned your oon-ham frie nds inlothinking_right?

So whal do )'ou really kno wabout comm un ications, o ther thankerch unkin g some repcat t.'rs o r add­ing stin more garhle 10 a pileup'! Ifsomeone were to as k you ahout pag­ers. what could yo u It.'ll lhem? Howmuch do they cos t" What ' s the irrange? Where do yOll gel 'em? Whatfrequencies do they use? What ser­vices are a\'ailahle'? Can yu u usesomc JUSl around your ownbusiness?

And ....hat can you lell peopleabout fa :l; -modems? The Inlernet,

ConHnued on page 74

Antenna Prunin g

An article b)' W311VS in the PortSI. Lucie club newsjetter re mindedme that it's been years since I pas sedalong a simplc antenna pruning sys­tem. You can CUI a half· ...ave dipole...ire antenna exactly to the fre­quency you ...ant wi th j ust oneprune, if you do it right .

You stan out ... ilh ue half-...avefonnula o f 468 divided by the fre­quency in MHz for the length in feet.Add on a Ioor or so, just in case. It' sa 101 easier to trim off a few inc hesthan to add it if yuu come up shon.The proble m is that the length ofyour aructma depends 10 some de­gree on its he ight above ground. andhow good thc ground is under it ,

Mak e it a little long and pur it upinto place. Now chec k for its reso­nant freq uency. An antenna brid ge isgreat here, but yuu can also justcheck for the frequency providingthe lowest SW R. Now yo u can use asimple proportion of the length andthe resulting resonant frequency 10

the des ired freq uency and the ne...leng th. T rim half of the diffe renceoff each end and )'ou 'll be a ll M:I.

You ...on· t do a lot on 20m wilh adipole, though my first s idchandrontact ...as wi lh a 1lJ.- ....a ll ucilerand a !'loin-lead dipole thro ...n out ofm y "indo..... I woried a VK and hada nil;e contact.

O n 75m rw worked lhe world.... ith a dipole . Everyw here , AI Ihetime I had a oooong signal on 20m.bUI .... ilh the S...eepsfakes Contestcoming up Ihe ne :\1 day I knew 1would ha~e to have some 75 m con·tac ls during the hours when 20 wasqu iel, so I cut a l.... in-Iead dipo le andhung it slanled from m y luwe r. Theresult was a Whopping signal on 75,and conlacts a ll the way ou 1 10

Okinawa.When I was visit ing VK3ATN in

Auslralia we worked W2:-l SDfl on20m . My signal was coming in 59+,so we decided 10 try 75 and see if wecould make it . It was 59+ there too ! Islill ha~'en 't gouen o~'er lhee~cilemcnl of lhat contact. Never wi ll .

ousty inarticulate kids learned to talkfreely with total strangers over the air.

Adopt-A-Ham

Europe would know when the bandwas open to my area. I made a codewheel out of aluminum, operating amicroswuch 10 key the rig.

As the new sunspot cycl e bu ild swe ' re going 10 see DX coming ha ck.MI it's lime 10 s tan planning yourdream location. dream lower, dreambeam and slate-of-!he-an ham '>Ialioofor b le 1996.1'", gulthe Ioc.1lioo. 001I reed SOffi£' help in deciding what Ishou ld use fOl" antennas.

In re rrospect I can almost feel ibeangel wings brushing me when Ituned 6rn and heard the panderno­nium Ircm out w est . That go t me onIhe air on stx. And Ih3t gOI me to puton my beacon station. Then, 310ngcame Perry Ferrell wi th an Air Forcecontract to s tudy 50-MHz prcpaga­rion . so I hc jpcd him with my recc p­non reports , plus the receptionreports uf my beacon. This wa sthe Radio Amateur Scienti ficObservation projec t, RASO ,

Perry awarded me a ce rtific ate forhelping the project. Then , a coupleyears later, he became the editor ofCQ. B)' then I was deep imo RTf)'.Perf)' liked my Amore"r Radio FTiJIl ­tiers magazine and asked me to do aRTfY colum n for CQ. That helpedgenerate more imerest in RlTY, hUImore imponant. I got to be goodfrie nds with PerT)', and knew heh3lt.'d CQ publisher Sandy Co... an.So I helped Pcrry gel the edi tor' l> johal Populo r El erlTVll ics_since I lno:wthe publishe~ Bill SlOcklin andO llie Read. That le-d 10 me becomingthe CQ edi tor, which I hadn 'l e \'enconsilkred before. Serendipity.

Ast ronomers at the Californialnvmure of Technology have rc­ported Ihe firs l sunspot of the newcycle. Pause a moment for a roundof cheers. The)' were surprised attheearly sian fur Cycle 23.lf s expectedto peak around 1998_since the spotslend 10 build up rapidly and thenfade a... a}' more slowly.

1( 11 he nice to have the HF bandsopen around tbe world again, and tohe able 10 make contac ts all nighl on20m. During lbe teuer sunspolpeals even 610 opens up, a llowing....orld wide comm unica tions with10.... po....cr. I remember one dayw hen I luned bm with my pre -warMeissner ~1 tuner and heard thesixes and sevens boi lin g through .That sen! me rightto my workbench10 build a 6m transmitte r. Well. 10

convert a surplus SCR-522 rig 10 six .Maybe you didn't know that the

pre-war FM broadcast band wentIrorn .'i0 -56 MH /" with us ham, onfive meters. 56-60 MHz. The two­and-a-ha lf rueter ham hand wentfrom 11 2-11 6 Mil l.. Well , me. act u­ally. since heft l. hadnr b«n in­vented yet as a rep lacement forcycles per~nd. The 5D radar onmy submarine wa s on 11 2 me. w Ifelt righ l at home .1lIe main prohlenlWi lh that was Ihal !he Japanesequiclly inslall ed 11 2-\1HI. receh'cf"';in Iheir planes w they could Ill,me inon our radar, Thallcnded 10 di scour­agc us from using it other man fOf anoccas ional qu ick blast .

The SJ radar, whieh wa.. ma inlyfor surface work. was up at 3,OClOMH , . ... here the Japanese apparenl lyhadn' l figu red out how 10 hmld re·cei\'crs. So l u, t.'d the SJ for spoiling I wa s reading in lhe Daymn clubboth ships and planes. and kCpl Ihe new, leiter aboul Ihe program sel upSI) orf most of lhe lime. by lhe Upper Valley Radio C luh with

Ral'k in 1949, I was olle of lhe sh Reavcrcrcek ' s Brookw()()d Ele mt.' n-meter pioneers. I was the only one w ry S\:hoo l. The)' lined up fo ur 9-Oil si.\ in Ncw Yurk Cil)', Wc were all and 10-year-old student s 10 la lk overcrystal-\:ontro lled in lhose days, so [ the loca l repe aler to each of sevencould lell lhc call leiters of any sig - d uh memhers. Th e aim wasn't pri-nal , j ust by measuring il5 frequency maTi ly to get thl'm infere ' led in ham ·with my surplus G eneral Rad io minI., hut ral her 10 help the kids de ·lR-1 frequency meter. Big sucker, velop Iheir ahili ty 10 talk withwilh nearly a hundred tu bes. people. Th3f s called oral skil ls the ~e

I got a 50.I -M HI. c ryslal and sel da}'s. However, two of Ihe kid s didup a ht::acon so hams out \Vesl or in ge t their tickets. aoo many pre ~'i -

4 73 Amateur Radio Today . Ja nu ary 1996

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willing 10 use and explore ne....·ertechnologies : after all, from the be­ginning thai i~ the major reason wewere allocated our bands. If any test ­ing changes are made they should stanwi th the e1iminatiun of the IB and IC el­enerss, .....ith funhcr CfT11ha'>is placed onluby's and~'s Il'dnologie<..not yesterday's. Grow. ordie.

When hundred~ of ham clubs, un­der pressure from the ARRL. wroteto the FCC claiming tha t the Morsecode was of enormou s importa ncefor ib poten tial use In emergencies, Isaid. if you honestly believe ..... ha tyou testified 10 the FCC. then .... e o b­v'iou~ly should require code tests forevery license renewal. Oh. the fren­lied screams of an gui vh that raised .

JIIID H air /liSL\'1 After readinglhe letter on Senior Ci li len~ L'p­grade, l thuught I' d .... rite a respo nse.Maybe who is regankd a~ a "Se­nior" is relative 10 a pcrson ' s age , Ifirst acquired a General Class li­cense in 1956. Following Ihat year,we added 10 the family' until we hadfi\'e harmonics. Bu' y'ness ilhfamily and no anlenna shul me do nfor 17 yea rs after th t: expiration of

Continued on page H?

NQ, 110, Ihey memJ/ that newcomerssho uld learn IIU' code . . . l\aUl1'

Richard A, Medhurol KmUro ,In response ttl the letter from TerryWeinhold :-.I3EUL as published inthe October 1995 issue. I must saythat the facts do not support his con ­clusion that [he code requ irementmak es for a "higher.quafiry opera­tor," A review of the "Happenings"column in QST for the ca lendar yearo f 1993 woul d tend to disprove thisconclusion. The fact!> arc thai during1993 14 licensed amateurs had mon­ctary action or revoc atio n of licensehy [he FCC. One Tech (7 .15%), fiveGeneral (35 .7%), two Advanced(14.3%) and six EXIra (42 .85%). Asyou can sec, 92.85% have 13-...ordor better licenses. During a recen tpublic S<':t\'ice eve nt in San Diego, al.....o-by-IV1..0 ,all maliciously andwillfUlly inkrfered with (:m nmuni­cations . TIlaf s a "higher-quali[y"operator? If the 2 meIer band soundslike CB in ~l r. Weinhnld' s area thellthere is no one to hlame olher thanthe pre-no-code amateu~. It \loa,> upto them 10 educale lhe new licenseesas to proper repealt:r protocol. Iflhey do not know Ihe rules, hI}w callyou condemn them? To infer that Ihennly "good" operators are [hose withcode is eu,[ly the Iype of narrow­minded attitudc thai keeps Ihe yuungpeople out of amateur rad io. I do ootad\ocate the eliminalion of CW,only lhe t:a\ing of the 13-.....ord re­quiremenl. I also a"hoca te morestringent lechnical tesling for HFpri vileges. I may he a lowly Tech.but I ha ve man y frit:luls who arcGeneral, Advanced and Extra Class..... ho come to me for technicalassistance.

Riebrd Hepper-t KC4\'QL Inthe October issue there was an inter­es ting article by a ham ..... ho had fi­nail)' pU~hed himseff to gel his Extraafter 46 years. He was no...' fincting ilrewarding to work testing sessionsand Elmer others through the up­grade proc ess . Bravo ! But he wasalso finding too many of his fellowlongtime operators were reluctant 10

anempt to upgrade because . al·though the)' could handle the codespeed. they fell the y could nor learnthe necessary math. He proposedcreat ing a special upgrade licensefor these old-timers as a reward fortheir many years of "service," andrequested feedback on the idea. I hadto check to be sure that it wasn'ttheApril issue . This past weekend I par'ticipated in a di\CUssion al a loca lham fest thai worked its way aroundto the code requirement. II was theopinion of one fellow (my guess ishe was 50ish) that he would rathersee the FCC drop wriuen tests alto­gethe r than see an elimi nation of thehigher speed rode requireme ms-c­after all, " nobody builds or repairsanything anymore so the tests are ir­relevant." T~ "logic" of the IWOproposals eludes me -c-or j ust maybeTsee it too well: Screw any relevanttechnical knowledge. theory, andregula tions. and give higher licensesto those who have nothing better 10

do Ihan practice the oldes l fOOl! ofcommunication know n 10 hams­C\Ii. A\ for the firs l propo...,,1, Ihesalisfaction of having pcrfonned ser­vice , had i[ actually heen perfunTIed,shou ld have bt:en its own reward ,Had thes<: old-timcrs grown and pro­gressed with the hohby's technologylhey ... opld hav'e had linle lroublepassing lhe lechnicallesh . or at leas tbeen less scared to try . As for theproposal 10 elimillate wri Ut:n lesLsahllUt regulatiolls, procedure. propa­gation, antenna theory, safelY. bandplans, and modes, not 10 mention ba­sic eleclm nic tht:ory. but keepingCWoIhis is a blatanl cry ror elilist "Idid it- Ihe)' should too- men talily. lfCW is so imponanl, I' d like 10 pro­pose re· tes ting every five years onwrillen and code. If you dun' t passyou 're husted ha,k to Novice andhave ttl work your way bad. up, Dowe see a few quaking in their bootsat that thought'! Seriously, [he FCCtC'>b for eac h license class shouldchange/grow ... i[h [he h:chnical ad­vanceme nl of the amateur radio "ser­,'ice.- and for a large part Ihey have_The major exception has h...'Cn theElements IBand IC CW require­men[s (I A is still lIeeessary to mt'etITU regulations ), The olily way weare goin!! to keep our bands is to re­cruit. encourage and reward the in­nov'atot'>, not reward hams formerely e xisting and Ilot causingtrouble . Extra privileges alld bandspa,\! should go to the pcople

felt like cheating. It was so easy Ididn ' t gel the sense of accomplish­mem that should have been there.

From the Ham Shack

Michuel U. Zandel' AA8QI, Gee..... hiz Wayne, we bener keep the codereq uiremenl and six license clasSes,or we won' t hav'c anYlhlng at all todiscuss on Ihe air. Here' s my 1.....0, eOlSon Mr. Weinhold N3EL'L's lei­ter. I' m sure )OU Clln [t:ll the new no­coders. but not for long. The)' eitherconfonn or [he old heads run themoff. Then !\-1 r, Goodman W3UWH 'scall for a 'l:n ior upgrade : If lhey.....ant il bad eoough tht:y would timl away. It's tOO bad your friends ... on·1e\ en try. I ...eOl from no lickel at allto E:liIra in four months and found it

You call adj ust the sourness ofIht' coleslaw dressing by adding1Il0Te sugar OT hone)', IIS also Q

fabulous d ip f OT Til'" "egg ll'S.Cheapt'T Ihlln Ihe hal/led drt'ss ing.100 , . l~aYll e

reading you r future colums too. Wetried your old recipe for celestaw, Itwas vel')' good and we'll be using itagai n. but with a little Ie\ S vinegar.Then we'll have a good comparisonto make againsr our favo rite recipe .Thanks for giving it out. We both tryfor low fat foods (and high tiber) sowill be givlng it try with the lowlnon- fat ingredients .

Allhou!!h not a ham as long asyou Waync H'm 65), I hal e had anumber of honors as re~u lt a o f be­ing a ham. My highes t one wa v whenI lived in [he Phoenix area hack inlate <60s and became one of BarryGoldwate r's !\-1 ARS operators, I ranphone patcfes from his home 10 scr­vicemcn ill the Pacific and SoutheastAsia, To this day' I don 'l believe thepubfic, or hams, reall y know \lo hal acon tribution he made 10 the moraleof our servicemen in [hose areas.when I was out there he had twocomplete stations. one was Collinsequipment capable of running 4kW,and one ....·ilh Drake equipment run­ning 2kW. A~ide from spendingsome long eve nings after a day' s.....on, it was fun and most satisfyingfrom a personal standpoint. If s stilla great memory.

LETTERS

Dirk Sm ith \\'4KH\' Over theyears I have enjO)'ed )our cofurnnsand find them nOI onl) enlighteningbut thought-pruvok ing. wnue I havenot a l..... ay s agreed with all you han:said (docs anyo ne always agree witheverythin g one says?), I do find my­self ~ iding with you r thoughts mostof tnc lime. Superfluous for me tosay. keep it up. as I know )'OU will.Thanks. After readi ng your Novem ­eer editorial I would like 10 com­ment on a number o f subj ects youtouched on, First. you asked for let­ters abou t most recent buildingprojects. etc. Well. I do huild smallelec tronic projects now and then formy other main hobby, RC modelplanes. I have been in mudd planessince J was a kid and RC planessince 1949. I have been a lice nsedham since 1953 (W IZVG). How­ever. I do not build milch ham equip­ment now, other [han a QRI' rig thispast year. My antenna will have [0

be improved before it's a real suc­cess. I still huild quite a few plane,with my largest being a 9' (.... ingspan) replica of a WW! Sopwith"Pu p" hiplane. This is an RC planewhich is 1f3 scale. 1 fly on both 6meters and 72 MII7.. Rad iO "con­tests" do nor move me. nor do nets.About 80% of my hamming is on 40CW, and I enjoy it. Yes. I know CWis dead 10 many', antique. etc.• andnol promoted hy people such as)'ousell". But Slill. ir s fun-isn't thiswhal this hobby should be? An.1yes,lhc other side of the coin is to dc­velo p new ideas, ted miqucs, invent ,and pioneer. Thi s ..... here you r insighlis so \'aluab le 10 those technicallycapable. I also pan icipa le on a localIe\'el in \arious ronununi ly' projccb.inclUding ARES and Skywam. Yourf\'o\'ember column ..... as one of yourh<: ller illfo .:olumns, In fact, I askt:dIlly wife to read it from stan to finish(she did), It wa~ the first [ime shehas e\'er read an)'lhilig from a "ham"magatine. She was really taken byyour ohsel'\'ation\ ahout the Go\'em­ment cover-ups, roadblocks 10 cutc'S,health. eiC. I' m ~ure she' II be

6 73 Amateur Radio Today · Ja nu a ry 1996

.,HWlA.-.....__ R139 Is The Afford-able WeSat Rcvr!

Join the growing ranks of eamateurs who gel striking NEWImages directly from theweather satell ~esl we

used our 30+ years of • •perence in designing high-quality ",hi receiven. 10 bringyou a r- enhanced ve<Sion of our Iong-popu\ar WeSat receivers, The r- R1 39is a very seosIIrve wideband fm receiO'er optimized lor amateur ,eeepticw'l of NOAAAPT and RU$$ian Meteor weatl>er facsimile images on the 137 MHz band. Usewith any popular demodulator and software. Covers oil five popular u lellitechannels. scanner cirOJ it and recorder control alloW you 10 automabcally &eaf'Chl or and tape signals as satellites pu s overhead. even while away from home.• R139 R. ce iver Kit I• • • ca.e $159• R139 Receiver Kil with cllSe and 12Vdc po_r adapte r $189• R139 Receiver Wiredltested in cas. with 12Vdc power .dapter $239

REP-200 REPEATERA fully microprocessor-controlled repeater with autopatchand many versatile dlmf control features at less than youmight pay for a bare-bones repeater or controller alone!Kit still only S1095w&t still only $129550 . ....

. Available for the 50-54. ;143-174, 213-233, 420­475, 902 ·928 MHz bands,

• FCC type .ccepled forcommercial service in1SO & 4SO bands. (Request c9l8Jog wOOll1h.)

You get more features for your dollar wi th our

Also available in if-tight e nclos ures, and w ith d ata modems.

FM EXCITERS: 2Wcontinuous duty,FCC type accepted for com1 bands.

• TA51: 50-54 , 143-174, or 213-233MHz..TA451: 42Q--475 MHz . New.bwonce'Either model: _ kit $99 , wft $169.• TA901: 902 -928 MHz. (O.SW out);Newlowf)nC8' w/'l$199.

XMTRS & RCVRS FOR REPEATERS.AUDIO & DIGITAL LINKS. TElEMETRY. ETC.

VHF & UHF AMPLIFIERS.For 1m, asb, atv. Output leveis from10W to 100W. Models . ts rtlng.t $99.

FM RECEIVERS :~""'-1..,. R10Q FM RECEIVERS for 46-54,"NEW~ 72-76. 140-175. or 216-225 MHz.~" Very sen.itive - O.l 5uV. excep­tiona l selectlvlty _ both crystal & cerami<: iffillers for >100dB at :t 12kHz (best a~airable

anywhere). fl utter_p roof squelch .. " New low pricel kit $129. wll $189.• R451 FM RCVR, for 420-475 MHz. Similar10 above, New""wpnee' kit$129, wlt $189.• R901 FM RCVR, for 902-928MHz, Triple­conversion. New.bw pnoa... $159. wft $219.

""~ R150 MONITOR RCVR lor 143-164 or 216-22 5 MHz. • -<:hannels.""N~~ Great for mon~omg repealerS, amateur calling freqU' " CleS, packet ra­'"'11-" dlO. COITlmefCIal~ay radIO, poIice/fire freqlJllOCleS . or weather fore-casts. Good sta rte r kit, easy to assemble and align kit only $99, wit $189.

• R120 AIRCRAFT RCVR lor 110·138 MHz ,.... , , kit only $99, wit $219.

REP-200T Voice Message Repeater. A$ above, except irdudesDigital vOCe Recorder. AIows message up to 20 sec to be ~tefy l'S'C:orded orrthe air. Play back at user request by o mF command. or as a periodical VOICe id.or both. Gre.t fo r m. king cl b . nnouncem.ntsl _ dd. ont, $1001

REP·200C Economy Repeater. Uses COR-6 Conlroller (no DTMFcontrol or eutopatch), F. atures re.l-volce ID " ......,....... Kit only $795, w&t $1195

REP-200N Repeater. Wanl to use your own controller? NQ problem! We'~

make you a repealer with If modules onty Kit only $695, w&t $995

,

COR". COR &RNI Voice 10on one boardDigllal it recordsup 10 20 sec­onds of yourvoice. Can rec­ord mu~iple idmesuges. Ta~and lme-ouI t~, courtesy bel!P. solid·stale relay 10 key trlln$tl'litter ,___ kit $99, w&1$1.9

COR-1. COR,IImers. court beep kit $49CWlO. Diode programmable kit $SiCOR.... Complele COR and CWlD all onone board, CMOS log;c for row powerconsumplion. EPROM programmed:(specify eall) k it$• • , w&t $149

(speedy canl .

ACCESSORIES

TO~

SELEC TIVECALLINGMODULE.Vef$llble dtmfcontroller with 1lalching output.M..... . pe..k. r...ntil someonecalls by sending your 4-dtg ~ II code. Oruse it WlIh a long tt :r:aro dig~ 10 alert any­one in club for emergencies, Also may beused 10 control . utopatch or other de ­v ice, like TD-2 except only one output.....................................,...ki1 $49, w&t $79

1tI-3 CTCSS DECODERJENCOOER Pre-­ve-nts~ 10 repealer or receiver un­less proper lone is pre5enl. Tone outputfortransnVllen.. too. . kit $29, wft $59

DVR.1 DIGITAl. VOICE RECORDER. Re­cord$ up 102(l see of your \Ioice with buill­in mic. or elctema! mit. Temfic as voce10'er fOI repeaters or fox hunt xmlr. con-­

test call. r. radionotepad. etc Ex­tensive manual leltshow 10 use multiplemessages adapt 10many applicalions.......klt $59, w&t $99

AP·3 REPEATER AUTOPATCH. Reversepatch and phon. line remotlt control .....•_ k it $89 , wired & lested $139

AP-2 SIMPLEX AUTOPATCH TI'IlingBoard Use with ab<we for smpIe_ oper_ation using a transcei'lef _ kit 13910-2 OTllF DECODERICONTROUER.16 dIgits , jumper--programmable. l oll-callrestoctor. Can tum 5 funct ions on/off.

." ,- .kit $79, wired & tes led $129

••MO-202 FSK DATA MODULATOR &OE.202 DEMODUlATOR. Run up 101200 baud digital sigr'131s through any fmtransmitter & receiver .....kits $49, w&1$79

9600 BAUD DIGITAL RF LINKS. Call forjnfo on Iow-eost paclc et netwonung sys_iem: MO·96 Modem and special versionsof our 144. 220. or 450 MHz fm xmtrs andrevrs, Use directly with most TNC·s. Fast,diode--sWllched PA's oulpul 15 or 5f1W.

LNG·(·)st ill only 559wl<t<l&lested

LNW·(*)MINIATURE

PREAMPstill only $29 kil, 544 _ a_ted

• l ow-coat MOSFET preamp.• Smlll.ize, Only 518"W x 1·5J8"l. x %"H,• N11.2dB vI1l. 1.SdB uhf.• Solder terminals for coax & pwr connect"Speedy tllrnnp rlnge: 25-3~, 3~~, ~90. 90-120.110-150. 1M-ZOO. 200--270, 400-500 MHz

LOW NOISERECEIVER PREAMPS

Helical resonator

~lilten. may red uce

: • • your Intermod &cross-band inter_ference.

MODEL HRF" ( . ), $59 ",hf, $99 uhf."SoedfY tll'"'Pll ""ll'" 136-140. 142-150, 150-162,102-174, 213-233, 420-470

XV2 for vhf . nd XV. fo r uhf. Models toconvert 10M sab, ON, fm, etc. to 2M, 432,435. and atv. tw output. Kit onty $89(vhf), $99 luhf). PA's I-'P 10 4!1W ,,~aiabIe

HELICAL RESONATORS

FEATURES:• Very low noi.e: O.7d6 nf vhl. 0 8dB uhf• High g..in: 13-2OdB(~s on freql• Wide dynlmic range _I'e$ISI 0YefI0ad• Stable:d~e GAS FET"SpM:ify ILfW>g' f&'IlI'I ' 26-30. 456. 137· 1,w. 130­152. 1~1l2. 210-230. 400-4711 BOO-!l6OlIfHz,

Gel time & Ire­quency checkswilhoul buyingmultihand hi rcvr. Very IoeftSfWe and &e­

lective xtal eotltrol\ed superhet. dedicated10 lislening 10 lINN on 10,000 MHz,PertOflTlarlCll rivals the mosl expensive re-ceivers, , only $59 kit , $99 wft.

Low noiseconv.rt... toretel",. vhf& uhf b..nd. j .. 9on .10M rec.lver.• Input ranges l...,ai!; 50-52 . 136-138.144-146. 1.501. 7, 146-148. 220-222.222­224 104Hz. 432-434. • 35-437. 4355-437.5.and 439 25 (atv corrv 10 chan 3).• Kit less c..e $<Ct, kit wlc... & BNC!locks $79, w&t In c..e $99.

QRH • • •

At GE's request, Part 18 of the commissions set this amount based on the Consumer Price In-regulations has been waived. Part 18 limits 00 the del betweeo September 1994andSeptember 1995.amount of RF energy thai can be conducted into II's an increase of 17 cents from ,he current $5.90the erecec p:lWer lines by RF lighting devices in fee.the band 2.2 to 2.8 MHz. GE proposes marketing Actually, nobody really makesanyprofit from hamto consumers an unlimited number of RF light bulbs radio testing fees. Volunteer examiners and votun-that comply with the con duction limits for leer examiner coordinators are permitted 10 chargenonconsumer RF lighting devices in this band. examinees lor out-of-pocket expenses incurred in

Commission rules already permit RF lighting preparing, processrq. administering. or cooromat-devices used in commercial environments to place ing reexaminations lor amateur operator licenses.this signal level on the AC power lines. The FCC The amount of any such reimbursement fee fromsays that there has been no record of significant any one examinee for any one examination ses-interference problems from the useof these devices sion, regardless of the numberof elements acmm-in commercial environments. It also says thaI radio etereo. most not exceed the maximum allowableoperations in the range 2.210 2.8 MHz are not nor- fee. TNXAmateur Radio Newslinemally employed or intended lor reception in rest-oenuer environment. GE was granted a waiver tor FCC Wireless Chief Movesone year, and the FCC reserved the nght to revokelhe permit if it determines that RF tighting devices Regina Keeney, Chiefof theFCC's Wireless Te!&-operating under the conditions 01the waiver create communications Bureau, which oversees Amateursevere interference problems. Radio, has been promoted to chief 01the Commis-

Three years ago, a Californ ia co mpany, stone Common Carrier Bureau. Keeney, who haslntersocrceTechnologies,promoted anRF-powered beenchiefof theWTB since the bureau was formedlight bulb that operated at 13.56MHz. ACCOrding to last December, replaces Kathleen Wallman atlhe manufacturer it was designed to keep uninten- Common Carrier.uonarradiation to a minimum.Thecompanyclaimed Regina Keeney is the daughter of John Markeythat its as-wert RF bulb could generate as much W2AAW and Marge Markey N4XZD. When shewasvisible light as a l00-wan conventional bulb but named as chief of the WirelessTelecommunicationsthese lamps were never marketed. Bureau she is QUOted as saying that she had grown

And the ARRl says it has a definite interest in up in an enthusiastic ham radio family.what kind 01 interference the GE RF bulb may gen- The FCC, in announcing Keeney's move over toerete. The l eague says that it will obtain samples Common Carrier, said that during her lenure at theof theGEbulbs for testingas soon as they areavail- WTB, she oversaw the commission's auctions ofable.ARRl laboratory Supervisor Ed Hare KA1CV eledromagnetic spectrum and work.ed to developsays that the new bulbs should not, it properfy de- lair ru les of competition in the wireless communi-signed, create any more interference to Amateur cations marketplace. Thanks to her leadership, saysRadio operations than nuorescent bulbs, dimmer the FCC, the previous backlog in licenseswitches, orother Similardevices lound in the hOme. application processing has been cut in half.Other experts disagree. They point to the problems No successor to Keeney in Ihe Wireless Tele-that a bad incandescent lamp dimmer can create communications Bureau has yet been announced.for the average ham. TNX Amateur Radio Newsline TNX Amareur Radio Newsline

Paralyzed AssistanceAirwave Auction Needed

The Supreme Court has given the Federal Com-Bill Farley WASFLG has posted a packet mes-muntcatlons Commission approval to go ahead with

sage asking for help for a paralyzed ham. Bill saysits planned December 11th auction of 498 licensestor small businesses. A company called Radiofone thaI lowell Richardson WSUBW, anavid OXchaser,

Inc. had Challenged the commission's cellular per- hasbecome paralyzed but wants to be able to com-

sonar communications services cross-ownership nwucate.Bill says that l owell no longer can speak. Bill isrule, which limils cellular companies to 40 mega-

hertz 01spectrum in their cellular service areas. lOOking lor anydevice that would help his friend who

But in vacating a stay issued by a Federal Arr has the use oj one hand only.

peals Court, Justice Stevens noted thatallOwing the If you have any ideas, send them by packet to

national auction to go forward would not prevent WASFlG@KSWPH or call Bill at (505) 437-5508.

the federal appeals court from granting Radiofone He is in Alamagordo, New Me~ ico , and is on Moun-

appropriate relief if it later foundthat the company's tain Standard Time. TNX Amateur Radio News/ine

case has merit As a result, the multimillion dollarCanada Adopts IARPauction will proceed. TNX Amateur Radio NewsJine

1996 VE Test Fee On the international scene, Canada has an-• nounced that it has agreed to adhere10 the Region

The cost of getting a ham radio license is going 2lntemationai Amateur Radio Permit. It's thefourthup again in 1996. Effective January l si, the maxi- country to do so and has issued the first two

mum allowable reimbursement fee lor an amateur permits. These went 10 Radio Amateurs canadaoperator license examination will be $6.07.The FCC Continued on page 87

Bob Bruninga WB4APR may become the firstham with his own amateur radio eeteme in space.The Glen Burnie, Maryland, hamhopes to havethenew amateur radio satell i te In orbi t by nextsummer,

No, ttns is not a JOke or a pipe dream. Bruningais the director of the Satellite Education laboratoryat lhe Naval Academy in Annapolis and the satelliteis a departmental project. Its primary aim Is to pro­vide every school in the country wilh packet radiosatelhte access:

-We try to cernccete in all the SAREX misSionswith our students. The only problem is probably only1% of the orbital passes is operational in the packetmode on the SAREX and you never know in ad­vance. It is very hard for the snceots to go to alltbts effort and not be able to make a packet link tothe spacecraft, So, we think that there ought to bea very towbudget, low tech packet satellite up therethat isalways on, always cceretcoetAndevery timeit comes over any high sct'IOOI in the country thestudents will see something."-Bruninga

Bruninga says he ptans 10 fly a one-wan Picosatlransponder operating on 2 meter FM packet at1,200 baud. The system is specif ically designed fordigipeating position reports.

"Once you get the satellite up there then we cantrack guys driving across lhe country in their recre­ational vehicles, we can track guys in their boatsout in the bay and up and down the Atlanlic...allover the worJd really_ That's why we think there istremendous potential tor position reporting.

' 1mean mere what amateur radio is, II's not sit­ting in your basement. As far as our ability 10 con­tribute to the slate 01the art and to public service,our abilities are not Sitting in out basements. Ourabilities are mobile."-Bruninga

Bruninga says that he already has a tentativeinvitation from NASA lor a free taunchon an exoeri­mental booster, The earnest possible launch daleis in May. But WB4APR says mat the date couldeasily slip. A Iol depends on when the satellite isready to fly. The parts are within arms reach, saysBruninga, but construction has yet to begin. TNXAmateur RadiO Newsline

Private Ham Satellite

RF Li9e.:h""ts~ _

Still with ham radio satellite news, Jim WhiteW00E reports that the DOVE DO·1 7 ham satelliteS-band transmitter is on. Jim says that a recentsoftware load allows tetter power oontro! and ceo­trollers now expect to be able 10 keep the peskytransmitter in operation on 2,401,220 MHz, TNXAmateur Radio Newsline

Dove S-band Is On

AF light bulbs are on their way and they couldadd to the QRN currently on the ham bands. Thisafter Ihe Federal Communications Commissionwaives its ru les to permit the General Electric C0m­pany to begin mar1l.eling a new RF-powered lightbulb,

8 73 Amateur Radio Today· January 1996

The SP-10 "Senior Spider"Transceiver

Mike Agsten WA8TXT405 W. Bogart Rd.

Sandusky OH 44870

YOU may have heard (or knowfi rsthand) that transmitter powerlevels of I wall or less can in­

deed "gel out" and have accounted forsome remarkable fears of OX. It's true .

It's also true thai I walt , in HFskywave service. has little endurance 10spare. You get lucky and snag a goodone when the band is optimum and twominutes later, you ' re talking to yourselfbecause of QS B or Q RM at the otherend! Clearly. some exira holding poweris called for if you want 10 che w the ragor make 5-WPM Novice QSOs that. ofnecessity, lake longer to complete. Thequest ion is, how much wi ll it take 10 dothe job?

When it comes 10 transmitter power.the sky's the limit of course. up ( 0 the lc­gallimit for your licen se class. but herewe also want easy construction andminimal cost to encourage beginners sowc' ll just split the di fference between ameasly I watt and the widely effective100 watt levels. And the an swer is... 10watts! That 's right. To j udge the effect ofa power change. you must think in termsof dB (deci bels ) and not he mislead bythe watts . Ten wans is 10 dB bener thanI walt and 10 dB worse than one hun ­dred. placi ng it on middle ground theo­rctically and in terms of on- the -airreadabili ty.

The rig to follow is a simple l O-watt .crystal-controlled CW transceiver thatmay he built for 80, 40, or 30 Meters.You can build it and learn a little abouthow it works. Should it ever malfunc­nonjust fix it yourself. There's no needto rely on the service of a distant repairfaci lity. That's independence!

The SP- IO

The SP- IO presented here is function­ally very similar to its predecessor. theSP- I (Jan. 1993 issue of 73) which hasenjoyed popularity in the QRP world.

The receiver front e nd is triple-t uned toimprove in-band sensitivity and out-of­band rejection. The dual-gate MOSH:.!receive mixer has been retired and itsjob turned over to a multifunction ICthat also includes an op amp for audiobandpass fi ltering and a very effectiveaudio muting switch. A low-noise audiopreamp stage for increased gai n roundsout the recei ver improvements.

The transmitter section is pretty muchthe same as the original "Spider" excepthere it drives a power MOSFET "a fter­burner" producing 8 to 12 watts of RFoutput. Physically. the highly successfulSP- I layout has been retained whereverpossible . The additional circuitry re­quires a larger circuit hoard which fitscomfortably in the next size up enclo­sure, an RS #270-232 measuring about8" w by 4" d by 2" h.

"l'{Jur brain needs a change ofpace and here you get itwhellever yOIl close the key !"

The net effect of these changes is aquantum leap in overall transceiver per­formance and j ust a modest increase incost and complexity. By strictly avoid ­ing "dinosaur" and nne-of-a-kind com­ponents in the design , easy dupl icationand maintenance for years to come is al­most assured. So get with it and. nexttime. you' ll be the one to say "Rig hereis home-brew!"

Circ uit Description

The heart of this radiotelegraph trans­cei ver is continuous wave osc illator QI(refer to the schematic . Fig. I). You pluga quartz crystal (more on crys tals later)for the desired operati ng frequency intothe top panel soc ket and QI circuitryprov ides the needed gain and feedbackto sustain crystal vibration and supply

P/lOfo A.. Top d pw of the SP-/O.

RF drive to other circuits via the second­ary link on TI.

During. receive. incoming signals passthrough L5. L4. L3 and series resonantC231L6 to receiver input circuits T21C32and T3/C33 (which are top coupled byC34) and onward 10 the receive mixer atU3 pin 18. There. in conjunction withoscillator signal via CIS to U3 pin I.they are convened direc tly to audio atU3-3, fi ltered by C59 to remove un­wanted RI" byprod ucts and then audiobandpass filtered by the op amp at U3­12 and U3-1 3. which provides a distinctpeak at atxmt 400 Hz. In recei ve. the au­dio muting transistor at U3- 16 is off(open) allowi ng signal passage to AFpreamp Q6. volume control R47 and AFpower amplifier VI (pin 2 in. pin 5 out).U I employs a sma ll amount of negativefeedback (C52) to roll off unnecessaryhigh-freq uency components in the AFoutput.

Receiver line-tuning is accomplishedby using RIT contro l R23 to vary thetuning volt age (via R l ) to 0 1. This spe­cial tuning diode transforms RIT rota­lion into variable capaci tance which. inconjunction with LI and Y I. alters theoscillator freq uency. Normally. this re­ceiver is properly tuned when there is a400-Hz difference between signal andoscillator. The resulting beat note pro­vides peak output because it is centeredin the audio bandpass response. Fre­quencies higher and lower rece ive lessamplifica ti on. This is how select ivity is

73 Amateur Radio tcaev-January 1996 9

prov ided; the desired sig nal is louderunless interference is overpo we ring.

Automatic recei ve-tra nsmit switch­ing (Q SK) is ini tiated by closing thekey. QS switches on , rapidly energiz­ing the 12T bus which. in tum, accom­plishes the changeover to transmit byswi tchi ng se veral ci rc uits . 12T via 0 8mutes receive audio by placing a shortcircuit at U3·16. It turns o n sidetonegenerator Q 7 (a un ij unc tion transistoror UJT) via R38 and R39 . Sidetone al­lo ws you to moni tor you r telegraphsending quality by pro vid ing a nice ,tight feedback loop that includes ear.brain . fist , and key. The sidctone inthi s rig also provide s an important sec­ondary funct ion . Its co mplex , har­mon ic-rich output soothes your brainby di spersing all those headache-form­ing neural knots that may co me fromexcessive sine wave exposure duri ngreceive . Your brain needs a change o fpace and here you get it whene ver youcl ose the key!

Movin g o nward. 12T via R25 andQ5 ground s 01 tun ing vo ltage to pro­vide transmit offset which allowssame-freq uency tra nsmi t-rece ive withother stations . It switches Q3 on. en­hancing oscillator output level via R5and as si sting transmit o ffset with C3.Finally. 12T keys Q4. which permitsQ2 to amplify the incoming osc illatorsignal. Ql output via lo w-pass filterLl a nd re sis tive pad R 14-17 thendrives fina l RF power amplifier Q9 tofull o utput of S to 12 watts, dependi ngon band. po wer supp ly and transistorgrade .

Harmo nics present in thi s raw powerare attenuated to insig nificance bylow-pass filter L3-U -L5 and associ­ated capacitors. Si nce the recei ver inputis tied di rectly to transmitter output atC13. 04·07 are included to protect thereceiver. Transmit RF turns them on and ,while in conduction, they place a near­short at the j unctio n o f C23 and L6.breaking up the series resonance andfo rcing C23 and C22. because of theirrelatively low capac itance. to look like ahigh impedance during transmit. thusblocking most of the RF. This techniquewas actually developed for radar equip­men t where a sensitive receiver andhigh-power transmitter had to share acommo n waveguide, What you see hereis the same principle in a less pure burstill adequate fonn.10 73 Amateur Radio Today . January 1996

-

I'holo R. Bottom view ofthe sp· /0.

Const ruct io n

In the top view photograph o f the SP­10. you can see the oc tal-type crystalsoc ket in the Ie It -rear com er. Since thissocket holds two Ff-143 or similar crys­tals. DPDT switch 5 2 is provided just infro nt to select one or the other. TB I. afour-lug terminal board. mounts alongthe rear edge o f the top panel, near therig ht-rear comer. Its terminals are num­bered I to 4 going from left to right.Connections to TB I are DC power to I(+ ) and 2 (-) and ant enna system to 3(coax shield) and 4 (ce nter). Along theright edge are 3.5· mm jacks for speaker!headphones (J2 -rear) and external tele­graph key (It -front) .

The bui lt-in telegraph key is just letto f the jacks. Its arm, a 3" strip o f .025"thick brass or aluminum. is mounted on114" spacers and grou nded to the toppanel by its two mounting screws . Thekey knob. a rubber o r plastic equipmentfoot. is fitted or glued to the hex nut at­tached with machine screw. up throughthe arm. The head of this screw is the up­per contact. The key contac t be neath thearm is a 6-3 2 brass machine screw withhead filed nat. This screw is insulatedfrom the top panel with a shoulderwasher above and fibe r was her belo w.and sec ured with flat washer, solder lug(for con necting to) and hex nut .

The two kno bs fro nt and ce nter on thetop panel are Volume control R47 on theright and receiver incre mental tuni ng(RIT) R23 on the left. Just left of RIT isslide switch 53, unused here but avail­able for ex tra audio fil tering (to impro veselec tivity) or other contingencies. Lefto f 53. in the left-front comer is DC·power contro l switch S l .

Runni ng front to rear between RITand Volume. and below the top panel, isa I" wide by 3" long by 3/S" thick solidalu minum slab that provides heat sinkand mo unting platform for RF po wer

amp Q9. Thi s slab, to further increaseheat dissipation , is attached directly to

the aluminum top panel with three ma­chine screws. heads visible in the photo­graph.

Most of the project is contained on thePC board depicted by the etching patternin Fig. 1 and the parts overlay. Fig . 3 . Ofspecial note on PC board assembly. volt­age regulator IC U2 needs 2 to 3 squareinches o f heat radiator coupled 10 itsmounting flange. I cut and bent a pieceof .025" aluminum sheet as shown inphoto B (ins ide view) and o n the partsoverlay. and installed it between U2 andthe PC board.

T4. the trililar-wound matching trans­former, uses two of the speci fied coreplaced side-by-side . The wire windingholds them together, no problem. Don"tbe intimidated by "trifilar wi nding ." Allyou do is cut three equal length wiresand twist them into a bund le. Thread thebundle onto the core until you have thespecified turns count. It should look likean oc topus with six tentacles coming offthe bottom. Trim excess wire but allowenough for co nnectio ns and installatio n.Now you have three wire s on the core.arbitrarily designated A. Band C, andcolor-coded o r tagged for eas y idcntifi­cation . Connect the end of A to the be­g inning of B. Connect the end of B tothe begi nning o f C. The beginning of Aand the end of C remain single and go to"Com" and "Out" at T4 on the PC hoard.The two cross-connections go to "X"and '"in'" Voila!

Because Q9 is the last part install ed.even after the PC board is mounted tothe top panel, provision must be madefor connecting it to the top side o f theboard. I used short "flea clips" as mo unt­ing posts at holes G. D, and S. Anythingsnug enough to remai n tight when re­heated will do the trick here. In ot herwords. you don't want the mount ingposts to come loose fro m the PC boardwhen you're attempting to solder theleads of Q9!

With the PC board complete. usc it asa template to mark its corner mountingholes on the inside of the top panel asshown in Photo B. The heat sink slabmentio ned earlier ru ns fro m beneath therectangular Q9 cutout to the area be­twee n Volume and RIT. Drill and tap a 6­32 mounting hole for Q9 's flange in thehcatsink. positioned so Q9 leads willbend and reach the PCB mounting posts.

mous 3 KW Antenna Tuner. . here is the fin est 3 KW tuner money can buy!

Super Heavy Duty BalunYou get a super heav)' duty cur­

rent balun for balanced lines. II hastwo giant 21/2 inch powder irontoroid cores and is wound withTeflon- wire connected to highvoltage ceramic feedthru insulators.It lets you operate hi$h power mrobalanced feedlines Without coresaturation or voltage breakdown.

Ceramic Antenna SwitchA two wafer 6 position u romic

antenna switch with extra large COIl­=Jtaetsgives you trouble free SWItching.$34995 Pius much.much mere

with this roller inductor. Cross-Needle Meter You also get a 300 walt dummyFinn springs put high MFJ·989C You get a lighted peak and load, full one year unconditionalpressure on a plated contac t wheel average reading Cross-Needle guarantee, flip stand. all aluminumfor e xcellent e lectr ical contac t. Swg/wenmeter with 200 and cabinet, lough baked on r aint.

Wide. low inductance straps 2000 walt ranges. Its new direc- locking compound on al nu ts andare used for high currents and a uonal coupler gives you accurate bolts, 3 KW PEP. 1(}J/. :\41Ju 15 in.new core minimizes RF loss. readin s from 1.810 30 MHz. Don', u nle/ or less. getJOurs todtl, !

MFJ's woIfyou won't settle for less .

The MFJ-98lX:' is not for everyone.However, if you make the

Investment. you'll gel the fi nest 3KW antenna tuner money can buy.

Here's why . .•Messlve Transmlttmg Capacitors

You gel lwo massive 25 0 pftransmitting variable capac itorswith detailed logging scales. Theycan handle amps of RF current andwithstand 6000 RF valls becausethe plates are smoothed and polish.ed and have e xtra wide spac ing.

Precision Roller InductorA precision roll er inductor. 3

digit turns counter and spinner knobgives you exact ind uctance controlfor absolute minimum SW R.

Rail bearings o n stee l shaftsgive you a velvet smooth vernierfeel and lon~ tenn durabili ty.

You won t have arcin ~ro:::b!~,~m~'~~;,;;;;;:;;;~~,::::":::":~:;,,,_,,,,:~~;;~::::,.r~~:"::'~=-""::::::":';':::::'~;':::::;~~::::;';:;::;;:!.;J

-,

•-=-.:---­

''- ' ,'.' ."~l ·· : · '

MFJ·945D

'99U~

, .'"''- -

• -0- .:--- .-..-

MFJ-92! or MFJ-924 Ie:' 5 ~ ... 116 9 1 1 , _ . .• ..., ....~v.. ~

Mf'J·921 covers 2 Metersl220 MHz, MFJ·924covers 440 MHz. s wgzwanrreter. 8x21/1ll3 in.Simple 2-knob luning for mobile or base.

MFJ's a..mcia/RF Grounde n-sits MFJ-9J I

artificial RF '7 9 95ground, Elimi- naresor reduces RF hot spots,RF feedback. TVlfRFI. ""weak si¥nals causedbl' ,poor Rf grounding. A soelectr ically places a far away RF ground direclly alyour rig by luning out reactance of connecting wire.

Nearest Dealer/O rders: 800·647-18002-l Ho u r FAX: (601) 323-6551

Technical Help: 800·641-TECH (8324)

MFJ Cala ME:JMFJ ENTERPRISES INC.ree og P. O. Box 494. Miss. Stale, MS39762

Write or cat! toll-free . . . 800-647.18(J(} <6!?1 )323-5869; 11-4:30CST, Mon­Fn .76206 .1 763Ocomllllserve.com; Add sIh

making quality affoi ;l;ib..tii'-~"" · '~"" · 'W$.m"......... ,~

._-,- -F.·"·"''C..'' . :'.';_. ,, : '"' -..:=.=- ' .

" ..-

MFJ.94IE The new MFJ-94IE gives you a 300' 10 9" watt PEP tuner with lighud Cross­

Needle Meter. Covers 1.8-30 MHl..Anten na switch selects 2coax lines (direct or thro

tuner), random wire, balanced line or external dummyload. 4: I balun. I (X)(} vol t capacitors.

2 Kn bD renti

Don'tleavehome withoutthis mobile

tuner! Le t the MFJ·94:5 D extend your antennabandwidth so you don't have to slop. go outside andadjust your mobile whip.

Small 8:\2x6 inches UM:S little room. LightedCross-Needle SWRlWattmeter with lamp switch.1.8-30 ~Ulz. 300watts PEP. Mobilt mou nt . MFJ-20.$4.95.

Mf'J-986 The MFJ-986lJifferential-T'"' 2 9 9 15 2 knob tuner uses a differential capacitor

10 make luning foolproof and easier thanever. It ends constant re-tuning with broadbandcoverage and gives y~u minimum SWR at only onebest setung. 3 KW PEP. 1.8-30 MHz.

Roller inductor makes luning smooth and easy.Turns counter lets you quickly re-tune to frequency.

Lighted Cross-Needle Meier reads SWRlforwardlrenectedfpeallaverage power in 2 ranges. Currentbalun reduces feedline radiauon and forces equalcurrents into unbalanced antennas.MFJ's mo&ile Tuner

• •

•

MFJ.

,MFJ-949E vtcre hams use the M~J-949E than113 9's any other antenna tuner In the world!

""'hy? Because you get provenreliabi lity, the ability to match j ust about anythingand a one year unconditional guarantee.

Yuu get a lighted peak and average readingCross-Needle SWR/wattmeter. antenna switch, 4:1balun for balanced lines. 1.8-30 MHz coverage andafullJ i lt! dummy load thateasily handles 30()wattsof abusive tune-up power.

:'IJtW8 position antenna switch lets youpre-tune into dummy load 10 minimize Q RM.

The inductor switch is designed fOf" high RFvoltages and currents-cit's TIOI a plastic switch madefor small signals and wired with tiny gauge wire.

Each MFJ-949E cabinet is chemically treatedand has a newtough scratch-proof vinyl cladding-- not paint that can scratch or chip off. You won'tfind a tougher. longer lasting fi nish anywhere.MFJ's "ersati/e 1.5 KW Tuner

MrJ -91i2C Use your barefoot fi g now and have'2 4 9 95 the capacity to add a 1.5 KW PEP

amplifier later! Lighted Cross-NeedleSWR/Wattmeter. 6 posi tion antenna switch.Trflon- wound balun. ceramic feed thru insulatorsfor balanced lines. 1.8-30 M Hz. ID-'/.x·Wn 14,/. in.

MFJ's porfalo/e/QRP TunerTUnts .C03x. ~FJ-97 1 ..=--:=...

balanced fines, 18 995 ~ N ,-'-' ,..,random wire 1.8. '~ .. .J \I ~ '"30 MHz. Cross-Needle Meter; _.-SWR, 301300 or 6 watt QRP ranges. 6x6111x211: in.

C6 .1 uFR17

R1,120 2

R18 10k

1202 ~h;~ ~L2 * -=- R16

I R14

1'2R114.7k

01PN2222

R410k

S2A

L."

DT

R484TO2

1N91 4

D4

C54 22 u F

"E,f J2 P'D.L7" 'Phones

R4710'ki

Volume

'T" co..1 uF~

L·"I

CO2100 pF

+24

02112

031C3S ~ 470

22UF+ ~ 2

R46 10k

s4 -:=C53

R45 1051 ;;F' .1 uF

Ul •LM386 ~ >;-1----'I(-;;g:E~

+12-R28C36 120

221')"1'-"-+ 2 '- I I R29 C38

AF 3.3k -. 1.1 uF

PreampG

C511rE 2.2 uF

2 •

-s- AF Power Amp.

021

.1 UF T

D34f-11N5226B

R202 .2k

112W

R30l OOk

R4410 2

+1 2 l--.......--,---r---,coo

C50 ~:::' ~ !:::'220 uF T T 22UF

-=- -=-. .

R43 100k

2M

".{"~V

.0015 uFMyl"

I-'w--iR10

C8..!:.lL 1k

22uFJ'

Notes: 1 • diMtes p artv81u e oanes \On1l1 ban d. See Tab le I2 •• WI·J leptesenl bale \Onr" lum pe rs nee ded .....1l1 1t>e 8ccomp."",ng pcb 1'I'Qut

1 BOI1l Og and U2 tequ". ahntilnk See ,e"(l and plloklgl aphs for dmole.

( ComPOntnl "'~"'llS Unlne epttllioro., rvSlS!O<1 aI' 1I( W, ll'l ll<1r(llojll t (iPi( lIO<'; are 35 V andctrilmiC dte~ capa<1IM$ .', , 00V.

R9

Q4PN2222

4.7k AI

R42

'Ok,"

R3S

220k

R332Tk

12T

l'aT

2N602TA

~"" C46

G K T·1 u F

- -~ ~

SidetoneR412M

Gen.

W2""

D111N52398

+24

9.111_"; T~F C1S ·W3 ""

""112W *"'- ,

4 17 1 sR27 10k 14 Vee G,d LD In G,d 18Mute In RF

"

C3 "f '

C59.;Oc.1 uF T 3 AF

. -b , OutC59

040. ' " T .luF.1 uF ~

R32 470k

C4622uF

Dl0 33 V1N4752A lW

~

1 I 21*13 14

(S) 8 <D 0 I+24 - Gnd. Ant.

1+12

R26 390 2

091N914

R241k

Built-inK.y

DutLI2

7812

"~'"~

. C4T220uF

\'N •

D9 1N4001

51

lBl I

J l CM .1 u F

:~D • +Ext.K.y R3.

Uk 12TC4' as.OO1 F

) : ) 2N3906R36

~ R37 +1} 4.7k10k

RITR2310 k .f

~R26 27k

Q5 't' l~TPN2222

RllOOk

Figure / . Full schema tic diagram of the SP·/O "Senior Spit/a "

1 2 73Amaleur Radio Today · January 1996

=.­---"5

Wefax ExplorerIntegrated Wefax I APT Receiver and Scan

Conve rter with Qfax software.

$695.00 co m p le t esbipping and taxes not included

Th e Best Price / Performanc e. Per iod!Constructa Wcfax I APTreceptionsystem from individual component receivers. scanconverters and image processing softwareand you 'll spend more money for fewer features. poorer performance, no au tomation and ajung le of wires. w i th the WefaxExplorer. s imply connect an antenna and a few mouse clicks later you' re receiving the highest quality images possible. TheExplorer is backed by a 1 year limited warranty and the extensive experience of the leading Wefax hardware manufacturer.Quorum equipment is used by virtual ly all wefax suppliers in worldwide amateur, commercial and military systems.

..-_ ...-~~ - -,

• Integrated Satellite visibility pre­d iction with automatic capture f orup to 8 satellites sim u/laneous/y

• A utomatic time and ephemerisstamping for navigation

• 2 7 day programmable schedulers

• A utomatic digital gain lock inAU~ modes, ru. clocking

QFAX Features• GOES / Meteosa/ We/ax Reception

• NOAA t Meteor A PT Reception

• HF Nafax Reception

• Dual RI'" ports for geosync and polarreception under software control

• Integrated preamp and down con­verter power inserters

• 50 user deftnab/e configurations

• Sof tware controlled receiver with 2UHf~ 10 VHF m emories and scan

• On board audio amplifier andspeaker with sof tware controlled vol­ume, squelch and mute

• A utomatic Unattended Animationworks continuously

• 8 bit data for up to 256 gray levels

• View at up to 1280 .r 1024256 color

• Use TIFF, GIF or PCX f de f orrnnlsand convert to BM/', JPEG, EPSand binary

• Contrast, Brightness, 3D effect,Sharpen, Smooth, Noise, Histo­grams and other image process ing

• Ephemeris based NOAA A PT navi­gation with geo-political and Lat­Lon overlays

• NOAA Tools sho w satellite path,IA1-Lon ofcursor, distance andbearing to reference paint

• A utomatic Temperature Calibration

• Color Palettes and NOAA curves

Quorum Communications, Inc. FA X( 2 1 ~) 915-112 711X311~ Esle rs Blvd.· Suite X511- Irving . Texas 751163 ( 2 1 ~) 915-11256 BBS ( 2 1 ~) 915-113~6

CIRCLE 257 ON READER SERVICE CARD

f 411.AMPR~n · 1110

, ..SPAOE UlG5 _

/

R R R R

T. 1tI'-4

Fig. 5. Terminating RF detector:

The ke y to a smooth . une vent ful tune­up is to do a careful job d uring

Gelling crystals is like order ing pizza.Unless you arc buying a stoc k or popularfrequency. they are tailor-made by amanu facturer upon receipt of an order.That 's why delivery can sometimes take2-3 weeks or more: yo u must allow fo rlead time! Some manu fact urers requirethe Y I specifications prov idcd in theParts List while others will do the j ob ifyo u merely order "amateur-gradecrystal" and speci fy the frequency.

If you ' re a No.... ice. don't crowd theedges of yo ur subband whe n orderingcrystals , unless you have the means toensure the crysta l you ' re us ing is " in­band ," The reason is. a gene ral purposeor amateur-grade crystal o rdered for.say, 7 102 kHz, may actually put out on7 100. It' s a matter o f manufacturing tol­erancc and circuit correlation. If indoubt. give band edges a wide berth.

construction. Having done yo ur best,let's see if it works! On the PCB. set R 19Bias and R42 Sidctone each tom idrange . Co nnect the po wer supply toTB I·I (+) and T B I-2 (-) and a 50-ohmdummy load with rela tive po wer meteror wattmeter in line to T B I-3 (coaxshield) and TB 1-4 (center conductor).Lacking this test eq uipment. bu ild thesi mple termi nating RF indicator sho wnin Fig . 5 and connect it 10 TB 1-3 andTB 1-4 . T his gizmo pro .... ides a suitableresistive load for low power transmittertesting, as well as a visua l (and ther­mal- it gets warm to hot!) indicator ofRF output.

Plug a speaker into 12. Insert a crystalinto the socket a nd select it with 52.Switch o n power with S l , dose the te le­graph key and adjust TI for maximumRF output indicati on. Adj ust R42 o n thePCB for desired stdctone level. Replacethe dummy load with an antenna or sig nalgenerator at the crystal frequency andadj ust C 23. 1'2. and T3 for best reception.

Tune-L'p

~TO"I1-2

3A

C +

4700 tJIr35Vrl7

C = RS272 - 1022

The operating freq ue ncy of the SP-IOis controlled by a single crystal in tran s­mit and receive. With crystals, you givcup the ability 10 wander (or dri frl )around the band in exchange for exce l­lent frequency stabili ty. intri nsic di alreadout (f requency is marked on thecrystal) and simplified project tune-up.requiring very li ttle test equipment. Forthe beginner. or the old-timer into "r adiokarma," crystal control is a toed way to go.

The actual crystal is a thin square ofquartz too fragi le and sensitive for directhandling , Rather, it is mou nted in aholder which. dependi ng on type, plugsinto a crystal socket or is wired d irect lyinto the equipment. T he octa l crysta lsoc ket on the SP- IO accepts two of thepopu lar FT· 24 3 holders. having a pinspacing of .486" and a pin diameter of.093." Types HC-17 and Petersen Z-9arc also co mpatible. In general. any fun­damental crystal with a freq uency in thechosen band wi ll work if you can adaptit to plug in. For example, c ....en the min­iature He - IS holder with leads insteado f pins may be wired to the base sal­vaged from an unneeded octal vacuumtube. which will then plug in.

Photo C. The SP- IO at WI angle.

C r ysla ls

fuse if po ssible and , i f a ll goes well, up­grade it to 2 or 3 amps for normal opera­tion . This conservative approach tofiring up new. untested equipment willminimize casualties should anything beanuss .

+24BR + f-----,.---- ... ~~--<> To TU1.1

AC

AC

SA = RS276 · 1171(4A, 100 PIV)

18 10 21VAC

120VAC

1A

A suitable power supply for the SP- IO,one supply ing 18 to 28 VDC at I amp.can be as sim ple a, a DC wall adapte r ora pair of 12V baucrics wired in se ries.There ' s no need for a fancy. elec troni­cally regu lated unit. Precise regu lation,where needed . is already supplied byU2 . The e xternal supply should. how­ever. be beefy enoug h to hold its o utput....o ltage within 20%, go ing from key-upto key-down . For example, a sourcemeasuring 25 vlJe should drop nolower than about 20 ....o lts when youclose the key. T he no-load input can beas high as 32 VDC: beyond that point.pro tection zencr D 10 may cond uct and ifit docs. it will probabl y short circuit inthe process o f protecting the 5 P- IO fromovervoltagc.

If yo u wish to bu ild a power supplyfrom scra tch, the classic transformer­rec tifier- fil le r arrangement shown inFig. 4 will work just fine. Regardl ess ofthe power supply you choose. be sure toprovide an inlinc fuse in the plus leadrun ning to T B I-I . Start o ff wi th a l -amp

:14 73 Amateur Radio Today · January 1996

Power Supply

Fo llow the photos to lay out and installthe remaining top panel parts. the posi­tioning of which is much less critic althan the need to keep Q9 cool.

Except for the sho rt ANT/GND andYI wires. connect the PC bo ard to toppanel compo ne nts as shown on the sche­matic diagram or parts o verlay. Hingethe 00an1 over and moun t it to the toppane l o n 5/8" metal spacers. and thenconnect the short wires to TB I and 5 2.C heck to ensure the copper side o f thePC board is not touching any panel com­po nents like potent iometers or j acks.Lastly. install Q9 to the heat sink using aheat conduct!....e insulator pad and 6-32Te flon or nylon screw or a TO-220 tran­sistor mour ning kit, to coup le the flangether mall y hut not e lectri cally to the heatsink slab.

Ftg• .,. sr-JUJIO'''''r j'III'PI.':

Fig. 1. PC Board foil pattern.

Some patience is called for with theantenna method; you may need to waitfor a sig nal strong enough to he heardthrough the as yet unpcakcd fron t end. Atemporary clip-lead jumper from the an­ode of D6 to the upper lead of C34 mayhelp by allowing yo u to get 1'2 and T3 inthe ballpark firs t. Then remove thej umper to peak C23 and touch up 1'2 andT3.

On the Air with the Slq O

Like all modem transceivers. the SP­10 prefers to see a 50-ohm antenna sys­tem with low SWR. The classichalf-wave dipole comes close 10 idealwithout the use of extra matching tech­niques. Other antennas like the G5RV orrandom wire will requ ire an antennatuner to provide an acceptable load. If

operation into a less than perfect matchis unavoidahle, it might he wise to re­duce the operati ng voltage from, say. 24VDC to 18 VDC . This will reduce theadverse effect (Q9 overheating) of asomewhat high SWR.

With its rather broad selec tivity. it canbe q uestionable whether or not signalsheard on the SP- IO are close enough toyour crystal frequency for a QSO. Thosethat decrease in pitch and approach zero­beat with RrT control moved fully co un-

terclockwise are very close . Others maybe workable if the operator tunes aroundfor yo ur sig nal.

Though 10 watts is considered lowpower, it' s right up there with the pop u­lar one-tube 6L6 transmitter (and cou nt­less variations) that propelled tens ofthousands of hams into the ether in their

early rad io careers. The receive sectionis certainly no worse (and probably bet­ter) than those "dn fty," broad-tuningsuperhet Novice receivers we once cher­ished and still remember fondly. Theydid the job! And on most any night theSP-IO can be your doorway into a won­derful world of Morse and static , face­less names. exotic places. and colorfulQSL cards-all the more e xciting whenyou build the rig yourself!

SP-IO Condensed Parts List

C I-C4, CII-CI2. C IS. C22. <::2..~~(see table: I )

C23 4·20 pJ' lrimmd. Muu.'Il.'I' 24AA022

C56, C57 0.OOI 5-llf MylarT..

Dl MV2104, ECG612

D2.[»..[)S IN9 14. RS 276- 11 22OJ J .JV.5WwIlTdiode(IN5226Rj

D9 IN-Il lJl . RS 276-1101DlO JJV 1W Z(IJlTdiOOe ( t l"475~j

0 11 9.1V .5W 2l:nC£diode (I~5239RJ

11 -12 J.5 nan cksed circuil mini phone jalt.

LJ·L6 (see table I)

QI. QJ-Q5 PN2222. ECG t23AP. RS 276·2(X)9Q2 2N2219A. ECG I2l'1. RS 276-2030Q6 ~WfI02. ECGJ I2. RS276-2O'">2

Q7 '):-wl27. ECG6·KJ2

Q8 2.....3'XX>. PN29lJ7A. F.cG159~ lRP.iJOR t9. R42 1(1( PC trim pOllTlUomel<;:r.

RS 271 -282R2J. R47 I(l:. audio taper pOlcrniol\ll.,tcr.

RS 271·1721

RR: I 22·IlH ~,...uy coaed,Mou'\ef 43LS275

lI -D ~~4!lF I 23

Tot 8 tlIr'm " 24 enamel ....-re, rrifilarwound (1Il (W() 1''1'50..0 (Amidon) CJ(~

TR 1 4-lug tenuinal board. Mou_o;cr 534-4tWUI L\B~Jlktio alllp. RS276- 173 t

U2 781 2 voltageregulator, RS276-177 1

UJ MC3359P\Circuil Specialists)

y t FWJdamentaI O)"lila!. SJll!Cify

desired £requeocy. parallel I 32-pf

1oad..005%IO~. tddtT type

Ff·243. HC-t71lJor equivalta

No te: C heck the ad verti sing inth is magaz ine for parts supp liers.For a free list o f parts sources fo rth is project. send th e author anSASE requestin g SP- IOLST. PCboa rd s a nd proj ect kit fo r the S P- IO" Senior Spider" are avai lable fromLcc trokit, 40 1 W. Bogart Rd .,Sand usky. O H 44870 (no te lephone) .

Continued on pagt> 17

73 Amateur Radio Today · lanuary 1996 15

Low Cost Switching PowerSupply For HF Transceivers

by Phil Salas AD5X1517 Creeks ide DriveRicha rdso n TX 75081

_ ....",- -t Lm

"'"

Fig. I, Switching power supply side \'it'w.

16 73Amateur Radio Today ' January 1996

well marked on the printed circuit board.along with an output voltage adjust potenri­ometer. So, first things fi rst--could I operatethe supply at 20 amps at 13,8 volts? I had a2{)...mnp load made up of twelve g-oranpower resistors. I connected a voltmeter andoscilloscope aL"l'OSS !he load which was at­ucbcd to the DC studs, soldered an AC lineconJ 10 the AC input pins and plugged it in,The output came right up to 12 volts! I nextadjusted ibc voltage adjust pot and easily got.13.8 volts! Final ly, I measured 15()...mV p-poutput voltage and 100mV p-p ripple on the

DC output at fullload with my oscilloscope.Now I nccdcd to make the power supply

uscrfriendly- I Jlee( kxJ to add a switch. fuse.indicator, line coed, and DC output cord to the

unit. This was pretty easy to do as the basicframe that the power supply is mounted inhas a number of small unused. hole'> in it. Ap­parently this chassisbase is used (ID a numberor different power supplies. Fig. I shows aside view of the powersupply with the coverI'L'IDJVOO and the components I added . On the.....718R

X 2_718M blank side of the sUWly, Idrilled out the two unused holes on the leftside (Sec Photo A) for a SPST IO-amp switch(Radio Shack RS 275-324 ), and an LED. Onthe hack. silk-screened side (See Photo B), Idrilled out one hole large enough to pass apairof #12 wires for the DC output. and onehole large enough to take a #8 screw for a

ground stud. The photogrJ.flh<; illustrate thisVL'T)' well.There is already a "halt-moon" cutout in the back that easily passes an AC linecord. On the inside of the power supply, Iwired an in-line fuse holder (with a 5-ampfuse) in series with one side of the AC line

cord and wired the line com to the s" itch andAC input pin.. on the printed circuit boerd, 1wired the LED with a 750-ohm series resistor

to the solder lugs on (he 12-volt studs. Next, Iattached #10 solder lugs to the # 12 wire thatpasses 001of the supply and then anacbcd the

"'..,.D D

A few days later the power supply arrived.It is a used Lambda LYS-W-12 power supplyrated at 20 amps continuous at 40 degrees C,18 amps at 50 degrees C. and 15 amps at 60degrees C. The input to the supply can be105-132 VAC at -t7--63 Hz.. or 130-160VOC. This power supply has no switches,fuses , connectors, or indicators. When I re­moved thc cover, I found that thc DC outputconnectors were # I0 studs on the PC board,and me AC inputs were just pins on the PCboard to solder a line coni to. Everything was

"This surplus treasure turnedinto a lO-amp switching powersupply that is smaller than a1'5-505, weighs less than sixpounds, and costs less than$60 total!"

switch ing power supply for only $.1.9. Thiswasa used Lambdapower supply lhal is9 R x4.-7/8" X 2_7/8R and hal a shipping weight ofonly six pounds. This seemed great. hut couldit be made to operate at 13.8-VOC output'!There was only one way to find out-so Iordered ore.

-...n

DC"'-[]JJ

Ihave been using a Ten-Tee 938

switching PJ....'er supply for sometime with my Kenwood TS-50S for por­

table operation. TIlls switching power supplyis very small. efficient. and lightweight (2.5pounds) and lets meoperatemyTS-50S at 50watts output continuously. However. for basestation LL'iC I wanted the full IOO-watl outputpower capability of the TS-50S. A full 2lI­amp linear powersupply weighs ibrec to fourtimes what the TS-5OS docs. and is two-to­three times larger than the TS-50S. It justdidn't seem right to have a power supply thatoverwhelmed theTS·.50S in size and weight.What I wanted was a small. lightweight

switcber with 2O-amp capability. Unforru­nately, no ore seems 10 make ibcsc at thistime for amateur usc. and commercialsw itcbcrsarc very expensive.Ob. what to do!

1, like manyof you. receive 101.0; ofcatalogsof surplus electronic stuff through thc mail.Many of ucsc catalogs list all kinds of OCpower supplies. roth new and used. My fa­verite surplus catalog... arc from Marlin P.Jones & Assccimes (407-s.m-S236). AllElectronics Corp. (818-904-0524), andHosfclt Electronics (8(X)...524.-646-l-). I re­cently noticed that Marlin P Jones & Associ­ates was advertising a 12-VOC 20-anlp

In #24

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Not used

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13Amaleur Radio TodaY 'January 199617

68 F

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Conlrol & User Codes & Timeouls

arts over ay.

C25, C31C26,C28C27 C29

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L6 Ff-37-6t

L3, L5 S0-2LA 50-2

E

2

3

1

Table 1 Band DataCom onent

The SP-10 "Senior Spider Conttnuedfrompage 15

Capacitors are lOOv ceramic disk type. For inductors, wind turns using the enamel wiregauge given on the toroid core specified.

SP-IOB BM, $ 16 ppd . US/CAN,include s bare PC board an d s te p-b y­step c onstruc t ion m an ua l. PC bo ardand parts ( inc lud ing band parts for80,40. 30 meters) , and c ase parts in­clud ing d rilled and tapped heat si nk .T he RS 27 0-232 case a nd c rys tal (s )a rc not inc luded but a m ail er fo rse nd ing in your top pan el fo r freem aster template marki ng (wi th metalwo rk o ption extra) is included. T hispricing is valid within four monthso f pub lica ti o n . Order direc t o r se ndan SASE for c urren t details. II

Photo A. Blank side.

WJ1~.!~:~GI~~n.s~~~m?• Elsily hi<ldeD-Install FISt · F,xod or I'onI blt ·

be..·• • 20 ·' , OX Poo<.looUt . io ,.... Y ) ;<.0.1_...p _ _ ) ., Bot ~ .....u OX_,....

__• _ -. . _,..6lt to-IO- XI ..•~Dr.2_ ' .. .,. ~,... . 1Oo<t.... ..,;,,- "'' '~..",.-..4 ':9..~

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Photo B. Back, silk-screened side.

_ lugs to the IX: OUIpUl #10 suds, The

IX: 0UIpUl is floating with respect to ground,SO anach a wire from the negative OC termi­nal to the ground pin on the printed circuitboard. Finally, I terminated the #12 wires onthe outside of the power supply with a 20­amp Radio Shack "Molex-rype" female coo­noctor (RS 274-154). The ground stud forlying into yoor station ground is a #8 screwwith the screw head mounted inside thepower supply. Usc lock washers inside andout, and a #8 nut on the outside to hold it inplace. I used a #8 wing nut and two#8 washers lO make an easy-connectground stud.

That's it This surplus treasure twned into a2O-amp switching power supply that issmaller than a TS-505. weighs less than sixpounds, and costs less than $60 total!And, itis perfect for both base station and portableusc. Since this is a surplus power supply, itwill probably show up from time to timein different surplus catalogs. So. keep youreyes out for this or similar power supplies.These commercially rated switchingpower supplies are real treasures and arcadjustable for amateur n .B-volt OCpower req uirements . flI

Simple Mobile ProtectionSafely ward off those evil spikes.

L. VanProoyen K8KWD8330 Myers Lake NE

Rockford MI 49341

Radiopowercable

---------- -I.::'c-- '

r ye seen similar relays for sale at autoaccessory shops a.s hom -relay replace­ments. The relay's contacts should berated for at least 50% more current thanthe specified maximu m current of yourrad io, and the relay should he a scaledtype (no sparks).

The power control relay must be wellsecured to the vehicle. The relay andfuse block should be screw-anchoredto the ins ide wheel-well cowling orso me o ther su itab le surface near thevehicle 's battery, Locating a place canbe a challenge in some feature-packedcars. A vehic le 's engine compartment isno place for loose items. Also. check outwhat you might be drill ing into beforedrilling.

M an y vehicles use batt e r ies wi thside co nnec t ion lu g s. I' ve seen some" interes ting" wi ri ng techniques done

5k

22k

Battery +...r ~ - - - --- -- - ,,cRelay & ,: fuse block :, under hood I

12 Volts from ' .......... _ '--- ~. • , 0 I~"ignition switch .. • ---I', :

1k h- -' :JVV\r~ :

-----+-- 1N4001

1500 ~F -Ii­16 V 1- - 4- - - --..::::=r

to the battery. Thi s is part icu larly impor­tant with 1OO-wall class radios. whichuse a lot of current. Also. many manu­facturers recommend shutting your rigo ff whe n start ing the car's engine. That'sbecause radios can be intole rant of ir­regular ities in the ir power source. Thestarting process can produce deep sagsin the vehicle's supply voltage and highamplitude spikes, which could zap yo urradio .

To meet my first need (d irect batteryco nnection), I used a relay mounted inmy en gine compartment near the battery(Photo A ). Use o f a relay is a legitimatemethod o f connecting power to a radio .The relay I used is one commonly usedin mobile two-way radio installations. Igo t it. together with a fuse block, from alocal two-way shop. It can handle 30amps continuously and has an oo-ohm coil.

Because o f my forge tful nature. I likeit when everyt hing turns off when l rc­mo....c the ignition key. Achieving totalkey shutoff can be co mplicated sincemost manufacturers recommend co n­necting the radio' s power cable di rectl y

The Ignition Key Control Solution

Iconsider a "good" mobile rad io in

stallarion one thai is unobtrusive.With the variety of radios with de­

tachable control panels. it's fairly easy togo mobile witho ut having your car' s in­terior resembling something like thespace shuttle 's cockpit.

As a further aid in achieving an unob­trusive installa tion. many vehi cles in­clude one or more blank DIN panels onthe dashboard. sized perfectly for instal­lation cf many of the detachable contro lpanels. I know of one instance where aham was ahle to install an entireKenwood TS·7-t l in place of such apanel. and when he completed the instal­lation it looked like a factory originaloption .

I have one problem with unob trusiveinstallations. though.Unobtrusive meansnot noticeable. which means I can forgetto shut my rad io off whe n leavin g: mycar, Even those "wheat grain" bulbs cankill a buttery. given enough time.

Pheto A.. Typical control relay and fuseblock suitable for use lfitll IOO-lI"att mobileradios. Fig. 1. Tile on-delav timer circuit.

18 73Amareur RadiO Today · January 1996

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73 Amateur Radio Today· January 1996 19

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"+

Photo C. Modified "blade -type" fuse usefulin connecting to a car s key-switch circuit.

While on the subject of fuses, ifthere's a rule to consider above all oth­ers, it 's fuse everything! Don't underes­timate the dangerous potentials of anautomobile's electrical system becauseof its low voltage. A car's battery is apowerful energy store that can produceexplosions, fire, and bodily harm, if nottreated with respect.

Special consideration should alwaysbe given to vehicle wiring. From a gen­eral safety standpoint there should neverbe any loose wires. Wiring in an enginecompartment should be routed to beclear of any potential hot spots, e .g. ex­haust manifolds, etc. Locations nearfans , pu lleys, and belts, should also beavoided. After locating a safe path forrunning wires in the engine compart­ment, the wires should be tied downusing cable tics .

The rad io 's controls should be locatedsuch that you do not have to take youreyes off the road to operate the rad io.

Safe mobBing, everybody! .II

tinker too much with the resistor valuesas they were selec ted to produce theproper base-emitter current flow. Notethat I used a lk-ohm resistor in serieswith the 2N3904's collector. This resis­tor limits the MPSU-lO's base-emittercurrent, and it also serves to keep the2N3094's collector current withinproper limits.

I mounted my entire assembly inside asmall snap- tight plastic box and drilledholes for the wires. The only connec­tions necessary are the source of key­switched +12 volts, ground, and therelay coil re turn.

Connecting to the Vehicle's KeyCircuit

A convenient method I've used to pickup key-switched +12 volts is by using amodified "blade" type fuse (Photo C)and inserting it into an unused slot in thevehicle's fuse block. Most newer ve­hicles use this type of fuse, and I canusually find an unused spot in the fuseblock that is key-switched.

In the event there is no available slotfor the fuse, you can substitute a modi­fied fuse for an existing fuse, e .g. the ra­dio fuse, but if you do I wouldrecommend modifying a fuse that israted correctly, not the 20-amp one Iused, The judicious use of fuses is veryimportant when doing automobile wir­ing (note the in-line fuse I use with mymodi fied blade fuse) . I used a l-ampfuse in the line to my delay timer circuitand power control relay.

One note of caution if you decide toreplace the broadcast rad io's fuse: Mynewest car has a factory radio that'sequipped with a password-protectedtheft-deterrent feature. If this radio isdisconnected from battery power with­out defeating this protection scheme, theradio will become totally use less whenreconnected. I'm told not even Delcocan help if you tum this feature ofT. Itwould be wise to check with yo ur dealerto find out if yo u may have such a radioprior to disconnecting it!

" The judicious use offu sesis very important when doingautomobile wiring (note thein-line fuse I use with mymodified blade fuse) ."

Photo B. The on-delay timer constructiondetails .20 73 Amateur Radio Today · January 1996

An On-Delay Circuit

A simple method of controlling thepower relay circuit would be to tap intothe car's accessory circuit, such as at thecar radio's fuse . Most vehicles are wiredso that the rad io's power turns off whenyou're starting . While this works O K, Idid n' t like power coming on. droppingout, then coming back on again, so I de­cided to use a delay circuit that wouldkeep the power relay from energizing fora few seconds after key-on.

After failing to make somethingsimple using a 555 timer IC, I se ttled onthe circuit shown in Fig . I. I used twotransistors I had available because Ineeded a combi nation of a relativelyhigh RC time constant circuit that limitedthe base current, together with high currentswitching. You could probably substitutea single, high-gain Darlington-type deviceand get the same results.

Using the values shown, the circuitprovides about 10 seconds delay beforethe relay pulls in. I built the circuit on asmall piece of perf board, as shown inPhoto B. The circuit layout is not criti­cal, although it should be built to fitsome type of enclosure that can be se­cured to the vehicle somewhere out ofthe way, like up under the dash .

I used a 1,S()(}..J!F capacitor as thebasic time-delay clement. It chargesthrough a 22k-ohm resistor until the2N3904 is forward biased and conducts,thereby switching the MPSU-lO on . Ifyou want to change the time delay,substitute other capaci tor values. Don't

when trying to connect a radio cable tothis type of battery. Most auto accessorystores carry an adapter block for con­necting auxiliary wires to such batteries;I recommend using one.

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Going PublicPut a different kind ofham on the screen!

Jeff Brane WB2JNA108 Shiley 51. ApI. B

Annapolis MD 21401

We need to make the public IncKe

aware of what we do. As ham{IPL'r..l(OI'S, wecould benefit much

by enhancing the public's knowledge of ourhoOby.l1lc rewards wouldbe great. We couldgain opcralors and have mxc influence in thework!. The pn.."\li~'C we acquired wockt giveus p ower; expan d our possibilities. andmaybe even help us get better tables at rcstau­rants. In the J1'l<;1 1 have mentioned 10 hcad­wa iters mal I was a ham. hul it did me littlegood, although I knew that they were im­pressed because they did that thing thatpeople do when they're trying to hide theirbeing impressed. Their eyes glazed 0\,(.'1" andthey looked borcd l wasn't fooled by thaI. but

I was still disappointed with my table. Thinkabout this: We harm; have a very excitinghotlhy. We handle emergency messages in di­s astcrs: we communicate with people alloverthe world; we funhcr good imcrnational relu­tiun.,:and we usc solder!What wedo is fasci­naung. yet relatively little is known about ushy non-hams. Why? In a \\i(lfd: popularculture.

Americans love their TV and movies. andwe hamsjust haven' t bccnexposed enough intbee avCt1l1CS. I believe that in the 1V pro­gram "Alf," wille.tbc fathc...., is a ham. andin "Tbc Simpsons," one of Marge's sisters isaham, as is H:U1'Ssch oolmate who cal ls him­sell: awrupriatcly, "Ham" (the hoy is kind ofa nerd. which really doesn't help us). Radiocommunications plays a pan of rn:N every<L"l..'P sea sub marine movie. 00t that's onlytangential publicity for us. Ido rcmcmbc.... lhatin the Mel Gibson IiIm "The Man Without aFace:' a1x"lll1 a deformed, lonely ex-scbool­teacher, I 1,I.'a.<; sure thaI Isaw SOU IC QSLcardson the wall of his character's hou.\C. Still,tbcse are small victories. If we are to hreakinto (he public's mind. it's going to have to heby our O ....-n band, or, as I shall expla in, pen.

Tbc solution is simple: Write the veh icleourselves. We need to write lhc SI.:Il.'eIl. play IXTV :J1ow uuu will give us the notoriety we sodeserve. With thar in mind, I have come upwith some ideas fix just that exact movie orTV program that will do lhc joh. And yes, Iwill remember all the little peop le thaJ: I meton the way to the I(fl.

22 73Amaleur Radio Today- January 1996

First, I JXUP.-lSC a TV situation comedy.America loves them. and the right ones cap­ture the imagination of tbc whole country.Mine is a delightful , family-oriented comedyabout Merconi- I call it "Dam thatGugfclrrotv ln it. Marconi is an average-guybrilliant inventor just trying to make endsmeet and keep his family happy. I envision{me episode where his wile is out of town andhe has to make dinner for his two childrenand his iocgh old boss, Mr. Prendergast. Theusual comic machinations ensue: Marconilets the r ice boil over, he pUL<; too much soapin the laundry, and hediscovers wireless radioand forever changes the face of communica­lions. Also, I think somcihing really funnycould happen with scm: spaghetti, trough Ihaven't worked oet the delails on that one.

I'd like to secTony Danza in the title role­he's funny, he's likable, and he's Italian. Ithink this show would he very popular withhrillianl European inventors living in NewEngland and the Canadian Maritime Prov­inces. I've heard that is a very impooantmarket group.

My next idea is exciting because, at last.we have a "ham radio hero" in a feature filmIt corcers a comhination ham and martialarts expert who specializes in CW opearing. Icall it "MOI".)C Code of Vengeance." As ayoung child. he was very shy and had diffi­culty talking with others. He finds himselfthmugh two pursuits:CW ham operanng. be­cause it allows him 10 overcome his fear ofspeaking up; and martial arts. because it al­lows him to break things. As he matures, heblends the rhythms of self defense move­ments with the rhyihm of Cw. Later, he iscalled on by his government to break up aninternational ring of electronic equ ipmentthieves. This film has everything: action. 00­venture, romance. and electronic kcyers. Inthe final scene the hero, and a small group ofelite commandos. dressed in green militaryfatigues and callsign baseball caps. infiltratethecriminal's lair while theycommunicareonHls.As thc hero confronts the head thief in afinal showdown, the hem dramatical ly chal­lcngcs his fcc with "C 'rron baby, let's QSO."

I'd like to 00d that there's 00 reason whythe hero in this film can't he a WOO1aJl, with

very few plot. changes necessary, Use of a fe­male hero may make the film even morepopular, although ito; name should bechanged. Some suggestions arc "Velvet Fistof Revenge" or "YL: This Tnre It'sPersonal."

Made-for-TV moves have a large follow­ing, and we could certainly tap into this mar­ket My idea is a steamy romance called ' 'CQfor Desire." It has deep emotional conflicts,searing passions. and radio equipment EddieR ibalski. a rough-edged longshoreman hamin Galveston, TX, uses the legal limit of out­put power and wouldn't think of operatingwithout his linear amplifier turned on. Heloves his loyal wife, Linda, and everything isfine until be nX'CIS Heather Arnold. a eateerwoman who has risen to the top of the break­fast cereal buying industry and operates onlylow power. Initially, Eddiehates her, but theygradually become friends until that climacticnight when he takes her into his shack and letsher operate his rig. She is intoxicated by thepower and can't get enough of it He isthrilled by his intlucnce over her and lets heroperate whenever they can meet. They knowit's wrong, but they can't stop. Finally,Eddie's wife fmds out and confronts himabout the relationship. He vows 10 break itofT, and Eddie and Heather meet later on awindy hilltop, right next to Eddie's antennatower. They say good-bye, and Heather tellshim, ..It WOolS 100 much. far too much foreitherof us to control, rot a little bitof)UI will be inmy fccdIine forever;"

I know what you all must be thinking:"How can I come up with brilliant conceptslike these'!' I mustadmit. I have a lot. of idcas,so many ttwr. it's kind of scary. Actually, myfriends call it "disturbing," but yoo see mypoint. However, you can have lots of fun get­ting ham radio into the mainstream in otherways. Gel involved in a special events dem­onsuation station. teach a class in radio, showa friend or reigbboe yoor rig, orjust Ict yoornatural enthusiasm show as yoo describeyour hobby to your friends or co-workers. Ifyou find yourself getting really carried away,take a deep breath and repeat quietly "Boy,this is fun: '

Please, don', steal any of tbese ideas, III

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In the spring of 1983 I was browsingthrough the Allegheny College Library and found a hook titled Prodigal

Genius, The Life ofNik.ola Testa by John J.O'Neill (19M). I had known about TesJaand his famous coil from my high schooldays 40 years earlier. but this was my firstopportunity 10 learn more about the manwhose coil made fascinating sparks. Re­grettably. his coil was the sorrowful extentof my knowledge of Testa. and likely it isas much us most people know, if indeedthey recognize his name at all.

The first two pages of O 'Neill 's biogra­phy are powerful.After more than 12 yearsI can't forget his words. In short, I deem ita book of epic proportion, When I lookedat the inside of the back cover, I wasamazed to find that the hook had beentaken out only eight times in the past 38years. How could this be? Was I overesti­mating the importance of ito; message'! Ididn't think so, and I still don't

The same can be said for the next Teslabiography I discovered, Te.\1a, Mall Our oflime by Margaret Cheney (1981). h has apowerful iruroduction by Leland Ander­son, our country's foremost authori ty onTesla. It is by far the most completelydocumented hook available tod ay onTesla.

Class Hero

I had been teaching English Composi­tion and my first thought was. "How inter­esting il might be for my students 10 learnthe story of Tcsla's life-it just might helpme breathe some fire into Lheir writing."TIle more I read, the more I was able toimpart to my students, and the more theybecame inflamed with cnthusiasm-c-notonly for writing but for a desire to wave'Iesla's banner. II seemed .....c had discov­ered a secret. if nOI an outright Oaw in his­tory. Why wax it that so few people had24 73 Amateur RadiO Today · January 1996

Tesla:Bust The Smithsonian

ever heard of Tesla? We decided to writeletter stories to people and tell them aboutour discovery.

At first. and without realizing it, Teslahad become our class hero, and my stu­dents now became excited about writing.We developed a mission-e-re tell as manypeople a." possible about Tesla. 1was revel­ing at the writing successes in my classes.so I continued this activity withsucceeding classes for se....eral years.

One school year, 1986-87, was particu­larly exciting. Someone brought 10 our at­tention an interesting situation that existedin Madison, Wisconsin. We learned thatseveral years earlier someone had namedstreets after famous scientists, includingTesla and Marconi. Tbe city fathersspelled "MARCONI" correctly, but some­how they had misspelled Tesla's name as'IElSA,. on their street sign. We alsolearned that a University of Wisconsinprofessor and chairman of the History De­partment had petitioned Madison officials tocorrect the spelling of 'Icsla's name, bet hispleas to City Council were rejected repeat­edly until he finally abandoned his crusade.

Num~r 24 on your FHdtulr;k card

John W. Wagner,W8AHB3890 Tubbs Road

Ann Arbor M148103-9437

This was exactly the sort of challengemy students wanted and needed. We bom­barded Madison with leiters to City Coun­cil. the newspaper, residents on "TELSA"Street, Lhe mayor, and even the mayor 'swife, chiding them to correct Tesla's mis­spelled name. We argued, "After all, Teslawas an honored American citizen whogave much 10 Lhe world;" and, "Howwould they like to sec Washington's namespelled incorrectly on street signs?" Thedispute raged for months and our storymade the front page ofthc Wisconsin StateJournal . One council member was par­ticularly distraught over the issue. Hecalled one day and begged in so manywords that we "get off their hacks." We re­fused to relent because we knew we hadtruth on our side. Five months later we rc­ccived a letter from the City Clerk advis­ing us they had corrected Lhe street signs.This was confirmed later by a photographone of my students took while travelingthere.

One Saturday morning two years latermy doorbell rang. It was a former studentand her father. She told me that for the pastthree years she had not forgotten our Testastory. It had made such an impression onher that she had persuaded hcr father, anaccomplished sculptor, to render a Teslabust for our cla...s.; that is, if this wassomething I really wanted. It took about amicrosecond fo r me to agree to Lheir gen.emus offer. They explained that I wouldhave to pay for the materials, but therewould be no charge for the work. I was ec­static and many thoughts ran Lhrough myhead. We could put the bust in ourclassroom,or perhaps donate it to sorre museum.

When the clay model took better shapeand I could sec how magnificent it reallywas, the sculptor asked what preference Ihad for thc final cast. We decided onbronze. We also decided on a granite baseand a bronze plaque telling of Tesla's

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eminence in the field of electrical science.I worked for weeks at my computer key­board composing various inscriptions forthe plaque and consulting MargaretCheney and Leland Anderson forguidance. Finally, I decided to use thefollowing inscription:

NIKOLATESLA1856- 1943

HIS NAME MARKS AN EPOCHIN A SINGLE BURST OF

INVENTION HE CREATED THEPOLYPHASEALTERNATING CUR­RENT SYSTEM OF MOTORS AND

GENERATORS THAT POWERS OURWORLD. HE GAVE US EVERY

ESSENTIAL OF RADIO, AND LAIDTHE FOUNDATION FOR MUCH OF

TODAY'S TECHNOLOGY.There will probably be several readers

who might wish that I had said somethingelse on this plaque. Nevertheless, thesewere 'Iesla' s greatest achievements.

Placing the Bw.1

My youngest son told me about a bandin California named TEStA that might beinterested in contributing to our campaign.I wrote to them. In a few weeks theirdrummer and a guitar player respondedpersonally with a check for $1,800. In ad­dition, we wrote to dozens of CEOs ofpower companies and large corponnions.Many responded with checks of $50 to$100. It seemed we were making realprogress because many people in high po­sitions were sympathetic to our message.

As we struggled deciding where to placeour bust, someone suggested the HenryFord Museum in Dearborn . They have anentire section of their museum devoted tothe history of electrical science. We be­lieved they would welcome with openarms a bust of this caliber for their display.

When I drove to Dearborn to conferwith their head curator, I showed him alarge fulJ ..color photograph of our bust andtold him our story about how it came intobeing. Then. on behalf of my students, Ioffered the bust fully expecting that hewould accept it. After all, the bust wasmagnificent and had an appraised value of$6,000. I was struck dumb when he re­fused our offer. It was simply beyond mycomprehension that such a prestigious rnu­scum would refuse to accept and displaythe bust of America 's greatest inventor inelectrical science. As I left the building,admittedly dazed, I noticed a huge modelof the Statue of Liberty featuri ng an

26 73 Amateur Radio Today · Janu ary 1996

Edison display. Tbc theme was a celebra­tion of Edison for making possible theelectrical energy needed to illuminate ournational monument. It was apparent ACpower was celebrated rather than Edison'sincandescent lamp.

As I walked out the door I looked hack.and there above the eruryway I saw an in­scription I had apparently missed when If irs t entered. It read, 'The Edison Insti­tute." Now everything suddenly fi t intoplace. Edison and Ford were close friends,and it was reasonable to expect the Fordcompany would continue to celebrateEdison's name. I thought, 'There mustcertainly be other museums that would nothave this kind of bias," so J visited the Chi­cago Museum of Science and Industry. Iconcluded it was nothing more than a ha­ven for commercial displays-c-certainlynothing to compare with. say, the TorontoScience Museum. Canada was out of thequestion though because we wanted tokeep the bust in this country.

Finally someone suggested we go to thetop----to the most august institution of thcmall, the Smithsonian. It is the one place in

" It was simply beyond mycomprehension that such aprestigious museum wouldrefuse to accept and displaythe bust of America sgreatestinventor ill electrical science."

our country where only the greatest havetheir places in history preservedforever...men such a.. George w ashington.Thomas Jefferson and Joseph Henry. Ccr­tainly their officials would understand andappreciate Tesla's stature.

I reasoned they probably had alreadyrecognized Tcsla's accomplishments andmight have a bust, so Idecided to travel toWashington in 1988 to visit theSmithsonian's National Museum ofAmerican History. I had visions of seeingnothing but the grandest of sculptures andextensi ve displays. Upon arriving I discov­ered that the electrical section was closedfor renovation. When I explained to offl ­cials my purpose of coming to Washing­ton. I was treated to a personal tour of theirarchives by none other than the curator'sassistant. He gave me a book descr ibingtheir displays, but I was also able to sec apart of the museum that was not open tothe public. There were numerous busts,but none were so great as to make our bust

seem inferior. Therefore. I saw no reasonwhy the museum could possibly refuse tt. Jreturned to Ann Arbor with the book undermy ann and feeling as if my trip had beena success. All that remained was to makeour fonnal offer and our project would befinished.

When the bust was finished, one of mystudents volunteered to write to the mu­seum. In a few days we received a replyfrom Dr. Bernard S. Finn, curator of theDivision of Electricity and Modem Phys­ics. He did not want the bust! My stude ntswere devastated, and again I was struckdumb. He explained they 'almost nevercollect busts in their Division.' Later. afriend who had visited the museum andtaken photographs sent me one revealingthat Dr. Finn was displaying Edison's bustnext to Tesla's first AC motor/generator.Tesla's U.S. patent number appeared onthe motor/generator, but the display wasarranged in such a way as to give credit 10

Edison. Needless to say. I was astonished.Further investigation revealed we were

not the fi rst group pressuring Dr. Finn torecognize Tesla. Several years earlier acongressman had chided Finn to create aTesla display. The display prepared by Dr.Finn consisted of a small glass showcasehousing a few insignificant personal arti­facts. The showcase was placed in a dark­ened hallway next to the men's room.while the main gallery was devoted to anelaborate Edison display.

By this time I had thoroughly read Dr.Finn's book, Lighting a Revolution. givento me by finn 's assistant when I visited themuseum. My fi rst 73 AmaJeur Radio To­day article (December 19(5) describesFinn's section tilled. '''The Beginning ofthe Electrical Age," naming 43 contribu­tors to the science of electricity. Tesla'sname was omitted! This was particularlydisturbing because, in describing theNiagara Falls Power Project, Dr. Finn aj­

luded to Edison's genius [hat made theNiagara project possible : "When theNiagara Falls power station began opcrat­ing in 1895, it signaled the final major actin the revolutionary drama that began inMenlo Park in the fall of 1879." In otherwords, in 1879 Ediso n invented DC elec­tricity! Then, in 1895. he invented AC and

harnessed Niagara Falls! The historicaltruth of this episode is that Edison foughtthe rise of AC and played no role whateverin the Niagara Falls power projec t. An ac­knowledgment on the inside of the bookrevealed that its funding was made

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possible by the Thomas Alva EdisonFoundation. I wondered if Dr. Finn's de­piction of electrical history was highly bi­ascd toward Edison because funding torthe book came from the EdisonFoundation?

In Science,Vol. 2~5. July - Sept 1989.p.768. a book review titled ""TIle RealEdison, The Making of an Inventor," byReese V. Jenkins cr al.. Eds. JohnsHopkins University Press. Baltimore.1989. carries a most revealing observation:"This volume renders untenable the popu­lar view of Edison as a Mcrlinesquc figurewho wrestles with mysterious forces andsingle-bandcdly conjures up stunninginventions: '

My daughter teaches physics and chcm­istry at a nearby university. l asked her to

involve her physics students in my cam­paign. They wrote numerous letters to thesecretary of the Smithsonian besieginghim to accept our bust. All responses werenegative because the Secretary was deter­mined to back Finn's personal bias towardEdison. amounting to the virtual exclusionof Tesla.

One of my students suggested we rnakcpromotional T-shins and sweatshirts tosell. We decided to PUIa picture ofour buston the front. My wife. who is usually notvocal. suggested we use the caption."BUST THE SMITHSONIAN:' We en­gaged an artist to create a seven-color li ke­ness of Tesla includi ng several symbolicfigures representing highlights in his li fefor the hack of thc shirts. The artwork andsilk-screening would be complex and wecould fi nd only one firm in Ann Arbor ahleto do the work. The end product was mag­nificent! We sold hundreds of shirts innearly every slate. the proceeds going intoa chari table account for two additionalbusts soon to be cast .

My next move was to write to U.S.Senator Carl Levin from Michigan. askingif he could exercise some of his politicalclout on the Smithsonian. Several leucrswere exchanged. bUI they had no apparenteffect. Then. in one final effort, SenatorLevin. on July 10, 19lXl. stood on the floorof the U.S. Senate and delivered a scorch­ing account of the Smithsonian's historicaldebacle regarding Tesla (CongressionalRecord, 'kI1. 136. No. 86): .....Nikola Teslahas not been grunted his proper place inhistory. In the Smithsonian Institution. forexample. Mr. Edison's inventions are justi­fiably well represented. However; al­though the museum has included Mr.Tesla's alternati ng CUTTCnt generators in28 73 Amatevr Radio Today·January 1996

their exhibit. no mention is made of Mr.Tcsla. In fact the generator is included aspart of the Edison exhibit:'

At this time several Michigan newspa­per articles telling our story appeared inDetroit and locally. Later. an AssociatedPress writer put the story in newspapersthroughout the country. I even receivedone report the article was seen in a HongKong newspaper. All thi s publicity had noelTect on Smithsonian policy. However.the secretary finally promised to have Dr.Finn create a significant Tesla display in1993. Their plan was to commemorate thehundredth anniversary of the ColumbianExposition in Chicago. This was the firstWorld's Fair. brilliantly lit by electricity-c­thc same AC that powers the world today,made practical by Tesla's genius.

"If, 01/ the other hand, a clubor perhaps some students readthis story and want to becomeinvolved; either by radio or 0 1/

the lnternet, they could maketheir feelings known."

I sensed that the secretary was only buy­ing time and that some excuse would hefound not to give Testa his due. It was notlong before my apprehension became real­ity. Dr. Finn was relying on obtaining afew Testa arti facts held in a Yugoslavianmuseum. Soon thereafter the war in Yugo­slavia erupted. Now Dr. Finn uses the waras an excuse not to create a Tesla display.The Yugoslavian museum items he deemsso important for his proposed display areonly insignificant artifacts...a suit of cloth­ing. a cane. a pair of shoes. a suitcase. etc.Obviously. the puhlic would not relatethese items to Tesla's greatest contribu­tions-his rotating magnetic field prin­ciple and his basic four-tuned circuitforming the necessary element of radio.Dr. Finn's plan is to explain Testa as an ec­centric loner who remained outside thearena of mainstream academe and indus­try. Would not science history he betterserved if hc highlighted and paid tribute toTesta's greatest contributions? These fun­damental discoveries serve as the founda­tion for our two most importantindustncs-c-powcr and communication.

It was Hans Christian Oersted discover­ing electromagn etism in 1820. followedby Michael Faraday making the first elec­tromagnetic generator in UB I. that reallyopened the age of electric power. Tcsla's

rotating magnetic field pri nciple indeed"signaled the final major act in the revolu­tionary drama"c.. but that drama beganwith Oersted and Faraday. not with Edisonat Menlo Park !

How to Protest

The Smithsonian was criticized severelyrecently. and rightly so, by veterans groupsand others for their wrongful depiction ofhistory regarding the bombing ofHiroshima and Nagasaki. The outcry wasso loud that Smithsonian officials had tomodify their Enola Gay display. I see litt ledifference in the historical bias theSmithsonian shows against Tesla and thenonsensical bias they preferred regardingthe Hiroshima and Nagasaki bombing. Ofcourse the main difference in these dis­pules is that 'Iesla does not have large seg­rrcnts of the general public complaining toSmithsonian officials.

When Wayne Green asked me to write asecond article for 73 Amatellr Radio To­day. I wondered who in the amateur com­munity really cares anything about Teslaor the Smithsonian's depiction ofelectricalhistory. I also wondered what I might ex­pect to accomplish hy writing a second ar­ticle . The logical answer to that questionis. "probably nothing," because amateurscomprise a small group...certainly noteven close to the size ofa national veteransgroup. Therefore, I cannot expect a largeoutcry of protest to the Smi thsonian. If, onthe other hand. a club or perhaps some stu­dents read this story and want to becomeinvolved. either by radio or on the Internet.they could make their feel ings known.

Unfortunately. the Smithsonian is a p0­

lineal organization. much the same asmany other groups in Washington-t.hcyblow in the direc tion of the wind. I believethe wi nd has been blowing for too long inEdison's direction. particularly in regard tohis entrepreneurial cxperiment with IX:'power, I want to Sl.'C credit given wherecredit is due...to Tesla for hi s polyphaseAC system...the system that works.

The History of Technology faction thathas emerged in recent years has subvertedour national museum and converted it intoan advertising medium promoting specificindustries that support them fi nancially.Also. the group that has assumed power atthe Smithsonian is methodically disman­tling and converting our national museuminto an instrument for social change. Whatwas once a tribute 10 America is gradually

Continued on page 30

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73 Amateur RadiO Today . January 1996 29

Tesla:Continued from page 28

being transformed into an assault onAmerican history. I strongly suspectthese issues were not even imagined byMr. James Smithson. a genteel and eru­dite Englishman. when he bequeathedhis estate to the government of theUnited States to establish theSmithsonian "for the increase and diffu­sion of knowledge." Smithson was a

scientist and man of letters. not a socialactivist. He undoubtedly envisioned amuseum that celebrated creativity ratherthan entrepreneurship, and tasteful dis­plays depicting an accurate account ofour society's accomplishments ratherthan focusing on its problems.

One way of changing the directionthat the Smithsonian has been heading isby voicing strong opposition to its head :Mr. Ira Michael Heyman, Secretary,

Smithsonian Institution,Washington,D.C. 20560

Much of the change in focus at theSmithsonian started with its formerhead, Secretary Robert McCormickAdams who retired in 1994. It appearsthat Secretary Heyman intends to con­tinue the course started by Mr. Adams. Ifany readers feel obliged to write to Sec­retary Heyman, I would be pleased toreceive a copy of your letter. II

Telephone FlasherDon 't miss any more phone calls.

Chet Garrison wszzs3544 E. Dayton Avenue

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so, you're at your rig with the earphones on and working somegood OX when the telephone

rings. You don' t hear it and it is yourwife at the beauty parlor and she needs aride home. Boy! Are you in trouble!

It you had built the circuit In this ar­ticle, it could have saved you from thedog house. Th is circuit, when connectedto AC and the telephone line, will flash alight every time the phone rings. Of

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Parts list

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course you must have a phone outlet inyour shack. Doesn't everyone?

The c ircuit is d irt simple and canbe hard-wired or you can use the PCboard accompanyi ng thi s article . Allthe parts can be moun ted on a 2"square ci rcu it board and will fi t intoa " wall transformer" case fromwh ich the transformer has been re ­moved. However, I'll leave thecabine t or enclosure choice to you.

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Fig. 2. The compoM nt side of the board,showing pans placement.

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Fig. 1. TM foilside oflhe board.

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Free ElectricityIs it worth the price ?

Mike Bryce WB8VGE2225 Mayflower Ave. NW

Massillon OH 44647

Ph010VOltaicS. electricity from thesun, is the ultimate source of energ)'. II's a clean. nonrotating, re­

newahlc SOUTl'C o f electr icity. Hamshave been taking ad vantage o f solar en ­erg)' since the fi rst surplus cellsappeared on the market.

I have been using the sun's energysince 1978. I' ve designed thousands ofsystems worldwide through mySunLight Energy Systems company.However. my personal favorite just ha p­pens 10 be located a few miles from myhome. Ir s the home of Clyde "Chuc k"Davis WA8YGU. Chuck, like me, hasalways been interested in so lar power.Pushed by the ever increasing cosr ofelectrici ty from the po wer company, en ­vironmental concerns, and self-suffi­ciency. he contacted me. Let's lake acloser look ur his "system" and how itcame to be.

Design Goals

Chuck wan ted a system that wou ldpo wer his entire home. So me o f theloads included were the furnace, washer!dryer, refrigeration. and a small ai r con­d itioning unit. Chuck also ope rates a 24­hour landlinc-based BBS. Severalcomputer calculations showed that theamount of energy req uired pe r day wasabout 50 kW/hou rs, At the current costof grid supplied elect ricity, Chuck's av­erage mcmhly electric bills werepeaking about S160 a mon th,

Since most of the loads speci fied wereAC, all loads would operate from a DC­to-AC sine wave inverter, A sine waveinverter was chosen since several of theAC loads wo uld operate unsat isfactorilyunder the modified square wave someinverters usc.

The Solar Panels

Most hams would look for thecheapest solar pane ls. 1n a design like32 73 AmateurRadio Today . January 1996

Phmo A . The three a rrays keep the hailer)'bank full)' charged. providing all the powerneeded for the home and hamshack:

this one. there were several other factorsthat had to he included. Aside from theactual cost o f the panels, we had to rakein to account the required panel mount­ing structures and the labor required toins tall the panels. Smaller watrage pan­cis. while less expensive. require moremounting space for a g ive n amount ofpo wer. The added cost o f interconnect­ing wires and cables also had to he takeninto account.

On my first rough draft. I suggestedtwo types of panels. The fi rst was theSolarex MSX -64. This polycrystallinepanel produces 64 warts under standardtest conditions. Its large extra-heavyframe makes it an ideal unit to use in ourlocal cl imate. It uses standard II2·inchelectrical co nduit. mak ing the intcrcon ­ncction between modules neat and easy.And it comes with a 20-year warrantyagainst po wer loss,

The seco nd mod ule I recommendedwas the Siemens ProCharger PC4-JF.It 's made of single-crystal cells and pro­duces 75 watts under standard test con­ditions, As with the Sola rcx pane l, thePC4-JF will also accept standard electri­cal connections via its j unction box. Italso has a built-in bypass diode , Th is isd ifferent from a blocking diode in that abypass diode will shunt current around ashaded panel. protecting it from damage .It has a IO-year warranty against power

loss. and costs Icss than the Solarcxpanels.

Chuck decided to go with the S iemensmodules. Given an array of 18 panels.the difference between the two would bea total o f 190 watts! That ex tra II wattseach pane l produces wo uld eq ual morethan two MSX -6-t pane ls. when config­ured in an 18-panel array. With aplanned three arrays . that's an ex tra ninepanels at a cost of zero dollars.

Naturally, right afte r the first PC4·JFhad arri ved. Solarex an nounced a new,higher-power version in its MSX"M EGA" series. Had the new MSX-83(8 3 watts vs. the 75 watts of the PC4-JF)been availabl e. then the MSX-83 wouldhave heen our choice .

There arc 18 panels in each array. Thepane ls arc wi red in series to provide a24--voh sys te m, The system voltage wasdetermined by the inverter, as I'll ex­plain later on .

Each subset of 24 volts is wi red in par­allel with the rest of the array. So, of the18 panels. 9 arc in series and 9 are inparallel. Each array then produces a totalof 91 8 peak watts. That breaks down to27 amps at 34 volts . The en tire systemproduces j ust shan o f 3kWpa (peakarray).

All three arrays arc wired the same.The power from each array is co mbinedin j unct ion boxes at the base o f arrays #1and #2. From the junction box. there arefour ru ns of four-ought weld cable rout­ing the power into the batt ery storagearea , Along with the po wer cables, sev­eral runs o f "data" wires were alsopulled though the a-inch undergro undcond uit. In the future. these data wireswill connect to d ifferent sensors. pro vid ­ing such data collection as array celltemperature. wind direction and speed.as well as indi vidual array current.

Each set of 18 panels is mounted o n adual-axis solar trac king mount. Dual­axis means the mount will track the sun

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73Amaleur RadiO Today · January 1996 33

from east to west and north to south. alla t the same time. At dusk. the "trackers"automatically reset back to the cast,awai ting the sun's return the next morn­ing. Each tracker is driven by two smallelectric motors.

A small battery ope rates the motors atnight so the array is pointing Iowan! theeast.

Contrulling the Power

Under a bright. clear sky the three ar­rays will produce o ver 118 amps con­tinuously. Peak current has been noted atover 125 amps. A Heliotrope Ge neralCC- 120E was used to control the currentto protect the batteries.

This controlle r is stare-of-the art inpower MOSFEf design. Using PWM(pulse width modulation ). the powerMOSFETs keep the battery ban k frombeing damaged by overcharging. AI·though the CC- 120E is specified fo r 120amps. the first un it did not surv ive. Afte rconsulting with Heli otrope General. wedecided to add additional heat sinking tothe controlle r. This heat s ink cons ists ofa half-inch thic k aluminum plate aboutfour feet square. In add ition to the alu­minum plate. several sections of a largeextruded heat sink were also attached tothe plate.

The CC- 120E has an internal coolingfan controlled by the temperature o f theblocking diodes. The fan will run whenthe case temperature reaches lOO°F. Atno time has the au tomatic thermalshutdown stopped the CC- 120E.

Balter)' Storage

We used good 01' lead-acid batteries.wired in a 24-volt system . The bank con­sists of 24 6V go lf-can buucrics. Eachbattery has a capacity of 220 amp/hrs. sothe battery storage ban k has the capaci tyof 1320 amplhrs at a 20-hour rate ofdischarge.

Loads

A Trace 2420 sine wave inverter sup-­pl ies AC to all of the loads. So far. therehas not been an y load that the Trace hasnOI been able to handle . This includes adeep well pump and various refrigera­tion unit s. The Trace has an internal DCcharger. but this feature is not beingused . With automatic shutdown from ev­erything from a low battery to an over­temp condi tio n. the Trace has beenworking without a gli tch since day o ne.

3 4 73 Amateur Radio Today · January 1996

It has also managed to surv ive severalvery close lightning strikes. when itwould shut dow n, wait a few minutesand then restart .

The Trace inverter. at the time the sys­tem was being designed. was availableonly for 24 volts . It is now available for48 volts. Had that unit been on the mar­ket. I would have chosen it. which wouldhave reduced the cost of the weld ingcable used to bring in the power fro m thearrays.

System performance

The sys tem has been on line for over ayear and has produced over 4 millionkW hours.

Two of the dua l-axis trackers failed.bu t they were replaced by themanufacturer. Since the replacementswere installed we haven't noted anyproblems wi th the trackers.

With the d ual-axis trackers. in thesummer months the array-to-load rat io isover 10: I . This means there is slightlymore than twice the array capacity thanload demand. The battery bank can bedepleted to 50 percent at night and befully recharged by the middle of the nextday.

During the winter months. the array­to-load ratio is a break-even 1:1 . Thebattery storage is s ized a bit too small tooperate all the loads during the winter.Increasing the battery size would pro­vide greater runn ing time, but it wouldalso increase the time requ ired to fullyrecharge . In the summer, Ohio averagesover seven hours o f sun per day whenusing the dual -axis trackers. However. inJanuary we average only three ho urs.

Things I Would Change

M y original design did not specify thedual-ax is trackers. I had specified a sea­sonal adjustable top-of-pole mount. Inthis local ion of Ohio. the trackers willno t produce much add itional powerduring the worst part of the year.

In Jan uary, the sun sits too low in thesouth for the trackers to do much good.but Chuc k had to have them.

I had originally specified Trojan L- 16batteries for the batt ery bank . Chuck de ­cided against them from two reasons .First. new 6-vo11 lead/acid golf-carl ba t­teries were available for $38 each from alocal source. 1hc L-16s., on the other hand.were SI90caeh. The L-16 is also 6 volts.

The gol f-cart battery weighs about 70pounds. The L- 16 is 120 pounds. Since

the batteries are in the basement, eachbattery would have had to be carri eddown by hand. Of course, when a bat­tery went bad. it would have to becarri ed up as well.

Why not use a different batte ry? Well.ideally. a forklift battery would havebeen my firs t cho ice . The problem is.you need a forklift to move one! Weconsidered NiCd batteries. but their costpUI them out of the question. When thecurrent batteries need replacing. we mayuse large 2-\'01t scaled lead-acidbatteries.

The Bottom Line

What is the payback period ? Well. thewhole syste m cost about 535.000. HadChuck gone with the top-of-pole mountinstead of the dual trackers. he wouldhave saved $7 .500. And using L- 16s in­stead of the gol f-cart batteries wouldhave cost him about $2.000 more .

As for the payback period ? Well.Chuck will more than likely never seethe system pay for itself. However.several months after the first array wentonline , Chuck 's electric bill droppedso much Ohio Edison sent out atroubleshooting crew.

St ill. not counting any maintenance ofbattery replacements. Chuck is lookingat around 15 years be fore he breakseven.

Caveats

Electrical space heating and refrigera­tion arc two loads that should be runon a source o f energy besides PV. Inthis case, Chuck is running both air

Continued on lJage 8 3

Pholo B. The array is supported by all 8"pipe which is seated tn five f eet ofconcrete.

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The CO~1 ET " Q uic k·D isconnect " Mobile An­tenn a Mo unt , Mo delC Q- 5M co ns is ts o f twoseparate sections: A trunk­mount base that is attac hedto the trunk edge with fourset screws. and an anten na­mount base that fits insidethe tru nk -mount base. Slid­ing a lever wedges the an­tcnna-mount base securelyin place. To re move the an­te nna. simply slide the le­ver to unlock. The antenna

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73 Amateur Radio Today · January 1996 35

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AEA recently introduced the new AEAACARS package for re­ce iving aircraft digital communications. AEA ACARS is a pack­age containing a small demodulator cable and DOS computersoft ware that. when attached to a scanner or receiver, lets you de­code the digit al communications taking place between ground sta­tions and ai rcraft. ACARS is a digital data link system designed toenhance air-ground-air communications. If you are near a majorairport. you can even monitor both air-to-ground and ground-to­air digital communications.

All you need is AEA ACARS, a VHF receiver or scanner ca­pable ofcoveri ng 129-132 MHz AM. and an IBM-eompatible (386or better com utero There are three ver­

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The new IC Master Catalogis coming out in February onpaper. and on CD in March.With over 120.000 differentkinds of integrated circuits soldby way more than 250 manufac­ture rs aro und the wor ld, youneed something to hel p you stayoriented. IC Master is ,I compre­hensive reference full of prod­uct information. The CD comesin DOS and Windows versions(sorry. Mac users). The Win­dows version even includes packaging and pin-out information.

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Transmit features include a type-ahead keyboard huffer. and the optionsof sending from ,Uly of the 8 prcprogmmmcd messsages.or from adisk liIe.Tbc transmit speed can be varied from 5 to 1m wpm. A message can heautomatically sent a a future time without ue t-.perator being present.

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36 73 AmatIWf Radio Today - J,muary 1996

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73 Review

Add-On 2 MeterReceiver Selectivity

, •• ~:=----=~- e--d .--t - -r-"-.....·_II-PholoA. The DCI- J46-411 2 meter bandpassfiller.

To give the DCI 2 Meter BandpassFiltcr a rea l-world operational test, Itook the unit to a nearby moun taintopwhere there is an abundance o f com­mercial FM and TV bro adcast trans­mitters and various commercialrepeater systems (on all bands). In thi sparticular area, the S-mcter (w hich isan LED bar grap h on my 2 meter trans­ce iver) dances all over, and, althoughthe sq uelch is not broken at all t imes.the receiver is qu ite desensed. Evenrelatively stro ng stations cannot beheard well.

very solid chassis with two coaxial cableconnectors. Helical resonators can bethought of as very high-Q RF circuits,passing o nly a vcry narro w band of sig­nals . In the case of thi s part icular unit,that passband range is 144 to 148 MHz.The skins are quite steep, as shown inthe chan. and provide up to -62 dBm re­duction in signals outside o f the filter 'spassband . The OCI filter is passive andreq uires no outside power source. Youreceive and transmit through it withpo wer levels up to 200 watts.

This type of filler (very narrow pass­band) allows the receiver to be undis­turbed by most out-of-band signals,providing for increased sensitivity andclearer reception .

Bill Clarke WA4BLC764 Alta-Voor RoadAltamont, NY 12009

With the prolife ration of radio sig­nal producers, both those that are

supposed to radiale signals and thosethat do anyway. 2 meters has become achore to listen to in many RF-dl..'llSC areas.

An RF-densc area can be a metropoli­tan area with loads of pagers. commer­cial repeater services, cable TV, and/orcomputers . 11 can also be a rural moun­tain, loaded wit h hroadcasters and leasedrepeater services.

Types of Interference

Nearly everyone using 2 meters hasexperienced some Conn of interferenceat one lime or anothe r. Generally. the in­terference experienced will consist of:

Signal suppressing or hlocking­caused by a strong RF signal which de­sensitizes the receiver, making itincapable of receiving the desired signal.Such signals arc from transmitters on"near the 2 meter band" frequencies. Agood example is the large number o fpaging sys tems located j ust above theIWO meter hand .

Sldelobe interference-s-occurs whena signal on a nearby frequency (notwithin the receiver's passband) bleed sinto the region of the passband andblocks the receiver.

Intermodulalion- usually referred toas intennod or ll\.1D. is caused by two ormore signals from outside the receiver 'spassband mixing internall y within thereceiver, then blocking or othe rwise in­tcrfering with the receiver 's operation.

Using a niter such as the DCI- 146-4Hcan reduce instances of 1hI.."'iC types ofinterference. etten totally eliminating them

The DC I-146-4H filter consists offour helical resonators mounted in a

38 73 AmaleurRadiO Today · January 1996

Specifications

Passband :Passband loss:Selectivity :

Power rating :V SWR:Dimensions:Weight:

The Test

144 to 148 MHz< ld l3-62 dB at 136 Mllz-50 d B at 156 MHz200 watts1.5:112 x 3 x 5 inches2 Ibs. I I oz.

Photo B. The interior of /he unit.

The test results on the mountain werequite posi tive. Only the slightestind ication of intrud ing signals on the S­meter could be seen, and that was verysporadic. No noticeable degradation ofsignals was noticed . even when work ingdistant repeaters and weak simplex sta­tions. A quick removal o f the filter gaveinstant proof that the filter reall y works,as without the fil ter the S-meter cameal ive and the distan t stations were lost.

On the test bench I fo und that theunit's passband was a very close up­prox.imation to that indicated in themanufacturer' s literature. Due to thevery steep skin s of the OCI- 146-4H, Idoubt CAP and M ARS users could usethe filter. The SWR seen during transmitrises very quickly a" you move out ofband . During static testing I used a com­mercial dummy load and input power of50 watts. alt hough the filter is rated at200 watts. Of note: No heating of the fil­ter was observed d uring testing.

As a fi nal operational test. I went nearthe transmitter site of a pag ing companythat operates j ust above the 2 meterband. Using an HT connected to my mo­bile 2 meter antenna. I fo und the re­ce iver to be blocked a large percentageof the time and the S-meter dancing aj ig. I connected the OCI-146-4H into thcantenna line and the prohlem ceased.with o nly a small amount of Svmeterj umping noted. This type of SClUp should

help the commuting ham using ahandheld in RF crowded areas.

Comments

Installation is simp le : Just put theOCI-146-4 H in the antenna line by using

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Availability

The OCI line of helical resonator fil­ters is available at most ham radio storesand from OCI Digital Communications,Inc.

Note that DCI Digiti! Cooummicalionsalso (rodoces m"", fer the 220 and 440 ama­teur bands. Commercial filters areavailablo-­call foc specific appIi<:aril:m. III

Fig. J. Graph ol tlle unit's passband.

a short jumper cable. The filter will doits job without any operator control-in­stall and forget. Due to its size, youmight wish to remotely mount the fil ­ter-just keep in mi nd that you want areasonably short patch line from the rigto the filter. Firewall mounting appearsto be practical on some vehicles (wherethere is space). Other choices are under aseat. in the trunk, etc . There are nomounting holes on the unit, and do notdrill any! My recommendation formounting is:

1. Use plumber's strap over the unitand fasten the strap to the mountingsurface with sheet metal screws.

2. Attach the unit to a surface withsilicon glue .

The DCI 2 meter filter makes up forthe wide-open fron t ends found on most2 meter transceivers (wide-open mean­ing the receivers easily receive 135through 170 MHz). When using theOCI- 146-4H. effective receiver sensitiv­ity outside the 2 meter band will begreatly reduced.

Too bad someone cannot design a fil­ter that will remove all the computer

73 Amateur Radio Today. January 1996 39

,®

Asst . General Chairman, Dick Miller, N8CBU

•NoTA YD

General Chairman, Ken Allen, KB8KE

+ May 17, 18, 19, 1996 +

• Giant 3 day Flea Market • Exhibits • Activities for the Non-Ham

When and Where M M NEW DATE THIS YEAR M M

May 17, 18 and 19, 1996; Dayton. Ohio at Hara Arena

CommunicationsFAXMail: (information sent to you via FAX): Set your Fax tomanual send/receive. then call (513) 276-6934

BBS via America Online: Keyword "Ham", then "Conference" ,then 'cooveotons', then ' Hamventon"

PHONE: (513) 276·6930. For fast response, please obtainthe committee Voice Mail box numbers via FAXMail or BBS.

FAX (incoming): (513) 274·8369MAil: Hamventlon. Box 964, Dayton, Ohio 45401-0964

E~MAIl: Hamvention @aol.com or n8emo @ix.netcom.com

WWW: http://users.aol.comlhamradclubldayton.htm

Specia l ServicesLodging information and special award nomination forms werein our 1995 Program. A limited number of Handicap parkingpermits are available. License Exam by appointment only.For Form 610, call 1·800-418·3676Call , FAX, Mail, or BSS for more information.

Bus service

Bus service will be provided between Hamvention , Air ForceMuseum, Salem Mall and Forest Park Mall parking areas.Many hotels/motels will have bus service for a nominal charge.

Returned ChecksA $25 service charge wilt be assessed on all returned checks.Dead linesIn order to have time to return tickets to you , we must haveadvanced registration orders postmarked not Jater than May 3(USA) or April 26 (Canada). Tickets w ill not be mailed beforeJanuary 15th,1996. Ticket requests that are received AFTERthe deadline will be processed and HELD for pick-up at theHamvention Office in the Silver Arena. Tickets can be pickedup beginning Thursday, May 16 at 8:00 a.m.

Flea MarketFlea Market Tickets (valid all 3 days) w ill be sold IN ADVANCEONLY. No spaces sold at gate. A maximum of 3 spaces perperson (non-transferable). Electricity is available in a portion ofthe last Flea Market row for $50 additional. Rental tables andchairs are not available in the Flea Market. Vendors MUSTorder an admission ticket for each person when ordering FleaMarket spaces. Please send a separate check for Flea Marketspace(s) and admission tlcketts). Spaces will be allocated bythe Hamvention committee from orders mailed by February 5.Please use 1st class mail only.

Notification of Flea Market space assignment will be mailed on orabout March 25, 1996. Please indicate in the box below if youwould like to attend regardless of Flea Market space assignment.

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73 Reviewby Dean Lewis IVA3IVGV

Oak Hills OHR-4004 Band QRP Kit

Ah! the joys ofbuilding!From OHR--IOO

For each hoard the parts arc separated bytype. such as resistors and capacitors. Iusually hate the fi rst stage of bu ilding.which Invo lves the sorting out o f theparts and checking to make sure thatthey arc all there. It used to take a greatdeal of time to separate and labe l theparts. Now 1 use little plastic parts binsand dump the resistors in one. the ca­paci tors in another, and so on. I find itfai rly easy to then use my magnifyingglass (even Oak Hi lls couldn't solve thisproblem for me) to make sure I get theright part when I start stu ffing the board .I fi nd that after a few minutes of separat­ing out the parts and documentation Ican get into the project fairly quick ly.

The cabinet for the kit is also veryhigh quality and has a great pa int job.The panel s are beautifully screened . Ibel ieve them to be as £000 in quality asthe major transceiver manufacturers'cabinets.

There arc two dist inct and equally im­portent aspects of a kit for me : howmuch fun it is (0 build and how much 1like to ope rate it when it is done. I havefound that there arc suffic ient variablesinvol ved in implementing a kit design sothat even the best designs may not workas they should when they arc buill. Somerigs arc just more fun to operate thano thers. I finally took some time recen tlyto po nder this aspect o f my building ex ­periences. I have built ahout every kit onthe market in the last three years. I canpi npo int exact ly what constitu tes a plea­surable bui lding experience for me . Theparts in the kit have to be hig h quality;

Jeff M. Gold AC4HF1751 Dry Creek RoadCookeville TN 38501

I had not built a kit in awhile and mypersonality had started (0 deteriorate

proport ionally. I seemed to have forgot­ten ho w therapeutic the build ing processis for me. I started 10 rationalize that Ihave buil t one of everyth ing and thaiplacing components o n a board was j ustnot as much fun as it used to be. Icouldn' t resi st the temptation when Iheard about the Oak Hills Iourbandcr.Four bands. three of my favorite (20. 30,40 meters) and one that I need 10 spendsome more lime on (80 me ters) anyway.So I told the XYI. I needed some moneyfor counseling, and sent off for the kit.

I anxio usly awaited the arri va l of thekit. My children arc now pretty wellgrown up. no grandchildren in the ncarfuture. so I guess this is the closest I cancome for the time heing to an an xiouslyawaited arrival. I got home from worko n Friday afternoon. This was a real bigweekend for me. Three days off and theweather was supposed to be nice for thefirst time in eight weeks. What morecould I ask for? I came home from workand there was the box from UPS that Ihad bee n waiting for. Having signifi­can tly matured (if you can believe thi sone), I went and cha nged o ut of mywork clothes before taking the prize tomy workshop to unpack.

The first thing I noticed when openingthe box was how carefully and profes­sionally it was packed. All of the littlecomponents were packed inside the caseand scaled so that you don't accidentallythrow them away. The re arc threeprinted circ uit boards, not counting theoptional kcyer. The hoards are the ahso­lute bcst l have ever come across (I haveseen some a.s good, bu t none better) .They are solder masked and have a tcr­rifi c silk-screening. There is 110 ques tio n

which parts go where . The receiverhoard has the parts fair ly well packed, sothe very high quali ty sil k-screening is adefinite plus.

Another thing I have noted is thatDick from Oak Hi lls really listens to hiscustomers. This is ev ident wi th thedocumentation . The documentationcomes in several sections which are in­d ividually stapled . The printing is topq uality and easy for even my oid eyes toread without the need for those newreading glasses (so in essence the kitmakes me fee l a little younger). The firstsection of the documentation is the As­sembly Instructions. Oak Hills has acouple of pages on things you need to beaware of to make your building experi ­ence more pleasant and more likely tohave you succeed with the project. Theinstructions arc step hy step, but not inthe hand-ho lding "put this part R3 inhol e in section IA" way Heat h used todo it. I really appreciate the clearness ofinstructions and not having to read andreread so me thing man y times to figureo ut if what I read and thought 1 under­stood is what the writer meant for me tounderstand .

Working with technical wri ting in thecomputer field. I realize how hard it is towrite good instructions . Oak Hills alsohas started to include very pro fessionaldiagrams for the final assembly in withthe documentation. There are separatesections for each hoard that list all thecomponents, a schema tic, and an e xce l­lent. e nlarged overlay. One of my maincriteria for p leasure in building a kit isknowing what the author really meanswhen building instruction s are given. Ifee l it takes some o f the therapeuticvalue away fro m the project when thereis ambiguity in an y o f the steps.

The parts for each board come sepa­rately wrapped . This is anot he r exampleo f Oak Hills ' listening to the c ustomers.

•

flack OJlR--I(){)

­••-

•

73 Amaleur Radio Today· January 1996 4 1

Pholo A. The OHR-400 QRP kit is sensibly packaged and logically arranged.

42 73 Amateur Radio Today . January 1996

the documentation has to be clear. tes tedand revised to eliminate errors. with noambiguity at all; the printed circuitboard needs to be high quality andclearly screened: and there should beseparate parts lists by circuit board, witha clear enlarged parts overlay,

The fun-to-operate part is much morenebulous. This aspect is very personal. Ihave come up with a scientific methodto dctennine this aspect. It is really quiteeasy. I have many rigs o n my work­bench. The number and type seem tochange constantly. I find there are somerigs that I j ust keep using after the initialtesting and evaluating. The reason forthi s is that they seem to me to work bet­ter and are more fun to operate. I put myNorcal40 in this category, as well as theOak Hills kits I have built. I think it ispretty amazing that small companieslike Wilderness Radio and Oak Hills canput out such high-quality kits. Theywork very well as long as they areassembled properly.

Building

I found no unwanted surprises whi lebuilding the kit. I built up the threeboards and put in the optional iambickeyer. All went together quickly, eventhough I checked my wo rk very care­fully to make sure the correc t parts werein the proper places on the printed cir­cuit board and also checked all of mysoldering joints with a magn ifying glass.

It can take quite a few hours to traceproblems such as diodes or electrolyticcapacitors being put in the wrong direc­tion, or havi ng the wrong values of resis­tors or capacitors placed on the board. Itis much more economica l and pleasur­able to take a few extra seco nds for eachpart and verify that they do indeed be­long at a particular locatio n. The boardwas a pleas ure to solder. The platedthrough-holes are very easy to solderand make for strong connections. Thesealso complicate unsoldering, so makesure you have the right parts in the rig htholes! If you should make a mistake(most of us do), I recommend a goodquality solder sucker (can be purchasedat Radio Shack) and with this boardsome solder wic k is helpful.

Testing and Alignment

It was another Friday evening and theend of a really tough week. I am sup­posed to take my wife o ut for dinner, andmy son is already at a friend's house forthe weekend. Sounds like a good timefor a romantic weekend...well, there wasone problem. I was super-stressed fromthe week 's events. I was in dire need of a..therapy session:'

I did my mandatory chores. changedto my "play clothes" and went into theshack. I went to the bench and checkedthe Oak Hill s Research 400 that I haveput hundreds of parts into and over 50wire connections and mounted many

mechanical connectors. switches. andjacks.

The project passed the initial smoketest. I was very relieved when nothingsizzled on power up. I then took o ut thealignment procedures and was ready to

roll . If you don 't have the proper equip­ment or can't get it aligned, Oak Hillswill align the completed rig for $65. in­cl uding shipping it back to you.

The initial frequency setup went veryquickly. Three of the four bands came upexactly o n frequency with no adjust­ments necessary. Ge tting the founh onfrequency was a matter of adjusting atrim capacitor. It was very easy. using afrequency counter as is suggested. Iswitched back and forth between thebands and the oscillator for each bandstarted with no problems. The only time­consuming adjustment involves adjust­ing a coil and a trim capacitor to get thecorrect bandwidth o ut o f the VFO. I alsolike to get it so the dial reads near thereal frequency. I didn' t encounter anydifficulti es with this part.

You next adjust two coil s on the oscilla­tor board for each band for peak signalvoltage as measured on a scope. I laterfound that I did not tune the 20 meter bandcoils correctly. I noticed this when I testedout the rig and found the SWR was highon 20 meters, even though I knew I wasusing a resonant antenna. There were twopeaks for the coils, using a scope to moni­tor. You need to check to make sure youpeak them on the correct frequency, asstated in the manual . On 20 meters I no­ticed that when I was peaking on thewrong frequency the power output wentup to about 10 walts on my QRP wattme­ter. but was right in range at the designatedfrequency.

Your next step is to move to the re­ce iver board and adj ust the volrage at agiven point using a trim pot. That is allyou do o n that hoard at this time.

Moving on to the TXlREC board, youtune a set of coils for each band to getmaximum signal output as measured ona QRP wattmeter. The two coils interactso that you need to go back and forth afew times. I noticed that 20 meterswasn' t putting out a full 4-5 watt s. Ifound that I had the power supply turnedback to about 9 volts. I turned the supplyup to 13 volts and the power came rig htup. All the bands tuned up easily and Igot the correct power o utput on eachband.

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73 Amateur Radio Todar January 1996 43

rhoto II. "The board, are the absolute best I hare ever come across. There is no questionwhich pan .\' go where. "

The rest o f the alignment went fairlyquickly (well. I actually missed dinnerand was in the doghouse for a while. butit seemed like only a few seco nds). Yo uadj ust a trim capaci tor on the receiverhoard to get the signal centered in theright place for the audio filte r. The di rec ­tions are quite clear and should be fol­lowed care fully. You then only need lO

adjust the sideronc level and one moretrim capacitor lO make sure that you aretransmitting and receiving on the samefreq uency. Another transceiver is a goodtool for this. If yo u have installed the op­tional kcyer the re is a simple adjustmentfor the iambic keyer weigh ting to ge t itto your pre ferred setting .

"I would recommend this kitvery highly to hams that havea building project or twounder their belt .. . "

To fi nish fine-luning the recei ver I de­cided to take it to my operating benchand hoo k up an antenna. I put the rig on20 meters using a gel cell for power. As Iwas connecting the ante nna I heardEA3DKR calling CQ. I finis hed co n­necting the antenna quick ly and gavehim a call. Carlos came righ t back to me .Who needs all those other alignments?He was a 559 and gave me a 559. Mytwo-element quad may have helped alittle. I worked an LZI KOZ through apileup almost immed iately after wo rkingCarlos . Next I switched to 40 meters andhad a long rag -chew. then back to 20 towork some more OX . I wo rked a Cubanstation otT the back of the beam.

Later in the weekend I workedUX3f-W , Yura. S59AA. in Izrnail. Franc44 73 Amateur Radio Today ' January 1996

S P3WYQ. George T77BL in the Repub­lic of San Marino (it took awhile to fig ­ure out where that was), and Franc9A2HF. I also did so me rag-chewing on30, 40, and , yes, 80. One QSO o n 80meters was an ho ur long. I hadn 'tworked 80 in quite awhile and was verypleased with how we ll the rig workedwith 5 wa us on this noisy band.

r received comments like "Your newrig sounds great: ' "Did yo u say QRP?,""Congratulations, QRP, sounds FB,Je ff! " (this guy started at 100 watts andwe ended up going QRP-QRP on 80meters), "solid copy: ' The last guy Ital ked with went on and on about howgood it sounds. I wo rked anyone I heard .even DX thaI was real weak . I had ni celong QSOs with no problem, on everyband .

The rig was putting out about -l wattso n 20 meters and I turned the po....'crback to 4 waus when using the otherbands. Listening to the OHR-400 nn acommercial transceiver, I found it had areally sweet note.

I noticed on 20 meters the SWR wasjust a lillie higher than it should be. Itook out the alignme nt tool that was pro­vided and adjusted the oscillator board

coils for 20 rnctcrs. It hrought the SWRright down to 1: I and the rig was puttingout 4 watts as it was supposed to.

I had the covers off a number o f timesd uring the weekend. This is standard up.crating procedure for me. It usually

takes me a few times to get things set upthe way I like thcm. I guess yo u co uldsay I am a "tweak freak: '

The receiver is sensitive and selectiveand quiet. The VFO is ve ry stable. Theaudio filter and RIT work wcll . The

QSK is fantastic, very quiet and quic k.The optional Curtis keycr works fine.The audio is enough to drive a nice sizeRadio Shack speaker. The transmitterhas a variable power control so you canwork very low power if yo u choose to.You can adj ust the power fro m about 5waus on 20 and 30 to about 8 watts o n40 and 80 to close to zero.

I mu st say that I reall y enjoy operatingthis little rig. There is an intangible vari­able that I have with both the buildingand the operating of one of these kits. Icall it the enjoyme nt factor. The buildingof this gets m y top rati ng. A great deal o ftime and energy went into making it avery pleasurable experie nce . Doc s thismean it is perfect? By no means . I couldspend time critic izing minor aspects. butthey were minor enough that they in noway detracted from the building experi­ence or my operating experiences . Iwould recommend th is kit very highly 10

hams who have a building project or twounder their belt. or even to a new builderwho may want to ge t a little help withthe alignment . There is great pleasureand sat isfac tion to be had when us ing arig that you built yourself and that worksvery well. ED

Specifications: 8O-W-30-20 M~terRands

Receiver

• RF preamp• Diode ring mixer• Selectable AGe manual gain

control• -t-pole crys tal ladder filter• Selectable a-pole audio filter• Very stable VFO• VFO covers 150 kH z each band• RIT + I kHz

Transmitter· 4--5 watts all bands• Adj ustable from rear panel O--full

power• Smooth QS K circuit• Sidetone ge nerator with level

adjust• Both iambic and ma nual key j acks

NUfIlbfw 45 on your FHdbac l a m

Kill Your InterferenceSteve Katz WB2WIKl6

21101 Celtic StreetChatsworth CA 91311

This subj ect has been so well cov­cred over the years that I can' tadeq uately bibliograph past ar­

ticles. Yet. I still hear a dozen times a weekfrom hams, both old and new, that theycan't operate various bands (or at varioustimes, or whatever) because they caLL"C in­tcrfcrence to televisions, radios. tele­phones, intercoms, compute modems. faxmachines...you name it.

Hey, folks, this is 1996. we're all parto f the information supe rhighway, like itor not. Elect ron ic tri nkets abound, andthousands more will follow. Whodoesn 't have a PC! wbo doesn' t have a faxmachine? Who doesn' I have a stereo system?And surely, who docsn ' t have a tclcpbone?

In many parts o f the country, cable TVservers and telephone companies are co­operati ng to replace copper wiring withfiber-optic cables to create in teractivetelevision and telephone services withfantastic bandwidth. These services willbe more difficu lt to interfere with, be­cause you can 't create e lectromagneticinterference to an optical transmissionsystem. But it might be many years be­fore our homes arc suitab ly cabled, andwe'll still be using conductor-typeappliances for the foreseeable future.

The solutions are amazingly si mple,But many hams don ' t seem to want toknow, or do, anything, to help the m­selves. If you ' re not a total d imwit, fol ­low some simple advice : Interferenceprohlems can be resolved, and it's up toyou to resol ve them,

TVI

T his is a relatively easy one , Televi­sion se ts are intended to be receivers,they ' re just no t particularly se lec tiveones. If you and your neigh bors arc on"cable," and you' re having TVI prob­lems in your ow n home or those of yourneighbors, the first order of bus iness isto reduce the number of peripheral wires

connected in the cable signal line, If you(or your neighbors) have appliances otherthan an approved cable T V converter boxor a TV set connected, disconnect every­thing else (VCR", preamps, switches, etc.)and see if the TV I persists.

The coax ial line from the cable ser­vice to the television set sho uld he as di­rect as possible, Don ' t connect VCRs inthis path ! Ifyou need to use a VCR as mostof us do, connect its input/output ports usingaudio cables to the television's audio input/video input and audio output/video outputjacks. All the modem sets have such provi­sions. I sec many licensed hams who haveVCRs and other eccesscrics connected toibcir cable lines. when it is completelyunrec­cssary Why convert audio and video signalsto Channel 3 and feed them imo the TV'stuner when you' ll get far better results justplugging them directly into the audio and

video amplif iers in the set, wi thout usi ngany RF? It doesn't make sense,

If you're on cable, do 1101 use apreamp, T hey' re a total waste o f time forcable televisio n services. The signallevel from the cable should be suffic ientto provide a good, strong signal to four,five, or s ix televisions without the needfor any kind of preamplification. If youthink you get "better reception" with 3

preamp in your cable line , eithe r yo u' rekidding yourself, or there ' s someth ingseriously wrong wi th the s ignal levelprovided by your cable company. Askthe m to come out and perform a mea­surement on your cable signal level.

They all have small. hand-held deviceswhich let them know immediate ly ifyour signal level is sufficient. If it isn' t,

then it is their responsi bili ty to fix theproblem, nor yours.

Another warning if you 're on cable: Ifyour cable was installed more tha n a few

years ago, it is very likely the service hasdeteriorated due to lack o f adequatemaintenance . The coaxial cables used

need to he replaced every few years.They don ' t last forever, T he connectorsare not waterproof and often fill up withwater, creating a red uction in signa lstrength and the possibi lity of mixings ignals with yo ur transmitter, which inturn creates interference. Connectorsshould he e1ean and dry. You can chec kthem yourself. if you can reach them. Ifyou disconnect the cable from the " feed"(either above or underground), and wa­ter drips from the connector, this is a realproblem thai needs to he add ressed. Wa­ter in an Rf co nnector almost always in­dicates that water will also he present inthe coax ia l cable attached to it. T his, too ,adds attenuation and red uces signal lev­els. Nonnally, maintenance of the cableright up to the entry point o f your homeis your cable company's responsibility,T he cable inside your home is normall yyo ur respon sibili ty.

If you or yo ur neighbors are not oncable, you may not have sufficient signallevels to o verride interference. Unlessyou can literally see the televisiontransmitter's antenna from your TV an ­tenna site, the s ignal will not be all thatstrong. Replace old. oxidized antennaswith new ones, and make sure they areproperly aimed . Avo id using 300-ohm"twin lead " for TV antennas! Use a 300­ohm-to-75 -ohm balun instead, installeddirectl y across the antenna terminals,and feed the an tenna with high-qual ity,double-shielded RG59~ or RG6-typc

CATV coaxial cable , (RG6 "quad,"which has four shields and is ·' 100%shielded" is an excellent choice. It's

wha t the cable TV companies use, andit ' s not expcnsive.) If you don't have theproper crimping tool for type "P' T V

connector installation, borrow or buyo ne. T he best ones arc not expensive,

and are a good invest ment, s ince itseems these co nnector", arc here to stay,If your TV I problems are from HF

73 Ama'eur Radio Today · January 1996 45

( 1.8-30 MHz) transmissions, try using ahigh-pass fil ter in the coaxial line toyour television set, with the filter in­stalled right at the rear panel connectorof the TV, or be tter stil l. inside the TVbetween the rear panel and the tuner. Trygroundi ng the case o f this filter. If thatdoesn't help or makes the interferenceworse, remove the ground.

A word about high-pass TVI filters:These come in several "flavors." andperformance is unrelated to cost in myexperience. The most effective ones arcreally the 300-0hm "twin lead" filte rs,where each side of the balanced line isfiltered. Unfortunately, the most effec­tive TV transmission line is coaxialcable, not twin lead . Herein lies a di­lemma, but it's an easily w ived one. Forstubborn cases of TVI, I' ve often fou ndthat usi ng a coax ial feedline to the backof the set. followed by a 75-ohm (C0 3X)­

to-300-ohm (twin lead) balun. followedby a 3m-ohm high-pass filter, followed byanother 3OO-ohm (twin lcad}-to-75-ohm(coax) balun. into the 1V SCI'S tuner, is whatWOI"ks best. Sure, it seems crazy to transformfrom coax to min lead and then fum t\\inlead bock to coax again jll..t to install a 300­oIun filte r, but there is a method to thismadness.

The problem with most 75-ohm co­ax ial cable high-pass filters is that whilethey do a splendid job rejecting interfer­ence conducted within the cab le. they doabsolutely zero for "comrnon-modc'' in­terference, which is carried on the o uterconductor of the coaxia l cable. Such in­terference conducts right past a 75-ohmcoaxial filter, and enters the televisionset on the o uter conductor (shield) of thecable alone, and can create nightmarishproblems. By breaking up the cable 'sshield using isolation transformers and abalanced filter, suc h common-mode in­terference is thwarted by the "broke ncircuit" created . (P.S.- Good 75-ohm·to-300-ohm baluns. and 300-ohm high­pass filters, have almost no insertionloss, so don't worry about los ing a 101o fsignal strength wit h this system. If youuse good coaxial cable and a good300-0hm filter, it won' t happen.)

If the interference prohlems arc fromVHF· UHF transmissions, the best high­pass filter in the world won't help.You'll need to use a "stub," which istuned to reject thc specific freq uency o fthe interfering signal. Such a "stub" willneed to be one quarter-wavelength long,46 73 Amateur Radio Today· January 1996

measured in coax, at the interfering fre­q uency, and connected in parallel withthe coaxial feedl ine to your TV set'stuner, as close to the tuner as possible.One q uarter-wavelength in coax will besho rter than a real quarter-wavelengthbecause the length needs to be correctedby the velocity factor of the coax used.For solid-polyethylene coaxial cabletypes, the ve locity factor is usually 0.66;for "foam" dielectric coaxial cabletypes, the velocity factor is higher, typi­cally 0 .78 to 0.80 or so. Such a "stub" iseasily connec ted to the backside of atelevision receiver us ing a "T' (or "tee")adapter having a single type F malc fit­ting and two type F female receptacles.Suc h items can be picked up for a coupleo f dollars at Radio Shack or s imilar re­tail stores. By the way, in case you didn' tknow, a quarter-wave "stub" reject ionfilte r has no connection to the "opencnd'' o f the coax. Don't shan-circui t theopen end, and don't terminate it withanyt hing , or it will be completely inef­fective . The quarter-wave "stub" workson the principle that the impedan ce of atransmission line is inversely propor­tional to its termination impedance ev­ery quarter-wave, If you leave aquarter-wave stub ope n-circuited at oneend , the refl ected impedance will be ashall circ uit at the opposite end, on thefrequency where the stub represents aquarter-wavelength in coaxial cable.Thus , a quarte r-wave "open-circuited"stub will look like a short circuit on itsresonant frequency, and will shuntinterference to ground. It works.

If you try hard enough, T VI is pos­sible to eliminate. I' ve ne ver seen a situ­ation yet where I couldn' t do it. It maytake several hours, it may take a fewdollars. but it can always be done.

Telephone Interference

This is a broad category that applies toall appliances connected to a telephoneline: telephone instruments , computermodems, fax machi nes, etc.

Telephone interference is rare at VHF­UHF levels, but can be very troublesomeat HF. One reason is that VHF· UHF sig­nals are Quite well shunted to commonby the capacitance o f the lines and in­

struments connected to them, but at HFthis isn't the case. Another reason is thatwaveleng ths are so much longer at HFthat the near field interfering signals

might be as far as a few hundred feetaway o n HF. while the ncar fie ld is veryshort on VHF-UHF. Radiated signals arcreduced in intensity by an inverse squarelaw based on the wavelength being used.While 100 feet is very "close" on 80meters, it is very " far away" on 2 meters.

Man y telephone interference prob­lems can be eli minated by terminatingunused jacks. Si nce telephone lines arcoften "daisy-chained" (connected fromj ack to jack to jack within the house),any unused jack wiring becomes an an­tenna which can be an efficient receptorof signals . If you have telephone jacks inyour home (or a neighbor' s home ) whichare untermi nated (no telephone instru­ment connected), these can cause prob­lems. The easiest solution is to terminatethe m, whether a telepho ne instrument isused there or not, with correct passiveterminations. Such terminations providea 500-ohm terminating impedance (not aresistan ce alonc t) across the line, simu­lating a real telephone-type instrument,and they are available for a couple ofdollars from your local phone companyor at Rad io Shack.

If you 've tried this and still have inter­ference problems. try another trick : Goto the point of entry of the telephone lineto the house and find the connection boxlocated there. T his is often a four- termi­nal "block" wi th brass machine screws,flat washers and nuts, where the tele­phone line from the util ity connects tothe house telephone wiring. Frequently.you will find unused wires j ust "Iloar­ing" (not connected to anything) there.Any and all wires floating at this poin t(wires just twi sted together and not con­nected to anything) can he grounded,si nce they're not being used. anyway.Strip the insulation off the unused wires,twist the exposed copper cond uctors to­gether, and tic them to the nearestground po st, which is likely to be closeby, s ince the telephone utilities usuallyprovid e an earth ground inside of ornearby this junction box . By groundingunused conductors in telephone wiring,you can short out so me RF current whichmight be causing interference directly toground. Also, since telephone wiring is of­ten "t wisted" alon g its route, groundingunused conductors tends to "shield" theentire bundle o f wires, which can also helpreduce RF interference .

If you try both of the measures oUI­lined above and st ill have interference

problems, try usi ng si ng le-instrumenttelepho ne filte rs. These arc sold bymany manufacturers as "aftermarket'fixes , and usually ha ve modular te le­phone plugs and jacks included . If tele­phone filters are used, they often workbest when installed right at the telepho neinstrument (or computer modem, orFAX modem, or whatever), as close aspossible to the equipment. Don' t botherinstalling a telephone fil ter at the wallreceptacle when a cord will be used be­tween the wall socket and the instru ­ment. It will be much more e ffectivewhen used right at the telephone (orwhatever). Sometimes a filter might henecessary in the handset cord ax well. I' veeven seen situations where one filter didvery little to reduce interference, but twoor three filters in series at the same pointworked perfectly. These filters usually re­tail for about $10 each and, if they work,arc well worth the investment.

If you try all the tricks above and s tillhave telephone interference, take a lookat how your antenna transmiss ion line isrouted. Is it close to, or in parallel with,your (or your neighbor' s) householdtelephone wiring? If so, move it ! Is yourHF antenna close to the telephone wi r­ing from a street utility pole to yourhome ? If so, move it! You are free to re­route telepho ne wiring as required tocure interference problems. You don ' tneed the telephone company's permis­sion. Just be sure that if yo u do rerou tetelephone wiring outdoors, usc the tele­pho ne company's original cable , whichis designed to withstand the abuses o fmechanical stress and weather. Insideyour home, these factors arc unimpor­tant an d you can pretty much do what­ever you want, since yo u own thiswm ng. anyway.

If in the process of investigating tele­phone interference you happen to findfrayed, worn, or broken cables outdoors(between the telephone company's streetwiring and your home), call the phonecompany and ask them to replace it. Be­ware of telephone lines. As benign as theylook, they do carry a "ring" voltage ca­pable of inducing quite a shock, and theyneed to be well insulated. Don't hand le ex­posed conductors with bare hands. (Thishazard only exists during a "ring," but younever know when that might occur.)

You mig ht also try different telephoneinstruments. T he complicated ones wi thelectronic memory for telephone

number storage and redial are sometimesmore prone to interference than the old­fashioned " 00 frills" phones, purely be­cause they contain additional electroniccircuitry. TIle old western Electric-builttelephone instruments (remember the1960s and 1970!<?) which had a simpleone-transistor tone oscillator, carbon mi­crophone element and mechanical bellringer were pretty "bulletproof" comparedto most of the chcapic imports we use to­day. You can still find these simple buteffective te lephones, both new and used .

If worse comes to worst and you can ' tfix a telephone interference problem, trycalling the phone company. Although

"Grounding station equipmentcan also help preventlightning damage ill the eventofa direct or secondary strike,but is by no means a"fail-safe" precaution."

their line filters are rarely effective , theydo occasionally help. and they mightfind some unique problem in your localwiri ng or instruments. (But don't counton it : Since the divestiture o f AT&T sev­eral years ag o, I' ve found the local oper­ating companies critically lacking intechnical talent.)

If worse comes to really worst (likecivil actions, threats with deadly weap­o ns, e tc.-don't underestimate the ac­tions of a neigh bor who can ' t usc histelephone !). experiment with band andpower changes. If you clobber yourneighbor 's phone when using lQOW on20 meters, try 10, 12, 15, 17, 30, 40, 80meters instead. Or you might try reduc­ing power to the minimum req uired tomake contacts (which is a procedurewe' re all supposed to fo llow accordingto FCC Part 97, anyway). Although I' man ad vocate of " Why use low powerwhen a kilowatt will do the jo b'!" think­ing myself, experimenting with operat­ing freq uency and power level mightreve al some useful data. You might findthat the interference is frequency-spe­ci fic , for which the obvious conclusionmight be that the telephone wiring in ques­tion is resonant on so me band you chooseto operate. This is good to know, becausetelephone wiring can be altered in lengthwithout any no table change in perfor­mance, and simply adding or subtracting

some length to your neighbor 's telephoneinstrument wiring might shift the reso­nance out of the band you' re trying to usc.

Alterna tives

Filte rs on your transmitters will be ofabsolutely zero help with telephone in­terference; however, a good low-passfilter on your HF transmitter might helpreduce TV I ("might" is the ke y wordhere-don' t co unt on it). If you're usingmodern-day equipment, with a high­quality coaxial transmission line con­nected to resonan t antennas that are wellmatched, a low-pass filter may not helpat all, but that doesn't mean yousho uld n' t try one. If you do try a low­pass filter on your HF tran smitter, getone that is well-shielded and rated forconsiderab ly greater power output thanyou ever intend to use. Transmitt ing fil ­tcrs used o n VHF-UHF transmi tters al­most never help reduce interference toappliances not intended to receiveamateur radio signals.

If you' re using an "end-fed wire" HFantenna, this is often asking for trouble.Although end-fed wires work just fineo n any freq uency where thc wire lengthis not a half-wavelength , it usuallymeans strong RF fields inside your ownhome, which can coincide with angryfamil y members. There are some com­pe lling reasons to use end-fed wire an­tennas (like no transmission line loss,regardless of VSW R), but if you haveTVURFIIte lephone interferen ce, theyare best avoided.

Experiment with ground ing. Some­times a good, low-impedan ce ground onyour transmitter, or the interfered-withappliance, or both, can help. However.I' ve seen as many cases where a goodground makes 00 difference at all, and somecases where the grounding acb.Ja1ly made in­terference WCKSC. "Grounding" is 001 a magiccure. If you decide 10 tty grounding. there area few points to ponder:

I . The primary reason for a sta tionground is not to red uce interference . It isa safety precaution that can he lp saveyo ur life should other grounding sys­

terns (such as through your three-wireAC line cord) fai l. Grounding sta tioneq uipment can also help prevent light­ning damage in the event of a di rect or

secondary strike , but is by no mean s a"fail -safe" precaution. At least o ne ham Iknow lost his home to a direct lightning

73 AmaleurRadio Today · January 1996 47

strike. even though his station was aswell grounded as any I' ve seen.

2. There arc differences betwee n typesof "grounds." A DC ground is anyground path that eventuall y leads toearth. no mailer how long or resistive itmay be. An RF ground is one offe ringlo w impedance (not necessari lyresistance) to earth on a speci fic fre­quency or range of frequencies. It is al ­most impossible to achieve an RFgro und at VHF·UHF since the path toearth would have to be just a few incheslong at most. At HE a true RF ground isachievable. bu t not easily. One exampleof a reasonably effective RF ground isthe one that I use : a pa ir of 8'-lo ng cop­per-clad steel ground rods driven intothe earth directly below my operatingbench (which is in the garage). con­nected to the station equipment us ing 2"­wide tinned copper braid capable o fconducting more than l ,l)( )() amperes o fcurrent. Such braid costs about $5 perfoot retail. and isn' t easily found . Also.not many folks can install ground rodsdirectly be low. and less than five feetfrom the ir station equipment. I did it byusing costly masonry drill hits ( I "cdiam­eter) to dri ll through about one foot o fsolid concrete in my garage floor. thenusing a 16-(XlUnd sledge hammer topound the ground rods in. This task tookseveral hours to acco mplish. since drill­ing through 12" of concrete isn' t easy,and the ground was fairly hard . It alsoused up two masonry bits costing morethan $30 each. And the work wou ld ha vebeen impossible to do if the station hadalready been installed. (I did it prior tobuilding the ope rating bench or install­ing any equipmcnt.) Was it worth the ex­pense and effort'! Probably not. Do Ireally have an e ffective RF ground?Maybe. I wouldn't bet the farm o n it.

If you have a second-story (or higher)ham shac k. the likelihood o f get ting areal RF gro und to your stat ion is mini­mal. You're too far away from earth.Ho wever. this docs not mean you cannotachieve a tuned. or Irequcncy-spcciflc .RF gro und for a particular freq ue ncy ofoperation. One reasonably effective"counterpoise" (art ific ial ground. whichworks for RF but is neither a DC groundnor a haza rd-preventing ground) is touse a quarter-wavelength "radial" ofwire connec ted to the ground pest ofyour equipment, with the free end

4 8 73 Amareur RadiO Today · January 1996

connected to nothing at all ! Trust me . itworks. The MFJ product which e ffec tsan arti ficial ground and is tunahie migh talso work in some cases.

Cable T V converter boxes also vary inworkmanship and engineering quite ahit. Some are in plastic cases which arccompletely unshielded. Some are inmetal enclosures whic h appear to be aneffective shield. hut really aren't. Mosthave only two-wire AC line cords whichprovide no grounding at all. In somecases r·ve seen. simply shielding theconverter box using household alum i­num foil has helped reduce TVl. These"boxes" arc really cheaply made and de­s igned to a price, rather than pcrfor­mance. specification. They should costhundreds of dollars to perform their in­tended tasks, but in reality they sell forvery litt le and barely work . Most havethe ins ignia of an American company o nthem. but they're actually built offshore.in Taiwan or somewhere with evenlower labor costs . There 's nothingwro ng with offshore manufacturing. ex­cept that these factories often cut cornerson what were already cheap designs . If ithas an AC power cord on it, the equip­ment is undoubted ly "UL Listed." which

"Many consumer devices suchas personal computers andmodems are "FCC Class B"accepted, which similarlymeans nothing at all."

means absolutely nothing wi th regard toperformance .

Check yo ur antenna system, too. If it'san old install at ion . your connectionsco uld be ox idized or corroded. whichcan help generate higher levels of in ter­ference than a system built with shinynew components. Also check your co­axial cable . Brand-new. high-quali tycoax made hy reputab le manufacturersis usually pretty good; hut lower-costcables. surp lus cables. or o nes that havebeen in usc for a few years or mo re maynot be . Coaxial cables. especially whenused outdoors. do deteriorate and requirereplacement.

While SWR is not a figure of merit forantenna performance. it can be an indi ­cator of something being right or wrong .If you arc using an antenna wi th a highSWR and "tuning" it in the shack to

make it match better, there is st ill a mis­match between your feed line and yourantenna. and there arc still standingwaves on you r transmission line . An­tenna mismatch will often cause trans­mission line radiation . which may tendto make interference problems worse.Adjust your antennas so they match yourtransmission line. T his is not only moreeffecti ve than using antenna tuners ,transmatches. ctc., it can also helpreduce radiated interference.

You might also cons ider raising the el­evation of your an tenna. to get it fartheraway from the appliances you' re inter­fer ing with. I had an interesting experi­ence with T VI on 6 meters (50 MHz).T his band is notorious for caus ing prob­lems with TV Channel 2 reception. since50 M Hz is very close in freq uency to TVChanne l 2 to begin with. I was runningI OOW output power to a six-element beamup about 35 feet. and causing TVI to twoor three neighbors. I tried several cures.none of which worked. In desperation. I fi­nally tried raising my 6 meter antenna. Iraised it to 45 feet, then to 55 feet. and fi­nally to 60 feet. while testing for TVI. Allthese changes took some time. as I wasadding tower sections!

Two weeks or so later. after add ing thelast tower section that raised the beam to60 feet. I ran some TVI tests with theneighbors aga in. T he interference hadliterall y vani shed ! I raised my transmi t­ter power. Eventually. I had 120QW out­p ut power on 6 meters ( from a pair of3·500Z·s) and literally zero TVI. Previ­ously. I had severe TV I with the sametransmitting eq uipment (and much lowerpower) and the same beam antenna. bu tthe beam was up o nly 35 feet. The dif'­fcrcnce wax that when the beam was up35 feet. it was only slightly above myneigh bors' rooftops. and nearly in linewith their T V antennas . By raising theantenna anot he r 25 recti was well abovethei r homes and their antennas. thus con­sidcrably reduci ng the strength of my ra­diated signa l to their TV antennas. evenwhen operating at far greater outputpower.

Agency Approvals

They mean absolutely nothing. Really.Man y co nsumer electronic and electricalap pliances are "UL Listed. " ··UL recog­nizcd," " FCC Class B approvcd ." and soforth. It doesn' t mean a thing. V.L.

(Underwriters Laboratories) and C.S.A.(Canadian Standards Association), aswell as many foreign agency approvals(r.U.V., V.D.E., etc., ad nauseam) don'tmean anything in the real world. Manyconsumer devices such as personal com­puters and modems arc "FCC Class a"accepted, which similarly means nothingat all . Wh ile Pes and peripherals are all"Class B approved," they radiate RF en­ergy like mad, and can similarly receiveRF energy that can re nder them uselessin strong RF fields.

U.L. and other agency approvals havenothing to do with performance. U.L.employs almost no real engineers, andhas literally zero experience in RF inter­ference or other real-world situations.They "list" or "recognize" equipmentbased on safety criteria (meaning, theequipment probably won't catch fire

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when operated accord ing to instruc­tions), irrespective o f any performanceratings or cri teria. I've dealt with themquite a bit over the past 25 years or soand am extremely unimpressed withtheir knowledge of electronic circuits.To wit,l as ked four different V .L. "engi­neers" how they determine if electronicequipment is safe for use. Without refer­ring to manuals, not a single one couldanswcr my question. After referring to

"This can open a Pandora 'sBox ofproblems that willhaunt you forever."

manuals, none gave a satisfactory an­swer that even peripherally indicatedthey had any experience with electroniccircuits. If these folks arc the "experts,"we're in serious trouble.

When All Else J.'ails

Ask your neighbors to contact theFCC . Don't be afraid! The FCC isn't outto "get" you. If you' re a licensed ama­teur radio operator and are using yourequipment within its ratings and limits(and the limits o f yo ur license class),you're probably in good shape. The FCCrecognizes that amateurs are licensed totransmit, and your neighbors are not li­censed to receive. Reception of televi­sion and radio signals is a privilege, nota guarantee. Even telephone calls unen­cumbered by interference are not guar­anteed by the FCC. Indeed, your localtelephone utility company guarantees itsusers some degree of communicationswhich should not be encumbered by ra­dio interference, and if its users findtelephone services (0 be worthless, theyreally don't have to pay their telephonebills until the problem is corrected .

Utilities are regulated by the PublicUtilities Commission, which guaranteesusers some degree of service in returnfor fees paid. Communications servicesare further regulated by the FederalComm unications Commission, whichrecognizes the weaknesses of many userappliances and are usually empatheticwith amateur rad io operators. It is aham's responsibility to try his (or her)best (0 resolve interference problemsprior to requesting FCC intervention.But when all else fails, you'll be sur­pri sed to find that the FCC is not an

enemy, but rather an advocate. I've dealtwith the FCC on interference problemsmore than once, and they've never askedme to stop transmitting yet.

Summary

Interference problems can all be re­solved . It takes mutual cooperation onthe part of the amateur and the com­plainant. If the complainant won't letyou help him or her, you won't get veryfar in negotiating with them.

Don ' t try to "fix" your neighbor'stelevision, radio. telephone, computer orwhatever. This can open a Pandora'sBox of problems that will haunt you for­ever. I o nce voluntarily installed a high­pass filter inside a neighbor's 1V set(more than 20 years ago), which did helpresolve an interference issue. 1\vo yearslater, that neighbor tried to sue me for min­ing her television, when her picture tubefailed and required replacement. (Trustme, 1never touched her picture tube.) It'sbetter to recommend filters and so forth.and reconunend they be professionally in­stal led or installed by the user. It's even anice gesture to offer to pay for such filters.I've done it, and I'd do it again, ifit makesmy neighbors happy.

For a short while I lived in atownhouse community where I hadneighbors quite close by. I didn't get intotheir televisions, but I did cause q uite aproblem with their telephones. As a

neighborly gesture, I offered to buythem all telephone filters . The filtersworked great, but it cost me more than5200 to buy all the filters required. Thissounds like a lot of money, but I don' tregret the decision. It quelled a real

problem and allowed me to operate theHF bands without having neighborscomplai n about it! (One case of tele­phone interference was so severe, noamount of filtering seemed to help. Lof­fered that neighbor free use of my por­table cellular telephone, which had nointerference at al l, when he needed to

call someone and I was on the air. Thebills amounted to maybe SIO or SI5 amonth, but the neighbor was satisfied, Iwas working OX, and the world was anice place.)

If you still have problems, write orcal l me and I'll try to help you out. Ifyou don't, then this article served itspurpose. 73 and good OX!

73 At7l8teu( Radio Today · January 1996 49

Your Input Welcome Here

Numb« 50 OIl your FHdIMeII t:Md

HRM TO HRM

Dave Miller NZ9E7462 l awler AvenueNiles Il 60714-31 08

Since we began this columnthree issue s ago. a number o fworth .....h ile ideas have been re­ceived and they continue to arrivedaily. Many thanks to all who'vc

contributed thei r time and effortto make this a success. and I' mhopeful that the respon se secn sofar will grow even more enthusi­as tic in the future .. .remember,this should he your column , withyour ideas and suggestions.

Here 's a basic rundow n o fwhat I'm looking for in the wayof reader input. Everyone hasdif­fe rent experiences in amateur ra­dio. with different equipment andvarying setups: each o f us has en­countered any nu mber o f in­s ta nces whe re we've mad eimprovements, both major andminor, to what the eq uipme ntmanufacturers "think" that wewant. Some of the modificationsare primarily operational in theirnature. others make the eq uip­ment more technically sound. I' dlike to hear about your in nova­tions, with the possibility o f pass­ing them on to all of the othersreading this column. That's what"Ham To Ham" means, one ham'shelpful hits, ideas or suggestions10 anomer who might be in a simi­lar situation or have similar needs.Hams ha...'e always enjoyed help­ing one another, that's pan of thefun of the hobby, and this columnis a way o f extending that help­fulness to many, man y others allat once.

Not everyone wa nts to write acomplete , long, drawn-out articleon an innovativc idea that theymay ha...-e come up with. so here 's)'our chance to jot down the basicdetai ls, in casual form. and I' ll putthe fin ishing touches on it, if needbe. for the column. Don ' t worryabout your writing sty le. j ust tryto be as complete as you possihlycan, but even if you're not sure.send it to me and I'Illet you knowif I feel that more information isneeded. I' m primaril y interestedin down-to-earth, pract ical idea.'>Ihat others can duplicate with

rel ative ease. Here's an exampleo f a simple idea, so mething that 'seasily dupli cable by most hams,yet many may have been re luc­tant 10 apply i t to th eir o wnsituation.

Pilot Lamps and Today'sRadios

Haw you noticed ho w difficu ltit 's become to change a burned­out pilot lamp in most o f today'smo de rn tra nsc e ivers ? In the"good old days..- when radiosand pilot lamps were both a lotbigger-changing a dead lampwas a preny straightforward, eas­ily accompli sh ed job. L am pswere usually mounted in sockets.and normally just a twist o f thewri st popped the lamp right out.ready to install a new one. Not soanymore ! Mosr Iarnps are now ontiny wires, soldered in place ando ften buri ed d ee p with in theradio 's front panel wiri ng. It's be­

come such a problem that manyhams don't bother changing thelamps whe n the}' do bum ou t. orthey wait until something el se

much bigger in the set needs at­tention , changing the pilot lampthen as something of an aside tothe large r problem.

What follows may not makethe task o f lamp replacement any

easier. but it might just double ortriple the lime between pilot lampfailures, and it's nOI usually too

difficult to accomplish.Here 's the first t ip: When a pi­

lot lamp docs bum out, most hamsprobably th ink in term s of goi ngto the radio's manufacturer for a"direct replacement ," but o ftenthat's the most expensive andtime-consuming route to take .Here ' s an alternate app ro achthat ' s o rd in ari ly muc h , mucheasier. Radio Shac k stores stocka number o f small, low-vo ltagelam ps, most of which work onwhat your transceiver supplies aspilot lamp voltage- usually 12

volts DC. By the way, using a re­placement lamp rated at a highervol tage is fine. just as long as itwiIl provide enough brightnessonce it's in place. In fact. a higher

voltage lamp \\; 11 last quite a bitlonger than one that 's rated rightat the no minal supply v-oltage.Thai leads us into the rest o f thestory, How do you extend the lifeof those tough-to-get-at lillie pi­lot lamps?

If you lowerthe supply voltageto any incandescent lamp, you'llincrease the lamp' s life dramati­cally. Tests have shown that thelife expectancy o f an incandes­cent lamp zooms upward as thevoltage across it goes down. ando f course, vice versa. Loweringthe vol tage across a 12-voltlampby just a couple of volts, for in­stance, will extend the lamp's ex­pected life by two or three times!Just a series resistor in the lamp' ssupply lead will do it for you , bu tthere are some other consider­ations. You'lI hav'e to determinehow much light loss is acceptablein your particular operating con­figuration, because there will beloss of brightness if the voltageto the lamp is reduced. Once youhave determi ned how much illu­mination you can afford to lose ,you' lI need to know the value ofthe resi stor needed to drop thevoltage just enough to accomplishthat objective. Finally. the power10 be dissipated by the resistorwill de te rmi ne wh at wattageresistor is needed .

Lowering the voltage across anincandescent lamp will definitelyreduce its light output and it willalso shift its color somewhat to­ward the red region. The more thevoltage is lowered. the more red­shift occurs.

I ha...-e a couple of flood lampsillum inating the front of my houseeach night thai are wired in series,i.e.. the lamps run at 1/2 voltageacross each lamp. They' re verymuch on the "warm side"-red­shifted--but have been going foryears an d years each night withoutburning out. because voltage-rat­ing-wise, they're loafing along!

Gelling back 10 our pilot lampd iscussion. you can easily deter­mine what resistor to use in se­ries wit h e ac h lam p hy usingOhm's Law: Voltage drop desired(V) divided by the lamp's ratedcurrent (I) equals the correc t re­sistor (R) needed and Vo lt agedrop (V) desired times the la mp'srated current (I ) eq uals theresistor's wattage (P).

By way o f example, let's takethe Radi o S hack # 272- 11 4 1lamps mentio ned earlier, whichhave a c ur ren t ratin g o f 25milliamps--or 0.025 amp-andassume that we would like 10 dropthe 12-volt lamp supply by 2.5volts---down to 9.5 volts . Plug­ging in these values we get: 2.5\lolts + O.025amp = IDOohms and2.5 volts limes 0 .025 amp equals0.06 watt.

Now we know that we' ll needa IDO-ohm resistor in series witheach lamp. and that a In-walt di s­sipa tion ra ting o n eac h re sisto rwill give us a good margi n o fsafety.

An o th e r way to lowe r thevo ltage to all of the la mps in these t at one t ime would be to usea 3-terminal adjustable voltageregulator supplying so methingle ss than 12 volts to the lampsupply bus, but in most c ases.that's something of an overkill .Yo u would also have to be surethat nothing else is tap ped off ofthe lamp supply bus thai mightbe adversely e ffec ted by a slightvoltage red uct ion . T he i ndi­vid ual re sis to r in serie s witheach lamp is usually the sa fes tapproach unle ss you know thetransceiver's circuitry well .

Remem ber, the more you canlower a lamp' s voltage from itsno minal ra ting , and sti ll haveenough light output from it, thelo nger that new pilo t lamp willlasl once it' s in service.

Reducing Scratches

Sometimes accidents happen,and a plasti c meter face . dialcover o r even a wristwatch face­plate can beco me marred withan ugly sc ra tc h o r d ig , o fte nmaking it di fficu lt to even readthrough the snatch mark.

Nex t ti me th a t happen sto you, try usi ng a small amounto f metal poli sh . s uc h a s

Bra s so w . t o poli sh o ut th eimperfection .. . it really works.Most of these prod ucts are co m­

po sed o f a ve ry fine abrasi vet h a t , if u se d p rop e rl y, wille l iminat e or minimize man yscratches-even relat ively deepo nes- restoring th e damagedpiece to usable condition again ,

Try folding a paper napkin, andwith th e t ip of your finger

so 73 Amateur Radio Today· January 1996

months. Please se nd them 10 theadd re s s at the top of t h iscol u mn, not to 73 M agazin t'di rectly.

Note: The ideas and sugges­tion s co ntri buted to this col umnby its readers have not necessar­ily been tested by the column'smoderator nor by the staff of 73Mo gozine. and thus no guaran­tee o f o perational success is im­plied . Always usc your o wn bestjudgment befo re modifyin g anyelec tronic item from the orig i­na l equ ipme nt manufacture r ' sspecifications. No re sponsibilityis implied by the moderator or73 Maga: im' fo r any equipmentdamage o r mal function res ultingfro m in formation su pplied inthis column.

Please send all co rrespondencere lat ing 10 th is co lu mn to 73Magaz jne s " Ham To Ham" col­um n. c/o Dave ~till er NZ9E,7462 Lawler Aven ue. Niles, IL607 14-3 108, USA . All contribu­tions used in this column will bere imbursed by a contributor 's feeof $ 10, which incl udes its excl u­sive use by 7jMa~a:.ine. We willattempt to respond to all legiti­mate contr ibutors' ideas in atimely manner, but be sure to sendall specific questions on any par­ticular tip to the originator of theid ea , not to this column'smoderator, nor to 73 Magazine.

73, de Dave NZ9E. m

Uncle Wayne'sBookshelf

X'.~ 274 ·n73 .... tJO) ·Y2-l"'IlJ:I~ . b\XJ-Y!4 8613. or """ ordo:r rnfln on~ 88 r",.

flknnll, nformalJOIl

GreatAntenna Books!

the second 2S3375 ·•.. .acts as anauto matic antenna tu ner. Thelower the impedance. the higherthe c urrent" dra wn from thisstage. The need for an e xte rnalantenna tuner is therefore mini­mixed . ex ce p t pe rhaps a s atu ned circui t for harmonic re­duction. since no tuned ci rcuitsare employed within the two­stage rransrmuer itse lf. Thesedays , so me sort of harmo nic re­duct io n wo uld he well ad vised.

Luvc e bu ilt his unit into ave ry smal l copper box. boil ingthe 2f'\ 33 75s directly to the bo xand b ringing the RF o ut via anRCA·lype "phone" jack. Directpoi nt-to-poi nt wiri ng is used .wi th all grou nds so ldered rightto the copper box itself wit h theshortest possib le leads. With 24volts keyed DC applied . he wasable to realize about 5 watt s o fRF o utput o n 20 met ers. He fur­the r c autions that the box canget very warm afte r a ti me , soe ither add itional heal -sin ki ngmight he req uired, or key-d owntime kept to an absolute mini­mum-lower Vee in put voltage

wo uld also red uce heal , a lo ngwith the output power. A small12-VDC fan might be a worth­while addi tion if the heat dissi­pation is still too g reat. Le veecommented that afte r fina l le st­ing , he cove red all o f the in ter­n a l c o m po ne nts wi th aheat -d issipating e poxy fo r ad di­ti on a l co mponent mec ha nicals tability as well as better heattransfer.

Fro m 4X-l and . this is an in ­terest ing c ircui t wit h lo ts o f po­te nt ia l for Q R P e nth us ias ts .Questions and comments shouldbe d ire c ted to : L uvee ls ra e l4X I UFo1.'/0 International E lec­tro n ics S erv ice s . 12/ 21 GotLevi n St., Haifa 329 22, Israel.

That's our " Ham To Ham"column fo r th is mo nth. Pleasekee p your ideas, tips. sugges­tion s a nd shortcut s com ing andwe ' ll usc as many of the m aspossible in each o f the coming

schr-

•

.A. ............

"The need for an external antenna tuneris minimized, except perhaps as a tuned

circuit for harmonic reduction."

need it. Je we le r' s rou ge is al soexcel le nt fo r cl eaning tarni shedco nnector contacts and intermit­te nt battery connecto r springs.as well as your XYL's gold ringsand bracel et s ! Bra s so . me n­t ioned above . is a reg is te redtr ade mark o f Re c k itt &Cole man o f Wayne. NJ.

Two-Stage CRP Transmitter

a brasive au to mobile ru bb ingco m po un d o r an o pti c al lensg r indin g c ompo u nd as wel l.Je wele r ' s ro ug e . a ve ry fi neabrasive in an oil- based cakeform . is al so very useful in thesa me manner- you mig.ht checkwith a jeweter's su pply house oryou r own neighborhood jewele r10 sec abou t obtaining a smallco ntainer for the next time you

A ll th e way from Isra el ,La vee -lX I UF contributed thisin tere sting li ttle t wo -st age, 5­watt , zu-metcr C W QR P tran s­mille r circu it for ex peri me ntalp urpo ses.

In the circui t di agram of theFig . 2, the firs t 2f'\3375 transi s­tor is wired as a Pierce Oscilla­tor. and is capacit ively coup ledto a second 2N3375 that fu nc ­tions as a buffer as well as animpe d anc e co n ve rte r. Le ve ewrites, "i.. by drawing as muchcurrent as needed by the stage: '

---~-.----r--=~'I o(h ._ t:>,.c. _

...... ......... ..... .......

I,

Fig. I. 4X1UF i ultra-compact 20 mn rr cwQRP transmittermafic diagram. See tess for [urther details.

backing it u p . a pply a s ma llamount o f pol ish to the da magedsurface. Take your lime, apply­ing only the amount of pressureneeded to remove enough of thesurface plastic to polish out thesc ratches in question. You mightwan! to try this o n a cou ple ofscrap plastic pieces first, just togel a "feel" for the procedure.Ru b o ve r the scratch severaltimes and then wipe the driedpolish completely off. If the sur­face has " fogged" a bit, repeatthe procedure. bUI thi s time us­ing progressively lighter pres­sure.

For very ligh t scratches, eveno rd inary typing paper may hej us t abrasive enough to polishthe surface sufficiently. T ry us­ing the paper just as is- wi th­ou t a ny addi ti onal ex te rnalabrasive applied to ir.

Mo s t reaso nabl y s iz e dmarks- a nd eve n some prettybig ones-ca n be remove d orgrea tly reduced in thi s manner.It e ven works o n scratc hed C D­RO~t disks. but agai n. bette r topractice on a "throw-away" onefirst.

S ub mined by : Herb Fo st erAD4U A. 30 20 Pe n ns y lvan iaS treet, Mel bou rne, FL 321)04­9063

M oderato r ' s Xot e : mo stcleansers and polishes will ex­hibit the abrasive e ffec t thatHe rb refe rs to above. so youmight want to try a number ofthem-e-keeping notes o n whic hwo rk best for you-on se veralsa mples o f sc rap plasti c. Yo umight also want to try a mild-

73 Amaleu,Radio Today · January 1996 51

/'/1010 C. Marv in JohnsonKE61lTS picked this high spotoverlooking {he ocean to take abea ring, He look first place inthe Senior Division.

On the other hand, the hi gh hori­zontal dipole o f Fox #2 must havecaused some unusual signal re­flect io ns, becau se many hu ntersrepon ed that bearings to il crossedon top of a hi ll 400 feet northeastof it. The fox fou nd by the mosthu nte rs (28) w as #5 ; the o nefound by the fewest hu nters (8)

wa s #1. Both had been expectedto be medium difficulty foxes,

This foxhunt was the last eventof the convention. on Sunday af­tcmoon. A ll day Saturday. a halfdozen o r so "micro-Ts't uu nsmit­led for a few seconds each fromhid ing spots aro und the Quee nMary convention site, incl ud ingthe hotel, exhibit area. and park­ing lot. Thi s gave everyone achance 10 check OUI RDF gear andpractice techniques.

A few eager entrants di dn 'twait unti l Saturday to get ready.Ric k Ba rrell K E6 DK F. who

Photo H. The mO.ft dastardly fox hiding spot wasdeep inside this drainage channel. 200fen from thebeach. The orange card-marking puncn is j usrbarely visible in the ..mil-climbing plants,

The shortes t possi ble routereached the foxes in the foll ow­ing order: #3, #5 , #6, # I, #4, #2.Hunters traveling that route di­rectly would h a ve gone 1.35miles. Thi s is about one half ofth e shortes t route in a ty picalIARU championship foxhur u. O fcourse, nobody's route was clo seto be ing that short. Ov era ll win­ner Scot Banh KA6 L' DZ foundall foxes in 66 minutes and Se­nior Divi sion (ever age 46) win ­ner Marvin Jo hnston KE6HTSdid it in 76 mi nutes (Photo C ). Bycompari son, a Hungarian and aRussian completed a much lon gerfi ve-fox 2 meter course in j ust 47minutes at the 1994 World Cham­pionships in Sweden.

According to the fox -hi dingcorollary to \1urphy's La w, " E\'­eryone will easily find the foxesthai you thin k wi ll be hard, an dvice versa, " The pit didn ' t crea tea pool-table effect fo r Fox #3signals. Eighteen hunters found it.

world cham­pionships archeld, bUI theywo ul d h a vebeen far tooconspicuousin the fort ar­eas.Sowedid

not use them.The bright or­ange puncheswithin f ive

feet of eachtr ans mitterwere easy tospot and pro­vided suffi ­c ient vi sualidcntif icarioo .

Fox #3 wassuPJXlSCd- to be very hard. It was onthe steep slope of a Su-foor-dccpfootball-fie ld-sized pit that used tobe pan ofa World War I mortar em­placement (Photo A). Its antennawas a twin-lead J, most o f whichwas buried a couple of inches intothe dirt next 10 the long s tairs. Theidea was to "light up" the entirepit wi th lots o f RF and createmany signal reflections. Th e ulti­mate chall e nge was Fo x #4 ,which was underground , five feetinto a sea-lev'el drainage channelnear the southern end o f the park(Photo B). All foxes except #4were at lea st 50 feel fro m thene ares t trail.

Radio Direction Finding

INHOMING

first international-style radio di­rccnon finding (RDF) champion­ship. II was held September 3 ontheFort M acArthur Military Mu­seum grounds in the San Pedroarea of Los Angeles. I served onthe committee of Southern Cali­fornia Six Meter Club memberswho put on this 2 meter event forthe 1995 ARRL SouthwesternDivision convention.

Hamconlfo1JlunI-95 simulatedas closely as practical a European!Asian foxhum. Our rules werebased on Internat ional AmateurRad io Union (lARD) ru les for di­rcction-finding championships.Unlike IARU events, there was noseparate division for women andcompetitors in all di vision s wererequired (0 search for all foxes.Age divisions were different fromIARU class ification s.

Internat ional-style foxhuntingis new to Southe rn Californi a, butthat doe sn't mean all HamconJFoxhunt-95 pan icipan ts werecomplete gree nhorns . Many ofthe fony who signed up were ex­perienced mobile T-bumers whohad learned techniques for " sniff­ing" out tra nsmi tt e rs o n foot .whe reas othe rs had never triedRDF before. How could we puton a hu nt that challenged the ex­perien ced 'It-hun ters but gavefirst- timers a chance to do well?

The fox -hidi ng subcommitteedecided to put out six fox es. Twotransmi tters would be ea sy tofind, two would be really to ugh.and two would be in-between .Poxes #6 and #2 were intend ed tobe the easy ones. We hid #6 un ­der the concrete cover of an aban­doned 40-year-old undergroundcommand post for Ni kc defensemi ssile s o n a hill top 900 fe etsouthe ast of the start point. Theantenna for Fox #2 was K6M I'shorizontal dipole in a tree 400 feetwest o f the finish line. Both of

Pholo A. Fox #3 was next to the these foxes were high and in thelong staircase on the edge of d ear. relatively speaking. so hunt­Batteries John Barlow and e rs shou ld have gon cn sharpSaxton , em abandoned WW/ bearings,

shore defense site at Fort IA RU rules require red andMacArthur. One hunter hasn't wh ite flags (calle d pri sms) nextrealized vet l oot he is standing to each fox. They are appropriateon rop ofit. in the deep-co ver forests whe re

52 73 ArMleurRadio Today " January 1996

Hide-and-Seek With Radios

Joe Moell P.E. KOOVPO Box 2508Fullerton CA 92633

Unlike more familiar mobile"f-hu nts," an internat ional-ru lesfox hunt is an on-foot search forseveral concealed mini-t ransmit­te rs in a large o utdoor se tti ng.Kids love it, and so do adults. Iexplai ned the concept in de tail inlast month 's "Homing In.'' I alsobe gan the s tory o f lI a mconlFoxhunt-95, Southern Californi a's

"We need more you ng peoplein ham radio!" Wayne says it, I' vesaid it , and yo u have probablysaid it, too. What if I told you tha tthere is a way for kids o f almostany age to learn about radio with­Out reali zing they arc bei ng edu­cated, wh ile they have !K) muchfun th ey won 't wa nt to s top'!They ' ll al so be ge tting lo ts o ffresh air and exercise, fur morethan the y wou ld ge t silt ing infront o f a computer screen. Besto f all, the kids don't need 10be li cen se d ; they ca n startimmediate ly.

Yes, such an activity exists. Insome eastern European and Asiancountries , it is so po pular that it'spart of Physi cal Edu cation inschools. The sad fac t is thai it'srarely done stateside. Hams in oureducarion indus try haven 't d is­covered it yet. Th is best-kept se­cret is a s!XlI1 called "foxhun ting."

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Photo F. KD6SNE cruised the foxhunt course inhis wheelchair. Christie Holoubek KCIU, hisExtender, went into the brush on his command touncover foxes and punch his competitor card.

73 Amateur RadiO Today. January 1996 53

lARU foxhmt ndes fa this sat ofsituation. Mike didn't want a specialcoorse just for him, In' did he want

the coorse Illalkeasieroo his acro.mt.Alire reeded was away to finishcJns­ing in after he had done the rosie RDFwOO< on wheels.

Rxtunately. 1hadanexpert nearbyfor consultation. My wife AprilWA60PS is a Registered Occupa­OOroI~andformer rehabili­tation department head at a majormedical center in Orange County.Occupational Therapists aretrained to find creative ways forpersons with disabilit ies to adaptto their physical limitations and

ranging in age from 11 to 70 (PheW

D). Tbe median age was 38. Then:were no cross-country runners, aOOtwo rouId not run at all. The story ofthese two isproof that foxhunting isasport for almost everyone,

Mike Obermeier KD6SNE is aregular at SouthernCalifornia mobileT-hWlts. 8l'cmse ofa spinal cord in­jury. Mike hac; adaptOO hisT-hmt ve­We to include haOO cootroIs for theaccelerator and brakes (Photo E).In just a few seconds. he can ma­neuver himself out of the truck andinto his sport s wheelchair fo rsniffing out the T.

wben Iprormted this foxhunt atamobile T-hunt inAugust,Miketoldme he reallywanted to com­pete. He kept ask­ing. "Cen 100 it inmy chair?" Iknewthesite had plentyof paved aOO WI-­

paved trails. butthere wook1 be 00

wayto~anthe

foxes so he rouJdroll right to themThere are noprovisions in the

Everyone Is Able

Fox hunters woo win inlemationalchampionships are true athletes whotrainjust likewOOd-classcompctitcn

in any other ruming spot, By em­uas, HamconIFoxb.tnt-95 entrnnts

were across 5iCJ 1i ;X lofordiray tans,

it after dark so we would not seeeach other hide them. This al­lowed us to get used to o urequipment. so we could trust itand not just what we saw."

Photo E. Mike ObermeierKD6SNE "sniffs " in his wheel­chair and T-hunu regularly on 1meters in a convened mail deliv­ery truck with a 4-element quadand a Roanoke Doppler. Thephoto isn't backwards; thesteering wheel really is on theright side .

placed third in the Prime Division(ages 18 through 30), was glad hehad practiced diligently. "ScottBarthKA6UDZ, rnxm huruer,amIweft uptoGIendoratoakx:aI sp:xts

park several times." he told me."We would each hide a fox in thepark. and then we 'd hunt eachother's foxes down. Once wefound all of them, we'd movethem and find them again. We did

Photo D. Tom MirabellaKD6AAN, age 14, took firstplace in the Youth Division . Hefo und more foxes than his dud,Ken KM6YH.

,1

I

try 10 find another good Extenderso that Dennis could hunt.

WB60 BB liked the idea. soApril asked an acquaintance whohad expressed interest in amateurradio to be his Extender. April'sinstruct ions were that she couldact only as eyes for Dennis. andcould not do any RDF for him.Besides insuring his safety. shewas allowed to describe to Den­nis the terrain features and thepresence of other hunters in theare a in wh ich they weresearching (Photo H).

No one at the foxhunt startingline was more excited than Mikeand Dennis. Of course, not allsporting events tum out like aRocky or Mighty Ducks movie.Neither Mike nor Dennis won amedal. However,bothreccivedcer­tificates for successfully fmdingfoxes.and theirextendersgot a realworkout. I'msure all four are bop­ing that organizers here and abroadwill improve the rules so all futureinternational-rules foxhunts are asaccessible to handicapped hams asthis one was.

As you can see from the photos,Hamcon hunters used a wide vari­etyofRDF gear. from thecommer­cial sets used by KE6HTS andKD6SNE to KD6AAN'syagi andthe fo il-tube auenuaror ofWB60BB. Every hunter has per­sonal preferences for equipment.Selecting just the right sniffingsetup for your needs will be thetopic ofan upcoming "Horning In"column. Meanwhile. keep me in­formed aboet both mobileT.hunt­ing andon-foot foxhunting in yourarea. Write to the address at thebeg inning of this. artic leor send e-mail to me viaInternet (Homing in@aol.com)or CompuServe (75236,2165). 11

Photo H . Lang-time T·hunt~r

Dennis Scnwendmer WB60BBdidn't let his blindness keep himfrom having fun at lfamcon/Foxhunt·95 . Future ham LindaR~agan served as his Extender.

rerum to regular activities of theirdaily living.

April suggested that Mike beprovided with an assistant on thefoxhunt course to perform searchduties in areas of the park thaiwere inaccessible to his wheel­chair. I countered that the com­petit ion was for individual s only,not two-person learns, and thaiother contestants might considerit unfair to go up against the teamof Mike and an assistant. Aftersome discussion. we agreed thatthe assistant would be selected bythe hunt committee and would beallowed to act only as an exren­sionofMike's range. Mike woulddo all the RDF work and maneu­ver his chair as close as possibleto the faxes. Then Mike ' s Ex­tender would go into any inacces­sible places and search. withoutequipment. at his d irec t ion(Photo F).

Mike thought th is idea wasgreat and quickly agreed to theterms and conditions. ChristieHoloubek K0IU agreed to act ashis Extender. There was no con­cern about Christie being able tokeep up with Mike, because sheis an accomplished marathon run­ner (Photo G).

One week before HamconlFoxhum-95. I received e-mailfrom Marvin Johnston KE6HTSof Santa Barbara. He and DennisSchwendtner WB60BB werecoming to the hunt and he wanted10 know if Dennis could partici­pate on a team. I already knewthat WB60BB's keen hearing hadmade him a successful "naviga­tor" on mobile T-hunl5 in SantaBarbara for many years, despitethe fact that he is sightless. I toldMarvin that there would not be ateam competition. but we would

Photo G. On the downhill,K@lU had to move f ast to keepup with KD6SNE.

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54 73 Amaleur Radio Today . January 1996

Amateur Radio Via Satellites

morning talks. all dealing withprogress o f the Phase 3D pro­gram.

Proj ec t Le a d e r Dr. KarlMeinzer DJ4ZC brought partici­pa n ts up to d at e on lau nc hopportunities. fin ancial consid ­eratio ns a nd an overa ll pictureo f the program . The plannedlaunch is to occur late in 1996on the seco nd fl ight o f an Ariane5 vehicle . If there are diffic ul ­ties with the sc hedule. the sat ­elli te may be launched as late asmid- I997 on an Ariane oJ rocket .Phase 3 D is o n schedu le. butstill needs more money to payfor lau nch costs and the manyother items that come with anylaunch campaign.

Most o f the mec hanicaleffo rts fo r Pha se 3 D are there spo ns ib i l i t y o f A MSAT­NA ( No rt h A mer ica ). Dic kWD oJ FAB presented details onthe s t ruc t u ra l an d the r mald e s ig n . wh ile Stan Wo o dWAoJ r\FY fo llowed wit h an ­tenna location and other consid­erat ion s. It has been quite ach allenge to o rie nt the space­c ra ft a nte nnas o n o ne face o fthe satel l i te wi tho ut ca us inginteraction problems .

AMS AT Board o f Directorsmember Dick Daniels WoJ PUJre lated informatio n on the pro­pulsion system. The satelli te hasa kick mo tor similar to the pre­vious Phase 3 satell ites. but italso has an ammonia arc-jet mo­tor that will be used for manymonths during fin al " tuning" ofthe orbit. The plumbing for themo tors is in pl ace and waiti ngfor fi nal wiring.

Lyl e J o h n so n WA 7G X Da nd C h uck G ree n N0 A D I

Saturday

/'11010 B. A MSAT VP of Eng i­neering. Dick Jansson U'D4FAB,coordinated flu- Phase 3D tailsat the AMSAT Symposium.

VN AMSAT·2 is nearly com­ple te , waiting for a chance 10be­c ome a n OSC AR ( O rb it i ngSa tell ite C a r ry ing A m a te u rRadio).

Da n Sc hu ltz N8FG V de­lighted the audie nce with h ispictures fro m the Hub ble SpaceTe le scope . Dan showed severa lnew and exci ti ng image s fromthc tel e sco pe taken afte r theShuu le repair mission. He hada few picture copies which wereincluded as handouts for tho seattending.

Bruce Paige KK5DO fin ishedthc Friday talk s with his descrip­tio n o f the efforts in Houston tog e t th e lo c a l Ho u sto n A re aA ~ISAT Net o u t to as ma nyhamsat enthusiasts as possiblevia co mmercial geostat io narysate llite lin k and HE The 1I0 us­ton net can be heard every Sun­day night at 10 p.m. Cent ral timeo n Telstar 302. Transponder 2 1.5 .8 ~IH£ audio subcamer or o n1860 k Hz a m from Missouri .Many VIIF and L:ilF repeatersin No rth Ame rica also carry thenet via the satelli te feed .

Ac tivi ties began in earnest at8 a .m. A~SAT President Bi llTynan W3XO gave an o fficialwelcome to the symposium par­tici pants.

With the scheduled launch ofPhase 3D o nly a year away. thefocus o f the symposium was o nthe new satellite. A~1 SAT VPof Photo C. SIan nbod WA4NFYEn g i nee r ing Dick J an s son and his cake-pull, J.2 GII;; hack­W D4 FA B mo der a te d th e fire al/tl'lll/o.

73 AmateurRadio Today · January 1996 55

various BB Ss. whi le registeredcopies can be purchased fromWBoJAPR or A~1SAT. AMS ATVP for Manned S pac e Act ivitiesFra nk Bauer KA3H DO, Joh nNi ckel WD 5E EV, and Ma ltBordelo n KC5BTL updated theg rou p o n t he p rogre s s ofSA REX , the Shun Ie AmateurRadio E Xperi ment. SA REX didvery well in 1995 with ran domQSOs and ma ny fine scheduledcon tac ts with sc hools fro m theham-astronauts .

Ignacio Martinez CE2~tII ofAMSAT-CE (Chile) desc ribedthe Fodtrak tracking and tuningsoftware. The program was de­ve loped in Chile to help fund thesatellite CESAR·\.

Oth er aft ern o o n t at ksincluded methods o f de velop­ing and ut ilizi ng sa tellite gale­way nod e s b y Barry Bain e sW DoJA S W. dev e lo p me nt o fmicrosat grou nd sta tion so ft ­wa re for Linux and x -wtndowsb y J o h n Melton G0 0 RXIN6LYT, .....ays to extend the li fe­time o f scie nti fic satel li tes byPh ilip C hien KCoJYER. a nd de­tails on the success o f the jointAMS ATrrAPR (Tucson Ama­te ur Pack e t Rad io ) DS P-9 3project. The Te xas DSP-93 c re wincluded TAPR Presi dent G regJones WD5IV D. Bo b DiersingN5A HD. Bob Stricklin f'5BRG,and Frank Perki ns WB 5IPM .

F in is h ing the a fter noon ac­t ivi ties wa s Phil Karn KA9Qw ith a de mo nstratio n o f d igi ta lvoice via the Wo rld Wide Webo n the Internet.

A brief dinner break followed.Eve n in g p re se nt ation s beg anwith a sli de show on sate ll iteDX by Mikio Mouri JA3GEP.

Do ug Ho ward KG50 A fol­lowed with the la test exploits ofballoo n enthusiasts in Texas. Hed escribed the many payloads inpre vious and current packagesthat the groups se nd to the edgeof space.

Da vi d Liberman XE lT Vshowed a " ideo of the attemptedla u nc h of V N A MS AT· I o na conve rte d Ru ssian IC BM.T he la u nc h f a il ed . b u t

Photo A. Phase 3D SatelliteProj ect Leader: Or. KarlMein:.er lJJ4ZC. mit/rent's theICJ95 AMSAT Span' Symposiumin Orlando. Florida.

HRMSRTS

T he 1995 A~SAT Annu a lMeeting and Space Sym posiumwas hel d Oc tober 6-8 i nO rl and o. Florida . O ver 200satellite enthusiasts listened 10dozens o f pre sentations and vis­ited the Phase 3D integration fa ­ci lity. For all partic ipants it wasa fantas tic weeke nd . STS -73was scheduled for launch duringthe weeke nd o nly 40 miles awayal the Cape. but d ue 10 we atherand other delays. it was a hamsatwe e ke nd and no t a ha ms ut/shunle weekend.

T his year the presentation sbega n Fri day be fore no onwith a paper by Bob BruningaWBoJAPR about a new softwareprog ra m ca ll e d APR track .G wy n Re ed y W I BEL o fPa cCo m m d e sc ri hed t hecapabil ities of the progra m andit s usc fo r d e termini ng t helocat ions o f g round stations a ndspacecraft using packet rad ioand G PS (Global Po si tioni ngS yste m ) d a t a . S ha re wareve rs io ns c a n be fo u nd o n

Andy MacAllister WASZIB14714 Knights Way DriveHouston, T X n083

Friday

The AMSAT AnnualMeet ing

was inacc urate in the earlyd ays fullowing the launch ofthe satellite. Ke n dete rminedthat the upper-stage vehiclehad explode d leavi ng man yradar target s in the area of thesatel lite . De termining whichspace objec ts were no t h ingbut debris. a nd whic h wasRS -15 became a c hallenge .W hile NORAD used theirsophisticated radar systems tocatalog the objects, Ken usedboth the NORAD/NASA datai n conjunc tion w ith the 10me te r ham -radio sig na lstransmi tted by RS- I 5 toc haracteriz e the orbit andidentify th e satellite.

Aft er Ken ' s talk , AMSATPre s id e nt Bill Ty nan int ro­du ce d the officers and Boardof Directors ' me mbers. Eachofficer or director was givena chance to speak to the group.It was also a lime for questionsa nd an swers from the atte nd­ing AMSAT membe rs.

Following a short break toallow everyone to catch theirbreat h and rela x. a fter data in­put ovc rload , the yearly ban­quet beg an. T he speaker wasDr. Paul S huc h N6TX. Las tyear he talked a bo u t "The

['ho ta H. Th e ammonia arc­jet motor will be on forseveral months after launch to[inc-tune the orbit of Phase 3D.

lo w earth orbit. all using VHFand UHF freque ncie s. Whil esti ll in th e ear ly planni ngstages, the program is thoughtp rovoki ng a nd may p ro vid efut ure satellite buil ders withideas .

S te ve Bib le N7HP R dis­cussed his efforts wi th t heWorld Widc Web A mateu rSa tell ite Groun d Stat io n.For those wit h Internetaccess, the add ress IS

h ttp://gndstn.sp.nps .navy.mi IThe system Steve created

m aintai ns data rece ived fromt he 9 ,6 0 0 -b a u d amateu rsatellite (UoSAT-Oscar ,22,Ktt sa t-Oscar 23 and Kitsar .Oscar-25). Steve also g ave anupdate on the PA~SAT projec tspo ns ored by the Nava l Po st­g rad uate School in Monterey,Califo rn ia . Us i ng spread ­spec trum tech niques, thi ssmall satell ite is sc hed ule dfor launch in 19 97 and wi ll usethe frequen cy range from 435to 43 8 MHz for both uplin kand dow nli nk . Work has beg unwith TA PR 10 provi de eart h­station hard ware and softwareto communi cate with t hes a t e flite . Up d a tes on thePA NS AT project can be foundvia t he I nte rnet at http ://ww w.sp .nps.navy.mil

SE DSAT Proj ec t Man age rDen nis Wi ngo KD 4 ET Ab rought everyo ne u p todale on the s tatus of theSEDS AT program. SEDSAT­1 is a mtcrosat -class satellitethat wi ll be part of NASA'sSmall Expendable De p lo ye rSystem (S E DS ) . Changes inlaunch schedu les have causedd e l a ys with this hamsat.SEDSAT will carry seve ralscientific and a mate ur-radioexpe rimen ts. The m a i npurpose of th e s at cllit c isto te st the dy namics of te th­ered satellites a nd remotesens ing . The SEDSAT pro ­g ram also ha s a World WideWeb home p a g e at h ttp://seds .lp l.arizona .edu

Ke n Ema ndes N2WWDcompleted the afternoon talkswith an en lighteni ng descrip ­tion of his effo rts to proper lyide nti fy the R us si an RS - 15sate llite and its orbit. Orbit ald ata from NO RAD and NASA

Photo G. A pmlotype of theJapanese SCOPE Digital ColorImaging Experiment camera wason display at the symposium.

equipme nt will be loc ated inthe s pacec raft wi t h ho lesstrategically located to all o wthe cameras, one wide angleand the o th er narro w, 10 viewthe ea rth at the orbi t's highpoint o r apogee.

AMSAT Imc grau o n Labura­tory Manager Lou Mc Fad inW5 DID wrapped up the morn ­ing talks with data on the com ­plex wiring harness for Pha se3D and methods now used inthe lab to keep up with all theparts to be bu ilt into the 1,000­pou nd satellite. Lo u joined thep roj e c t afte r ret iring fromNASA at the Joh nson SpaceCenter in Houston .

Afternoon sessions concen­trated on futu re satellite pro ­grams. Peter vekinis KC I QF!El4GV got things started withideas about very small sate l­utes. or pi co sats . Measuringo nly five inches on a side andincorporating active th ree-a xisstabilizat iun, Pe ter proposed aconstell ation o f picosats in

Photo F. tmegnnion LaboratoryManager Lou McFadin W5lJJD illlhe clean room with Phase 3D ShOK'Sthe loco/ion of one of the 12magru:lorquer rods to be installed.

characterize d vanous Phase3D co mputer syste ms . Themain o perations co mputer iscalled t he IH U o r In te rn a lHo u se k e e p in g Unit. Othercomp uters incl ude the GPSsystem and the RU DA K digi­tal communications controller.

Pete r G uelzow DB 20 S cov ­ered the Controlle r Area Net ­work or CAN that will be usedfor digital co mmunication be ­tween subsystems onboa rdPhase 3D.

AMSAT Pre si de nt EmeritusDr. Tom Cl a r k W3 1W I de ­scribed his Global Positioni ngSystem (GPS) experime nt forP h ase 3 D . Bd a le G a r be eN3EU A and his crew h a vebe en wo r k ing on t he GPScomputer subsys te ms a ndwriting software for use in thespacec raft . Bdale passed sev ­eral prototype boards aroundthe audience d uring his talk.

Hir oyu k i Ohara J M 3 MAJbrought a prototype of t heSCOPE digital color imagi ngexpe riment with him from Ja ­pan . Hi s presentation providedde ta il s on the specifications o ft he two -ca mera u n it. The

Photo E, The Phase 3D satelliteis progressing well at theAMSAT lab in Orlando, Florida.

Photo D. AMSAT Board memberand past President, Dr. TomClark W3IWI, shows 0111' of theL-band "salad bowl" antellnas

for Phase 3D.

56 73 AmateurRadio Today· January 1996

MORSECOACH

1972 , a group of satellite cbas­ers dec ided to try their hand atsome straight key CW via OS·CAR-6 during SKN. The ideacaught on and the tradition hasbeen maintained whenever therehas been a satellite available forthe event.

AMSAT Vice President of In­te rnational Affairs Ray SoiferW2RS invites interested satelliteoperators to participate in the24th annual SKN via OSCAR.He reports that there are no roles.no scoring. and no need to sendin a log. Just ca!1 CQ SKN in theCW passband segment of an OS­CAR between <XXXI and 2359 UTCon January I . 1996, or answeraCQ SKN call from another sta­tion. Contac ts via the moonalso count. Norninari:n> for best"fis t" can be sent toW2RS@WA2SNA.NJ.USA.NAvi a packet or toW2RS @AMSAT.ORG via theInternet. You can al so use hisCallbook addre ss. II

COMMODORE-USERS

8524 DAKOTA DRIVEGAITHERSBURG. MD 20877

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by 11 -, 182 pag e s , andsoftbound . It ' s well worth theco ver price of 51 2.00. AMSATcan be contacted at 1-213­5 89- 6 0 62 fo r det a il s onshi pping charges .

Straight Key Night

For many years the A RRLha s s pon sore d St rai ght KeyNight (S KN) on New Year ' sEve and New Year' s Day. In

G .AN =:! G ELECTR ONICSOF M A"'lYL AND

Photo M . Steven Bible N7HPRdiscussed Internet connectionsjor sareUite telemetry monitoringandj'utlw modesjordigitaJ saselluecomnuuIicalion. beyond Pbase 3D.

wh ic h las te d th rough mid ­Mo nday with a fe w breaks forfood and sleep . T he agendacovered many items includ ingpublicat ions, SAREX, the DS Pproject s ta tus , lon g -r an g eplanni ng , co m merc ial re la­tionshi ps , ne w sa te ll ites andthe budget.

The Phase 3D program wasth e mai n top ic th i s yea r.AMSAT still has a s ignific antchallenge ahe ad to pay its partof Ph ase 3D a nd ma i ntai nothe r ac tivities . Work on fundrai sing will continue to domi­n at e AMSAT' s o p e ra t io n suntil lau nch .

Pa ra lle l to Sunday' s BoDmeet ing , gu id ed tours we repro vided of the AMSAT lab fa­cili ty at the Orlando ai rport . Achartered bus furnished trans­portat ion fo r those inte restedin vie wing the progress on thesate ll ite and improvements toth e lab . M any di sp la ysand dem o ns t ra t i o ns wereprov ided.

Tucson, Arizona, is the sitefor the 1996 meeting . It is su reto be a fas cinating event s incePhase-3D will be co mple tedand waiting for launch. Don'tmiss the Friday ta lks . Be sureto come ear ly. Copies of theProceedings of the symposiumare availa ble from AMSAT orthe ARRL. The book is 8 112-

Ph o'o L. A microsat model fro mfive years ago resides in onecorner of the AMSAT Jab In

Orlando.

Photo K. One of the rest equip­ment benches in the AMSAT labin Orlando.

Ph oto I . Stan Wood WMNFYand Tom Clark W3lWI discussone of the GPS antennas beingprepared in the AMSAT lab inOrlando.

the result of the ARRL Match­ing Fund program run earlierin the year to help fin ancePhase 3D.

Prize s and AMSAT awa rdsfi ni s he d th e even in g . Thepri ze s ra nged f ro m bo ok s .T-shirts and ma ps to gear fromSS B Elec tronics, 50 copies ofWindows NT from Microsoft ,and a mobil e transceiver.

Sunday

Followin g the Field Opera­tions Breakfast at 7:30 a.m.,Bill Tynan started the AMSATBoard of Directors ' meeting,

Search for Dark Malter." Thist ime he provided details aboutthe SETI League. Paul is nowthe Exe cutive Director o f theorganization and prov ided ev­eryone with an in forma tive ,ye t light , d isc uss io n on these arc h fo r extra-te rrest rial in ­telligence . He has that un iqu eab ility to make the most com­plex topi c both understandableand fun.

Bill Burden WB lOR E of theAmer ican Radio Relay Leagu epresent ed AMSAT wi th acheck for 5305,000. This was

Photo J. A mock-up of the"eann" side of Phase 3D isused to tes' antenna locations inthe lab .

73 Amateur Radio Today . January 1996 57

Amateur Radio Teletype

lIS11II

WJth all these docks, you migttwant 10 kmw what urre it is - forreal! Tha need takes us 10 our website of the menh. a page wtric:hwill give you the ro:It::ct time,Wwn 10 the fraction of a seoond.direct from the U.s. Naval Cb­servatory Master Ckrl.. Pointyour web browser to:Mp:tAydkl.usoo.navy.rniJIwhoLJmIIand you will see a DaI~ graphicaOO a00tt0n to pJSh. Pushing the 001­100 will give )till a spreai of timesfrom a variety of sources. Given thedelays inherent in the cornmurUca­tioos system. I woold IKt calibrate aclock to the hwxlredth of a second,001 it is more accurate than that sun­dial in yourbackyard Enjoy!

Albeit a bit tale for some of you,my apologies to anyone I have keptwaiting for either a list of~orsoftware collections. While Iwouldlike to spend most of mydayon hamrndio or computers, the demands ofmy practice, family, and other pres­suresoccasionallydelay myrespond­ing to yourinquiries. Bythe time thiscolumn is published, Ishould bepretty

much caught up. If you have beenwaiting formyresponse form:re thana month or so. feel free to dropme aline, I may not have received the

original """""Work isprogressingon setting up

a R1TY Loop Home Page on theweb. Stay tuned. by the time thiscolumn is published it may well beonline. Try one of the search en­gines and see, you might be sur­prised. In the meantime, the RTfYLoop Software Collection contin­ues 10 grow. Get the latest list byscdiitg astamped. self-adiresseden­velope 10 the adlress 3lthe top or thecolumn, or by E-mail to me onAmerica Online (MarcWA3AJR),~(750J6,250I~"' ''''the

Internet (marcwaJajr@aol.com).~ again. if you're lucky, maybeyou' Ube aNe 10 downIood il from ahome page yo=elfl IillI

insfatlat:m p LttSS.Alttwgh the p0­

gram conf~ itself 10 open withfour clocks. th is is quite easilydIangc:d to ~ver )WI" heart de­sires . Additional clocks may beopened 00 the fly. so 10 speak. aro.closed again wi1hoot affectingthe rest

of the program.Unf_y,unimtillingthepo­

gram isrD soeasy.While there is anwrinstall l"CllJliD:. as required erwin­cows 95 compatible ptogJ::U lIS, it failswhen called, irdica'ing Ihat itcannctfmd the Wlinstall iog me.Sinceall thefiles appear 10 be installed in one di­rectory, erasing thai: directay etfec­lively gets rid of the program.However. I cannol leU, ill this point, ifthen: art rD some scattered IN1 files,pointers, or registry data remaining.

InsOOn. ifyou have aneed for sev­eral clocks on the screen aI one time,wmZones may be just whal you arelooking for. Wmdows 95 comes withaclockof its own. on the taskber, So.ifyou havenotrouble converting fromlocal time 10 GMT or Ihe time zoneof your CUJTent contact, this prOOuctmay beoverkill. Hyoe are interested.oonIact ExIeOO aId leU IWnyoo readabout it in "RITY Loop."

Now, if all yoo want is an analogclock 00 the screen, in.'itCad ofthelittledigital taskbar icon, check outrclockexe, one of the "powenoys"from Miaoooft. Available free ontheMicrosoft Home Page,as well ao><lta'bulletin boards near you. this littledarling puts a rwnd d ock 00 yoorscreen, through the magic of win­WlNS 95's sophisIicaJed windowingsystem. Of course, you can con­figure il 10 be a digital clock aswell. While you can' t use it to putmultiple clocks on the screen, and

it can only display the syslemdod .time, it may be all yoo reed If youwart this little darling aro. can't fmdif. in your TEigttotDod. I wooJdn'tbe surprised if it didn' ( tum up on aRTfY Loop Software Collectio ndisk, real soon!

Visa, Me. UPS CODTom (W60RG)Maryann IWB6YSS)

may be set to any time zone. Avariety ofcities are p:ovicbl. in adatafile. whrl1allowsthe geurntedclocksto highlighl time zones arooOO theworld. The four clocks from myscreen cerronsrare the degree ofCUSIOm;zatjoo p:x:;sible. Clocks mayhe analog. using Arabic cr Romannumerals, or digital. Typefaces, size,and color of the clock may all bechanged a will.1h:reisevenooa1lmtfunction. in<ficared by 1he red arrow00 the Jerusalem clock in the Fig. 1.tha can beused for any PJIllOSe 'tIo'I'cean alarm migtl: rome in handy.

Indicatas 00 the dock face iOOi­eate daytinl: cr nigtu:tim:: by a littletree in the SlID or moon being dis­played, .oodayliglxsmings tim: maybe activated individually for eachclocktoallow C<rdifferen:es in day­ligtt savings time observance in dif­ferent areas.

The program installs easily, usingthecommon "a: setup.exe"~. Itopens the Setup Wizard, whichquickly steps you through the

(8l8) 447·4565 M·Th 8am·5:3Opm

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TV<:-4Gonly $89

SEE THE SPACE SHUTTLE VIDEOMany ATV repeaters and individuals are retransmittingSpace Shuttle Video & Audio from their TVRO's tuned toSpecenet 2 transponder 9 or weather radar during signifi·cant storms, aswell as home camcorder video. "it's beingdone in your area on 420 • check page 538 in the 95-96ARRL Repeater Directory or call us, ATV repeaters arespringing up all ever - all you need is one of the TVC-4GATV 42Q.450 MHz dcwnccnveters. add anyTV setto ch 2.3 or 4 and a 70 eM antenna (you can use your 435 Oscarantenna). We also have ATV downconverters, antennas,transmitters and amplifiers for the 400, 900 and 1200 MHzbands. In fact we are your one stop for all your ATV needsand info. We ship most items within 24 hours after you call.Hams, call for our campl.tel0 page ATV catalogue.

Marc I. leavey. M.D., WA3AJR6 Jenny LaneBaltimore MD 21208

I guess I """'" begin this monIhbyplying ane:ntion to thed:u on therover of the magazine. and wishingeach and every one of you a HappyNew Year! My most secee wishesfer aHealthy aOO Happy 1996 10 allof my readers.. Wilh this inlm:st intime, I have several items of interestto the ham paying anention 10 this

detail ofour lives.Tbbegin with. anew~ has

hit the: markd.called WtnZooes. bill­ing iIsdf as a ''comprehensive timezme tCilily fexWnbws." Pnxh'CCdby Extend, Inc.. in~ Cali­fornia, the programgereraes a num­ber of rostomizable clocks on theWuxklws desk1cp. II is available inversions fa both Wtrdows 3.1 ardWtnlbws95. andIhavereviewed theWto:k:lws9S version.

As you can see in Fig. 1. theprogram's window can he filled by a

clock, either analog or digital, which

58 73 Amateur Radio Today· January 1996

Your Tech Answer Man

.I' Female Voice & Sound Effecls

.I' Programmable Courtesy Tones.I' ProgrOlTlmilble Codes and TU1Iers

(8ITletere]

(2 m e tere](220 M Hz]

[7Dcm]

DXP-L180DXP-V1 7 5DXP-V220

DXP-LJ 1 5J

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Tel: (BCXJ) 77B-0551 Fl!'Ix : [8 1 B] SSB 81 80VlSA,I'MASTERCARD

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THIS IS NO MIRAGE.

TELETEC

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T h is is rea l . 'reieeec OXP a mplifie rs . te's c r..sriy theb ast; V HF amp li fi e r s roun d. Uns u r p s s sedccrri rr-e r-c tei-r..v e l qua lit;y. P rice . P e r-fo r m a n c e .Fsaturea. A n d m ade in tho!! U SA. It;'s t h O!! a mplifiereverybody wanta to own. N o w a vaila b la tor 8 , 2,2 20. and U HF.

CAT-300 Controller Board $299.00 Wired and Tested

Write or Call jor a brochure describing the CiT-JaJ Conuouer,including schemoric, voice word list, and CQ/llrol functions,

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Online and other online services.Rep rin ts of the article areavailable f or $3.00.-ed.]

Using a computer as a TNC re­quires adding a small modem. Youcan buy one for about $50 (consid­erably less than the price of a hard­ware lNC), or you can build one,which will be a nice introductionto lhe technical side ofthe hobby. Ibuilt mine for about $20, and itworks fmc.

As for CW, there's all kinds ofpublic-domain software that willhelp you. You can get sudycccrseswith audible practice drills. You canalso get programs which will actu­ally key your rigand send CW, andsomecan evenreceive itprettywell,showing the decoded characters inplain language on your screen!Truthfully, though, CW is not themost machine-friendly mode; ifyou practice. you can learn to re­ceive Morse more accurately thana computer can. Besides, it keepsyour skill up. I do have both trans­mit and receive on my CW pro­gram, but I never use the receive.SUlI, the transmit funct ion saves a101of wear and tear on my arm, andlets me send bettercode than Icouldwith my iambic keycr. It 's not asmuch fun, though.

If you get into contesting, log­ging programs can help you avoiddupes (duplicate contacts with thesame station). And, when you' redone, you can have the machineprint out your logs, ready for send­ing in for your awards. I don't carefor contesting, so I don't use any­thing like that. BUI , manynoncontesting hams still like log­ging programs, simplybecause theymake it easy 10 keep track of con­tacts. It's quite nice to answer a CQ("calling anybody") and call up00lcS regardingthe lastconea withthesane station. The other ham willsure be surprised when you say,"Hi, Bill, how's your dog's arthri­tis these days?"

If you get a C D-ROM drive foryourMac, youcan install a callbookdatabase that'fl let you look. otheroperators up by theircallsigm. Es­pecially if you want to QSL (ex­change reception report cards), thaI

HumbfW S' 011 row FNdtMcIc CM'fI

KRBOOMRSK

Michael J. Geier KB1UMc/o 73 Magazine70 a cute 202 NorthPeterborough NH 03458

MaIlC8111

This month. I'd like10 devote thecolumn to answering some ques­tions. Keep those letters coming,folks. but please don't includeSASEs; I just can't answer letterspersonally. Those relevant to thecolumn will be dtscusscd here in themagazine. Here goes:

Dear Keboom,I recently bought a Radio Shack

OX390 receiverandam oowthink­ing about greater involvement inham radio. I was excited by yourarticle in which you discussed how

computers can be integrated intoone's shack. I have a Mac Plus with4 Megs of RAM. How arecomput­ers actually used in ham radio. andwhat kind of software is available?

G~tling My Feet WC"t

Dear Wet Feet.The computer has loomed as the

greatest advance in ham radio sincesKieband and FMcame along. Howdo we aetually use computers?Lotsof ways! They depend, though, onwhat facets of ham radio intrigueyou. You mentioned you were in­terested in CW and packet Packetis.ofcocrse, acomputermode rightfrom the: word "go." In pecket, youcan use your computer as a termi­nal foc a separate hardware TNC(terminal node controller- thething that actually makes and de­codes packets), or you can savesome money and use the computeras the TNC itself. That's how I doit here, because it saves methe 0051ofalNC. Several "software lNC'programs which let you do that areavailable for the PC, and there's atleast one for the Mac. Some of thePC programs are Baycom, SoftlNC, and Poor Man's Packet.

(See "Packet on the Mac, .. inthe October '92 issue oJ73. 1n thearticle, KD6CMT mentions aConto l Panel ca lled SoJt Kisswhich emula tes a THC in KISSmode. KD6CMTsuggests using itin connection with NET/ Mac,

73AmareurRadio roaer - January 1996 59

NumbtH 60 on your FeedNcll c.rd

CRRR'S CORNERcan save a great deal of time andeffort on the air, because you don'thave to exchange addresses.

Particularly because you're justgetting into the hobby, you' ll lindyour computer very useful as astudy aid. Any ham-oriented BBSshould haw lots of exam simula­tors and study guides 10 help youearn your license. Good luck, and Ihope you're on the bands soon!

Dear- Kabocm,The schematic in your ankle for

the Kenwood ~C-85 microphonemodification did nOI show the re­sistor numbcrs for the 22k and ~.7k

resisoo Alsomissing is ttr capaci­tor number for ihccap between IC Ipin 2 and the 12k resistor. I'd liketo modify my mike to work likeyours,hut Ican' t figure nut thecon­version without those numbers.Canyou help?

Miui",~ Info

Dear Mi...~in~ ,

Sorry about that ! Somehow,those numbers got removed fromthediagram. Here they arc:the 22kis R9, and is connected between thewiper of the compression control(VR2) and ICI pin 6. The 4.71 isR23, and is connected between oneend ofthe same control and ground.And, the 3.3 IlF cap is C8. and isconnected between Ie I pins 2 and6. Hope that helps.

Dear Kabeom,I've been off the air for months,

due 10 a failure of the MRF 485driver transistors in my KenwoodTS-930. I was told th,lt Motorolano longer makes these transistors.I tried a pair of NTE 236 transis­tors, which arc listed as replace­ments, but they promptly failed. AKenwood technician told me thaithe company docs have a replace,ment transistor, btU he no longerdocs the~ repairs. Abo, there areother modi fi cations necessary. Isthere a retrofit?

Unwillingly Silent

Dear Silent.1\1y ECGcrossrefcrcrk:chssuese

a.s ECG 236. I haven't heard aboutthe retrofil prdtlcm. bul it would payyou to try and get that Kenwoodicchto send you the details ofthcrequiredmodif icai. lit Pnnlhly. it'sjust the ad­dition of a capacitor or somethingsimilar. I.!U'fllX1.ltkugh. thai the1\'1£

2365 failcd foranotherreason. MOSIlikely. both they and the originalpan s blew because something elseis wrong, If I had to guess withoutactually seeing the radio, I'd won­der about your fi nal transistors. Areyou sure ihey'rc not shorted'! Driv­ers usually don'l go when the final sare good. and shorted finals willblow drivers faster than you can hitthe -ort" switch. Before investingin yet another pair ofdrivers, checkthose final s. Also, try RF PartsCompany. (6 19) 744-0900. and seeif they have any other replacementsfor the MRF pans. They carry allkinds of RF power transistors.

Dear Kaboom,I enjoyed your articl es on oscil­

loscope usc. I picked up a scope .uthe last hamfcst. hut I don't under­stand one thing: when I hook myprobes to rbc calibrator termina l, Iget a nice square wave as long asthe probe is in the XI position .When I set luc X. though. the wavelooks like something from outersp ace! It has big spikes at the topand bottom which then slope in­ward grad ually to the end of thewave. Did I buy a harnrcsr night­mare'

Dear Puzzled,Nope! Your scope is fine. It just

watches the X-Files too much! Se­riously. though. all that' s wrong isa simple adjustment, and you don'teven have to open up the case to doit. Take a look at your probe andyou' ll see a little hole with a screw­driver adjustment slot in it. Usually,it' s on the pout you hold, but it mayalso be on the pan that plugs intothe scope,This adjustment sets thecapacitance of the probe when it'sin the X10position. Due to the veryhigh input impedance of about 10megohms. the amou nt of capaci­tance ha.s it great effect on the re­sulting waveform.Just seuhc pruheto the XI0 position. connect it toyo ur calibrator. and adjust theprobe's trimcap until the waveformstraightens out. You' ll find thai ifyou then usc that probe on the otherchannel, you' ll haw to readjust it;that's how critical that selling is! Bythe way. that's why calibrators hawsquare waves, instead of just sup­plyi ngcahbrutcd DC voltages withwhich to set the channel gain.Until lU'xl time, 73[mm KB IUM.

Joseph J. Carr K41PVP.O. Box 1099Falls Church VA 2204 1

Another Potpourri

Several times a year I dean upmy "in box" and take on a fewtopics that are not worth an en­tire column, bUI are of interest toreaders because most of the ideasca me fro m questions or com­ments in my mail box , Whichbrings up a litt le hou sekeepi ngmatter. You can reach me at mypost office box (P.O. Box 1099,Falls Ch urch, VA 22Q.1I), or byInternet E-mail at carrjjwaol.com

Science Fair Project for aRadio Buff?

One of the topics that r ye writ­ten about e xtensively over thepast Iive years is what I call "ra­dio sc ie nce o bser ving." Thiscoined term refers to radio as­tron omy, pro pagation observa­tions, an d VLF SID (sud denionospheric disturbances) hunt­ing. The latter requires a VlF rc­cciver. which can be built usinglow-cost components. VLF SIDhunters look for the effects of so­lar fl ares on the ionosphere.

Because the distance betweenthe Earth's surface and the bot­tom of the D-Iayer of the iono­sphere is only a few wavelengthsin the 15 to 30 kHz band, a sud­den increase in ionization (as oc­curs during a flare event) causesthat space to act like a waveguideat VLF frequenci es. !I. friend ofmi ne uses a ge iger co unte r \0

record solar na rc even ts, He looksfor sudden increases in back­ground radiation levels. It mightbe interesting 10 look for solarflares using both the VLF receiverand the geiger counter, and notewha t correlations do or do notexist.

If you do nOI own a VLF re­cetver, and are not inclined to buildone, then you might wish to con­vider using the shortwave bands.The HF sbonwave bands are not thebest bet because there is a 1<)1 ofvariation in those bands under thetest of circumstances. But you canmake some recordings using theapparatus described below.

The trick is to monitor a sta­tion that stays on the air most ofthe time. The National Institutesof Standards a nd Technology("' 1ST) rad io st ati ons WWV(Colorado) and WWV II (Hawaii)are pretty good bets.Try monitor­ing the 5,10, or 15 ~1U l signals.

Recordings can be made witheit he r a s trip cha rt reco rder(which can be obtained relativelycheaply on the used market ), orby using an NO convener feed­ing a receiver. Althou gh AID con­

verters were once expensive toys.nne can now buy them relativelyreasonably.There arc models thatwill plug into the paralle l printerport on the hack of your computer(yep , that' s what I said ...thc par­allel port). These devices use thefour bidirection al handshakinglines to take in the AID signal.Others are available that will plugd irec tly into the RS-232 serialcommunicat ions port on the backof the machi ne . Radio Shack nowoffers a digit al multim eter thatcontains a computer interface, andthe software to drive it.This meiercan be used as a data acqui sitionAID converter.

Doing radio science observingmay seemli ke a waste of a com­puter, hut today you can buy non­Windows pes for a song and a

heartbeat. I' ve seen 286 machinessold for S10 hy a local hospi talthat had just upgraded to 486­DX4 machi nes . The used ad s,hamtests. and local used com­purer Sluff stores can sell an .80svintage PC·XT class machines for$50 to $100, and 286 mach inesfor a bit more. I recently bought a386-33 machine at a loca l usedcompute r Sluff shop for $200complete with monitor. So, as youcan see, setting up a monitorings tat ion ne ed no t be te rr iblyexpensive.

Fig. I shows the circuit neededto obtain a DC signal that is pro­portionalto the signal strength. Ofcours e, if you can get to thereceiver's automatic gain control(AGC) signal , then use it. But

that's not so easy as it was when Iwas a Novice , so many readerswi II want to opt fo r the circuitshown in Fig. I.

60 73 Amateur Radio Today · January t996

Uncle Wayne'sBookshelf

specific frequency and Input/out­put impedances that you need foryour application .

The ARRL Handboo k has asoftware di skette acco mpanyi ngit wh ich makes the calculations ali ttle less tiresome for those forwho m a firs t course in high schoolalgebra was mOTC traumatic thanus ing up a li ttle hard drive space.

It carne as a bit o f a shock whenI ordered the Hum/bo ok. It' s beena couple years s ince I bought acopy. so I was a litt le taken abackby the S38 price tag , That's morethan te n t imes the price I paid formy fi rstARRL Handbook...wh ichdales me a bit, uoesn't it??? Youcan get the ARRL Ham/book fromlocal ham sto res or f rom theUncle Wayne 's Bookshel f (seeads in this magazm c j. m

I'tlont ~Jll..l 7..\ -nJj .". t1U ) . ,,!"\-(.~~. h\XlIOl-9U-H61l . .". II« <>rdor fomo o.~ 88 forord<ruo. ,ofoona_ .

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Harmonic ene rgy from our trans­mi tt e rs wi ll clobber o ther ser­vices. notably television and fl\.1broadcast radio hands (those fre­quencie s that a re harmoni call yrela ted to the ham band frequen­cies). For transmitter harmonicsuppressio n we would usu allywant to simply buy a 3()()...walt or2.000-watt low-pass filte r and bedone with it . T hose fi lters have acut-off frequency bet ween 30 and40 .\1 Hz . so o ffe r a subs tant ia lamount o f attenuation in the 54­~tIIz . and up. ba nd occupied bythe te levisio n sta tions.

But what do you do if you wantto make a fi lter for another fre ­quency? For example. supposeyou wanted to bu ild a 3-kHz au­dio filter for usc as at the input o fthe speech amplifier in a transmit­ter, or at the outpu t of a direct con­versio n receiver. Well. you builda circuit such as Fig. 2. One wayto design your own fi lter is to lookfor a " norm alized" design. andthen frequency scale it. Such fil ­ters will show the val ues for somefrequency such as I Hz, I kllz.or I MHz. and then you scale itby dividing the pri nted co mpo­nent valu es by the actual 3 dB cut­oIT frequency you want. That's theway my "FilterMaker" softwareworks. Crude. hut you get results.

But wha t do you do if you don ' twant a 50-ohm filter? Most of thetables published are for filt ers thathave 5O-0hm input and output im­pedances. which is the standardfor RF systems. But in those au­dio cases mentioned above youm ight prefer to use 1000 ohmsrather than 50 ohms. Also. if youdesign ci rc uits for the N E-602

chip . you can avoid the use ofImpeda nce t ransfo rme rs at th einput and output terminals (pins1/2 and 4/5. respec tiv ely) if yougo ah ead and design the fil te rs forthe 1500-ohm impedance offeredby the NE-602 device. rather than50 ohms.

The 1996 ed ition of The ARRLHandbook fo r Radio Amateursho lds the solution fo r you. O npage 16.6. the circuits for bothcapacitor input and inductor in­put low-pass filt e rs arc shown.along with the table for the I ra­

d ian/second. I-ohm capacitor andinductor values. You can use theequati ons shown in the art icle tocalcu late the values needed for the

,

levels are generally sufficient touse n early any po te nt io m eterfrom 10k to lOOk. In my case. Jhad a pair o f likely 25 k lineartaper pote ntiometers, so I pressedthem into service ,

By the way . i f you or someyoungster you kno w is bu sy withthe science fair act ivi ty in thei rschool. then you might want topro vide the m with a copy of mybook The A TI of Science ($ 19.95,l ligh'Iext Publications, PO. Box1489. Solana Beach. CA 9 2075;1 -800-2~7-6553) . The chapter onwinning science fairs is worth thepri ce of the book alone. Bes ides.

the rest o f the book will te ll themhow to do science and ho w tohandl e data .

Bill Orr W6SAI. whom any b on­est technical writer today will rccog­nize as the guru of gurus. wasextremelycomplimentary in a reviewofthe book in anothl..T ham magazine.He was especially enthusiastic ahoJtthe chapter titled "Counterfe its ofTruth," which deals with the logicalfallacies. If you have any interest atall in intellectual honesty. then you

might want to bone up o n thefauccies...andcompare wi th the newsmedia and our politicians.

Low-Pass Filters

A low-pass filter (Fig. 2) isneeded by nearly all ham o pera­tors w ho u sc t he H F ban d s.

l2 L3

This circuit has two part s: arecti fi er and an integrator. Therectifie r is a vol tage doubler typethai uses IWO capacitors and IWOd iodes. The capacitors are each 10J1 F units (the straight line side be­

ing positive), whil e the diodes areIN60 germanium signal di odes.That may surprise you in this sili­con era. hut those 1950-type di­odes a re prefe rred In th isapplication because o f the lowervoltage drop (0. 2-0.3 volts ra the rthan 0 .6-0.7 vo nsj compared tosilicon diodes. Radio Shac k andother sources still offer I~3-1 and1r-;'60 diodes , usually in a blister

pack of about a gozillion diodesfor a few bucks.

The integrator produces an out­put that is the time average of theinput signal, so it tends to smoothout very sho rt varia tions in thesigna l (e.g .. noi se spikes). leav­ing the signal strength variat ioncompone nt. There are ac tu allytwo methods of "integrating" thissignal in this ci rc uit. First , theaction of the output filte r capaci­tor, which is also part of the m il­age do ub le r c i rc ui t , tends tosmooth vari at ions. The secondfac tor is the inert ia o f the metermovement and the recorder penassembly.

Levels to the meter and (if youuse it) the I- rnA recorder as scm­bly can be contro lled with poten­tiomet ers . I found th at signals'

Fig. 2. Low-puss fil ter circuit.

L'

T

J1

Fig. J. Audio-to-De com'enrr fo r recording signallevels.

cr ; ~

.,....DC ...,."

73 Amaleur Radio Today. January 1996 61

Monv spin-off lessons cOllie af ter a guest speaker lia s visited a hamradio classroom. Here's Kristy; Blh grade.

62 73 Amateur Radio Today · January 1996

Uncle Wayne'sBookshelf

If each kilowatt-hour costs 10cents. about ho w much does itcost to light your clas sroom forthe year? Can you think of twoways to cut lighting c o sts inschool and at home?

The students enjoyed runningallover the cl assroom. jott ingdow n the wattage inform ation .More importantly, it made the maware that there is a real cost toconsumption o f electricity. m

PhI,n" MlO·174-7JH <If W3-~14·(l).~ " . ~AX

603·924·"613. 0' ''''' "".ler I""" 0" POll" "" forordctinll inf"rmll~,n

Books and Tapes for

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Hands-on rxperimems can be "energ i::Jng."This is Mohammed. 7th grade.

can becl a sse s

Procedure:

L Pour about t inchof water in the pan.

2. Place the spoonsand the glass rod ortube in the hot water.Whieh object do you

think will become thewarmest?

3. After 2 minutes.re m o ve the o bjec tsfrom the water. Whichone feels the warmest?W hich one fee ls thecoolest? Children wereasked to ex plain why

on their papers.This wa s a reall y

s imp le ex pe r im en tde sig ned fo r lo w e r

gr ade s. O f co ur se i tad ap ted fo r o lderaccording ly.

1. Find o ut how man y li ghtbulbs are used to light your class­room.

2. Find out how man y watts ofelectric ity each bulb uses. (Morewatts means more electrici ty isbe ing used .)

3. Total the watts. Be sure to

include the watts for each bu lb.4 . Divide the total by 1000.5. Multipl y your an swer by the

average number o f h our s [h ebu lbs are left o n during eachschool day.

6. Multiply your answer by thenumber of school days in the year.This wi1ltell you roughly the numberof ' 'kilowatt-hotm;" of electricity the

Iigks will use in the school year.

The ne xt activi ty led to severalspin-off lessons in math and sci ­cnce. " How To Figure ElectricityCosts" brou ght us many favorablecomments fro m the parents. Ma­terials needed : classroom lightinginformation (wattage and number

o f bulbs in the classroom).

Electrici ty is a fonn o f ene rgyused widel y in homes. schools,and other bu ildings . Choice anduse of lighting and applian ces af­fec t electrici ty costs. This ex peri­ment will give you a rough ideaof how e lectr ici ty costs aredetennined.

Procedure:

How To Figure ElectricityCosts

limited and costly. That 's whyconserving energy is so impor­tant. After the expe riments werecomp le te d , the ch ild re n wereasked to add to the list they hadmade.

The first experiment dealt withco nduction. The materi als neededare: hot water, shallo w pan. metalspoon. woode n spoo n. plas ticspoon. and a glass rod or tube .

Heat is an important fonn o fenergy in the home. Heat is "mol­ecules in mot ion." Molecules arepanicl es th at are too small to seewith the ey e. All things arc madeof molecu les. They move backand fort h slowly at cool te mpera­tures-c-faster at wanner tempe ra­tu re s . He at can move byconduction-heat pass ing di ­rectly from one thi ng to anotherthrough touch. Convection is whenso mething heats air (through con­duction), which then rises. carryingthe heat elsewhere. Radiation is in­visible "heat rays" which carry heat

away from somemmg. (No touch­ing of oO.i«l~ or movements of airis needed.)

H o me s, schools an d o therbu il din g s lo se he at in coldw e athe r, an d ga in heat inhot we ath e r by co nd uc tio n .He at is " co nd uc te d" th roug hwalls. doors. window s. etc . Inthis e xperime nt yo u ' ll " fee l"conduction at work.

Background:

WITH CLRSSHRMSCarole Perry WB2MGPMedia Mentors Inc.P.O. Box 131646Staten Island NY 10313-0006

Energizing Experiments

There are lots of obvious goodreasons for including a unit onenergy in your ham radio curricu­lum. Whi le lining up my gue stspeakers for my classroom thi sterm. I dec ided to invite a spokes­person fromour local electric util­ity. Con Edison. Guest speakersare alway s a good idea. Theybring a change of pace and facefor the youngsters. or to whom­ever yo ur daily aud ience is. Wewou nd up having sev eral assem­bly programs be ing given so thatother children besides the hamradio students could benefit fromthe visu. Here are SOI1'le of the ex­periments the children seemed 10enjoy the most.

All of us know that energy is abig pari o f our li ves. Scientistsdefine energy as the ability to dowork . There are man y fonns o fene rgy; for example. there areheat. light. electricity. movementof air. water. and machines. andgravity (the earth's pull ). Therearc many so urces of energy; forexample. there are foss il fuels, hy­dropo wer, nuelear power. and so­lar po wer. Sheets of paper weredistributed for the students to listthe ways in which energy makestheir lives better. II was pointedou t that some energy sources are

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In Phoro A, you' ll see the finalresult of my work. Agai n. lei mestate this is /lot a finished project.T here is e nough information foryHU to pick up where I have leftoff. Thi s is nul the las t word in ad igital SW R meter by any means.

I have also tried to add the sec­o nd circuit to the DPM . Ratherthan reading the vol tage producedby the RF sensor, I tr ied to makea digital fi e ld strength meter, Inits s implest form. the me ter willdi splay the resulting voltage de­vetoped by the detec tor. Again. anop amp is used to up the voltageto a mo re suitable level.

Notice. the field strength meterhas no tuned circuits. In fact, ithas a response from DC 10 light.

By add ing some tuned ci rcuits.one shou ld he able to sniff out RFon a very narrow frequency range.If yo u like twisting knobs and di­al s, then insert your tuned circuitbefore th e detector an d th e an­renna. Use shielded coils to pre­" em unwanted pick up from coilto coil. Digi-Key stocks a largeassort ment of RF coils in theircata log. A plastic A~1 broadcast365 pF variable capacitor fro m adefunct transis tor radio wou ldmak e an ideal capacitor to tuncthe circuits into resonance whilekee pi ng the size of the fieldstrength met er down.

There is st ill one more projectI wanted to try with the digi talmeter but have not had the time. Iwanted to measu re the vo ltagede veloped across a dummy loadand then di spl ay th e result. Intheory. it should work. In FIg. I .a s imple RF detector. will convert

o ff the project. If you don't hap­pen to have a 3PDT swi tch. justleave the DPM on as it shouldoperate for the shel f life of thehattery. That's not the case wi ththe op amp circuit.

Projects

Photo A. Micnoot U,,:,re digital panel meter with micnranp RF pickup.

by my QRP rig, did nOI generateenough for a large readi ng . The

re flected reading was eve nweaker. as it should be.

Looking back. the micrustrip isprobably not th e best th ing In useat HF frequenc ies. Instead a tor­oi d pickup wo uld be be tter. Icould modify the transformer' ssecondary to increase the result­ing voltage ge nerated by the RFpa..sing though thecore. I also fig­ured the toroid would he morefreq uency to lerant.

I ended up us ing an RF pick.upfrom a an o ld project I had layingaround. I used one of many cl as­sic RF sensor projects. man y ofwhich 'Ire in the ARRL Ham/book.My pickup wi ll ge nerate hoth thefor ward and re flected volt agege ne rate d by th e RF flowin gthrough it. E verything goes insidea deep dra wn aluminum box. Allleads leaving the box go th rough.00 1 feedthro ug h ca paci to rs.which I might add. are ge ttingharder to come by,

Once the RF sensor had beenbuilt. the next step is to increasethe vo ltage developed by the sen­sor to a usable level needed by theDPM. To do that, I used an op­amp a." a voltage amplifier.

Ha ving spent most of a Satur­day night working on the the volt­age amplifier. I found that thepopular 7~1 op amp did not pro­vide a low enough o ffse t with nosignal. So. a LTC lOOI op amp byLinear Technologies was put intouse. An OP-07 op amp may alsobe used. bUI are much harder to

come by. Dig t-Ke y stocks theLTC 1001. The LTC 1001 is about$2 a po p.

Instead of sweating blood try­ing to co me up with a du al-volt­age po wer suppl y. I cheated andused two 9-\'01lIransis tor bauer­ie s. A third bat te ry is used topower the DPM . Th is DPM musthave its own power MlUTCe. Ajunkbox 3PDT switc h is used to tum

reifIpuIt<> OPM

"l>P\)T s-._ _1heloronu-d RF _ ... ,..,,_RF sc:ale /rcftl eeRF -'b_

OK 10 uSc 7~ 1 amp, 0u1 addi tcnal""' , 'PO'oents may be mqu,f9(j 10DaIa"Cll~ outpulll$ _ lei zero aspo II'e

Problems

carrying the RF from one connec­tor to the other. It required only afew cuts with the side cutters 10remove the unwanted parts. I keptthe metal case and added some.001 fcedthrough capacitors be­tween the RF section and thedigital section.

The diodes used in the originalmeier were 1N9 14s. I replacedthem with t wo hand-se lectedI~34As. Better diodes are ava il­ahle for this purpose. but I hadthose guys in hand .

The DPM has a input imped­ance of ove r 100 megohms, soloading of the senso r would notbe a pro hle m. A t wo- pos itio nsw itch allowed me to se lect eitherthe forward RF position or therefl ected power position. Themeter will not read out SWR, butrather the voltage generated hythe forward RF and the reflectedvoltage caused by any standi ngwaves on the feedline and an­tenna. To read the actual SWR, ag ra ph wou ld need 10 be con­structed to show the voltage gc n­crate d by the refl ect ed RF. Ofcourse. the voltage would only becorrect at a specific RF OUipUI.This is something I have nor done.Common sense should instantlytell you the highe r the reflectedvo ltage the highe r the SWR is o nthe antenna sys tem.

Even with an input of 200 mv,the resul ting vol tage developed

17~K 1%

••

-.

174 l( 1%

"

"

n._.. -.pIily ..-.dfOps~" 56l<_

"1_"' ,..,;110 be_

,'"

From RF d<!tec1Cf

We ll , anot her new ye ar.

It 's a perfec t time 10

start new projects, a nd plunge

into the unknown . Jo hn

N8ZXB and Scott N8JSKhave taken up tattoo ing Yaks .

A rewarding and hi ghly sa tis­

fying hobby- as Scott c alls

it.I am nOI into Yaks, but I do like

to play with digital panel meters.In the past. I' ve mentioned the 0 1International DPM 5035L as arather diverse DPM. So. to startout the new year, I'll show youwhat I've been doing with th ismeter.

Instead of di splaying a voltageobtained fro m a po wer source,I've been tryin g to m arry theDPM to a microst rip Rf pickup.Up to a certain poi nt, I' ve beenmaking some progress. Here's thebasic idea.

The firs t thing required is someway of picking o ff a smal l amou nto f RF comi ng out of our rig. Ihave been work in g on severa lmethods, bUI the stripline seemsto work best for me. In fac t. myfirst auempr was in usi ng a de­funct CB SWR meter. It had theproper power capacity and th emeter had a microstrip already inplace . Instead of using PC boardcopper traces for the actual mi ­cro lines, me C u SWR rueter usedtwo large copper wires placed inparall el to a si ngle conductor

QRPMichael Bryce WBSVGE2225 Mayflower NWMassillon OH 44646

Low Power Operation

Tattooing Yaks

Fig. I. Schematic a/the DPM.

64 73 Amafeur Radio Today · January 1996

Welcome NewcomersWayne Green W2NSD/1

73 is looking for hamrelated photos

for use on the cover,Call 800-274-7373.

in their area to upgrade.I' d hoped tha t I could make a dif­

ference with Radio Fun. The hams Idid get to subscribe liked it a 101_Ithink ....e had one of the highesl per­centages of rene....els in publishinghistory. But, as I explained. I'venever had any interest in doingsomething just because it makesmoney. If it isn't go ing 10 somehowbe a bene fit to mankind, the heckwith it.

ulOk, the ARRl o bvio usly isn' lgoing to do anythmg about this, andI' ve failed, so it's all up to ) '00 Stanseeing .... ha t you can do to get theseTechs to upgrade and haw some funwith us on the low hands . Get ' emon packet. sate llite s, or maybe aDXpctlition to Suuth Yemen, It' sbeen a while since I operated fromthere . Or perhaps New Caledonia.....here the local hams are veryfriendl y and will le nd you their sta­lions, so you don'l even have 10carry your rig and antennas along.Get on from there and work 10,000J's in a week, and YOU'll sec whatgood operating sounds like. m

[

I get a lot of club newsletters . butI dlln' l recall seeing one with a re­quest from the cdaor for the mem ­bers to .....rite about any ihi ng excitingthey' ve done in the hobby. Amateurradio has provided a lifetime of ex­citement for me, ..... hich I try to sharewith you. If I can get on the air fro mSouth Yemen. so can you. It d idn'tcost me anything because I kept Illyeyes open and grabbed the opportu­nity when il turned up. I keep askingyou 001 to just enjoy life' s merry-go­round, but reach ou t for tha t IlTaSSring. You can get it, but only if lOU

really reach.When I stancd 71 I put every

nickel I had into the first issue. Ididn' t start ou t rich. I wasn't a greatstudent in school. Hec k. I jus t hardymade it with C's. It was ham rad iothat pushed me to go 10 a tec hnica lunivers ity. It was ham radio that gotme into the Navy as an electronictechnician. Later is RTIY chum gOime a job on a Guggenheim grant.woning on a color organ. And an­other R'rTYer got me a job as thehead of the Music Research Fo unda­tion, My ham ming got me intobroadcasting as an engineer-an­nouncer, and then into TV as an en­gine-er, cameraman, then a producer­director. It was RTIY that gOl meinto publishing .

We know thai the key to makingmoney lies in technology. and ....e

also know that hamming mm~':k:'~' ~i~'~.'::============~fun to learn about erec- r-rromcs. As transporta-tion cosrs drop andcommunications sys-tems improve and getcheaper, unskilledpeople in America .....illhe more in direct com­peti tion with unskilledworkers in the lowest­wage co untries (If theworld, So we' re goingto sec more and moreof a difference between....hat educa ted and ig­norant people earn .

I do get upset overthe bleeding bean lib­erals taking my moneyand giving it to peoplewho spumed Ihe freeeducation they were of-fered, thereby guaran-teeing themselves pov-erty unless !hey go intocrime . Grumble.

I ..... ant to read inclub newsletters aboutthe clubs descendingon their local schoolslike locusts and gettingthe kids interested inhamming. 1 want to secthem never-say-die ongett ing the new Techs

As I wri te this, I am about 10

undertake a maj or projec t­

cleaning off my w ork bench :F o r s ilt ing on a table in the next

roo m is a T AC P I by S&S Engi­

ne er ing . Thi s rig is the fir st syn­

thesize d QRP t ransceiv er to

come f rom S&S Eng ineeri ng

utilizing a tu ni ng k nob fo r fre­

qu ency select ion . T h i s i s th e

secon d version of the TACPl.

The first m o d e l w a s a vai la hle

o nly o n the 80 meier band. There

is now a TAC P l for 40 meters. the

bread and bu tton o f mo st Q R Pers .

Stay tuned fo r a full-blown re vie w

of thi s excit ing ne w ri g . m

Major Project Plus New Rig

They're S30, and that include s

fi rst class sh ipp ing. Send 10 my

atte ntion at the address at the top

o f the colum n.

Radio Fun. Maybe this will a llowme 10 spend mort' lime pushing coldfusion, .... hich has is fa r greaterpotential for benefiting the world.

Can anything be done to blastthese ex-Caers off 2m and into Gen­eral tick ets? I' d like to see some

clubs make an e ffort to (a) get thesguys to come 10 club meetings: ( b~

provide them with upgrading classes;(cl send me photos of their grad uatin,classes, along with stories on hOIlllthey did it. !

We can' t win this by hasshng thTcc hs. Rid icule won ' t work ci the~

What we have to do is get them inte rjested enough in what the IIF bandhave to offer to get them to go for ..General or Advanced ticket. ThaI',why I' ve been harping about our set,ting up crossband repeaters, makin!club meetings more fun, getling somlzing into the club newsletters wi th re ,pons on what h\>t DX some membershave worked recently, and anythine lse exci ting that the members bavbeen doing.

"Get on from thereand work 10,000J's in a week, andyou '11 see what goodoperating soundslike. "

the RF across the d ummy lo ad

and then output the re sult as a DCvoltage p roport ional to the in put.

The old He athkit Cantenna ha s

such a circui t built inside a smallbox mounted on the dummy lo ad

lid. A s a matter o f fact , I p lugged

i nto the o u tp ut jack o f my

Camenna a nd was able 10 d isplay

a re ading o n the DP:\1. A ga in , a

graph co u ld be made 10 comp ute

the number di sp layed o n the DP~1

into something more u se fu l. O r,

if you w anted 10 get really mad

and wild, a s mall e m bedded mi­

croprocessor such as the PIC 16X

series cou ld be programed to con­

\'<:0 the inco m ing voltage into

something re ally useful o n a LC D

di splay

For those o f you who want to

e xperi me nt w ith the digital S W R

meter, I have some of the 0 1 In­

t e r n a t io n a l D P:\1s i n s to c k .

When I saw the FCC's licensefigures for the: last 10 years I

could see dia l we'd had a substantialiocreese in Techs, hUI it wasn't untilI drew lhe graph ) 'OU see here Ihal Igrasped the full ex lem of whal hasactually happened. Check it OUI andtct me message sink in .

The graph explains severalthings: (I) Why hamfest attendancehas mopped so much in the last fewyears; (2 ) Why our ham dealers andmanufacturers are really hurting forsales: (3) Why our ham bands seemless crowded than they did 30 yearsago.

The General Class license num­bers have increased at about 1.1%per year over the last 10 years. Hutwhen you consider that the FCC ad­nus that over 40% of the old lice ns­ees are nOI renew ing when their tick­ets expire. thai looks like a possibleloss of 4% per year! The obviousfa, ' is thai the no-code Techs, withpitifully few exceptions, are just notinterested in upgrading. Our repeatersystem is much belief than the 40channels of C8, and that's all theyseem to want in life .

And that means that Radio Funhas failed in it!> mission , We haven'tbeen able 10 se ll the current new ­comers on the great fun amateur ra­dio provides via satellites , huildingkits, packet, ATV, SSTV, RTTY,DXing, DXpeditions, fuxhuming,ham clubs, and so on. 1don't run anyof my businesses just to makemoney. They all have a mission , soI'm discontinuing the publication of

73 Amaleur RadiO Today· January 1996 6 5

Communications Simplified,Part 1

Peter A. Stark K20AWPO Box 209

Mt. Kisco NY 10549

If you' re into ham radio. then youare already into electronic commu­nications as well. But if you arc a

beginner, or if you' vc limited yoursclf In

contesting or cbuuing on your local re­peater. you've probabl y missed OUI on alot of the more interesting technicalpans of communications. This series ofarticles will try to bridge thai gap. bUI ina simple (and hopefull y interesting )way.

These articles are the result of a com­munity co llege course I have beenleaching for some years. Since I haven',been able 10 lind just the right textboo kfor my course. I' ve decided to write myown course notes. Eventually. thesenoll'S will hccome a textbook. but fornow you' rc looking at j ust the notes.

But don ', be scared by the idea thaithis comes from a college course- itisn 't as co mplex. as you think . First ofall, I teach a survey course . That mean sthat it's an introduction to communica­tions for students who haven 't taken anyother communications courses before ,So it start.. fai rly simply, and doesn't as­sume a lot o f prev ious knowledge. Inthose areas where it assumes someknowledge from a prior course, orwhere it seemed like a good idea to dis­cuss some related top ic, I' ve insertedwha t I call "dctoursr-c-short discussionsthat temporarily break away from themain subject.

Second, I teach a survey course thattries to cover a big area in just o ne se­mester. That means that there isn't timeto go into tremendous depth on an y onetopic. Hence, we have to stay fai rlysimple at all times. The course has a lotof descriptions and pict ures, and almostno math .

Third.. this is a (.xxnmunity college coursein the second ycarof a technical program It'sintended for student.. who ....'11 become tech­nicians, fI(( engineers or mathematicians,66 73 Amaleur Radio Toc/ay · January 1996

Finally, Wayne has made me promisenot to sho w o ff with fancy form ulas andtheorems, and to add a little sugar tomake the material go dow n easier. (1guess that means I have to crack a badjoke now and then, such as " What doyou get from a Mafioso college profes­sor? An o ffer you can't understand!" )

But before I start off, let me add alillie fine print for the benefi t of thema ny readers who probably kno w a lotmore abou t this subject than I do. Pleasekeep in mind that these articles are in­ten ded for beginners . As such, I will of­ten provide explanations that may seema lill ie (may be l'ery ) simple-minded toyou. While my explanations will not bewrong, they may be very incomplete,Please don ' I barrage me with long trea­tises and reprints from other texts andjournal s if I've omitted or simplified toomuch (but do let me know if I saysomethin g that isn' t true).

So let's get started.

Communtcat lons

Communications is s imply the mov­ing of information from o ne place toanother.

An Engl ish teache r thinks of commu­nications as the process o f writing or

<lUtooa en.....in . .....11 Clip

Fig, I, Telephone-type carbon microphone.

speaking words, whic h tell your reader(or listener) so mething you want him orher to know. There is even somethingcalled mass communicat ions, which issort of like journalism. but for TV, ra­d io, and film, In this course. on theother hand, we think o f communicationsmore as the electronic process andequipment needed to send informationover long distances.

For our purposes. we are interested inthree aspects o f communications :

• What is being sent'! In other wo rds,what kind of information are we send­ing; is it sound, pictures. or perhapscomputer data?

• Through .....hat is it being sent? Thatis, .....hat is the medium through which itgoes-wire, rad io waves, sound, light,fi be roptics?

• How is it being sent'! All by itself asin a telephone wire, or co mbined withother signals? Analog or d igital?

II would be nice to be able to look ateach one of these q uestions separately.Unfortunately. they all interact, and soour di scussion will have to flit back andforth occasio nally. Still. let's try to startwith an orderly approach.

Let's start off with what is be ing sent.The information you send can be sound,video (pictures) , or digi tal information ,Let's look at each in turn .

Sound

Sound is simply the vibration of ai r.When we speak, our vocal cords vibratethe air coming out: the sound travelsthrough the air until it vibrates the eardru m in someone's car, which eventu­ally winds up in send ing nerve signalsto that person's brain .

In electronics, a microphone is usedto convert the air vibrations into anelectrical signal. The ai r vibrationsmove a thin metal or plastic plate

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(called a diaphragm) inside the micro­phone; a motion-to-electricity converterthen converts the motion into an electri­cal signal. This signal is amplified andsomehow sent from o ne place to an­other, and then converted back into airvibrations by a loudspeaker. Both themicrophone and the loudspeaker (moreoften just called the speaker) are calledtransducers, a term describing any de­vice that converts energy from one form(such as mechanical vibration of the air)into another (such as an electricalsignal). (See Detour I.)

In simple sounds such as someonewhistling, the resulting waveform maybe a sine wave; in more complex soundsthe waveform may be much morecomplex as well.

Let's now look at the output of a mi­crophone o n an oscilloscope. What yo usee depends o n the sound that the mikeis picking up.

Suppose you stand in front of a mikeand whistle a pure note into it (makingsure to be far enough away so the mi keisn 't picking up the sound of the air hit­ting its front) . You'd see the signalshown in Fig. 4. This kind of a wave is

called a sine wave because of its rela­tionship to the sine function from math.

On the other hand, suppose youwhistle another note, but this time anoctave higher. The word octave is a mu­sical term, meaning eight while keyslower on a piano keyboard. This timeyou'd see the waveform of Fig, 5.

Both of these waves have the sameshape, but the second o ne goes up anddown twice as often as the firs t. In elec­tronic terms, its frequency is twice ashigh. More on this in a moment.

Now suppose you do the same th ing,but this time look at the signal createdby the sound of some ins trument suchas a trumpet, rather than a whistle. Fig.6 shows the resulting picture .

The sound in Fig. 6 has the same fre­quency as that in Fig. 5 (since it has thesame number of cycles in a given timeperiod), but it looks very different. Amusician might say that it has the samepitch (that is, it is the same musicalnote), but different timbre (a differentsound qual ity). Some repetitive sounds(like the pure tone of a flute) have awaveform almost like a sine wave;other repetitive sounds (l ike those from

a violin or trumpet) have a waveformpossessing a basic frequency, but whichlooks much more di storted and "kinky"than a sine wave.

The frequency of a note determinesthe pitch; two different instrumentsplaying the same note have the samefrequency. But they sound different be­cause their waveshapes are different. Fi­nally, note that the amplitude of thewave-its height-determines its vol­ume , Quite often the amplitude of thewaveform changes with time. For ex­ample, when you playa piano note, theamplitude builds up to a maximumfairly quickly when you hit the key, butthen g radually decreases as the notedies away.

Note also that only repetitive sounds(like a whist le or the note of a guitar)have a defi nite frequency; other sounds(like the beat of a drum or the crack of awhip) do not.

Sound normally involves freq uenciesfrom about 20 to about 20,000 Hz. butmany people cannot hear that entirerange. Children often hear up to almost20,000 Hz; as you get older, you hearfewer and fewer high frequencies.

73 Amatoof Radio Today. January 1996 67

vibration• •

_ diaphragm

F ig. 3. A Telephone-type earphone.

signal----­input

same as that of the square wave), plus alarge number (actually an infi nite num­ber) of extra frequencies , each of whichis an exac t odd multiple of the funda­mental. We say that the square waveconsists of a fundamental plus an infi­nite number of odd harmonics.

Fig. 10 shows a computer simulationof this situation . It shows a fundamentalplus four harmonics (the third and fifthare labeled; the seventh and ninth arenot), each of which contributes a little tothe output. When they arc all added up,we get the wave that looks squareshaped. except that its sides don't gostraight up and down, and the tops andbottoms are not quite completely flat.The reason it only approximates asquare wave is that it has only a limitednumber of odd harmonics, whereas aperfect square wave requires an infinitenumber of them.

This is an important concept to under­stand: The square wave consists of an in­finite number of components. Of course,the components have to be just right­they must have the right frequency, theright ampli tude, and even the rightphase . For the square wave, the rules arcfairly simple:

• The harmonics must be exact oddmultiples of the fundamental frequency.For example, the 93rd harmonic of aI,OOO-Hz fundamental would have to beexactly 93,000 Hz .

• Their amplit ude m ust be just right.For example, the third harmonic must beexactly one-thi rd the size of the funda­mental; the fifth harmonic must be ex­actly one-fifth the fu ndamental's size,and so on, all the way up. Thus the 93rdharmonic would have to be 1/93 the sizeof the fundamental. This point>; out thai.eventually the harmonics get so small thatperhaps they can be omitted wiihout makinga noticeable difference in the square wave.

voicecoil .......

out of the 2,000-Hz fi lter, while a small3,000-Hz sine wave comes out of the3,000-Hz filter. What's going on!"! (SeeDetour 2.)

Returning to Fig. 9, we have three fil­ters all looking at the same original1,000-Hz square wave. We see threethings:

• The I,OOO-Hz filter outputs a 1,000­Hz sine wave, so there must have been aI ,OOO-Hz component In the sq uarewave.

• The 2,OOO-Hl. filter outputs nothing;thus, there was no 2,OOO-Hz componentin the square wave.

• The 3,OOO-Hz filter is also outputtinga signal, and we see that it has threetimes the frequency of the square wave(there are three times as many cycles inthe same amount of space); so it seemsto be at 3,000 Hz. Moreover, if we wereto measure it carefully, we would seethat it is exactly one-third the height ofthe I,ODO-Hz sine wave.

If we had more fi lters, we would seeother frequencies as well . Any filtertuned to an odd multiple of l,OW Hzwould show an output, while any otherfilter would show nothing coming out atall . For example, if we had a filter tunedto 5,000 Hz, out would come a small5,OOO-Hz sine wave, and so on.

We can sec from this that a 1,000-Hzsq uare wave consists of a large num berof components. The I,OOO-HL sine waveis called the fundamental , since it hasthe same frequency as the originalsquare wave. Each of the other compo­nents is an exact multiple of the funda­mental; the frequency of the 3,OOO-Hzsignal is exactly three times the funda­mental frequency, and is therefore calledthe third harmonic; the 5,OOO-Hz com­ponent has a frequency of five times thefundamental, and is therefore called thefifth harmonic. In other words, a squarewave consists of a fundamental sinewave signal (whose freq uency IS the

Signalconnection

Fig. 2. Simplified crystal phono cartridge.

So far, we've explained that(I) The frequency of a sound deter­

mines its pitch or tone, and two ins tru­ments playing the same tone will havethe same hasic frequency. That basic fre­quency is called the fundamental.

(2) The amplitude of the sound deter­mines its volume.

(3) The waveshape of the sound iswhat gives it its tone quality. For ex­ample, a trumpet or violin can play thesame note, but they will have totally dif­ferent waveforms; that is what makesthem sound different.

Consider, for example, a square wavelike Fig. 8. What is it that makes thiswave different fro m a sine wave?

Suppose this square wave has a fre­quency of 1,000 Hz. An interesting thinghappens when we send it through sometuned bandpass filters- that is, filtersthat let through only one frequency. Thisis shown in Fig. 9.

When the I,OOO-Hz square wave issent through a I ,OOO-Hz filter, out comesa 1,000-Hz sine wave! Nothing comes

6 8 73 Amateur Radio Today· January 1996

Harmonics or Overtones

When you reach 60 or 70 years of age,you will be lucky if you can hear up to10,000 Hz. On the other hand, many ani­mals (such as bats or dogs) can hearmuch higher frequencies than humanscan .

Fig. 7 shows the freq uencies producedby each of the white keys o f a piano. Forexample, if you look at the note labeled"Middle C," you will note that its fre­quency is 261.6 Hz. If you then go anoctave to the higher-counting exactlyeight notes to the right-you get to thenext C, which is at 523.2 Hz, exactlytwice the frequency. The piano has aboutan eight-octave range, and its frequen­cies range from abou t 27 Hz on the leftor bass end, up to almost 4,200 HLat theright or treble end. Fig. 7 also shows thefrequencies produced by various otherinstruments. For example, the trumpetproduces notes only in the range fromabout 160 Hz up to about 890 Hz.

That brings up an interesting question:If the frequencies of musical notes rangeup to about only 4 ,200 Hz (and mostmusical instruments have even less of arange) , why do hi-f equipment manufac­turers stress that their equipment goes upto 15,000 or even 20,000 Hz? The answerhas to do with harmonics.

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Fig. 4. Waveform ofa whistle.

• Their phase has to be just right. Toget the steep rise and fall of the squarewave, aU of the sine waves making it uphave to go up together. and down to­gether, as shown at points a and b inFig. 10. If anyone of them is out ofstep, the result will be some wave otherthan a square wave.

We can extend this concept in two irn­portant directions. both of which arecritical to understanding many of the

Fig. 5. Whistle waveform an octave higherthan that in Fig. 4.

circuits in communications:(1) Just as the square wave consists of

a fundamental and harmonics, so anyrepetitive waveform consists ofa funda ­mental and harmonics. although someof these might be missing in specialcases. The sine wave is a special casesince it has no harmonics at all; thesquare wave is another. in that only oddharmonics exist. they all rise and fall

Fig, 6. More complex musical sound.

together, and the harmonics get smalleras their frequency rises. In a more gen­eral case, there might be both even andodd harmonics. some harmonics mightbe large and others small or missing.and they might have all sorts of strangephase relationships , You may haveheard of the FFf or Fast FourierTransform; it is simply a mathematicalprocedure for finding out what compo­nents make up any particular waveform.

73 Amateur Radio Today. January 1996 69

if you don 't consciously put them in. Forexample, one way to generate a square

-.c=====;"~"."

I"t.liddle C·

Fig. 7. Frequencies produced by musical instruments.

(2) No matter how you generate thatwaveform, the harmonics are there even

. ' " • • 1. - - ---1 MusicalInstruments

Frequency1Hz)

Planokeyboard

wave is to set up a switch that rapidlyswitches between a positive and a nega­ti ve vollage. This setup obviouslydoesn't put in any sine waves, yet if youlook at the square wave with some tunedfillers, the fundamental and harmonicsine waves are there.

Let's think about fi lters again. A filterlets you look for specific frequencies (orcolors) in a signal (or in light). But usingcolored t1Iters to look for specific co lorsin light is a hit-or-miss proposition ifyou don 't know what to look for; youmight need many speci fic color tilters toident ify the components in a part icular

DETOUR 1

OK, now you see how detours work. Lee s de­tour to talk about transducers. Microphones (alsocalled mikes) come in many different types. Mostcommon is proba bly the carbon mike, because itis used in every older telephone (the otd-fash­ioncd kind, not the newfa ngled little phonesmade in the Far East. But nor just the real oldones, as in PhOlO A: more modern ones, (0 0 ) .

Like every microp hone. the carbon mike has adiaphragm, which vibrates whe n hit by a soundwave. The diaphragm in turn moves a thin metalsheet that presses on carbon granules in a smallcup. The electrical connection is made 10 themetal sheet and to the bottom of the cup. asshow n in Fig. 1.

The carbon granules arc small parnclcs of car­bon. which ucr as a resistance between the cupand the diaphragm. The value of this resistancedepends on how closely the granules touch, Asthe diaphragm vibrates, it alternately squeezesthe granu les 10 increase the pressure betweenthem, or releases the pressure . This changes theresistance of the mike in step with the vibrationsof the air. The mike is in series with a battery(hack in the telephone company's central office,not inside the phone), and thus varies the curren tin time with the sound. The current variations arcconverted 10 voltage variations when the currentpasses through a rests tnr or a transformer.

It turns out thai a carbon mike has very hadsound qual ity, hut it has one advantage-the volt­age variations in the series circuit can be quitelarge, which means that the electrical ,ignal fromthe mike can travel long distances without anyamplification. This was obvious ly necessaryback in the early days of the telephone. beforethere were any amplifiers,

Carbon miles were uvcd in the early days ofradio, too, hut they were soon replaced by better­sounding mikes.

Onc inexpensive mike still commonly avail ­able is a crystal or ceramic mike, This kind ofmike uses a crystal (usually quartz) or ceramicmaterial that is piezo-electric, This kind of male ­rial is a naturaltransducer: If you connect a set ofterminals 10 a small block of the crystal or ce­ramic material. you get a voltage when yousqueeze or twist the block; alte rnatively. theblock twists or changes shape if you put an cxtcr­nal voltage across it. So it naturally changes me­chanical movement into an electrical signa l, orvtce versa.

Piezo-electric materials have many uses. Forexample, Fig. 2 shows the idea behind a crystalphonograph cartridge. The needle is attac hed to asmall block of crystal. As the needle rides in the

70 73 Amateur Radio Today. January 1996

record groove, it twists the crys tal, and the twowires attached 10 the other end genera te a voltageproportional to the needle movement. When suffi­ciently ruggedized. it also works backward. Forexample, some 40 years ago, Astatic created a re­cording head that used a crystal to male records.When fed with 50 or 100 volts of audio, the crystalwould move a sharp needle and cut a record

Although crys tal cart ridges are no longer popu­lar, piezo-electric materials are still often used.One modem application is for lighting a gasflame. When you push a button. a small weighthits a piezo-electric block, whic h in tum generatesseveral thousand vol ts, This causes a spark thatlights the flame .

In the crystal or ceramic mike, the diaphragm iscoupled 10 the piezo-electric materia l so that thesound vibrations move the block; this in tum gen­erates an electric voltage that is prc portional to thesound signal. The mile can genera te a volt or soof aud io, though only at a small current.

Crystal and cera mic mikes arc somewhat frag­ile, but back in the days before inexpensive ICamplifiers were available, they were popular he­cause their output didn't need much amplificationto he useful. Rut roday's integra ted circuits pro­vide lots of cheap gain, so the mos t popularcontemporary mike is the dynamic microphone.

Dynamic miles work on the same princi ple aselectric generators in powe r plants or even in yourcar: When a coil of wire is placed in a changingmagnetic field. the coil genera tes a voltage. Thiscan be done in two ways-either keep the coil sta­tionary and move a nearby magnet, or else keepthe magnet stationary and move the coil.

Since the coil is usually lighter and smaller, it'stIIOTe common to move the coil. In the dynamicmike , the diaphragm is attached to the coi l, andthe magnet is stationary. When the diaphragm vi­brates, the coi l moves in relation 10 the magnet,and thus produces a small voltage .

Dynamic mikes and dynamic earphones havemuch in com mon, since the earphone can work asa mike, and the mile can work as an earphone (ex­cept tha t the earphone usually isn' t rugged enoughto produce much sound). For instance, Fig. 3shows the earphone from a typical telephone. Inthis case, an elec tric current thro ugh the coil(which is called the voice coil] produces motion.The voice coil is attached to a diaphragm that thenvibrates and produces sound. Modern speakershave a simi lar construction, except that thediaphragm is much larger and is called the COI le.

As I mentioned above, dynamic mikes and ear­phones work in both directions. For example,some years ago, after placing a call from a payphone, I discovered thai someo ne had apparentlystolen the mike from the handset. By yelli ng intothe earpiece, I was able to complete my call any-

way, But since dynamic mikes (and earphones")produce much less output than a carbon mike,even with yell ing my signal was very hard 10hear.

Dynamic mikes can produce very good soundquali ty, mainly because the mass of the dia­phragm and attached coil is very small, and sothey eas ily vibrate in step with the sound wave.Since the vibrations of sound occur vel)' rapidly.a heavy diaphragm cannot move fast enough 10accurately reproduce these sound waves. A car­bon mike is worse, since it has to move a lot ofcarbon granules. A crystal or ceramic mike is bet­ter, but it still has to apply some force to thepiezo -electric material and this increases themass. A dynamic mike is an even greater im­provement beca use the diaphragm and coil can bevery li ght. The bcst mike would be one in whic hthere is just a diaphragm, and nothing attached toit at all. There is a form of a dynamic mike, calleda ribbon microphone, ill which the diaphragm isactually a thin strip of foi l acting as the coil. BUIthese mikes are very fragile (a strong wind canruin the foil) and a lso provide a tiny DutpUI, andso they arc not very common.

Instead. professional recording studios oftellusc an excellent (though very expensive) mikecalled a condenser microphone . In the condensermike, the diaphragm acts as one plate of a capaci­tor. As it moves. the capaci tance changes. and anamplifier picks up that change and converts itinto a voltage change.

Condenser mikes require a powe r supply. par­tially to charge lip the capacitor. and partially topower an amplifier right inside the mike. The am­plifier is needed because the condenser mile out­put voltage is tiny, and so it has to be amplifiedright inside the mike before being sent out thecable, Professional recording studies usuallyhave a 4g·volt power supply inside the recordingconsole to supply power 10 condenser miles.

The cheap 1I101.lt:m version of a condensermike is the electret microphone. These mikeswork on the same principle as older condensermikes, but the diaphragm is made out of a penna­nently charged semiconductor material that docsnot need a separate power supply. There is still anamplifier inside the mil e, hut the amp lifier needsonly a volt or two 10 run and so can be poweredby a sing le battery. Electret mikes arc not as goodas professional condenser miles (since their dia­phragms arc heavier), hUI they arc cheap andsmall. Radio Shack has some electret cartridgesfor $2: these cartridges are ofte n found insidesma ll cassette record ers. When you buy an actualelectret mile, most of its cost is in the case andhardware , since the cartridge ins ide is often thesame $2 cartridge (even cheaper in largerquantities),

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CIRCLE 351 ON READER SERVIce CARD

to brea k analyzer it is spread out so it looks like anents and very tall but thin be ll.)

en as a Leaving the analyzer at the same set-to the use ting, Fig. 12 shows the spectrum of a

trum of square wave. This time there is a big blipat I kHz (I added small numbers at the

. sures the bottom of the figure to mark off kHz) in-signal and dicating the fundamental, and progres-omponcnt sivcly smaller blips at 3 kblz, 5 kHz. 7ample. if kHz, and 9 kHz. showing some harmon-

Hz sine ics. If you examine Fig. 12 carefully.t a picture Conftnued on page 77

1000 "' f\f\(il ler J\.T\

ftR:- 1000 111. sint: W3ve

2000 liz1000 liz filler no signal

square wave

3000 I" MfVIM(iltet3000 111. iWN: ,,,,ave

.

can use a spec trum analyzerdown a signal into its compodisplay them all on a scope serespectrum (notice the similarityof the word in referring to a speccolor).

The spectrum analyzer mewfrequency compo nents in aplots the voltage of eac h cagai nst its frequency. For exyou were to look at a pure I ,()()().wave on the analyzer, you'd gclike Fig. 11.

If you imagine that 0 Hzis o n the left of the scree n.and each divis ion to theright represen ts 1.000 Hz.then the "blip" toward theleft would be at 1.000 Hz.and (in this case) have aheight of 7 divisions. (Ide­ally, the blip would be just athin line, but on the spectrum Fig. 9. Separating a square K'UV~ mto compon~nts.

73 Amateur Radio Touay· Janual)' 1996 71

light source. You can save a lot of timeby looking at the light through a prism.which lets you see all the color compo-nents at the same Lime in the form of arainbow or spectrum. The prism acts likea very large number of fi llers. all work-ing together to check all the colors at thesame time. You can then immediatelyspot whether a given color is in the light.or whether it is missing.

In communications there is an instru-mcnt that does the same job. Rather thanlooking at a signal through filters thatlook at just one frequency at a time. we

Fig. 8. A square wave.

Tum your old ham and computer gear into cash now. Sure, you can wa it lor ahamfesl lo try and dump it , but you know you'Ugel a far more reenstc price ityou have it out where 100.000 active ham potential ooyers can see illhan thelew hundred local hams who come by a Ilea market table. Check your enc.garage. cella r and closet shelves and gel cash for your ham and computergear before it's 100 aiel to sell. You know you're not going to use it again , so whyleave it for your widow to throw oul? That stutt Isn" gening any younger!The 73 Flea Market, Barter 'n' Buy, costs you peanuts (almosn -comes 10 35cents a word for individual (noncommercial) ads and $1 .00 a word lor commer­cia' ads. Don', plan on telling a long story. Use abbreviations, cram it in. But behonest. There are plenty of hams who love 10 Ii. things. so if it doesn 't work,say so.Make your list , count the wom s. including your call , aocress and phone num­ber, Include a check or your croclit card number and eJolliration_ If you're plaCinga commercial ad, include an add itional phone number, separate from your ad.This is a monthly magazine, not a da~y newspaper. so figure a couple monthsbefore the action starts; then be prepared. II you get 100 many cans, you pricedII low. II you don't gel many calls, too high.So get busy. Blow the dust off, check everything out. make sure il stdl worksright and maybe you can help make a ham sure it still wonts righl and maybeyou can help make a ham newcomer or ret ired old timer happy with lhat rigyou're not using now. Or you might gel bUSy on your computer and put logethera Iisl 01small gear/parts to send to those interested?

BRRTfR

The deadline for the March1996 classified ad section IsJanuary 12, 1996.

ALL ABOUT CRYSTAL SETS. Theoryand coostrocnco cr crystal sel radios.$9 .95 each, ppd USA. Send 10 :ALLABOUT BOOKS, Depl . S, P.O.Box 22366, san Diego CA 92192.

BNB200

NOW ON 40 METERS! NEW, KNOB­TUNED w/DIGITAL DISPLAY, SYN ­THESIZED ORP lransceiver. CompIelekit onry$199,95. S&H $7.50 (continen­lal US). GUARANTEED TO WORK.For inlo send SASE: Call /Write 10 or­der: S & S ENGINEERING, 14102Brown Road, Smithsburg MD 21783;(301) 416-0661. BNB334

Rc r-2950/2970 : New mcotuceuonmanual including Power inc rease ,Clarifief modification. Modulalion in­crease. Operating hinls, and more.Parts ioc:IuOed. Only $20,00 ppd in U.S.(Missouri resioenrs alkl $1.15 tax) .SCOTT. P.O. Boll 510408, 51.. LouisMO 63 151-0408. (3 14) 846 -0252 .Money Orders or C.O.D. BNB340

NI-CD BATTERY analyzer cycler. PCcontrolled, DOS software. $289 POBox 672, London, cntanc Canada N6A4Y4 Lamantia Products (519) 472­5566, Fax (519) 472·1702 BNB385

Ir s BA CK! The return of Ibe HW-8HandbOok! Second printing, Modifica­tions for the Heath QRP figs. First classmail $11 . OX alkl $4 for air mail Ship­pHlg . Mike Bryce, WB8VGE. 2225Mayflower NW. Massillon OH 44647.

BN....

WANTED; BUY AND SELL All types01 El9clron Tubes. Call (612~29-9397,

FIJI (612) 429-0292. C & N ELEC­TRONI CS, Harold a ramstect. 6104Egg Lake Road, Hugo MN 55038.

BNB915

Nil","" n OIl your FHdbKIl c.rd

BUY

CODE 5 News and Pet ition informa­tion . SASE to KB7PNQ. 503 Duboisstreet. Cheney, WA99004. BNB1012

ICOM IC-735 HF All Band Transceiver$500.00 0 80 (907) 235-5655.

BNB1051

PACKET RADIO. Join TAPR. connectwittlltle largest packeVdigilal group inthe U.S. Creators of the TNc.2 sian­care. Benefits: newsletter. soltware,discount onkilslpublicalions. $151yearU.S.• $18 Call1Mex, $25 elsewhere.VisalMC, When joining. mention 73.receive TAPR'S new book , PacketRadio: Whal? Why? How? ($9 value)FREEr Internet. tapre tacr.orq Web:hltp:/Iwww.tapr. org (817) 383-0000Mail: 8987-309 E. Tanque Verde Rd.' 337. Tucson AI 85749-9399.

BNB1 027

HAMS- NEE D CO MPUTER RIB­BONS? Lowest prices . Color or black.Stal e your needs . Free info .HARCLY(I). P.O. Box 830A. CoquilleOR 97423 BNB457

MAHLON LOOMIS, INVENTOR OFRADIO; by Thomas Appleby, (Copy­right 1967), second printir.g eveueeietrom JOHAN K.V. SVANHOLM. N3RF.SVANH OLM RESEARCH LABORA­TORIES, P.O. Box 81 , Washington DC20044. Please send $25.00 donationwith $5.00 lor S&H BNB420

ELECTRON TUBES : All types andsizes. TransmIttIng, receiving, Micro­wave ... Large inventory . same claysh ipping . DAILY ELECTRONICS.10914 NE 39th ST_, Sulle B·6 ,Vancouver, WA 98682. (800)346-6667Of (360)896-8856. BNB719

Amal eur Radio T-ShiriS & Sweatsnrne. Electonics Books. Send lorcatalog :Pau l Washa, 4916 ThreePoints aivo., Mound MN. 55364·1245

BNB805

R-390A SALES & SERVICE. INFOSASE MILTRONIX POB 80041 TO­LEDO. OHIO 43608 . R-390 POWERINPUT CABLES $25.00, ANTENNACONNECTORS $12.50. EXTERNALAGC MOD $20 .00 PPD. MON-FRI9AM--6PM E.ST (419) 2~6220.

BNB813A

ELECTRONICS GRA B BA G! 500pieces of new components: inductors,capacitors, diodes, res istors. $5.00postpaid, ALLTRONICS. 2300 ZankerRd.• San Jose CA 95131. BN8855

TIRED OF IRONING? Single/smallquantity ss PCB service . Most boards$25. We scan magazine artwork free.Gel oul Iho se back issues! FIRSTPROTO, (919)403-8243. BNB1022

HEATH KIT WA NT ED! S.B. Series'Green FranI' ror par is , Ro bertSchlegel 2302 286lh St. East. Roy WA98580 BNB910

HEATH COMPANY is seiling pncto­copies 01most Heathkit manuals, Onlyauthorized source for copyright manu­als , Phone (616) 925-5899, 8-4 ET.

BNB964

PRI NT ED CIRCUIT BOARDS lo rprojects in 73, Ham RadiO, OST, ARRLHanctJook. List SASE. FAR CIRCUITS,18N640 Field Ct.• Dundee IL 60118,

BNBsee

WANT ED: We,tern Electr ic AudioEquipment. Amphliers , pre-amps ,tubes, speakers , parts, mixing boards,etc. 1-800-251-5454. BNBI OSO

AZDEN SERVICE by former factorytechni cian. SOUTHERN TECHNOLO­GIES AMATEUR RADIO INC" 10715SW 190 SI. #9, Miami FL 33157. (305)238-3327, BNB979

DTMF Rad io r elephone Interfac e,Build your own. Simple step by stepmanual with schemalics - $11.95. P.O ,Box 237. Rock Sprir.g GA 30739.

BNB1035

ROTOR PARTS ROTOR SERVICE.ROTOR accessories: Brak-D·Lays,Quik-Connects, Pre-Set mods. NEWmodels for sale. Free calalog, C.A.T.S.,7368 State Aoad 105, Pemberville OH43450. BNB996

SELL : 100' Tower, HEAVY DUTYVERSION AB-l 05C1FRC. For SeriousAntenna Person . Includes GlIywire ,Screw Anchors, Galvanized bolls. 2'sloes, 10' secnons. Best Offer over$2.000 plus shIpping. Detailed Litera­Me available. K3VJH (407) 288·7399

BNB1042

COMMODORE 64 HAM PROGRAMS·8 dtsk sides over 200 Ham programs$16.95. 32-cent stamp gels unusualscnware catalog 01 Utilities, Games,and British Disks. HOME-SPUN SOFT­WARE , Box 1064 -6B, Este ro FL33928, BNB1052

SUPERFAST MORSE CODESUPEREASY. &.t*niIBI cassetle. $12.LE ARN MORSE CODE IN 1 HOUR.Arr8zing supen'laSy Wlcl lliqUe $12. 80Itl$20.McrI8ybadI~. Free catalog:SASE . Bah r-T2. ISO Greenfield.Bloomingdale IL 60108. BNB 1025

RESTRICTED Top Secret Hacker In­formation. Cellular I Cable / Survelt­lance / Satellite / VideoCipher I Books/ vioeos . scnware. Make $100/hour.Calalog · $3.00, TELECODE P.O. Box6426-BNB, YUMA AZ. 85366-6426,

BNB1 024

Morse Co de Compuler Inl erfaces$49_95. with CW Filter $79.95. FreeIBM Shareware and Ham Calalog .Dy na mic Ele ctro ni c s , Box 896 ,Hartselle AL 35640. (205) n3-2758,FAX·(n 3) 7295. BNB1034

Test Equipment: Fluke 335A DC Volt·age Standard $750 ; Fluke 7260ACounterffimer $350: HP 181T/1809A11825A 100 MHz Oscilloscope $300; HP355C Allenuator $75: HP 355DAllenua­lor; HP 461A Amplifier $75: HP 1725A275 MHz Osouoscope $450: HP 86408Signal Generator $1700:HP 861 4A Sig·nal Generator $450; HP 3400A RMSVoltmeter $125;HP 33OOAI3302A Func­tion Generator S125; HP 3437A Voltme­ler $200; HP 5OO5A Signarure Muhimeler$300: HP 5006A Signa ture Analyzer$200; HP 5150APrimerS150;HP 5326BCounteriTtrner$loo. Lisl of OCher equip­meot available. .1m 8IellellSOll, Phone:(908) 722--6157, FIX; (908) 722-6391 .Power Supplies : HP 6130B SOV lA$100; HP6131 B 100V SOOmA$lOO; HP6140A tcov l00mA $300; HP 6200B10V l GOA $300: HP 6282A 10V l OA$200; ust of other equipment available.Jim Stevenson, 3401 Sunny SlopeRoad, Bridgewarer NJ 08807, Phone:908·722--6157, Fax: (90S) 722-6391.

BNB1053

Tektronix 1240 Log ic Anal)78r Ac­cessories: l2OOC01 R8232C CommPack $75: 1200C02 GPIB CommPack $100 ; 12OOC1l Parallel PrintefComm Pack S50; 12RM02 8085 Mne­monics ROM Pack $50; 12RM03 8086MnemoniCs ROM Pack $SO; 12AM048088 Mnemonics ROM Pack $50;12RS0 1 8K RAM Pack $30; 12RS0264K RAM Pack $40 ; 12RS12 32KEPROM $30; PM 206 68030 MicroSupport MOdule $100; Phone: 908­722·6157, Fax: 908·722·6391.

BNB1 053

AMATEUR RADIO REPAIR, most makesand rrcoee.disoou:lIlabor rates ur(iIJune1995. WESTER N AMATEUR RADIOREPAIR CO. JoIYI~ Box fS7, t<b1hCave WA96547: (360) 267-4011 . Tha.-..sAB70R. Bt.el015

RF TRANSISTORS, Japanese lraJ 1< 'Sand aees need dealers, repair sl'qls. kilmakers. etc. lor 2SCl 969, 25<;2312 ,MB8719. MRF455. MRF454, 2SC2879ancI more. WESTGATE (800) 213-4563.

BNB950Con tinued on IJQ[}f:' 83

72 73 Amafeuf Radio Today ' January 1996

R.S.I page351 Absolute Value Systems ••• 7 1161 Advance DeSign labs 43

• Advanced Info Group, Inc. 7 1194 All Electronics

Corporation 23• Alphalab .•••••••••••. •.••.•.•.••.•.• 67• Altematlve Solar .••. •.•. ••.•. ••. 31

57 Antennas West 5116 Antennas West 39380 Antennas WesL 30332 Antennas weer . 17135 AnteM as weet ., 8 1

5 AnteMBS West ......••. ••••.••.• 43107 Anternas West 8 189 Ant&B1aS West ••••••••••••••••.• 49

340 Anteonas West .............•.... 3316 Astron Corporat ion 21

• Autek Resea rch 29272 Azden Corporation 23

41 Barry EJec:tronics Cofp 3342 Bilal Company ••••••.•.•••••••••• 43

168 Buckmaster Publishing ••••. 1956 Buckmaster Pub lishing •. ••• 69

7 Buckmaster Publishing •.•.• 53• Burghardl 77

R.S. I page222 Byers Chassis Kits •....•...... 19184 C & S Sales. Inc. ._..•••••••••• 19

• Cable x -eerts. jrc 31• cee lnlemational 53

156 Commpute Corporation .••• 8199 Communication Concepts 69

268 Computer AutomationTechnology 59

• CuOex 69• Cutting Edge ..................••• 71• Dayton Hamvention •.•••.•••• 40• Doppler Systems ••••••••.•• •••• 27

11 4 E. H. YOSI 53• Electronic Distributors 25• Electronics Book Ckb ._.•.•. 83

169 G&G Electronics ••............• 57193 GGTE 20

• Greater BaltimoreHamboree 25

286 Hambrew Magazine ....•••••• 3378 Hamsure ••••...•.•.••_ 19

• Hamtronics. Inc 7179 100M America, Inc CV2

• Indiana HamfesL. 8142 lsotron 43

R.S.I page159 Japan Radio ••••••••••••••••........ 1

• J.M .S 7127 John Bel 25 & 37

• JRS Distrbutors 192 Kawa Productions •............ 33

151 KOC Sound 81• Kenwood USA Ocrp CV4• Unk·Com ...•..•. ................... 43• LogSat Software 27• Maggiore Electronics 67

88 MFJ Enterprises 11• MiChigan Radio 39

160 Micro Compuler Concepts 17193 Morse Tutor Gold 20248 Matron Eleclronlc:s _•••••• .•••• 27114 Mr.Nkd ••••••••.•................... 53

• Norcon Englneering •••••••••• 69102 ONV salelY Belt _...• 53

• Orlanoo Hameaoon ..........• 29• P.C. Electronics 43• P.C. Electronics •••...........•.• 56• Peel Bros. .••.•.•.................. 23

49 Polyphaser •....•.................. 29257 Quorum Communica tions . 13153 Radio CilY 31

R.S.' page58 Radio Engineers ..•............ 39

• RAJ Enlerpnses 33254 Ross DiSlrlbuling ••••••••••.•_•• 69

36 SCl3mbling News ..•........._. 43167 seecoe. Inc 53

• SGC, Inc 54• SiriO Antenna 2• Smiley Antenna Company 39

250 Software systems 6769 Spectrum Elect ronics 53• reietec Corporation 59

269 Tlgertronlcs 3722 TrI· Ex 27

• Tropical Hamboree 37• Uncle Wayne'. BooksheIl 88-+• Universal Radio _. 43

259 Versalel Comrml"licatiOns . 30104 VIS Study Guides, Inc 33191 W & WAssoeiates 73

• Yaesu EIeetronics Cotp . CV3

When you buy productsfrom these advertisers,please tell them that yousaw their ads In 73.

Subscribe to 73 right now...call 800-274-7373 (9-5 Monday-Friday EST).

If you have two different radiosYOU'll only need one charger toaccomodate both radios. Now bysimply switching the swItch to theleft or right.. you can determinewhich charging cup to activate.

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CIRCLE 1111 ON READER SERVICE CARD

73 Amateur Radio Today· January 1996 73

NCUCR SRV tu«Continued } rofll page 4

Compu'Serve. Prodigy. bulletinboard systems . and so on?

There arc almost endless commu­nicat ions services out there. Now, i tyou. as a bona fide communicationsexpert. can', answ er even simplequestions about 'em. imagine howconfused the average business per­son is when faced with choi ces ofte lephone switches, cellular tele­phones, teleconferencing. security sys­tems. computer networking, and so 011 ,AU this is so far beyond the average per­son 10 deal with lim you have a trctrcn­

{k,US opportunity to make somemoney-s-onc e you know your sluff,

No, you don't know all the an"swers I1I1W, but with your hUIIl back­ground, at least you can understandthe questions and you have somedues un where to lind the answers,Knowledge is nOI only power thesedays, it 's money. Then: are at leastlen million sma ll businesses thatcould be bene fited by better com­mun ications, sec urity, ami computersystems. That's one heck of a market

How long do you think it wouldtake you to become an expert onpage rs, just to pick one field at ran­dom ? You need to get literaturefrom the manufacturers, dealers, andservice companies. You'd want toread a couple books on the subject,subscribe to a magazine. Are we talk­ing six months? One month? A week'!

Next you'd want to visit some ofthe companies involved in the busi­ness and talk with them . Find outtheir problems. what success stori esthey have , which equ ipment theythink works bes t. and so on. Coupleof months in your spare time?

Now that you have a good under­standing of the technology, the play­crs, and have the contacts you need,what should you do nex t? My rec ­ommendation would he to sit downat your computer and write a briefhand hook on the subject-s-maybe32 pages. Write it for the nontechni­cal average bus iness person. Ex­pla in the benefits this service pm­vides and show how the costs aresmall compared to the benefits. YOIIcan make the handbook look profes­sional by printing it on a laserprinter. The first hundred copies canbe made on a copy machine. That' sthe way [ do all of my booklets untilthe demand gets out of handand practicality forces me to usc acommercia l print shop.

This will provide you with somesale s literatu re for your new com ­munications consulting service .With you r name as the author, thiscertifies that ) 'UU are an expert. It 'slike a Ph.D. Now you're in a posi ­tion to send letters to local busi­nesses offering the first phase ofyour communications consultingservices.

Once you know your stuff onpagers it's time to pick the next businessyou'll: going to bun. If you've made

any efforts toward sell ing your pngcr cx­pertisc. by now you'll know what ques­tions business people are asking aboutother communications services. Youmignttackletax-modems next.

Same deal. Get the lite ra ture.Read the books. Subscribe to themagazines in the field. Talk with themanufacturers, dealers, and services.Help some friends for free, learn ingon their money. It's alw ays best touse other people's mon ey (OI'M) asmuch as possible when you arelearning your skills and buildin gyour knowledge base.

Within a year, if you mak e anykind of an effort at all , you 'll he Mr.Communications in your town, andyou'll have dozens of sma ll husi­ncsscs turning to you for solutions.In the communicat ions business youmake money on sales. on installa­tions , ami on service. Grea t busi­ness. All communications equipmentbreaks , so the service business iswonderful. And computers , beingthe most complicated of all, breakthe most often. Plus there are vm,incompati ble software , s tatic elec ­trici ty, errant magnets, and so 0 11 , tohelp keep you living comfortably.

Oh yes, it won' t hurt to becomean expert on magnetic fields and goaround with your gaussrnetcr andhelp people avoid possibl y harmfulfields There'll he a very inexpcn­sh e guussmctcr Oil the market soonthat does a wonde rful job.

And when you r customers want tokno w whether cellular telephonesarc harmful or not, you'll know the an­swer and beable to give them a reprint ofan article frum 73 on the subject .

There's no reason for any hamwith even the slightest amount ofgumption not to he living in comfortand ha ve as hig a ham station as hewants, Or she, as a balm to militan tfemi nists, Gumption. Guts. The willto makc a change In your daily ro u­tine. The will to turn off the TV, IU

1101 go to that hall gam e, to 110 1 readthat newspaper. The will to lise yourtime to invest in yourself and abet ter future.

Expert Help Needed

If you arc already an expert onany phase o f communications , howabout writing an article for possiblepublication in 73 to help newcomersto the field? They need to know thesuppliers, publications. have a list ofrecommended hooks , how distri bu­tion works, what frequencies andservices arc available and theiraverage cos t-e-things like that.

If we can get a series of articles tohelp 73 readers come up to speed onbusiness communications services,that'll help a hunch of hams buildsome spare- time income, and maybehe ahle to take the ir new consul tingbusinesses full time as entrepre­neurs, So what 's our there in BRSsoft ware? In security products andservices ? In vide o conferencing ?Satell ite services?

Or arc you happy with your oldham ge ar and not having enoughmoney to comfortably buy a sub ­scription to 73 ? Tsk. The money isout there in great big gobs, you j usthave to make a little effort to grab it.And that means turni ng orr the hallgames and doing some home workins tead Gel olf the couch, put downthat can of beer, brush off the pretze lcrumbs, and get cracking, I don ' tcare if you're 20 or 70, you can learnnew things and it' ll he some of thebest fun you've ever had. Heck, I'm73 now and I'm tackling a wholenew branch of physics-c-one whichnot even the best scien tists in thewor ld understand yet--cold fusion .Nuw that's exciting.

I 'd love to know more about corn­uruni carions, so I'l l he readi ng anyarticles submitted for my own edifi­ca tion and well as yours. That meansthey' ve got to he simple enough so Ican understand them.

CW Fiends Alert

Just because 1 am anxious for us10 bui ld up our ranks before the FCCwises up and closes us down as nolonge r relevant . some code-lovingreade rs have misin terpreted this asWayne hatin g CWo Well. actu ally, Irea lly do hate C W, but that has not h­ing whatever to do with my efforts toget the code tes t the hell out of the li ­censing exam sy stem. No, the reasonI have always hated the code is be­cause my beloved guverrunent madeit mandatory.

l have an nbviousfy twisted genewhic h just naturally rebels againstany thing mand atory. ' wou ldn't havelasted long as a slave. Hmm. 1 won­der if the blacks may have a problemwith the natural selection processworking over seve ral generations asslaves. thus lending 10 make the mmore inclined to he followers thanleaders? Sure, call me racist , if thatmake s you feel supe rior. But itmakes sense, and I haven' t ever seenanyone come up with that conceptbefore. AmI it could help expl ain alot of what's been going on.

If the code had been vo luntary,I'l l bet I'd have been a whiz at it andhad 11 ball. It's always looked likefun, hut I'd he damned if ' was goingto be fo rced to du something. TheNavy and' had some problems withthis concept. with them being usedto the " How high?" response to acommand 10 jump.

Anyway, for those of you whohave had no problem with knucklingunder to the go vernment. there's agrea t lilli e CW magazine you'veprobably been missing. MorsulIlMaglllf ira! is in its fourth year and isrunning around 48 page s a month.Subscr iptions are $26.50 via airmailfrom the UK. Make checks out toWi'ie Owl. 43 14 West 238th Street,Torrance CA 90505-4509. Creditcards via 310-375-6258. You'll love thestories and photos of old-time keys.

Once the FCC gets rid of the code

tes ts I'H buy a key and start catchingup on the fun I' ve missed. I mighteven organize code certificateswhich can be awarded at ham fests. Istarted my ineffective campaign toget rid of the code tests in 1958. Will1 have made any headway when the40th anniversary of my windmill tiharrives? Probably not.

MARS News

Effective October '96, CW willno longer he used on any MARS cir­cuits, according to a recent Depart­ment of Defense orde r. "It is recog­nized that CW can no longer com­pete with the rap id advancements inradio tech nology. Therefore, CW isto he reti red from lise within theDO\) MA RS," Newer moues such aspacket, AMTOR, and PACTOR havealso replaced RTTY.

Digital Camcorder

Digital video has heen promisedfor some time. Well , it' s fi nally ar­rived, via Panaso nic. The camcorderprovides 500 lines, which is 50 %better than live TV broadcasts. Italso records Cfj-quality audio, andall on a cassette which is 1/12th thesize of a VHS cassette. Since thedata is digital. it 'll he able to connectto computers .

The cassettes usc 6.35 mm tapeand a eo-minute tape wi ll store 12.5gigahytes of information. Thatwould take about 8,700 flopp ies, sothis tape shou ld have lots of com­puter applications for storage andbackup, The 6O-minute tape is ex­pected to sell for about $14. Thecamera will be a little more , on theorder of $4,000.

Will we someday be seeing hamrigs with a tiny digital camera builtin? Only if the bobby doesn' t getwiped out hy the Cw-rorever mon­gers , Hey. would you like to seesome video of me swimmi ng withthe turtles off the coast of Maui? Orhow about the ham gathering on skison top of Aspen Mou ntain? Ormaybe our ham hunting safari in AJrica?Or maybe my visit to the Taj MahaJ witha group of Indian hams? Hilum ? Nepal?Navassa? News at eleven.

Okay, Who's the Quack?

The onl y ham doctor ' can thinkof right now, the last' heard, is inprison fur pay ing someone to kill hiswife. But if there are any ham docstuned in, 1 suggest yuu move on tomy next topic and skip read ing this,And that goes megadinos for anyonewho is a True Believer in our be­loved medical establis hment. Yes,I' ve been reading some more books.

My work with a new Illude! of themind some 40 years ago got me in­terested in reading up on the variousschools of psychiatry, psychoanaly­sis, and hypnotherapy. Using thismode l with some hypnotism I found1 was able to quic kly diagnose and

74 73 Amateur Radio Today . January 1996

repair just aboul an)' lind of menialprohkrru. . And lhal W ;b somethingno other approac h 10 mind repaircame even close 10 being able to do .

If you've read much uf the litera­ture yuu know that. in every carefu ltest, none of the menta l repair ap ­preaches are able to do any bonerthan just giving people tranquilizers.The who le psychiatry business issmoke and mirrors. promoted to agullible public as reality.

Ukay. so Lknew the psy,hologist ~

and p1>ychiatrists were humbugs, bUII still had faith in medical doctors.This faith has been shaken recentlyas I'v e read more and more about al­«mauves 10 the establishment' s useof drugs. radiation, and surgery tolad le the symptoms of illness. Do"tors aren't even taught how to avoidillness in medical school,

Now I'm reading, Immunization.The Htllli~' Bl' lIi1ld rill' Mylh. byWalene James. 2l:l5p, ISBN ().897l:l9-J60.-3. II's a very we ll re­searched book and it explains a 101a bout my own heal th. Anti probably,yours. You are so Ihoroughly incul­cated b)' the media in the reality ofvaccinations thai you'd better readthe hook. I know you' re not going tobel ieve me when 1 encapsulate wha tit says. 1really hate Ii llding (lUI that I'vebeen a grdlk-A SUCkLT all this time.

The bottom line is thai nOl onlydon't vacd nalions do any good,lhey' re doing ioca1culah k han n. Thelheory ilself is baloney. and lhe bil­lions of dollars doc lOT" and phanna­ceutical companies are maling isnoth ing compared 10 Ihe laler 'O'itsresulting from Ihe damage done.Yes, I know all ahollt lhe diseaseswhil;h mass vaccinalions are sup­posl;d 10 have eliminated , So docsIhe author. That ' s heen a huge conjob. Read the bool

I was a healthy youngster umil Ihad my firsl vaccinalion, "'hkh wasrequired for me to enll' r M:hool.Soon aflervoard I gOI sinus !rooMe,and for almost 10 )'tars, and despitenose drops of ;..loo 5 il\'01 Of Ephe­drine r.ewral lim~ a day. I was un­able 10 hrealhe Ihrough my nose,even for minutes. When I was se venI suddenly developed massive aller­gies, to animals, f\lods, trees,pollen'" lluSl, and so on, Hay fever,asthma, Ihe works.

These are common resulls of IhedestruC1ion 10 one's natural immu­nily system caused by val'cinalions ,Wai l until )'OU fead the list of prob­lems vaccinations caur.e! TIle)' li1l asmall percenlage of lids outrighl.Dol;:I\lf\ claim this is an acceptableloss, ,onsidering all the benefils reosuiting. Others sufTer hyperact ivity,auti stn, atfention Ilefid l, dyslexia,mulliple sclerosis, cancer, leukemia,an hritis, diabetes, meningitis, tuber·,ulosis, polio. sma llpox, chicl enpox, obesilY. bulimia, Ih)'roiddanlage, sen al disorders. CIC.

Before !he smallpo x v'accine wasdis.co\'cred lhere ....ere altl1O'it nocases of sma llpo~ in Japan. Then

Ihey instituted compulsory vaccina­lions. This resul ted in 165,000 u sesof smallpox, and 30,000 dc<lths.During the same period in Australia.where the y d id not haw compulsoryvaccinations, there were only threedeaths. I'm not sure tha t's reallyenough to get anyone 10 think .

And how about cancer specialis tsin Canada, the lJS, and Britain whopoint to a de finite link between thepolio vaccine and cancer? By theway, the polio vaccine has killed farmore children than the disea se e \'CThas unassisted by the vecciee. Dh,just read !he book and see if il getsyou to think.

I' d ascribed Ihe change in fam ilyvalues to Dr. Speck's teaching thebaby boomers nor 10 discipline theirchildren. But it could be that child­hood vaccinations. plus tater boostershOIS. are the real c ulprit. They ha vea tendency 10 mal e people morevbort-tempered and resis tant 10change. This could help explain oursoaring divcece r.ue and igJ u ed dIiJ..lh-n. -co 1.,aIdi TV and !JIm up."

As I've memioned in my ednori ­als, and in my htx.l o f WWII suh",a ­rine adven tures. the doctors camevery close 10 kill ing me with a leta­nus vacci ne. It was only my owncaution and fin n resolve that savedmy life. They were really pressuri ngme 10 ha ve the sho t, and il undou bt­edly would have killed me. Thou­!>antis of people have died from \':lC­cinalions and hundreds of thousandgonen seriously sick.,

If yoo l new Ihal pennanent ill ­ne~s or dealh was a distincI po:V:Vlbil­ily for you or your children, wouldyou \'oluntarily get those shols?Mayl>e you remem!>cr thaI laslYl'a r's Miss America was deaf as aresult of a childhood vaccination?l'nlt>.l bly nOloAnd I lhink her siS lerlost pM! of her hearing too.

Dr. William DouglaJOS has a ne.....book oul claimin g Ihallhe so-calledGulf War 5)'ndrollle is just the re'ac­liun to the t>.lrragc of shots all ourcom bat troops were giw n hcforeheadmg 10 Ihe Midd le East. 1llC' sol­diers from the European count riesdid nOI gel these ShOh and haw notrepon ed any of lhe resulting ill ­nt'sses. The military does not makeany tests before giving the shols, soir s no wonder Ihey ha\'e deaths anda wide array of other bad real;!ions.And on" your blood is poisoned byh)'passing ilS defenses againSI theseviruses and gl"TlllS, )'OU can"1 evcrunpoi son il.

1llere are endless repons of braindamage resUlting from vaccinalions,bUI nlll one report o f hra in enhance­menl . Yes, of , ourse they arc manda­lOry and the government will putyou in prison if you refuse to havethis poison injecled into your bod y,or try 10 keep your , hiltlten from ~­

ing pennanenlly poisoned.BUI please don 'l believ'e me . Read

the bool and lhe O\CN helming suh­stantiation of e)'ery aspect of this,l;OI'nplete with the trulh about a ll lhc

lies used to force vaccinations on us.The)' don't ....ort. 1lley have nolplayed an)' signifi,ant pan in ue re­duction of any diseases an)'....here inthe world. They are a giant mulu-bil­lion dollar scam that is doing us allterri ble dama ge.

I ley, maybe you can gel your doc­tor to read the book. He's j ust asbrain....avhed about vaccinations asyou are. in all probability. BUI thenmosl dennsts are by no.... aware ofthe serious damage pUlling amalgamfillin gs in your mouth can do 10 you,bu r they're slill using "em, and thei rpa tients are being slowly poisonedas a result .

I watched a debate between aDarwinian Evolutioni st ami a Cre­a tio nist on PHS the o the r r ngju. TheCreationis t ne t only believed that theBible' s Genesis s tory is the IflIth, hutthai il should be taught in schools in­stead of the Darwinian 10..'01)' ofe vo lution: the s urviva l of lhe finest.The Scopes tria l apparently didn'lco n vmce everyone,

The Creationis ts are upset be­cause the Hihle says man is buill inthe image of God. and the Evolu ­tionists say, in essence, Ihat he' s de­scended from apes. wen. that isn' texactly what Ihey say, but it' s closeenough. AC'l ually, Evolutionisls be­lie\'e thai man and apes are de ,scended fn.m a common ancestor.Bulone pan o f !he evolution theorylhal really slicls in lhe Creationisls'craw is Ihe idea Ihat e~'ol u t ion's mu­lation process is believed 10 I>e com­plelely random and nol divinelycontrolled.

11 annoys me when sl' ientists goabout their business with l>1i nderson. Blindcf\ '! Asl the ne ~ t seit:ntistyou meel anout ghosls. I have a grealdeal of lrouMe 10lally ignoring lhesincere teSlimony of thousands, andC\en millions . of people ....ho n:ponthings thai are currenll) outside ac­Cepled M:icnlilic beliefs. u l e .... hal?How abou l gOOs IS. UfO repons,conlaetee stories, crop d rdes, pre­cognition, reincarnation. pasl lives,near-death e~pericnccs , out-of-bodyexperienet: s, psychokenisis, telepa­thy, psychomt:try, psy, hi, .s, forlune­Ielling, the po wer of prayer, angels.pollergeish , \'oodoo, luck,synchronicily. serendipily, dairvo)'­ance, and so on?

Sure , some of ther.e may be 100%hooey. but where we h,1\'t thousandsof people all around the world re­porting Ihe same phenomenon, iI'sdifficult for mc to accept Ihat C\'erysingle one of them is either lying orcrazy. lIey guys, mayhe it' s time 10tale oil" the blinders.

Tens o r Ihousands of ncar­dealhers have reponed ba,l un Iheirvisil 10 heaven and meeting withGod. Isn' l it odd that Iheir reportsare remarkably similar, no matterwhal re ligion lhey bclieH~d in bd orelheir e~perience? And. C\'en odder,

w bcn they come hack after beingtold lhal they have more to do in life,they are usuall y more religious, bUIno longer follow the religion the ywem in with And they no longerhave any fear of death,

They do believe in God, but Iheyno longer conside r themselvesCatholic, xrostem.. or any standardbrand of Chris tian. and they' re nolonger sporting a "Hon k if you loveJesus" bumper Slicker. I'm 001push­109 an)' particular rel igion, oragainst any of 'em, I' m just tellingyou .... hal YOU' ll find if ) 'OU readsome books on the subject.

BUI tha t's a s ide issue which wi llundouhledly have the overly-re li­gious furious with me, just as arelawyers when I give fact s aboutthem. and ditto most doctors.. .atleast the well-indo c tri nated ones ,Ami teachers. No. I do n't conde mnall o f the above, knowmg that thereare exceptions 10 the rule. I' \'C melAfro-Americans wbc don't hateEcro-Americans. I' ve mel intelli­gem, progres sive teachers. I' \'C evenmet a few honest tawyers. and doc­tors who are actually open to at leastconsider alternatives 10 the usualdrug and slash arrack on symptoms,and never mind the causes of illness,

Thai long list o f weirdness all,utI1CS under the heading of "life"for me. Life is quite separate frommaller. Ihough il has It> use mailer 10dcal with mailer. I'll e~plain what Ithinl mailer is some other lime.

Anyway, somewhere losl 10 his­lOry, the firsl DNA mulecu le was as­semblt:d. Thi5 was a molecule .....hichcould nOI only repli, alt: itself end­lessly, but a I-so was ahle I n mlxlify il­self as 1l result of the t:nvironmenland lecp that IlImlifil;ation In

me11l1 lry, All kl1o \l,'n life dcpends onthis molecule.

Or. Fred Hoyle , in his bool, £ \'0­

Juthm From S{'(lC~. estimated theodds against Ihe DNA moll,,"ule be­ing as~mbled by chance . He COIn­pared il l0 lhe chance that a tornados.....ccping Ihrough a junlyard ....ouldassemhle a com plete 747. Well, ildoes ~em odd to some sd enliSlsthat nature hasn't , ome up Wilh alleast IWO basic life fonns, Hoyle , bythe way, is a world,renowned as­tronomer, so we're not dealing witha ~cience- ficl ion writcr off on ahare -brained crusade .

If you' \'e done mtKh homeworkin lhe occult field, )'OU l now thai aspeople get in bellet touch .... ilh Ihem­~hes Ihl:)' dcwlop a feding of one·ness ",'ith all life. I've been there,do ne thai, so I lno.... how il feels. I' lltell you about thai e~pcrien" SOI1ll'time . I' ve pUl Off wfiling about il be­C<lu.\e I don't wan l the Scientologist spUll ing OUI a contract on tile. I wish Iwas exaggerating.

Say, ha\'e you read The Secre'Lif~ of PJants, which I rcrom­mel1lk.'d ? Or Kinship of All lif e? OrTht ~C"t lif e ofYourCt lb ? Do lourhomc"'ori;: so ", hen ",e meet on 20mwe' ll ha\ 'e something: inleresting 10

73 AmareurRadio Today · Ja nuary 1996 75

cha ll enge~ I provide. He' s beenreading man)' of the books I' ve rec­ommended and enjoying th... m .

S ure , 1 could j ust wri te aboutamateur radio, but m y editorials arcmore like a mun thly contact withyou, where I ta lk not j ust about thebobby , but about anything else I thinkyou might find interesting. And that'swhat you like aboul some or the hamcontacts you make. isn' t it? So get offthe concept o( everything printed be­ing a leclure and get the idea of com­mumcanon.

Anyway. Frank ment ions tha the ' s intervie wed tw o people fromSylvania (G Al w ho had good closelooks at a UFO w hich had landedin a field n...ar rown. O ne was a re ­tired meteorologist from Ihe Dept.of Commerce. and Ihe other wa sme owner o r radio station WSYL,so their credi hilily was high.

unless you've he ... n living in acave wi th no radio or T V. you'veseen and heard plent y or Uf O sto­ries. I' ve got s tack s of UFObooks- some are kooky, bUI manyare we ll re searched. The a utho r ofone was a good friend of mine. JayS ta nton, I ' ve forgonen his hamcall. When I firs t moved to !'\e"Hampshi re he used to come up andvis it. He wem into the UFO bookproject as a skeptic , with the intentnf ex posing the whole bu siness asbaloney. l it: soon was conv inc edthai most of the reports were real.Millions o f people have seen UFOsand the y're no t all crazy. Thou­sands hal e re poned be ing ah_ducted. many repeated ly,

A no ther reader ~enl me a mostinteres ting lape of lJav'id Ja cobsta lking al>oul the rea l pu rpo se be ­hind the ahd ul;tions, More Na­ti c/1Il11 Euquira st uff , right? O nl yif yo u don ' t do your homeworl.It' s eas)' to dismi ss somelhi ng Y'oudon' l loow muc h aboul. Lool alIhe roo ls s \J lIle lOp scientists re·centl)' made of thems... h ... s in di s­mi ss ing cold rusion. And we hadIhe spel; lad ... o f Ihe medical es tab­li sh men t trying fo r years to den)'H. flylori as the l;ause tl f ulcers.And the onglling power companyfight agains t EMF dall gers , the 10­ha cco com panies and cark.'tcT. and theADA's fightlOCOIltinue tJ.: 1l.'oC of dentalamalgams do....ple aU the scicrnific evi­den:e of tho!ir dcstructiVl'flC!>S.

Widl Ihe Big Bang theury 00....hav'ing been prelty .... 1.' 11 d iscredited,scientists admit they haven ' t anycl ue as to the age or the universe.This te lllh 10 make the possibility ofIhere heing alien visitors rl\lI n more ad­\ 'anced cilfi1i /.alions mUl;h 1110.1I\' likely.And th.'fI tI1en:·s the po>.'oibility of timetravel 10 furttu confll'-C IhinSS. We' v-eerKlugh nvm of ycriflCd precognition10 know that we still have a n 10 Ieamabout how bU1l' "(ro.

I' ll ke ep !citing you know abou l

the hooks I' ve found which I thinkyou' ll enjoy. When you l;llllle across abook you think T should read. plC.'lsek l lllc"know. m

Somehow. in amongSI U)'ing 10leep up with the edil ing and produc­tion deadliocs for t"O magazines amomh (73 and Cold 1'usio/l). I a lsomanage to read my mail ami eV'lI:nanswer some o r il. f or in'tance, I go ta wunderfully chatty le ite r fromFrank Tholllas W4QDM , 11 didn ' lhun when he s tartt:d o il" sayi ng howm uch he hkes my editoria ls and the

Bird-Tompki ns 1976 bOllk, Th~ M ­cre, lif~ of Plants. There was achapter on how chickens are able 10convert the potassium in mica intocalci um fur thei r eggshe lls, 11 a lmostgo t me to think. So 1 chased downC hristopher Bird and 80t up to dateon some of his newer boob . His Se­crets of tile Soi' is fantastic. It's am ust read. I also 801 in touch withCleve Back ster, the chap who didm uch or the original " 'ori on com­municating with plants . And he putme on 10 Brian O ' leary and Tile Se­r ret Ufe of remr Cefis, another fa sci ­na ting book. Bill I' ve told yo u aboutthose and yo u should have read 'emby now,

Chris susgcsled I look up thetransmulalion worl> b)' ~ I ichio

Kushi. I found him and think youou ghl to know about his 1m book,The Philosopher s Stolle. Before youdismiss tra nsmuta tion via biologicalprocesses as baloney you should alIcas t joo k atthe remarkable researchda ta Kushi presents. He- makes avery good case for the heavie r el e­ments on ea n h being made biologi­call)' from carbon, oxygen, andnitrogen in, lead of havi ng to hal eoriginated from a supernova explo­sion. which is the current scientificdogma. It turns out that many scien­tist s ha ve researched Ihis area withvery posit ive results.

For instance. take llNa: l + .0"­> 10K", for sta rters. Kush i pu t 2.3mg of sodiu m in a vacuum. men ranan elec tric current through it until itwas melted . Then he added 1.6 mgof ox) gen. 11Ic resu lt wa s 3.9 mg orpotassium .

Then there is Ihe data from LouisKernan, whu carefull)' checl ed theinput and ou tput of rood and wastesfwm a gro up of men wu rking in theSahara in 1958. Th ey genera ted farmore magnesium outpul than input.Dino potassium. Mort' lha n could beaccounted ror in any way ot her thanbiological transmutation ,

I lhink )'ou' lI enjoy- the hook. andit ma )' a lmoS! ge t you to th ink. Ornol. II's $ 10 (plus s1h1 rrom OnePt:aceful World Press, Box 7 BecketMA 0 1223, ISBN I ·KK291\4-07· 2;41 3-623-5741 .

O ne or Ihe reasons I got interestedin transmutation is lhat the scientificcs tablishm...nt has hee-n pUlling co ldfu sion down because il s«ms 10 in­volve the changing or hydrogen intohelium. and "e \ erJ body knows" thaia lchem y died a dese rved death al;ouple cenl urie s ago.

Those Pesky ETs

Alcht'm~'- Today

The f CC is gradually phasing invanity cullsigns. They' ll cos t you$30 for a 10-year license . C heapenough. When they get s tarted. theFCC wi ll he accepting appli cations(form 6 10- V) for the reissuance ofcalls yo u may have had in the pastand lost, or the l;a ll of a deceasedc lose relative. Hmm. I WOOlkf if Ishould apply for W4l'SD orW8~SD. Of perhaps WRIAAB ? OrK2P.\-IM? I've had a bunch or callsdown through the years, hut I guessI' m stuck with W2NSDfI un til theCommission eases their res trictionsso I can get "W."

Phase two will be open to ExtraClass licensees. Then Adv'ancedClass. A nd when tha t' s all taken careof, any licensee will be abl... to investSJO to gel rid of KF4ZXZ, or someomer awful combo,

The Candy Com pany used to is­sue the same suffi x in a new areawhen you moved . That' s how T got\V4NSD, when I moved to Nc n hCarolina, And W8~SD. when 1moved to Cleveland 10 wori OIlWXEL-T V By the time I moved 10New Ham pshire in 1% 2. Ihc: CC hadstopped thi s generosity, sc evenIhough W INSD was open and avail­ahle, the y wo uldn't let me have it.They said they expected the rules tobe changed soon, so jus t to opera teportable and ho ld m y water. I'm . tillholdi ng 33 years lat e-r. I probablydon'l ha ve the record for operatingportable. bu t I'm righ t up mere.

II's probably heen months sinceI' ve to ld )'OU about my operalin g inthe Sweepstakl'S COOlest tn.-om Ohio in1951 a.s W2NSDI8, 1hI.'n, just a.s myW8NSD lil'l:nse came thl\l\lgh, I muvedi:Jal:k III New York. so I opcr.!lcd the sec­ond Weckl,ltJ oftht: CUIIll.'M a'i W8~SDI

2. The only common pie\:e or equipmentWa'i die rnicropnle. Eu:n so. I d id" 'ell in lhe contes l.

SOllll....:n: el-e ha.<; btxn i'>SllCd my1958 OC'efl5C f{X" Nav·a....'i3. KC4AF. so Iwoo' l be ahk to gel tha1 olle hack:. DrJlt

The address ror the vanily calls,once the FCC gets their com putc rprogramllied. is: FCC, Amateur Van­ity, Box 358924, Pillshurgh PA15251 -5924 .

Vanity Ca lls

If you know anything aboutChemistry al a ll you know lhat yu-ucan' l tum It:ad into go ld. Well. itseems that the old alchemist> wt:re aliltle further along than history hasheen leading us to be liev e, It wa" n'tlead_ it was mercury tha t they weretransmuting into gold. and the"philosopher's stone" lhe)' u'\.C'd 10help the aClion wa., made of phoo­phorous, I know you' re go ing 10 findthis diffi, ultlo be lie ' t:. but lhe Japa­nese hav... heen doing a good bit o rresearch on thi s more recent ly,and with considera l> l... success.

~ly interesl in lhe transmutatiunof elemenls bega n when I read the

76 73 Amateur RadiO Today · January 1996

tall aboul.. .o tha tha n the model rigyou're using.

Anyway, it seems reasonable tome thaI life , wha te ver it is, has agood deal ofpower tu influence mat­ter. We sec it in luck, psychokinesis ,and so on. So why . houkbl' t this lifeforce also he able to mOllify evolution Ill­wank its own goal<;? lftlleoriginal DNAdicki't arrive from spare a Ia Hoyle, per ­bapc it was the life f~ which as.~i.<.ICd

its original a'i.~ly?

Of course, if D~A did am ve fromspace, tha t j ust mov es back thedock. D~A had to start somewhere ,somcwhcn, And if earth is conunu­ally being peppered with D!'\A·based life forms from space, asHoyle proposes, it docs ex plain a 101of anomancs. Like why so man)' di s­eases. su<ldcnly spring up in a nUIlI­ber of wideI)' separated areas. a ll atthe same time. And why so manynew species. ha ve . udd... nly appearedin histo ry without an y apparent "' \" 0<lutionary bridges .

If " life" is infl uen cing evolut ion.that might to some degree mollifytile Crea tionists. It would certain lymake life simpler for Evolutioni sts.who have a really tough time ex­plaining the rapid evolunon of spc ­cialized species o f animals andplants adapting to new conditio ns,Shades uf Lysenko !

So let's do our be st ro take off ourblinders and be open 10 informationwhic h may not seem to be in linewith our inculca ted behefs. Themore you I...am. tile more I thinkyou' ll see how thing s. start fill ing to­gether. A ll living things u hibitawareness. nen C Ben , Where 1'.'"arc diff...rent from ani nmls and bogsis in ou r aware ness or uur aware­ness , Our drawbal;k is a lemlency tobelieve our senses , We l>c1ievc whatwe see, so when some joler comesalong and tries to convince us our!>Cn~es are wrong. we l ill him. EH'ry<one can pLainly see tha1die~ is goingaround die eanh. Ani the SL1rS. 100. Andlheo:anh sure Iool>s flat kl me.

lt coml'!> as a shtll:l lo some whenpeople find out tha t over 12,000years ago astronurtl crs worked (lutthe circumference of thc canh towithin a 163 mile s (th e)' didn' l allowquite enough for the bulge al Iheequator). And they elen knew thaiIhe ...anh wobbled on its a~is with aperiod of :!6,OOO )eOln.

COf'C11licus and Gah leo did nolha ve an easy time conv inci ng lhescientis ts of thci r day that Iheir he ­Iiefs and senses wt:re wrong. Sowhal's ch;lI1goo'! The m" nlal aip rroml>elieving that die eanh was the cenlt:rof all creation to ur"k rstanding that ilis a MlIa l1 plaoct in a relat iv'e1y neW!;(l­Iar system, out toward the l-dge of 0111:

of billions or solar s)'stems in ourgala~y ...and dial our galaxy is justone or billio llS of OIhl'T galu il'!>. is alem!>l" dowocr. And wh...re does Godfit in this miml'Nlgglingly enonnousuniverS<' "! If you have ;111 NDE amidlink to a,k The Rig G uy. pleaS<' letmt: m ow" hen you get hack,

AMATEUR CENTERProud to be -AMERICA '5 MOST REUABLEAMATEUR RADIO DEALER"

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Fig, 10. Making a square wave out of a sine wave.

If we have lighl from some unknown source,colored glass filters lei us tesl thai ligbl 10 seewhat colon; are in u, If we use I particular colorglass, and oo!hing comes Ihrougb n, then weknow that that particular color was 001 generatedby the unknown lighl source. But we can also in­terprel !his result in I differenl wl Y: if whalcomes our of the glass filter is differenl from whatwent in. then the original light must have hadsome colors in it thai did nol pass Ihrough theglas s.

In the same way. electronic fillers. like those inFigure: 9, let us test an eleclrical signal 10 see whalilS cornponenlS are. When we pul l I.()()().Hz squarewave into a 1,()()().Hz filter. but I sine Wive comesout,. this ens us that !he original square Wive musthave some other frequencies in It that C&fUM)I gelthrough the filter.

73AmareufRadio Today . January 1996 77

"square wave"(sort of)

Detour 2Let's talk aboul filleTS for a momenl Suppose

you get several pieces of colored g ins one red.one green. one blue. When you look aI • ligh!: bulbthrough the red glass. you see red light Lootthrough the green glass. and you see green light;look througb the blue glass and you see blue light.

000', think. of the colored glass as a filler thai ischanging the while light into colored light. Instead.remember that white light consists of many colors,all combined together, The colored glass is simply afiller letting one color through. while stopping allthe other colors. We can demonstrate that easily bepulling the green and red glasses together and trying10 100k through both of lhem. When the while Iighlgoes through !be red glass. only red Iighl comes ouLThere is no green light k ft. and so when that redlight hilS the green filter. it is all slOpped and oothingcomes CM ( • that the fihen In: ~"",!!,.~,,~,cJ-"'~!".~..'!!!~ ..J

Continued from page 71

you will see that the blip at 3 kHz is one­third the height of the fundamental at 1kHz, and so on.

The presence of harmonics has an im­portant effect on communications.Whenever we talk about sending a sig­nal from one place to another, we haveto make sure that all the components ofthat signal (or, at the very least. theimportant ones) get through as well.This brings us to the concept ofbandwidth.

Consider piano music. Obviously hav­ing a phonograph that covers the rangefrom 27 Hz to about 4,200 Hz will letthrough all the notes. allowing us to rec­ognize the melody.

But a restricted range like that doesnot sound like a very good piano. Tomake it sound realistic, you must letthrough all the hannonics-or at leastthe ones you can hear. That is why mod­em hi-fi equipment typically reproducesup 10 20,000 Hz (or. at least. that's what

Bandwidtb

the manufacturers claim') In fact.15.{)(x) or even 10,OClO Hz would prob­ably do for us o lder people whose hear­ing no longer ex tends to 20,{)(X) Hz(pityl)

Let's look at the frequency rangescovered by various pieces of equipment:

-SSB transceiver-cabout 300-2,700 Hz.-Telepbonc lioo- ahout 300---3,500 Hz.-AM broadcast stauon-c-abour 100-

IOJXXl Hz.-PM broedcasr station-about .50­

15JXXl Hz.- Compact disk- ahout 5- 20,OOO Hz,Looking at these frequency ranges, we

can clearly see which equipment willhandle music best. and which is merelygood enough for voice . (See Detour 3.)

So far, we've taken a short look at thenature of aud io. We have seen (hat audiosignals consist of frequencies in thcrange of about 20 HI. to about 20.000Hz, but that a narrower bandwidth suf­fi ces if we ' re nOI 100 concerned withquality. For example, a typical telephonecircuit can handle only the range ofabo ut 300 Hz to about 3.500 Hz.

A frequency range up to 3JXXl Hz or4,l.XXJ Hz is good enough to understandspeech and even 10 recognize the voice ofthe speaker. bUI it is certainly not hi-fi . Letus now look where time comes into this.

Time

Say you have 20 minutes of things totell him. You decide to record it on tape

Detour 3

While we're on the subject of hi-f equipment.leI's discuss 01 few more term s.

11'5 IIOt enough for 01 piece of hi-fi equipmenlto CO\"eT a wide range of frequencies: differemfreque ncies in the range have to be treatedequally. That is. an amplifier or tape deck Ihalcovers 20-20,000 Hz, hut provides a 101 less gainabove, say. 1,000 Hz than below, would soundvery bassy. Ideally, hi-fi equipment should beable 10 handle signals of different frequenciesequally welt. Evenness of response is usuallyrated in decibels or dB. For example, a typica lamplifier might bave a rating of "20-20.000 Hz± I dB," which means Ihat the gain (how much ilamplifies) does not vary more than plus Of minus1 decibel from some midscale value. (We' lI haveI detour later 10 explain decibels.)

In addition 10 having a wide frequency range.the hi-Ii device also should nol distort the signal.Thai is. its OUtpUI waveform should look like lheinput waveform (except for poss ibly being largerOf smaller). One way to rale distortion is as THOor total harmonic distortion . Remember that it'sthe harmonics Ihal make one signal of a givenfrequency different from another signal of thesame frequency. Hence if the output from an

78 73 Amateur RadiO Today . January 1996

at a low speed. Then you re wind the tapeand play it back, but at double the speedso that it takes o nly 10 minutes to play.Can you thus send 20 mi nutes ofspeec h, bUI pay fo r only a Hl-minutephone call '!

You can certainly do that, but yo urvoice will sound like the Chipmunks(that 's how they do their voiccs! ) andmay not he too understandable. Rutsuppose your fr iend record s yo ur vo iceon another tape recorder. but th is timerecords at high speed and play s it backlater at half-speed (try thi s wi th aChipmunks record !) T his stretches the10 minute tape back into 20 minutes.Will this work? (And if it does. canyou speed up the tape by a facto r o f 10and pay for o nly a 2-minute call '!)

Yes ... and no . What happens is thatas yo u do uhle the speed o f your tape.every frequency on the tape getsdo ubled too . A I,ODD-HI. compo nent o fyo ur voice hecomes 2,000 Hz, and soo n. The problem is that every co mpo­nent o f yo ur vo ice that is above 1.75 0Hz or so gets do ubled to above 3 ,500Hz. and there fore doesn' t make itthrough the phone line . In other wo rds.your friend will only hear those com­ponents in your voice that are below1,750 Hz. (And if you tried to speedthi ngs up by a factor o f 10. he wouldonly hear those parts o f your vo ice thatare below 350 Hz.)

In other words. it' s the ba ndwidth ofthe tel ephone line that limits how

amplifier or recorde r looks different from the in­pUI. its harmonics must somehow hav-e beenchanged. "The slandard way of measuring: this is 10insert a pure sine VoI\-e lest signal (thaI h~ 110 har­mon ies ). and look to see whether there are anyhan nonics in the output. If so, then Ihe signa l gO{distorted. The THO number is a percentage thattells how much hannonic voltage gill added 10 thepure signal. For instance. if the output from anamplifier (with a sine wave inputthat should haveno harmonics) is 10 volts of fundamental and 2volts of har monics. then there would he 20% THO(a terrib ly high number, by the way. THn valuesof under one or two percent are more desirable).

Actually, though. hannonic distortion is notnearly as had IS you Ihink. Since music andspeech non nally hOi \!: hannonies anyway. addingan extra percent Of so of harmonics to them is not100 noticeable. Amplifiers and other all--electronichi-fi eq uipment lend to have lo\\" distortion, bUItape recorders and mechanical components suchas phonograph cartridges and speakers often havea high THH (so mel imes as much as 5% 10 10% forspeakers).

Much more dangerous is 1M or intermod..lm;mrdistortion, which introduces new frequencies not

much information you ca n gel ac rossin 10 mi nutes. If you used a higher­band width line-such as the speciallines that broadcast stations lease fromthe pho ne company fo r studio-to­tra nsmitter links. wh ich cover up to

10 ,000 o r 15,000 Hz-c-you could eas­ily speed up your tape hy a fac tor of 3or 5 , and still t ransmit a ll o f your mes­sage (thou gh st ill o nly at normaltelephone-li ne quality ).

So the idea is thai there is a tradeoffbetween bandwidt h and time. If yo uhave a fixed amount o f information tose nd , you can send it fast if you have alot o f band widt h. But you have to sendit more slowly if the bandwidth issmall . That explai ns why, fo r example.a fax transmissio n can go throug h aregular telephone line, hut a full-motionTV video image can't. The fax takes upto a minute 10 send one picture. whereasthe TV has to send it in 1/30 of a second.

Summary

Although the discussion has rambledoff and o n about various aspects of au·die. we've actually covered a 10 1 ofground. \Ve have seen the characteristicsthat make up an aud io wave- the Ire­qucncy, wave shape, and amplitude of thesignal. We have looked at how harmonicsaffect the wave shape, and how the band­width of a system affects the sound qualitythat you can send through it. Next time wewill tackle transmission of vide(l. II

in !he original 011 all. Even 112'10 or 1/4'10 L\ t dis­lortion is grating and unpleasant- Unfortunatel y,1M distortion is not wry oft....n listed in specsneers for equipmeru . fortunately. however. 1Mdistortion sort o f goes hand in hand with lliO,and a bi-f de vice with low Ttl[) pmlwbly alsohas low 1M.

Finally, hi-fi eq uipment should have very lin lenoise. Noise can app....ar in the form of a low­puched hum (often caused hy a had power sup­ply. bad grounding. or had shielding of a wire)and a high-frequency hiss, Eithc r one ls bad, Hi­fi equi pment specs therefore often list the SNR orsignal-to-noise ratio . Thh is Ihe ratio between' he loudest music il can handle and the norse .Forexa mple. in a CD recordin g. the 10udcSI musicvoltage is typically about 65.000 times high....rthan Ihe noise voltage. while in a cassene record­ing it might only' be JOO or.wo umes stronger. Ina telcphone circui t. the ratio betw een the loudestvoice signal and Ihe noise might be as low as 1010 I . Since we're holding off on our discussion ofdecibels. let me just say .II this point that the65.0()() ratio is equivalent 10 abou t 95 d B. the ra­tio of 300 to 400 is about 50 d B. and a ratio of 10is only about 20 db .

Flf: . 12. Spectrum afa 1.000 H~ squa re a e.

Numb« n "'" your F~1c cMdListings are free of charge as space permits. Please send us

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JAN 13 J A."'i 13-14 the May issue. we should receive it by February 29. Provide

HARRISBGRG, PA The Harrisburg. SA RASOTA, FL The Sarasotaa clear, concise summary of the essential details about yourSpecial Event.

RAC will hold a Hamfest 8 AM·Koon Hamfest and Computer Show willat Oberlin Fe Social lIall. For info. I'll' held 9 AM-.:'i I' r.t Sat.: 9 AM- Ramada Inn in SI. Joseph MO. Spcn- ARC Big Event #18 will be held at thecall (7 [7) 232-6087; for table reserva- 3PM Sun. at the Robarts Sports sors: Missouri Valley ARC, Green- Canadian Auto Workers Hall. 124nons, write 10m Hall 1l'U3X, Bax 4 18 Are na, Sarasota Farrgrourds. 3000 tuns ARC, ,"" Ray·Clay ARe. Bunting Rd., 9 AM-2 PM. Setup at 7Halifax PA J7U32. Talk-in on 146.76 Ringling Blvd. Contact Sam Exerts COITUllt.'TCial exhibitors welcome. AM. Contact Marg S('M'ell l,'£]HOX,and 146.52. K£4BXF. (9411 927-8999. Talk-in will Contact Nonh.. est Mi~~oll ri l\inuor NPARC Po. Box 20036, Grantham

begin at 8 A~I each day on 146.311.91 Hamfest. d o Ga)ltn Pearson UBOII,: Pouat Outlet. St. Catht.lrlne~ ON 12MWn-:I.A.'IlD, CO Th< Nonhern and -U-J.9251+l9.925 Rpm. 111- Midw tf Rd., 51. Joy ph ,',10 no. Ttl. (9051 680-JZlI.Colorado ARC will sponwr the Win- 645()(j.ter Superfesr at the Larimer County JA.'J 14 ITB.4Fairgrounds, 700 S. Railroad. Talk-in JA."\ 21on 1+l.515/.115 PI 100 Hz;or 146.2.'i1 DOVER, 011 Th, Fusco ARC M IAI\I I, }' L The 36 th An nua l.85. VE Exams, tables, contact lIamfest will lie held at Ohio Nat'L YONKERS, S Y The Metro 70em. Tro pical Hamboree Ama teur Ra-l!'W!ClU' Gage NOrlly' (970) 351· Guard Armory, 21100 No. Wooster Network will present a Giam Elec- din and Compute r Show will be7327, For general info. f(/ll Mld wl'! Avc., starting at 8 AM. Setup at 6 AM. rronic Flea Market 9 AM-3 I'M at Lin- he ld a t Dade Co unty You th Fa irRobinson A1.0UB. (97U) 281· Jl67. Coeucr Howard /lUnd KD8KF, 62X8 coin H.S. VE Exams. Indoor Flea and Expo Ce nter. S .W. I [2 Ave .

Echo Lake Rd. N.£. , Nl'M-' Plrilltdel- Market. For registration. call Otto & Co ray Way. Sponsored byPHm -:f'IlI X. AZ The ARC of Arizona, phin OH 44663. Tri. (21M 364 -5258. Sllp/i$ki WB2SLQ, (9 / 41 969·1053. Dade Radio C lub of Miami . Tal k-bostcd b)' ThundcrBml ARC, will Tall-in on 146.730( -). Talk-in on +l9A25 ~I Hl PI 156.7; in on 1-16.925 . Booth and tablehold "" West Valle)' Hamfest 223.760 ~UJl PI 67.0; 1-16.910 Hz; info: call (305, 641·4 139: o r Fox(west r-nT) at Glendale Conun. Col- J A." 20 and+l3.350 ~fHl PlI56.7. {3 05 } 642-1648.lege. '''''" 10<. 6(XX) W Ohve(Dunlap & 59lh A. e.). Contact Mor- GO WER. ~IO 'ne 6<h Annual ITB' SPEC IAL E\'E"T STATlO"S, aa N7DLU; (602) 938-4356, ~ ;'Ik.rthwest Missouri Winter lI amfestMart N7KKQ. (602' 843.()96(). will be held 9 AM.... PM at "" Kl"OXVILi.F.. DI The Steioers of JA:"i 20

, Kerbela AR Service will spon sor theKerbela llamfest at the Kcrbela Slnine S AN UUS K Y, OR T he Sandu skyTemple, 8 AM-4 PM. Setup Fri. 4 PM-9 Radio Ex perime ntal Leag ue wi llPM; Sat. 5 AM·8 AM. FCC Exams by opera te W8 LB Z 1500Z· 2400Z toWCARS-VEe. Reg. until 9:30 A\-1. ce rebra te the 100th Anniversary~tail COlllplelOO 610 form with cteck of the "Boy with the Boot" statue,

. for 56 .05 payable 10 ",CARS- I,'EC, Sandusl:.y·s official symbol. Opera-Ray Adlll1/S N4BAQ. 5833 C/tnllHl tion will be in the Genera l oW. 20.l b .):. Suitt' 203. Knoxville TN 37912- 15m bands. 1-16.655(-). ,""2500. Tel. (423, 688-m l . -144.375(+) Rptrs. For a certificate.

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Fig. JJ. Spectrum of a I,OOO-H::. sine "'al·e. UPORTES

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v ~ t :5 Q ,• ) 2N381l1c.:)

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• - The Ultimate Crvstal Receiver- I\' \ .

73 Amateur RadiQ Today ' January 1996 79

1995 ANNUAL INDEXSubject/Article Author Issue Page SUbject/Article Author Issue Page

2m2m Col linear Vertical Antenna KAQNAN JUL 40 DTMF Decoder K7CAH JUL 46Coll inear SIS-Wave OMNI Ant, WOOD JUN 18 General-Purpose Wide-BandCQY2M3EL 'Stealth" VHF Y83 i KT2B JUN 44 Preamp NZ9E NOV '"First Look 81the R S.HTX-21 HF·SAT Antenna AC3l MAR 24

Mobile Transc. K7UGO JUL 30 Home-Brew Quagis KE6HVH NOV '0MFJ-208 2m $ W A Ana lyzer K4CHE NOV 46 Inexpensive Morse Code Kayar N2YMW JUN 366m K4SYU Loop Antenna K4SYU MAY 44AJinco DR·MOO WB6NOA MAY 36 Key II! KB1UM DEC ee10m l ow Norse Amplifier WA9PYH JUL 20OieoneAntenna lor 10m W,,,,,,, SEP 32 Mllhonm Adapter IOf Your DMM K4GOK DEC '"Pyramid Anlenna W9CGI JAN 14 N4UAU Super CW StatiOn N4UAU JUN '0Simple J-type 10 Vertica l W610J SEP 10 Poor Man"s Doppler K3BYCC NOV 3820m Portable Inlegraled 20m 5SBlPortable Integrated 20m SSB/CWz CW QRP Ham Station KB4ZGC DEC 10

ORP Ham Station KB4ZGC DEC 10 Portable Solar ElectricRamsey SX-20 OAP SSBICW 20m Power Gen. K4SYU OCT 20trensc. KT2B OCT 48 O RP Delight AD5 X OCT 10

60m O RP Mini Tuner WUOL OCT 46The 80140130m Trjpole W9CGI JAN 36 Serial Port CW Terminal N2HTT NOV 44160m Shortwave Converter lor YourSpecialized Top-Band SCanner WA 1KVL APR 54

OX Receiving Loop G2BZO APR 38 Simple J·type 10m v eneer W610J SEP 10Antennas Simple PrecisiOn Voltage2m Collinear Vertical KAONAN JUL ' 0 Standard K4GOK AUG 448OI40130m Tripole W9CGI JAN 38 Simple SimpleX Repealer KB6lT1J NCV 38Antenna Elevalor WB2DZF APR 38 The ceocos KB5AMZ AUG 50Build an EffiCient HF Tone Burst Generarce and

Mobile Ant . K5DKZ APA 42 neeooee WB9YBM JUN 46Cheap Dual·Band Vagi KAONAN FEB '6 'rrenstormeoes Amphher W6VBT AUG 48Coll inear 5/8 Wave Omni WDQQ JUN 18 Tube TNC WOXI AUG 10Comet HA4S - mobile HF N2PNG MAY 38 Tuner Helper K3PUR SEP 14COY2M3EL -s teann- Wart Remover WB8VG E MAY 16

VHF Vagi KT2B JUN 44 CW · CodeDual Bi-Square Loop lor HF K5DKZ FEB 18 An Inexpensive Morse CodeGAP Voyager OX vertical WB6NOA APR 32 Keyer N2YMW JUN 36HF·SAT Antenna AC3L MAR 24 Ham University Interactive WB6NOA MAR 38Home·Brew Ouagis KE6HVH NOV 10 KK-1 Irom AEA WM4U JUN 30Just Another Loop Antenna WB2EGO SEP 32 N4UAU Super CW Stalion N4UAU J UN '0K4SVU Loop Antenna K4SYU MAY 44 Porlable Integraled 20m SSB!Ma idel Anlenna·s HS-2 and CW OR P Ham StatiOn KB4ZGC DEC '0

H$- 75 HFNHF Vagis KT2B JUL 36 RamB:¢ ElectroniCs SX-2Q ORPMFJ·l796 Multiband Vert. K7VGO JAN '" SS W 20m Transc. KT2B OCT 48Pyramid Anlenna W9CGI JAN 14 Reading Morse Code on

Simple J-lype 10m Vertical W610J SEP 10 Your PC W6PRO FEB 22Specialized Top-Band OX Serial Port CW TerrTllnal N>HIT NOV 44

Receiving Loop G2BZO APR 38 O~ltal Modes: Packet, CW, ATTY, AMTOR, etc.ATV, FSTV, SSTV, Video R TY Loop WA3AJR JAN 46ATV WB8ElK JAN 66 RTTY Loop WA3AJR AP R 64ATV WB8ELK MAR 52 RTTY Loop WA3AJR MAR 60ATV WB8ELK MAY 6' RTTY Loop WA3AJR FEB 62ATV WB8ELK JUN 64 RTTYLoop WA3AJR OCT 60ATV WB8ELK JUL 64 RTTYLoop WA3AJR SEP 70ATV WB8ElK NOV 58 RTTYLoop WA3AJR MAY 58Books RTTYLoop WA3,lUR JUL 58ARRL 1995 Handtlk JAN 60 RTTYLoop WAJ,lUR AUG ,.ArtSCi Repeater MapBook 95196 US MAR 60 RTTY Loop WA3,lUR NCV 6'Cable Experts 1995 Catalog MAR 60 RTTYLoop WAJ,lUR DEC 58Contact EaSI 1995 Catalog APR 88 Direct io n Finding· Fox HuntEDCO Brochure APR 88 APRS Puts Doppler BearingsFocal Press Basic TV Tech NOV as on the Map KQQV AUG 58Focal Press Comm 'teen . NOV as Cooperat ive Tracking and WebGordon weer COurse Tapes Radiolelegrph JUL 88 Sur1ing KQQV NOV 78Gordon west license Book Advanced NOV as Dopp ler Antennas KQQ V APA 58Tektronix Portlo llo 'receencn MAR 60 soxh unnnq's Wide World K00V DEC 70Romance Enterprises Handy HamBook NOV es Good Deeds, Good Fun" . K00V MAY 52Telex Lapuszynski OCT 88 Hunts and Stunts AroundW21MB Ken COrnell Stall SEP 78 lhe US A KQQV OCT 62Xuron Corp. WB8GLQ JUN 80 Poor Man's Doppler K3BYCC NO V 38Cir cuits Single Chip Identil ier K4CHE AUG 30OR P MiN Tuner WOOL OCT ' 6 Stalking the Wild T KQQV JUL 52RIT Circuits WB8VGE NCV 70 T·Huntlng eases KQQV SEP 59Computers 8nd Software MultIPle f oxes . More Fun KQQV MAR 64APS Spread Spectrum Dev. Prog. Traett II With Packel KQQV FEB 58

IBM·PC Boa rd laj)U ki OCT 88 Up and Running wilh GPS KQQV JAN 62Hewlett Packard 200LX KE8~ AUG 40 Wideband Doppler. Part 2 KQQV JUN 54LOGIc 4 WA3USG MAR 40 OXConstr. Jan Mayen ,lUONJ1...A6US DEC 182m Collinear Vertical Antenna KAONAN JUL 40 Longwave-Plus OX Techniques G2BZQ SEP 38Armstrong u pdated KC3ZQ OCT 26 Simple J·type 10m Vertical W610 J SEP 10A Simple Wattmeter N7AP E NOV 20 Special ized "roo -Band OX ReceivingBattery Monilor and Charge Loop G2BZQ APR 38

ccorroller K4GOK JUN 32 EditorialsBUild an Efficient HF Cold FUsion, Forbes, Speed

Mobile Ant. K5DK2 APR 42 Readl~, Anomalies W2NSDIl JAN •Build an lnlell= Relay N8LXS APR 22 PsychIC henomena, Books.COllinear 518· ave Ornni Ant . WDOO JUN 18 Coup at 73- W2NSDfl FEB •C2Stal-Gontroiled Audio Gene KB4ZGC NCV 28 Dayton. 40th Anniversary.D S Dream VFO KD1JV OCT 14 Internet W2NSDfl MAR •Dish Anlenna for Weather Computers. Opportunl!y.

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SubJectlAnlcle Author Issue Page SUbject/Article Author Issue Page

Info Age. RTTY, 75m.~ Build an Eff iCienl HFBang? ARRL Fought A W2NSOJ1 MAY • Uob~e Ant KSDKZ APA "OXpedition?, M RL. Arrogant Comet HA-4S Review N2PUG MAY 3&SCientists. EMI W2NSOl1 JUN • First Look at the R.S.

Dayton Talk, Flea Martlet, ARRL HTX·212 K7UGQ JUL aove. FCC W2NSOJ1 JUL • Tuner Helper K3PUR SEP "Colorado Springs. Virginia ModificationsBeach. HlstD~ Repealing W2NSO/1 AUG • Using GE Progress Une Recvr.

35 Years, Psy okenesis, Strips KI5PGI JAN "Contests, ELF W2NSDJ1 SEP • New Producll (by manufacture~

Money Ideas, Scie ntific AEA AEA AX III sonware MAA '0Evidence, War on Poverty W2NSD/1 OCT • AEA LOG Windows 2.0 FEB BB

Brbery, Better uses. Contest. Amateur Radio Edu. "Ham UnIversity" FEB BBAids. Raw Food W2NSOJ1 NOV • -, PCS-96000 rreose. FEB BB

Builder's Alert. FCC Vs. ARRL W2NSO/1 DEC • Boyd Electronics RW Series receivers MAY '0Education ca~Lab' ProGold cleaner JAN SOBrighlldea lor a Trip WB2MGP JAN 60 CC Corp. GBC CCO-SOOPH MAR SONew Resources WB2MGP FEB .. CEC SP-SOO RF SEP 79Oass Experiments WB2MGP MAA 72 Connect Systems CD-2 COmm. Decoder APA ..Getling a Taste 01Radio WB2MGP APA SO ccsrcratt ASL-2010 Skylog JAN SOA Sakrte to Wes1 Point WB2MGP MAY 72 Encode Syslems S,_ APA ..Geog~ Resources WB2MGP JUN 72 F"18k:Ipiece Insl ruments LT60MM SEP 79Never 00 YOU'lg WB2MGP JUL 72 Hamlronics AS138 scan Aq)l Mod MAY SODayton Hamvention Youth Hamtronlcs CWlO·2 ModUe JUN SO

Forum WB2MGP AUG 60 ICOM IC-738 Transceiver MAR SOUbe~~nce Center WB2MGP SEP BB ICOM IC-2000HMars Simulation WB2MGP OCT 56 Jan Bexner SM70EW Russian C8llbook on NOV asNew Resources WB2MGP NOV 60 JPS Communications ANG-4 Ant. Noise Cnerl MAY SOSwltches afld Fuses WB2MGP DEC BB JPS ccmmcncencoe NIR-1 2 Noise Filler JUL ..Gener.l Inlerest Kan lronics KPC-3 TNC AUG 70A Boy SCOUI'S "Drab" Life KB7UIM NOV 16 Kanlronlcs KPC-3 ver. 6.0 TNG NOV asA Perspiratlonal Message W2NSO/1 DEC 17 LogSat Software Ver 5.0 lor Windows JUN '0Nostalgia lor the Future KC3ZQ DEC " Maggiore R1 Repeater JUL BBRadiOS. Telephones. and the MFJ 114 LEO o~ Clock MAR '0Amaleur W5UOJ AUG 32 MFJ MFJ-306 S Conv JUN '0

Senior Cil!zens Upgrade N6JSX OCT .. MFJ MFJ-452 CW KeCtd JAN SOHF MFJ MFJ-8621 Della adio FEB ..AJinco DX·71) HFJ6m Transc. WB6NOA NOV SO MFJ MFJ-9-420 Travel Radio JUL saBuild an Efficient HF MiCrolek RG-2 Radio Controller MAY SO_Am. K50KZ APA 42 Matron Electronics Au!o-Kal AK·16 AUG 70

Comet HA4S Mobile HF Ant. N2PNG MAY 3& Muhifa.ll Ver. 7 MFMAP7 sltwr JUN SOHF·SAT Antenna AC3L MAA .. Par Elect ronics VHFON152 2m l itter SEP 79lCOM 1C-738 HF Transc. WB2W1K18 SfP .. P1amed Products Circultworks greases JAN SO

"'" Ouantlcs DSP-3 K. APR ..oee HillS Explorer Kil ACoIHF MAY so RF AppIieal ions P-1SOO VSWR Indidr SEP 79RF InduSlrles Unicable Ki l WA1 RZW JAN SO RF Industries RFA-4017-1 ceex tstr JUL saS&S Engineering's PGl AC-4HFJCzuhajewski RF Industoos RFA-<W27 SMA Kit NOV asMAR 44 sescom 1995 Conslruct. Cat FEB ..

Mobile S&S Cable Copperwire APR BBAlinco DR·Ma6 WB6NOA MAY 36 SGC, Inc. Power Talk AOSP-SNS AUG 70Alden PCS-720 WB2WIK16 MAR 32 SSC PC GOESIWEFAX V4.0 FEB a,

73 Amateur Radio Today · JanlJBry 1996 81

Subject/Article Author Issue Page Subject/Article Author Issue PageRaymond Sarro Am. Radio 'r.snms JAN eo Dual-band HT KB1UM AUG 42RF Industries Unicable Kit JAN eo Explorer Kit CW RIg AC4HF MAY 30Shad( Anaell Handie Station SEP 79 HF Transceiver WB2WIK16 FEB ' 0Shack Attack Ceusqn Uc:ense Plaque MAY eo K. ye< WM4U JUN 30Telex Comm. OCU-1 Pathlinder MAY eo Linear Transvener KT2B FEB 32Toolpok Tool vest FEB 88 Mobile HF Antenna N2PNG MAY 38Tower Jack Tower dismanller FEB 88 Mooilor Scanner Nl0GS MAY 24VHF Products VHF-OX Software APR 88 Palmlop Computer KEaWO AUG 42WB2GMK Antennas G3TPW CobWeb JUN eo Pocket Shortwave Receiver KB1UM SEP 50Woodhouse COmm. APT-4X4. AUG 70 Radio K4CHE APR 2.Yaesu FT-8500 Mobile Trnsc JUN eo Software for Code, Theofy,Pac ket CW Games WB6NOA MAR 3819,200-baud Packet WB9JTK AUG '6 SSTV Interlace KB1 UM JUL 32TUbe TNC WQXI AUG '0 Transceiver (2m Mobi le) K7UGg JUL B2VE7PMR Sorer-powered Node VE7VMS AUG 12 Transceiver N1BA JAN 10Power Suppli es Vertica l Antenna WB6NOA APR 32Battery Monitor and Charge VHFIUHF Yagis KT2B JUL 36

Controller K4GOK JUN 32 SafelyPortable sour Elect ric Power Grounding and LightningGenerator K4S YU OCT 20 Protection, Part 1 W5UOJ FEB 52

ORP Grounding and LightningA ORP Receiver WB8VGE SEP 72 Protection, Part 2 W5UQJ MAR 26Dave N7NNG's 40m Transe. WB8VGE MAY 66 satellite Operation, EME, SpaceDDS Dream VFO KD1JV OCT 14 AMSAT Annual Meeting WA5ZlB JAN 42Field Day WB8VGE JUN 66 A New Russian Star WASZlB MAR 66ORP ConslT. WB8VGE MAR B2 Dish Ant. for Wealhef Sal IORP CW on a Mountain 8lke WB8VGE JUL 70 ~ge' WA9PYH JUL '0ORP Delight AD5X OCT 10 Field Day via Satellite WA5ZlB SEP 64ORP Mini_Tuner WUOI. OCT 46 HF-SAT Antenna AC3L MAR 24MFJ ORP Transe, modificahon WB8VGE JAN 66 low Noise Amplifier forPor1able Integrated 20m 169 1 MHz WA9PYH JUL 20

SSBJCW ORP Ham Station KB4 ZGC DEC 10 New Satellite Modes WA5ZIB AUG 64Ramst Electronics SX·20 ORP Phase 3·0 WA5ZIB JUL 6'

SSB/ W 20m 'rransc. KT2B OCT 49 Practical Weather SatelliteReceiver Incremental Tuning WB8VGE OCT 6' Receivin,x. System ZR6UM FEB 10The Dragon Slayer WB8VGE APR 66 Practical eatner Satel liteThe Xplor 32CA WBBVGE FEB 64 Receiving System ZR6UM APR ' 0Small Wonder Labs 450·30 RF Problems WA5ZIB FEB 62

ORP Kit WB8VGE AUG 66 TAPR DSP-93 WA5ZIB NOV 66Radios The ShtJllle and MIR WA5ZlB OCT saNostalgia For lhe Future KC3Z0 OEC " Transponders WA5ZlB JUN B2Receivers UNAMSAT·1 WA5ZlB MAY seSony IGF·SW100$ Pockel Wor1ting the FInal Fronlier N2CORlHl8 AUG 26

Shortwave Rae. KBlUM SEP 50 ScannersRepeatef"$ Tridenl TR-l 200 Nl0GS MAY 24Mmiore Hi Pro R l Rptr, K1ZJH OCT 52 Single Side BandP Conlrol lrom Receiver Portable lnt~ated 20mAudio KB8XI JAN 32 SSB/CW 0 P Ham Station KB4ZGC DEC 10Reviews (by manufacturer) RF Speech Processing VK3CA AUG 24AEA WM4U JUN 30 Test EquipmentAlinCO WB6NOA MAY 38 A Simple Wanmeter N7APE NOV 20Atinco WB6NOA NOV 50 Check Your SWR Bridge K1WVX SEP 34Azden WB2WIK16 MAR 32 MFJ-208 zm SWR Analyzer K4CHE NOV 4.Comet N2PNG MAY 38 S&S Engineering PC·1Program.Communicat ions Specia lists WB9RRT DEC 22 Counter Kit AC4HF/CzuhajewskiDown East Microwave KT2B FEB 32 MAR 44Gap WB6NOA APR 32 The Octopus KB5RMZ AUG 55Hamtecntcs WA3WGV DEC 30 TransceIversHam urev Interaclive WB6NDA MAR 39 Azcen PCS·7200 Review WB2WIKl6 MAR 32HElL WB6NOA JAN 41 Yaesu N1BAC JAN 10Hewlell Packard KE8WO AUG 40 Tutori alICOM WB2WIK16 SEP 42 6 MeIers - The In-BetweenICOM WB6NOA AUG 34 B" ,. WB6NOA MAY 34K~wood K6YAZ OEC 41 A Decibel Primer N50WK JUL 42Logic 4 WA3USG MAR 40 Allnco DX·70 HFJ6m Transe. WB6NOA NOV 50Maggiore K1ZJ H OCT 52 Builders Guide to the Universe WB8VGE MAY 10Maldol Antenna KT2B JUL 38 First Look at the Radio ShackMFJ K4CHE NOV 4. HTX-212 K7UGO JUL 30MFJ K7UGO JAN 34 ICOM ZlA WB6NOA AUG 34Midland Corp. KT2B FEB 2B MeaSlJring the Antenna fromOak Hills AC4HF MAY 30 me Shack WORKU JUN 40Pasokon KB 1UM JUL 32 Sailing with Ham and MarineRadiO Shack K7UGO FEB 42 Radio Equipmenl Wll6NOA JUL 26Radio Shack K7UGO JUL 30 Using GE Progres LineRamsey Elect ronics KT2B OCT 4. Receiver Stnps KI5PGI JAN 24S&S Engineering AC4HF MAR 44 UpdatesSGC WB6NOA JUN 22 PTT Control from Recei verSentect WB2WlK/6 FEB 39 Audio JAN Issue MAY 65Sony KB1UM SEP 50 The Traveller OCT 94 Issue JAN 51Standard KBlUM AUG 42 VHFIUHFSwiech COmm. KT2B JUN 44 1691 GOES Converter WB6IG P NOV 54Trident Nl0GS MAY 24 Converting the CATV Tuner WB6IG P APR 74Yaesu N1BAC JAN ,. ORO FreQ. Man.:er for 10 GHzYaseu WB2WIK16 FEB ,. From Salvaged TYRO Conv. WB6IGP JUL 66Yaesu K4CHE APR 2. GaAsFETs and the RadioReviews (by product) Amateur WB6IGP FEB 7.2m Oua gi WB2W1K16 FEB 38 MicTowave Surplus Evaluation WB6IGP AUG 622m SWR Analyzer K4CHE NOY " Switching Power Supplies for8m He Transceiver WB6NOA NOV 50 Portable Operation WB6IGP JAN 66em Moote Transceiver WB6NQA MAY 38 Surplus Cellular Telephone WB6IGP SEP 6220m Transceiver (OR P, SSB) KT2B OCT 4. Surplus Ideas lor GOES222 MHz Mobile Transe. WB2WIK16 MAR 32 1691 MHl COnverter WB6IGP OCT 66Antenna K7UGO JAN 34 Surplus VHF Downconverter WB6IGP MAR 66Antenna ("Stealth" VHF Yagi) KT2B JUN 44 SWR Primer for VHF ThroughAntenna Tuner (Iongwire) WB6NOA JUN 23 Microwave. Part , WB61GP MAY 60Base Station Ant. I<.T2B FEB 29 SWR Primer for VHF ThroughDigi tal Signal Processor K7UGO FEB 42 Microwave, Part 2 WB61GP JUN 60Dualband HT WB6NOA AUG 34 Ell82 73 Amateur Radio Today. January 1996

LETTeRSConlinuedJrom page 6

my ucense. fn 1987, 1 re-tested andqu ickl y acquired my General Li­ccnse again . La te in 199-* .1 passedthe Advanced Class upgrade. andin August 1995 I upgraded to Ex traClass. I have had to rene w my highschoo l memory of tri gonomet ry. aswell as tcarn how [0 usc: a scie n­lific ca lculator. :\Iy main tale nt issewing, nOI ele ctroetcs. bUI Ipassed Ihe lest. three months shortof I'>eing eli gible for Medicare.And I understand lhal keeping themind acnve wards o ff Al zheimer' sdisease and other ma ladies. I amvery appreciative of the ham com­mu nuy. which has kept the han dsacti ve throughou t lhe years in or­der that ' ho se of us who have beenless active sti ll ha ve frequencieson wh ich 10 operate. That meansthe old-rimers. The y prob ably havemore vuck -tc-It-ivenevs than someof the newcomers . If they haw notbecome biuer through the years,Ihey have more manne rs than someof the yo unger generation. Andmanners speak well for amateur ra­dio . And, o ff of that subject: May Isugges t/ request that il would beeasier to res pond to "Feedback" ifthe back side of the listing were anad . ra ther than an article o r printedcircui t dia gram?

Noud . . . ttln ·" ..

Jllck COD'" a". NSYIS I never go10 namfesrs, so I tho ught that I.... ould never ha ve an opportuni ty10 hear you speak. Whe n I read in73 that yo u had a tape for sale, Ij ust had 10 have one, Here is myfive huck s: After readi ng years ofgood money-making ideas fromyo u I thou ght I ....ould send youtwo thaI you can ha ve free ofcharge. Your o ffer to sell back is­sues o f 73 was tem pting. bUI likemost people I don"! have room forany more magazines . I do. how ­ever. na ve room for more C D­ROMs, so why don 't yo u scan allyour back issues onto CD ROM'sand sell them ? I know I would buythem j ust 10 read all the editorials.Why uon't you put your audio pub ­lish ing house 10 wor k purring 10­gelher a Morse code C O" Readingthe diffe renl magazine I read, Ihave al ways wonde red IIl hy no­hod)' pur togeth er a Morse codetrainer o n CD. .\o loS! C D pla yershave a random pla y feal ure . I lhinkit wuold he the t>eSI medi om forpractic ing code. Keep cranking ootthe qualily cdilOrial s,

SIITf' , 1'/1 btl / ('oliid se ll do:nrsof CIl ·RU,t ls of tlJe b/lck. iss ll es.Ufllll' kilO"· if you 'd likl' to sea" inflrl' 50,000 pagu f or me. Or ma.\-hi'/ cOrl(d gl'l som, Tf' tir,d ham 10

scan in m)· Ol"U 1,000 l'di torials.I' ll hl't I could stlt SCOTf'S of thost

0 " a CD -ROM. U.. did a CD ·ROMlisting of ""·U)· hOlm CD back in/ 989 and m id do:'...ns of ' n il. W....I'" " scann..d i ll thr color C01'""S

f or hundreds of 'em. and hadsamp le tracks of tile IIIlulc. It soldlike cold cukes . The code ? All Ittakl'J is 0I1t' one -hour tape a/ /3pe r 10 learn l il t" code f rom scratch.And one at 20 " pm for thai spud,Wh.v would 0")'0"" pUI an hou r ofcod.. on a CD ,.·h, n a tap.. dot'S itjust f in..? ... Uo.,n,

n n e Kaun :'Il9KM Y It is trulylime for nur hobby 10 mo ve intothe new tec hno logy age . We needto substitute a pplication o f techni­cal skills for Q&A manua l meUJI) ­ri zatio n and the co pying o f thecode as a method of advancement.vtemon zauon. po pular as a leach­ing method in prev ious genera­lions. is no longer the way learninglakes place lodaJ. While we expectour youngs ters 10 understand andapply huge ameums of tech nicalinfo rma tion. why are we still re ­quiri ng memoris-ation in am ateurrad io? l .er's make OUt hobby ana tural learning progress ion fortechnic ally literate s tude nts inter­esred in what ham radio offers .

Afte r man y years of being in­vo lved with electronics as a ho bbyand as my ca reer. I bec ame a Tech ­nician before the no-code licensewas offered. To me the tech nicalside of the hchby is much more im­portant. though I wo uld enjoy'working H F if it were no t for theartificia l barrier the code presents ,I find it q uite imercsn ng that manywho once long ago learned thecode can't ca rry the ir sid e o f atech nica l conversation equal 10 thelicen se the y hold, nor even remem­ber the code we ll e nough 10 use u.More than memorization is neededtoday 10 underst and techno logy:j ust ask an y en gineering stude nt iffonnula or fact memorization ise nough, Lea rning and understand ­ing applica tions h much more im­portant. We need 10 follow thatsame methodology of learning inamateur radi o . Keep up the goodwork and the exceucnt magazine .

Philip Wellnor VS6CT Wayne,n's been awhile since our pathscrossed. I am leav ing for the CRSADX Conven tion in Beijing later 10­da y and was remembering how wemet in lhe BY IPK Radio shack inBeijing back in 1 9B~. when I wasassisting wi tb the communicationsassocia ted wilh the Hong Kong -In­i:leijing "555" Car Rally. I reti redfrom Ihe 1I0ng Kong Gm·cm mentin February of Ihis year and I ha ~ e

nOI Slopped since . I will be da shingaround Asia for lhe neJO t IWOmonths, Wilh v-i sits 10 Bali. Thai ­land, Hainan Is land on the Soulh

Free ElectricityConHnued from page 3 4

conditio ning and refrigera­tion, A supe refficient SunFrost refrigerator will replacethe old co nventional uni twhen it dies. The Sun Frostunit retails for abo ut 52 ,700.A 16-cubic-foot Sun Frostuses 32 amplhrs. a day at 24volts. That 's about o ne tenththe amount of power the oldrefrigerator uses .

Chuck also has a landlineBBS operat ing 24 hours a daywith an Anu ga computer asthe heart of the system. Hecan save a lot of energy byconverting to a lap top com­puter.

As I mentioned earlier.when the wires were beingpulled through the under­ground conduit, severalmulti-conductor cahles werealso installed . These datalines will eventually be usedto mon itor system parameterssuch as array temperature.wind speed and direction,

Are there any 12-vo lt OCloads? Yes. and a Vanner bat­tery equalizer allows a 12­volt hallery bank 10 becharged fro m the mam 24­volt battery bank.

Author's Note

I' ll be happy to do a com­puter sizing for your repeateror hamsback. There 's nocharge for this. prov ided yousend along several fi rst classstamps for return postage , I' llneed your name and the near­est large ci ty with an airpo rthaving a weather station op­erated by the US govern ment.I' ll also need the sys tem volt­age o f your load (12, 24. 48volts), and an estimate of theamplhr load you expect. m

Coast of China , and KotaKinabal u. I so ld my fla l he re inHong Kong and will be lca \· ing forEngland in Ill..c embcr 10 join the QE2OUI of Southampton for a four-monlhround-the-world croi..e. I am hopingthai I will ha \'e man aged 10 orga­nize Ihe se lling up o f a ham slalio n

BRRTeR '/</' Bu yConrin uedfrom page 72

CHIPSWITCH - To give your HR·2510and HR-2600 the same lea lure s as theBIG RIGS, call (707) 539-0512, or wmeto CHIPSWITCH a t 4773 SonomaHWY11132. Santa Rosa CA 95409 'orFREE tnlorma tion. BNB1033

QSI. CARDS Many styles. Top quality.Order Risk Free. Plastic cardholders,'r-srsns. Personalized caps , mugs,shirts_Other ham shacll ex tras. Inlor­manon a nd samples. Rus print.1-800·962·5783. BNB1021

WA NTED: HAM EQUIPMENT ANDREI.ATED ITEMS, Donate your excessgea r, new-oto-m-env-conomon to theRadio Club 01Junior High School 22,the Na tion's only tun-time, roncrcutorga nization worlling 10 gel Ham Ra­dio into schools around the country asa teaching 1001 using our EOUCOM­Education Thru CommunieatiOn--pro­gram. seoc your radio to school. Yourdonated material will be picked upANYWHERE Of shippingarranged , andIhis mea ns a tax deduction to the lollextent of the law lor you as we are anIRS 501(c)(3) charity in our 15th year0'service. It is arways easier to donateand usually more fi nancially rewarding,BUT MOST JMPQRTANTl.Y, your gi ftwill mea n a whole new world 01eccce­tiOnal opportunity lor children naton­wide. Radio's you can wrile 011. kidsyou ca n't. Make 1996 the year 10 helpa child and yocrseu, WIlle, phone orFax the WB2JKJ"22Cre~ today: TheRC ot JHS 22, POB 1052, New York,NY 10002_24 hours call (516) 674·4072 or Fax (516) 674-9600. Join uson the WB2JKJ CI.ASSRQOM NET,7,238 MHz 1200-1 330 UTe daily. and21_395 MHz from 1400 10 2000 UTC.Meet us at the upco ming CharlotteHa mlasl. BNB762

on board and am ;l. lIl ailing wordfrom Chip Margelli o f Yaesu 10supply me with a radi o as the offi ­cia l spo nso r o f the station. I' ll reotu m to England in mid-Apri l andex pect to be bac k out here in HongKong in late May 10 u y to find aflat where I can put some decentantenna s on the roo f. I am verybullish and o pti mistic about the Iu­lure o f Hong Kon g, which is why Iwant 10 stay here . apart from theadvantag es o f be ing somewhereIhal I know. I've e njoyed !iv·inl:here for 11 yea rs , I just hope thatm)' failh will be justifi ed in Ihe fu ·lure . I still read your editorialswith e njoy ment, I jusl wish thatthey ~ould prod uce more resu lts .Keep al it Wayne.

I'Jli/, I hopl' .)"Our trust of Beij illg"01 rui-rlng Ho" g Kong is }uSlifi l'd.II :S- too hlld lh~ changfol·er isn 'I i"JO mOff )'l'ars. afur China hnshad an opponu"if)' to adjusl 10capilcl lism ... \Ia.\-n f Fa

73 Amateur Radio Today · January 1996 83

Two meter SSB/Satellite LoopsA whole new world offun lurks on the low end of2M ijyou use the right antenna.

Gordon West WB6NOA2414 College Drive

Costa Mesa CA 92626

The bottom end of the 2 me terband below 144.300 MHz is rcserved exclusively for weak sig­

nal SSB and CW communications. NoFM . Same thing between l otS.ROO MHzto 146.000 MHz- I/O FAt! This area isreserved for weak signal satellite com­munications using SSB and CWo Theterm "weak signal" describes running 2meter CW or single-sideband signalsover great distances, well beyond nor­mal FM IOO-m ile co mmunicationranges. Weak signal modes like MorseCode (CW) and SSB (upper sideband)cannot coexist with FM transmissionsbecause a nearby FM signal will literallycover up an ongoing SSB or CW QSO.So keep in mind that no FM is allowedbelow 144.300, and no FM between145.800 (0 146,(x)O MHz. Thanks foryour coope ration !

Down below 144.3fX) MHz is whe reSS B communications span distanceswell beyond 100 miles. It's not uncom­mon for atmospheric tropospheric duct­ing to carry 2 meter SSB signals overthousands o f miles. such as the path thatoccurred last summer between NovaScotia and florida. Last summer alsosaw the 2 me ter SSB reco rds shatte redfor the ult imate distance co ntact he­tween Washington and Hawaii. The con­ditions lasted for several days!

Almost all communications o n 2meier SSB below 1~.300 MHz usehorizontal polarization. rather than vcr­tical polarization. If you spot a beam an ­tenna o n a house that is mo untedhori zontal for 2 me ters. chances arcthey' re o perating a 2 r ueter multi-modeSSB sys tem . If you see a horizo ntallypolarized antenna or a combination ver­tical and horizo ntal Vagi antennapointed up to ward the sky. this is prob­ably a satelli te set-up for 2 meter work.But there is probably one horizontal

84 73 Amateur Radio Today · January 1996

ante nna that will really make you take aseco nd look , and it is the 2 meterhorizontal /oop anten na.

"How abolit that 2m SSBNovaScotia to Florida contact lastsummer?"

This is what mobile units must use inorder to obtain co verage. yet with a hori ­zontal 2 me ter patte rn. The new popularICOM 706 wi th 2 me ter and 6 meterVHF capabili ties in addition to high fre­quency capabili ties will lead mobile o p­erators o ver to a 2 meter hori zontalantenna for work be low 1~.300 MHz.

A popular compact 2 meter squareloop. called the "SQUOOP" is o fferedby M ! Enterprises, Fresno, California(209-432-8873). The little 2 r ueter"SQUOOP" is housed within a blackplas tic cover. and o ffe rs unity ga in om­nidirectiona l coverage in an aerody­namic design that works well on an yvehicle or mobile home as lo ng as youge t it well above the roof line. I havetested it against other loops. and its per­formance is O. K.

If size is not the object, cons ider thebig cloverl eaf horizontal loop tha t is alittle bit more at home on yo ur roof thanon the roof of your vehicle. It's big. butall that metal really captures weak in­coming horizontally polarized 2 meterwaves. It's available from LuddyReisinger N8EWU in Oceanside. Ca li­fornia (619-722·8563. I found its perfor­mance slightly above the M" little loop,since all that metal captures a litt le moreo f the inco ming horizontal signal.

Another Southern Californ ia ham.Norm Pedersen KB6KQ , Bel lflo wer.California (3 1Q.-925-0733». has dcvel­oped a ..Mini Loop" that has a high

performance for its small size and is eas­ily stacked fo r a s light increase in weaksigna l capture capabilities . We recentlytuned in Paul Lieb KH6HME. driving upthe side o f a volcano in Hawaii using asingle M ini Loop. and his signal wasmaking thc 2,5()()..milc path extremelywell. For the smallest loop with thegreatest signal capture capabilities. thisloop has it hands down . It's also a home­brew antenna offered to amateur opera­la rs on 2 me ter SS B.

An other attention grabber is from the1\12 gang. a Mike Staal K6MYC special.Fresno, Californ ia (209-432 -8873 ) iscalled the "Egg Beater,' This can bcused for both 2 me ter horizontal SSBcommunications with terrific signa l­grabbing capabilities. as well as righthand ci rcular polarized mobile satellitework up at 145 .800, too . The Egg Beaterhad best response to the Hawaiian 2meter beacon when it was coming in justabove the noi se level. The Egg Beaterdid best. wi th the Mini Loop coming in avery close second. followed closely bythe cloverleaf. followed relativelyclosely by the 1.F "SQUOOP..· All ofthese antennas look out of place on amodern vehicle, but hey, that's the priceto pay when you want to work 2 metermohile SSB and regularly talk to ot hermobiles o ver distances beyond 100miles. And we are not talking throughrepeaters. we are talking direct. The ad­vantage of SSB simplex over FM sim­plex is double. triple. and some timesquadruple greater o n SSH than what youcould do with wide and noi sy f1I..l.

I' ve also fo und many newcomers get­ting started with 2 meter SSB wan tingsomething nice and compact. The gangat Cubcx Quad Company rose to thechallenge of a compact pre-assembledquad specifically tuned for the 2 meterband and operated either vertical for f1I..t

-

Here san ultra-simple piece oftest equipment

RF Sniffer

Fig. I . Ho w simple can you get?

- r-, NE-2j

-

120k II :~o

Adju.~mentand Operation

Plug the sniffer into a scarce of 117 Vac. 0b­serve the neon bulb while adjusting the JXJt As re­sistance is decreased slowly, an orange glow willappear aroundone of!he two electrodes in the neonbulb. A further decrease in resistance will result intheornnge glow sunoonding bothelectrodes.

Slowly tuck offlhe pet until the ornnge glow isagain around only one electrode. Do net readjustthe pot from this point!

Using the sniffe r as a probe. with the trans­miner producing power. investigate coax con­nectors and jumpers. coax runs. ac wiring intheshack or elsewhere in the house where RF issuspected. while observing the neon bulb.

when leaking RF isdeteeted. the orangeglowin the neon bulb wi ll nicker and surround bothelectrodes.

IfRF seems to he detected put the probe hackand watch the neon bulb. If the glow retreats tosurround only one electrode. RF leakage ispresent where detected. If. however. the orangeglowconti nues to surround both electrodes. re­adjust the pot so it is visible around only oneelectrode and recheck for RF leakage. Becausetransients a.nd other minor disturbances on theac line are common. they can cause erroneousindications of detected RF when the sniffer isset at its most sensitive point.

J . Frank Brumbaugh KB4ZGCBox 30

Salinas PR 0075 1

11 0VIne corea nd plIg 500k to 1 Mn

Conclusion

This gadget is not frequency sensitive. It willwork a well at UHF as it does at HF and eventhe TV borirontal oscillator frequency. II is ex­tremely sensitive to low levels of RF. Best of allit is cheap. and can beput together from the usualjunk box contents. II

Making the RF Sniffer is simple. A smalldiameter wood dowel, or a stiff wire cut fromacoat hanger.about two fed long. has the NE­2 neon bulb and I20k Ohm rcsisice attached

at one coo with tape. The gl<K'I portion of theneon bulb must not be covered because itindicates the presence of RF.

A pair of wires connected to the neon bulband resistor should be taped along the dowelor stitT wire, lcehng 10 the cOO wbcre the5<XJ.: Ohm or one megohm potentiometer istaped or otherwi se fastened. A piece of woodor plastic, or a long loop formed in the end ofthe COal hanger wire, can serve as a handle.The AC line coni is connected to the PJI and

the ....ire from the resistor at the handle end ofthe sniffer and all connections taped to pre­vent accidental conuct.

An okl trick fer sniffing out RFleaking around the shack can beuseful in roodcm ham station instal­

lations.Any RF which does not reach the an­tenna is not only wasted power. itoftencan bethe source of interference to radios. 1V sets,

telephones and oee- home elcctronics. The

opposite is also true - if RF can get 001, it canalso get in - and RF from rroexs ali well asbouscbold electrical and electronic equip­ment such as TV receivers, VCR<;, etc. canraise the noise level in the ham receiver and

otherwise interfere with station operationOld, surplus coaxial cable and some new

coax. is so pocdy shielded it is little betterthanopen wires. Om which leaks RF should bereplaced with high quality cable. Poor, leakycoax not only wastes RF which never reachesthe antenna, it also can pick. up interferenceover its entire length.

Gaps in shielding. especially in high powerinstallations, and poorly solderedor loose RFconnectors should also be corrected to elimi­nate leakage and possible interference.

Thejunk. box solutionto visual detection ofstray RF is illustrated in Flg. 1.

Constructlon

O f horizontal for 2 meter SSB. CubcxCompany in Brea. California (7 14­577·9009) calls their little a -clemen t.pre-assem bled, lightweight cubicalquad the "Yellow Jackel," and every­thing comes pre-assembled where allyou need to do is 10 poke the suppliedfiberglass spreaders in through theholes on the boom . attach the pre-as­sembled and color-coded wire cle­ments arou nd the spreaders, run yourcoax, and sand off the ends of thespreader wire tips so they arc nice andsmooth in case someone should walkinto your assembled quad antenna set­up. You know, safety firs t! The quadsells retail for under $40, and givesyou a big boost in directional signalstrength well above a simple groundplane home antenna or equal gai n to alitt le 3-e lcment Vagi. The quad alsocomes with its own mast and couldserve as a wunderful di rect ion-find ingan tenna. too . Everyth ing is pre-as­sembled. su you don't have to do anymea.. uring or anything-just foll owthe instruct ions. snap everything to­gether, and presto, you are on the airwith eithe r vertical or horizon tal polar­ization. For 2 meier SS B and CW,make sure you go horizontal and pointthe quad for best signal strength.

During extensive testi ng of omnidi­rectional mobile loops, all did a ter­rific job in pulling in ex tremely weakSS B signals, includ ing the Hawaii anbeacon thousands of miles away. Butswitching over to the quad and aimingit in the right di rect ion defi nitely in­creased transmit and receive signalstrength. Same thing in working thesatell ite.

You can also build these horizontalantennas yourself, like the gang inCalifornia has done for resale. BUI Irecommend getting one already put to­gether, tuned. and tested rather thantrying to outdo what so mebody has al­ready spent years in design and test­ing. Lea rn from thei r hard work whatit takes to make a good horizontal an­tenna even bette r through refi neme nts.See whether or not bigger is alwaysbetter, and check out some of the tun­ing techniques these ex perts have usedto give you proper impedance match­ing and performance rig ht where youneed it on the weak signal portion ofthe bottom o f the 2 meter band. m

73 Amateur RadiOrcaev- January 1996 85

Line Voltage MonitorA one-hour construction project

with a parts cost ofunder $5!

J . Frank Brumbaugh KB4ZGCBo x 3 0

Salinas PR 00751-0030

There are a number of 04150-VACmeters available, bUI they're difficult to read when you're look­

ing for small line voltage changes. Amuch more easily read meter is a sup­pressed-zero, expanded-scale meierwhich displays only voltages between90 and 130 VAC . II can be read at a dis­tance and at a glance so you can take ac­tion should your household voltageswing too high or too low. The simplecircuit described here uses only fi vecommon components and can be con­structed in less than an hour. The totalcost. not including a box, should be lessthan five do llars.

Background

Power co mpanies attempt 10 controlboth the level of AC voltage and fre­quency delivered to their customers.Though limits on both are established byregulations. some companies arc betterthan others. However, as well all know,they have occasional problems whichcan possibly harm your equipme nt.

"Brownouts,' common in urban areasin the US when air conditioners or elec­tric heating systems require more powerthan anticipated , result in lower voltagesbeing deli vered to homes. Occasionalovervoltages occur when power isswitched from o ne substa tion to another,or to another point on the national powergrid. Although nominal AC voltage inthe US is 117 VAC, this can vary be­tween 105 and 130 VAC, while remain­ing within specifications . Mosthousehold equipment is designed to tol­erate excurs ions within this area. How­ever, AC voltages lower and higher thanthese accepted limits can causeproblems wi th your ha m equipment.

AC line voltage can often fall as lowas 90 VAC and stress AC operated mo ­tors such as cooli ng fans in amateurtransceivers and RF amplifiers.

86 73 Amaleur Radio Today . January 1996

damagi ng expe nsive power transistorsand ampli fier tubes.

High voltages. above 125 VAC, canbum out electric motors . Also. the in­creased peak voltages applied to filtercapaci tors. regulators, and transistors inpower supplies. especi ally if the filtercapacitors arc already operating at orvery near their rated working voltagescan explode an electrolytic capaci tor.

Such high voltages also increase thepower diss ipated as heat in the powersupply transistors. Thi s can cause extraheat at their junctions. causing them tofail , and th us applying a mu ch higherunregulated DC output voltage to yourstation equipment. This can cause ex­pensive damage .

How II Works

F iR. 1 is the ci rcuit diagram. AC volt­age ap plied through the line cord is half­wave rectified by 0 1 and app lied tozener diode D2, which greatly reducesthe peak voltage. Capacitor C I acts as apoor filter and the partially filtered pul­sating DC voltage is applied to meter MIthro ugh meier multiplier trimpot R I .When calibrated . the AC line voltage isco ntinually ind icated on M I.

The value of C I contro ls the voltageend limits. If you usc a different meter,or wish a different voltage range, try di f­ferent 150-volt capaci tors in p lace of C I .Be sure C I has at least a I 50-volt rating .Its type is immaterial.

Construcl ion and Calibration

T he meter should he moun ted in anenclosure to prevent any accidental con­tact wi th the AC voltage. which can helethal. A pla..tic or metal OOX can heused . The few components can hemounted on a term ina l strip. RI is restattached to either the rear o f the metercase or the interior of the enclosure.using epoxy, supergluc or hOI glue.

Look at yo ur meter scale. With luckthere will he four main di visions. If not,care fully take the meter apart and dividethe meter scale into four equal. to-voltdivisions. using a fine tip fe lt pen . Markthese points 90. 100 . 110. 120, 130. Re­assemble the meter and mou nt it in itsenclosure.

If you are un familiar with disassem­bling. meters. please see my article. "UscThose Surplus Meters: ' 73 Amateur Ra­dio Today, January 1992. page 42. If youcan' t locate a copy locally. the publishercan supply back issues or articl e pboro­copres.

With your meter scale properly cali­brated and all part s mounted in the en­closure. adj ust RI to maximumresistance. Using an accurate ACmeter- a digital multirnctcr is preferredfor accuracy. but a V-O-M can be used­measure the AC voltag e at the nearestou tlet , and note thi s value .

Pl ug in the Line Voltage Monitor. Be­ing very careful not to touch any pointscarrying voltage. adj ust R I so the meterindicates the same voltage you measuredprevio usly. This co mpletes calibration.

Operation is automat ic. When this in­stru ment is plugged into a live 117 VACo utle t it will conti nually monitor thelevel of voltage supp lied by the powercompany.

Notes

Be sure the meter you use has a mov­ing coil (D'Arsonval) movement. Do notuse an iron van e meter. If you can' t te llthe differe nce at a glance, a good rule ofthumb is: If it looks expensive, it prob­ably is a 0 ' Arsonval meter. If it is roundor square and has a cheap-looking blackpainted metal ease he ld together withbent metal tabs, it is probabl y an ironvane meter.

There arc s imilar-locking line voltagemeters commercially available costing

Bc sure 10 subscri be 10 73...only 524.97 for

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_ PlD<lh .. the ......,-" .. 1'l4l- 1'l45_ 11'''01'. I I<dy Ik on 0-....... ....... )'011-heqdopJl~Anl _ '. thedo)''' do)'w.oo. ,,*--IIU? 57.50WG6 l · w.._ 's ear.t.t- ..w.-...... 9t>.,.,.. ......,..,...•_ d.'".. • ......-lk~ .uilinI ..... ..,......""" ..... ".".. u )'011 ... ."...,.m io '-" I> n.d ._ '.;d)'._ ·• .,. ......... .,...lrtn~ !k ",. ..1lh lao ........... IhtWq 5p;>rL- Yw'B~ .... _1> '-11. .. ~ I doyo~A.-,m"WG7 l '..... "~ '. Tra.ofo-52 p. ....ay"" 1f3wtl.1O R"" WId...A~ -.l SL Mtno:lL Votma. "'*"".and~ _ ~

UJillJlll ....,,~ IIImr.o.tI ")oW m¢'IlhmlL 0.-"1' h )\'IlI'JU.• 55.0: 'wrn WI,.. Tall<.", ·Il",....' 1'195 -90 minuo' ,.-Wh.1I tao .....ldhave Ioaid Jl ·d I'fta 1..u.J lU 'I'<'Ik. ssmWG4 lll(lO F hl TIwrc~ 16 "~ "" the Do<:Iaro W"c bo.• •Ullp_ Fw1JJ<.'I l"'~.>'ial, f'1" "'~'inaCflU<:al Amm",," prol*'m•. wdJ .. ........ aA'"",:h 10 fin.......,g -!ITIil1l ~llSi'."••" . 00w 10~ R"" .. """0Iher <Ull"""', 0",1 n>aLe • profit o1>ing n. <tw: ",:d 01'P" ..hi<>ei<'<."'"""""netic.I. • ,",'" l<irkl oj polytc<:hnlClll "nivenrt~, .......ele<wnic t<ch...,~. ...h~ A1rica " in """h • ""''', ...h~ F'eroI bornh:oJ.""",. to hove lUI""" 1= urn"""'..... pllltl h mal;11I~ Cong ..... /lornhooesl. ",", PIL~~y nU", RU.'n.i<>Io>ly p<i<;t>J . SlO,OO

about $20. Some of these appear to usean iron vane meter. You can build abetter mon itor for a lot less money.

A major disadvantage of us ing an ironvane meter to which a voltage is appliedcontinuo usly is that they lose accuracyas the movement becomes magnetized.Yo u'll find that, if you unplug o ne after ayear in usc. the needle ""i11 not return tothe left end of the scale. Instead, it willindicate some level of voltage eventhough none is being applied .

An excell ent and inexpensive so urceof surplus name-brand meters withD' Arsonval movements is Fa ir RadioSales, Box 1105, Lima, OH 45802. A se­lection or five meters (their choice, notyours), Catalog No. 47-84, costs $ 10.Mostly basic O-I -mA movements will bein each selec tion. Usually the re will beone, possibly two meters with 100-I.lAmovements. Some may hav e internalshunts, multiplier resistors. or rectifiers.but these are easy to eliminate, leavingyou with the desired basic meter move­ment . This gets you your meter for only$2. and you still have fo ur more nicemeters fm future projecl~! F!

Martian Trivia

Man ufac t urers, we wo uld liketo rev iew your produ ct s a ndreport O il them in 73. Pleasecontac t Ron at 800-274-7373

for more deta ils.

A bit of ham radio lelevision trivia via paellel fromTim Ertl KE3HT. And this is really going to take youback a lew years.

How many of you remember the 1960s TV se­ries, The Munsters? No, not the recent movie seenon Fox but the actual black and white TV show thatfeatured Yvonne De Carlo as Lilly and Fred Gwenneas Herman Munster.

Well, Tim says one episode hada ham radiocon­nection. He describes the plot as Hennan playingham radio operator using the call sign W6XRU4.calling CO. Then, while tuning around he bumps into a couple of kids playing as Martians and as usual,things get OUI of control.

So Herman enlists the help of Gral1dpa MunSlerplayed by AI l ewis. Grandpa has a Radio Direc­tion finder 01sorts. Well ir s really a transistorizeddivining rod that they use to find the Martians whoare nothing more than some neighbortlood kids.

KE3HT adds that it isobvious lhatthe episode wasdone in fun, but he win bet one 01 the shows writerswas a ham. TNX Amateur RadIo NeW5line F!

my license. In 1987. I re-tested and quick ly ac ­quired my Genera l License agai n. Lat e in 1994.I passed Ihe Ad vanced Class upgrade. and inAugu~1 1995 I upgraded TO Extr a Class. I havehad 10 rene my high school memo ry of trigo-nometry, as ell as learn how 10 use a scientificcalculator, My main talem is sewing, not e tec ­ironies. but I passed the lest. three mon ths shorto f being e ligi ble for M edicare And t undcr­sta nd tha t keeping the mind active wards offAtznetmers d isease and other maladies. I amvery appreciative of the ham community. .... hichhas kept the bands ac tive throughout the yearsin order Ihal those of us ..... ho ha ve been less ac­nve ~I i ll ha ve frequencies on which 10 operate.That means the old-timers . The)' probably havemore stfck -to- u-iveness than some of the new ­COlliers, If the y have not become biller throughthe years, they have more manners than SOI11I;: ofthe yo unger generation. And ma nners speakwell for amateur radio. And, off of tha t subject:Ma y I sugges t/requesrrhar it would be easie r 10respond to "Feedback" if the back side o f theliSling we re an ad. rat her than an article orprinted circuu diagram?

Nolt·J . . . \l a )"11t'

OX S92p~o _Meantime 00 the high frequency bands, lOOk for

Principia Island on the air from November ztsttcDecember6th.Agroupof French operatorswill signS92P 00 alt bands 00 CWoSSB. and RnY. Theywill also be active in the CO Wor1d Wide DX CWContest. OSl via F6KEO. TNX Amateur RadioNews/ine

LETTERSConrtnul'dJrom page 6

Tropo OX

In ox,the Cuban VHF Group is planning someactivities to say goodbye to the ·old" 1995 and willactivate some "neww grids around the country.

From November 221h to the 26th, the group willoperate an IOTA DXpedition to 'cave Julia,· inGrid NA93. This is a little key 2 miles away fromthe north coast of Cuba's most western province,Pinar del Rio. Operators will be from Italy, Spain ,Portugal, France, Mexico, and Cuba.

Operation is planned for 6 meters. 2 meters,and 1,296 Mhz. Other bands will be added if gearbecomes available for 220 Mhz and 70 cm. TNXAmateur Radio News/ine

Cuban VHF Group Activities

ORK-CRNROR ROOPTS IRRPConHnuedJrorn puye H

President Farrell Hopwood VE7RO, and IARU Re­gion 2 VICE! President Tom Aikins VE3CDM. TNXAmateur Radio NewS/ine

Austrian Licensed

Nominations are open for ARRl Instructor ofthe Year awards, the ARRL Hertl S. Brier Award,the ARRl Professional Educator of the Year, andthe ARRl Professional Instructor of the Year. Sendnominations to your league secncn Manager byJanuary 31, 1996. TNX Amateur Radio Newsline

The Republic of Ausl ria will celebrate rts 1000­year anniversary in 1996 and Austrian hams willbe a part of tne celebration. This wtlh the govern­ment authorizing special call sign prefixes forradio amateurs.

Al the request of the Austrian Amateur RadioSociety, communication authoritieswill permlt.aus­trian amateurs to use the pre fix OEM lor the en­tire year. Use of the prefixes will be voluntary andthe nanonat society will sponsor two on-the-air op­erating awards in conjunction with their use. TNXAmateur Radio News/ine

Instructor Of The Year

Ken Rameriz KP3XS in Puerto Rico says thatthe best Tropo event he has seen in a long timeoccurred the evening of October 30th and was stillpresent at 1 AM EST on Tuesday the at st. Kensays, via the Internet's VHF Reflector, that he lookto the airwaves at 8:30 PM EST and found theband open to Florida, He then proceeded to wor\(every Florida grid down to me Keys. The only gridmissed was El S6.

Ken says that he kept hoping one of the Cu­bans would get on but no luck . He did hear one01 the Florida stations work KD4UPF in FM18and quickly swung the beams North East wherehis first contact was KM1X in Rhode Island! Kenthen we nt on to work 90 stations in the next 4hours inclUd ing WZ20 all the way to 1.2 GHZ!

Talk about a night of unbeli evable trope OX.TNX Amateur Radio News/ine

Wayne mites!

Parts List

O.O Hl.F ISO-volt capaci tor,lN4(X)7 rectifier diodelN4764A zener diode500-UA meter50·kU trimpot

CIDJD2M J"I

73 AmaleurRadio Today · January 1996 87

14 VP 15 VP 16 P 17 P-F 18 F 19 F-P 20 F·P

IJ

Zip _ _ Country __

He re ' s a nother ..... inte rti meOX band. Opcn after sunset. andpeakin g to the east around mid -night. and toward the est andPacific areas ncar da n. Bandcl oses during daylight hours dueto h ig h a bs or pt ion o f the selo.....er HF freque nc ie s.

Please le t me know how thesefo recasts are worki ng for you.By the way. keep your fi ngerscrossed because 1996 may spellthe su nspot min imu m of Cycle22. We can hope . can't we':' 73 .Ji m "X U" ED

160 Meters

80 Meters

the Pacific . Short- ski p du ringdays and longer skip after d ark .

This sho uld be your best DXband during hours o f darkness.pe aking around midnight andjust before dawn. Sho rt-skip indaytime and lo nger sk ip afterdark .

Fair to good DX during d ay­l ight hours. peak ing shortly af­ter su nrise for an hour or so. andagain in the early afternoon ; andclo sin g at, o r sho rtly afte r, sun­set. Short-skip up to 2.500 milesor so du ring d a yli gh t hour s.Again . listen on the Good andVery Good days. Check WWVat 18 minutes after any hour.

20 Meters

40 Meters

A s trange and unpredi ctableb and ! Someti mes li ke -to andothe r times like 20 . You r bestbe l for DX is late afte rnoon andearly evening hours. Short-skipduring day light hours will pre­va il.

30 Meters

DX to Europe and Africa dur­ing late a fternoo n and towardSouth Ameri ca afte r sunset. Af­ter midn ight. li ste n for Asia a nd

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Good (G ) o r Very Good (VG )days.

Short-skip and some DX open­

ings d uri ng day light hours onGood (G) and Very Good (VG)days. particularly during after­noon hours. The band cl o se searly. however.

• • • •• • •" • • •• • • •

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• •" .· "• • •to to to CI

Ie 10 010 to

EASTERN UNITED STATES TO:

TUEJANUARY 1996

9 G

2F-G3G·F 4F

,~~

~.=PHILPf'INES

PlJeRTO RICO

SOUTH AFRICAU.S SR

,~ ...~--....._._.., oood .... ....

MON

1 F

SUN

28 F-G 29 F-G 30 G

7 G 6 G

same.

An occasio nalF2 openi ng to­ward the tropicsdurin g daylighthours...bu t. as isusual d uringsunspot rrunrma.you can' t ex pectmu ch winte racti vity. L istenand call on the

10-12 Meters

Num~88 on your FHf1bK:I< r;.nI

PROPRGRTION

21 F-P 22 F-P 23 F-P 24 P 25 P 26 P 27 P-F

January is se ldo m a goodmonth fo r DX--or ......cathcr fo rthat rnancr-c-and this month is11 0 exce pt ion. so get ready forthe had news fir st.

There may he so me very se ­ve re geo-physica l co nd i tio nsaround the 15th or 16th and the25th and 26th ...g ive o r take aday or two . Be prepared ! Thebest days are likel y to occur in

t he fi rst , sec ­on d . a nd la stweek s o f th emonth, while allelse is trending.

However. theday s are getti nglon ger and youcan expect th eh igh e r H Fband s w ill h esla y i ng o penlonge r. 80 an d160 meters willstill provide ex­ce fle nt DX o nthe best days .and ao. 30, and20 ...... i ll do thc

Jim Gray W1XU210 Chateau CirclePayson AI. 85541

88 73 AmaleVf Radio Today · January 1996

FT-10001D FT-99OIDC

FT-2500

FT-840FT-BOO/AT(Includes YSK-900 Remote Kit)

FT-530

FT-5200

- -- --. .

FT-2200

FT-11RFT-41RFT-51R

G-2BOOSDXG-l000SDXG-BOOSDXG-BOOS

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III

Offer void who<o p1 0hibiled by _. C<:lo4>oo has 00 cash value . Umit 000 coupon per purchase. INot valid widl ..,..". ott- VItnu 011.... or <iscounls. Otlono 001 applicable 10 purchases made prior Ito October l4, 1995or aft ef Jaouary 6,1995.

II

DEAl..EJI~TE: _

FT-10001D, FT·99O/DCfT·530FT-900/AT, FT.a40FT-5200. FT-2200FT-8500, FT-5100, FT·2500, FT-11 R, FT-41R, FT-51 RFT-G-2800sDX, G-1000sDX, G-800S0X, G·800S

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function I Auto simplex checker I Built-in CTCSSencoder & optional TSU-8 decoder I Key functiondisplay I Modifiable for MARS/CAP'

TM-733AFM DUAL BANDER

For theadded safety, you can choose the Quick­release detachable front panel kit (Option). Thetransceiver unit can beconcealed under a seat orin the trunk.

Theft-Deterrent Features

Other Feature.172 multi-function memory channels I AlP (AdvancedIntercept Point I Buin-in DTSS with page I Cross-bandrepeater I Wireless clone fonction I Wireless remote

· _ ..-t:o WA$ ltd CW _ Si _ • __b __-..

ll<Jla Conneclar for 1200/9600 bps PaoelUsing the s-pm mini DINconnector on the frontpanel, you can hook up a TNC10 the TM·733A foreither 1200 or 9600 bps packet communications.

Six enti re operating profi les-inc lucling everything!rem the freq.Jency range b the drrmer IfM!I can bestored in the programmablememory for recall at ttepress ofa button. II's likehaving six nenscevers inone.

144MH. /440MH. Oual·Band OperationKenwood's TM-733A is aversatile fM dual-banderwith sophistication and power (144MHz; 50WI44QMHz; 3SW) lor high performance mobilecommunications. As well as receiving simulta­neously on VHF and UHFbands. it can receive twofrequencies on the same band .

Six·ln-One Programmable Memory

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Best Dual-Banders on Wheels

Separate (ontrol & Display Units

D U A I

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TM-742N642AF M

101 Memory (hannels

1200MHz (l OW), The transceiver can display andeven receive three bands simultaneously,

For each band, there are 100 memory channelsplus 1 call channel. Each channel can storetransmit and receive trequences independenllyor odd split repeaters.

B.n1) I Dale &IiTle lispIay.~ alarm, ootlfI tillerI Qoss-tm;I r~ bJ::fial lto.txifdEufNIRS-fAP'"""'*~ b l,W'ISa<l CN'lS< ~';.n1Ill:lb~ _ (J'Jf

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n l-HZA

144MH./440MH. & 144MH./220MH.Operation

The TM·742A (144MHz; 50Wt440MHz; 35W) andTM·642A (1 44MHz; 50W/220MHZ; 25W) dual-bandmobile transceivers can be converted into tn­banders with the addilion 01an optional FM bandurut 28MHz (50W) 50MHz (50W), 220MHz (25W;TM-742Ao~l J. (ll..tHz (35W; TM-642A only), or

Other Feature.I BuI-fl DTSS seIectiw~ 'MIn JilQe 11IllependEn:SOl & \/IX. controls lor ean b<n:l l EW-fl cressencOOer &optiora rsUo7 cEroder I Wireless remotecontrol furK.1ion I High-visibility illuminated panel keys

' t WK!e-ba!1d VHFt1JHFreceive coverage (iA::luding Air

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