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ecked d 1a w u ~s an d scoere rcs,d the dearesf. best focused andted ptdlS you can manage .1 lowwnte lor r r guiOOliiI9S are a vailablen reQ.J9Sl . US citizens , pleasecooe yw- SOCla I secow rllJrl1berth si.bmtted rrao uscrots so we canbmit rt to know wo .

On t he c ov er : See Wayne 's edito rial begi nn ing on p age 4 for mo re on W60B B. We are alwayslooking for inte res ting a rticles and cove r photos - wit h or without each o ther . Your name co uld be inthis s pace n xt month , and our check coul d be o n its way you /You couldn 't use a little extra cas h?

Feedb ack: Any ci rcuit wor ks be tte r wilh fe edb ack , so p lease la ke the time to re port o nhow mu ch you like , ha te , o r don t c are o ne way o r th e ot he r a bo ut th e a rtic les a ndcol umns in t his iss ue . G = g re a t , 0 = ok ay, a nd U = ug h . Th e G 's a nd O s will becontin ued . E no u gh u s and it s Sile nt Keysvi lle . Hey , th is is your co mmuni cationsm ed ium, so do n't ju s t si t there sc r a tchi ng you r .. . er. ..h ead . FYI; Feedba c k n um be r isus ua lly the pag e n u mber on which the a rt icle or co lum n starts .7 m eu r R dl o To d ay (IS S N 1052-25 22 ) is publis hed mo nth ly by 73 Mag azi ne . 70 N202 . P e te rbo rou gh NH03 458- 1107 . TI'Ie en ti re co n tents C 1999 by 73 Magazin e . No pa rt 0 1 th is pu blication Marchbe rep ro ducedwithout wrilt en permission 0 1 the PUblis he r , which IS not a ll tha t di fficul t 10 gel. The su bsc ripti on rate is: o neyea r $ 24 .97 , IwOye ars S4 4.97 ; Ca nada : one y ear $34 .21 , tw o ye a rs 5 57 ,75, includin g pos ta ge a nd 7% GS T.For e ign p ostage : $19 s urface , S42 a irmai l add itional per y e ar . pa yable in US tun e s on a U S b an k . Se condclas s postage is p aid at Pe terb oroug h , NH. a nd a t add it iona l m ailin g ctnces . Ca nadian se c ond class m a llre gis tration 178 101 Canad ian G ST r egis trat ion ' 125 3933 14 . Mic rof ilm edit ion : UniverSit y Microfilm , AnnArbo r MI 48 106 , POSTMASTER : Send a ddre ss c ha n ges to 73 Ama teur Rad io Today 70 Hancock Rd. .P eterb orou h N H 03 4 58 , 11 07 . 73 Am a l eu r R ad io Tod a IS o wned by s nao roma t Wa l td . o r Ha nCOCk NH.Co ntra c t : By be ing so n o se y a s to re ad this l ine p nn t . you h av e j us t enter ed i n to a bin ding ag r eemen t With 73Ama te ur Rad io To day You a re h ereby obl i ga le d to do scm ettunq nic e lo r a ha m ln e nd -e-bu y h im a su bs c npnc n10 73 Wh a t? All 0 1 yo ur h a m fr iend s a re al ready Sub scrib ers? Donate a s vo scnp uon to you r local sc ho ornb ra rvr

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NEUER S Y 0 IEW ay ne Green W NSD w2nsd@aol .com

Ar t Bell W60 BB sick, time trav el. UFOs , contactees, alien technol ogy, a

You probably d on t spend spa ce hotel in the works,mu ch time l is tening to AM those incredib le crop patterns.radio . But if you do, and gho sts, reverse speech. remoteyou v e eve r tuned in at n ight. viewing. Area 51 visits, and soyou've hea rd Art 's coas t-to- on.

coas t talk sho w from t he No. of course I don' t sit upKingdo m of Nyc all up and five hours a nig ht so I won' tdown y our dia l. That's N yc miss anyth ing. I record theCounty, Nevada, by the way . program every nigh t. And

In the Eas t, his show is on you should e doing this, too .the a ir five nights a week All yo u need is a cable befro m 1 Unlit 6 AM which twee n yo ur AM rad io an d amea ns that if you r e a c to VCR and you' re in busi ness .Sec unless yo u tum on you r For the techn icall y c halradio during a sandbox vi sit , longed , I have my $ 5 Wayneyo u ll probably never hear Green s Bell Saver Kit (se e p .him . I keep a li ttle So ny ICF - 63 that i nc ludes the neededSW I , a 3 t x 4 t X l a llb an d ca ble a nd co mplete ins trucdigita l rad io, by m y bed , so tions o n co nnecting it andall it take s is a pu sh of the on - prog ramming yo ur VC R. Ino ff butt on and I m listen ing th is way , you ca n li sten to th eto WPTH o ut of Philadelp hi a show when it ' s co nve nie nt foron 12 10 , New Yor k 's WA BC yo u . You can fast fo rwar don 77 0 , or WTAM Detroit o n through a nything th at doesn ' t1100 . inte re st you (l ike th e ne ws -

On we ekends the sho w is a cas ts) . When there s a phonelittle sh o rter an d co ns ists number o r We b site addressmostly of repea ts o f hi s be st you want to note , yo u ca n reshows . wi nd an d ge t it. A nd i f there s

Th e usu al form at has a a g uest you wan t to liste n tonew s broadcast fo r abo ut 8 agai n, or wan t to pl ay fo rmi nutes o n the hou r and ha lf someo ne e lse to he ar , you ca n

ho ur.Th e

first hou r

o f Art s sa

ve the tape ,keepi

ng a not

eshow has hi m bring ing you of the time o n the tape thatup to date o n som e o f the lat- you w ant to find. I hav e sevest happenings he thinks you ll eral boxe s o f tape s I ve savedwan t to know about. That 's for refere nce . They ' re notusual ly followed by listener quite as hand y as boo ks, butcall -ins , where they can disc uss if you keep a n inde x in yourwhatever th ey want. The next co mp uter, th ey r e easy tofour hours nor m ally feat ure find . Th e T-120 tapes willan interview with a g uest. a nd recor d 6 hour s, and yo u canArt s been able to get so me find ' e m for a bu ck i f youfasc inating gucsts . 1kn ow I v e w atch th e ads .learned a lot from them - and Art is seriously geared upso have you, via my resultin g for the Y2K cris is, w ith aneditorials . e mergency ge ne rator , sola r

Th e topics covere d ar e a ll p ow e r, a nd wi nd p ow e rov er the lo t - those str a nge backu p . Yo u ll be he arin gco n trails t hat a re m ak in g us WOO BB on me band s ev e n if4 73 mateur Rad io oday Sep tember 1999

the power grid goe s d own form onths .

Art d oe s hi s program fromhis ho me in Pahrump , Nevada . You ca n watch h im dothe show , if yo u r e up, v iavid eo o n w w w.ar tbell .c o m .

You ca n also lis ten to it viahis Web site a nd se e a list ofhis coming and past gue st s . you loo k me up you l l seetha t I ve been a gu est fivetimes an d we v e talked ab o utall sorts of things . Yo u can evenlis ten to these pas t shows,

I m a nxi o us to e on mo r eso th at we ca n tal k up am ateur radi o nd encourage morepeople to come into thehobby . Well, the ARRLdoesnsee m to be doi ng a damnedthin g , so someone has to do it.

Plumme ting

Th e n umber of ne w lice nses i ss ue d in Janu ary ha sdropped by a lmost 50 in th elast tw o years . Hey , ge t ou tso me graph paper and pl ot itfo r yourse lf. P lot 155 3-1053871 for the las t three yearsa nd sec w he re th ings arehe ading Th e line h its zeroar o und 2010 .

Th e s itu ation is n t an y be tter when it come s to upgrades either . They too redo w n 50 in the las t tw oyears .

Unl es s yo u ca n some ho wforce your ARRL d ire ct or tomake the League honor its respo ns ib ility t o p re se rv e t hehobby , it looks like we r ecr ash in g and burning .

Why am I le a n ing so hardon the A RR L about thi s ?

Well , there are on ly tw o o the rinterested part ies, th e FC C andthe ha m man ufa ct urers . Asfar as the FCC is co nce rn ed

amateur rad io is an expen siv enuisan ce , and the ha m ma nufacture rs a re un o rganized a ndap p aren t ly un in terest ed inwhether the ho b by c on tinuesor no o

Thus , whether amate ur radi o survives t hi s cris is or notseems tota lly dependent on

the ARR L

taking so me serio us ac tion. they c an t beforc ed to stan promo tin g thehobb y, we be go ne .

Ther e is n t any b ig se c re tabou t wh at needs to be do ne .I' ve wr it te n about it enou ght im es , so 1 wo n t rehash m yadvice . M ostly, the Leagu eneeds to figure o ut ho w to re-build the high schoo l radioclub Infrastructure they wipedo ut in 1964 . That was o urlarges t so urce of ne w hams.

It s go in g to be tou gh , forin a ddi tion to sports an d TV,no w we v e go t the Internet asa competit or for the tee na gers. Th e League has to get ki dsto think o f ham radio as coo l.No w , th er e ' s a ch a lle nge

A Slight Tinke ri ng

W ith the ARR L me mbe rship droppin g almo st 1 (pl u mme ti ng) in t he l as t yea rwith T shrinking; with manufac rurers and de l ers goi ngout of business all around theco untry; with the numbe r o fne w Tec hs dropping abo ut30 % in the last two years ;wit h the nu mbe r o f Techs upgra d ing to General droppingeven faster; I then loo k o verme A RRL s co mm e nts to th eFC C on re s tructuring th eho bby an d all I see t he m r ecom mending i s a s light tin ke ring. Wh at docs it tak e t o ge t

ala rm be ll s to go off in th ea tro ph ied brains of the directo r s yo u keep o n blind lyreelecting ?

For tha t man er , what is i tgo ing to tak e to ge t our o ldtimers to recog nize that th ewo rld has ch ang e d and that ifam a teu r radio is going to su rvive , i t has to cha nge, too ?I' m talking major cha ng es ,not tinkering .

Fifty years ago . amate ur ra -d io made a lo t of se nse as ase rvice. In additi o n to provi ding e ngineers and tec hn icians

Con t in ued o n p ag e

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Y

,ORO RtNGWO Sa .. ,Gua .. -.o1

EbIOdlyS ,naI...-a, ........ originIlbT l b n:t,n;L Add S69 > b

P lJ, r d (lrdo

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FCC Sets New Vanity Fee

.peak ing of Which ...

Abbott and CostelloMeet Windows

One went to Hollywood and be came a fam ousactor. The other stay ed beh indin the c otton fieldsand never amounted to much. The se co nd one ,nat urally, became known as the le sse r of twowee vils.

A neutron goe s into a bar andas ks the bartende r How much for a be er ? The bartenderreplies , For you , noch arge .

Two atom s are walking d own the stree t an dthe y run lmo each other, One says to the other , Are you a ll r i t ~ No, I lost an e lectron Areyou sur e 'Yeah , I'm positive

Did you he ar abo ut the Buddhist who refusedhis dent ist's Novoca in during root ca nal worlI?He wa nted to transcend dent a l medication.

A group of che ss ent husiasts checked into ahote l and we re stand ing in the lobby discussingthe ir rec en t tournam ent victories. After about anhour, the manager came out of the office a nda sked them t o dispe rse . But why? theyasked .as th ey moved o ff. Beca use, he said , I can 'tstand chess nuts boas ting in an open loyer :

Adoctor made it his regula r habit to st op offa t

a bar for a haze lnut da iquiri on his way hom e.The barte nde r knew of his hab it, and would a lways neve the drink wa iting atprec isely 5:03p .m,One a fternoon, as the end of Ihe workday ap-proached , the barte nder was d ismayed to findtha t he was out of h aze lnut e xtract. ThinkingqUickly, he thr ew togethe r a daiquiri made withhickory nut and se t it on the bar. The oxux cemein a t his r egular time, took one sip o f the d rinkand e xclaimed , 'This isn't a hazelnut daiqui riNo , I'm sorry, rep lied the bartender , it's a

hickory d aiquiri, doc .Ahungry lion was roaming th rough t he jungle

looking for some thing to ea t. He cam e ac rosstwo men. One was silting und er a tree and reading a boo k; theother was typ ing away on his typewriter. The lion quickly pou nced on the m anreading the book and devoured him. Even the kingof the jungle knows readers dige st and writerscramp .

There was a ma n who en tered a local paper'spun conte st. He sen t in ten different puns , in thehope that a t lea st one 01 the puns would win,Unfortuna tely, no pun in ten did.

Aguy goes to a p sychiat ris t. Doc, I keep having the se alternating r ec urring dreams . Firsl l'ma tee pe e , then I'm a w igwam, the n I'm a tee pe e ,then I'm a wigwam . It's driving me c razy, What'swroog with me? The d octor replies : It's verysimple. You're two ten ts.

A woman ha s twins a nd gives them up lorado ption. One of them goes to a family in Egyptand is na med wEma l. The o ther goes toa fa milyin Spa in; they nam e him 'Juen. Yea rs late r, Jua nse nds a picture 01himseff to h is birthm om , Uponrece iving thepict ure , sh e tells he r husband thatsh e wishes sh e a tso h ad a picture of Ema l. He rhusba nd r espond s, But they 're lwins l you ' eseen Ju an , you 've seen E ma l.~

Than ks (we think) to the Sep tember 1 998 issu e of the SCC ARAGRAM, the newslette r of theS anta C lara Co unty ARA, Gary Mitche llWB6YRU, ed itor, via the Feb rua ry 1999 ARNSBulletin.

Groaners

Hum 6 on your Fettdbec k ca rd

Abbott: OK, Lou. Wha t do you want to know?Cost ello: Iam having no prob lem turning it on ,

but I hea rdthat you should be very ca reful howyou tum it off.

Abbott: Tha t's true .Coste llo: o here I am working on my ne w

comput er, and I want totum it off. What o I do?Abbott: Wel l. firs t you click the S tart icon , and

then ...Coste llo: No, I told you I want to tum it off.Abbott: I know, you click Ihe S ta rt icon .Cos tello: Wa it a s econd. I want to tum it off. I

know how to start it So te ll me what to do Abbott: I did.Coste llo: When?Abbott : Whe n I told you todick the Sta rt icon Cos te llo: Why should I click the S tart icon?Abbott: To shut ot the com puter .Coste llo: I click Start to stop ?Abbott: Well, Start doe sn 't actua lly stop the

com puter,Cos te llo: 1 knew it . o what do f click?Abbo tt: Start.Coste llo: Start what?Abbott: S tart icon .Costell o: Start iconto do what?Abbott: Shut down.Cost e llo: You don 't have to get rudeAbbott: No, no , no' Tha t's not wha t I mea nt.Costell o: Then say what you mea n.Abbott: To shut down the compute r, click , ..Costello: Don 't say S ta rtAbbott:Then what do you wa nt me to say ?Cos te I/o: Look, if I want to turn off the com

puter, I'm willing to click the Stop bu tton , the Endbu tton, and the Cease and Desis t bu tton , but noone in their right mind clicks the Start to s top .

Abbott: But that s wha t you do ,Costello: And yo u probably go at St op S gns,

and stop at green ligh ts.Abbott: Don t be ridicu lous .Coste llo: I'm be ing ridiculous? We ll, I think it's

abo ut time we s tarted th is conve rsation.Abcon: Wha t areyo u ta lking abo ut?

Coste llo: I am sta rting th is con versat ion rightno w, Good-bye

Thanks to the Septem ber 1998 electronic issue 01 the TSRC M onitor the new sle tter of theTw in Sta te s Radio Club , Mike MaynardWB1GRR , ed itor. via the November 1998 ARNSBulle tin.

, Two Eskimos s itting in a kayak we rech illy, bu twhen they lit a fire in the cra ft, it sa nk, provingonce and for a ll that you ca n't ha ve your kayakand heat it too.

Two bo ll weevils grew up in Sou th Carolina .

Floa ting around the Intem et (brace you rself):

R

coeteuo: Hey, AbbottAbbott: Yes , Lou?

Cos te llo: I just go t my first computer .Abbott: Tha t'sg reat , Lou . What did you get ?Costello: A Pent ium /1-266, with 40 megs of

RAM, a 2 1 gig ha rd d rive, and a 24x CD-ROM.Abbott: That's terrific, Lou .Coste llo: But IdOt)'t know wha t any 01it means 'Abbott: You will in time .Coste llo: That s exactly whyI'm he re to s ee

you .Abbo tt: Oh ?Cost ello: I heard thatyo u 're a rea l compu ter

expertAbbott: Well, I don know ,..Cos tello: res se e e You know yourst uff. An d

you 're going t o train me .Abbott: Real ly?Cos tello: Uhhuh . And I am here for my first

le sson.

6 73 Amateu r Rad io Today September 1999

The cost of gelling a vanity ca llsign is going

up - but only a dollar. This as the FCC raisesthe l ee 10 apply for a n amateur ra dio van ityca llsign from 513 to $14 starting Sept ember 10th.

By the way. the van ity callsign sys tem is s tillgaining in popularity. The FCC sa ys that itrec eivesin excess of a thousand vanity a pplicat ions permonth.

Thanks 10 the FC C, via News ne , BillPast ernak WA61TF, ed itor.

Re ader s 01ou rQ RX column , a long with many.ma ny thousan ds otlist eners elsewhere , via repea ler, a re wellI amiliar with NewsUne . a ma teurrad io's hard-work ing, not -for-profit, totally independen t, nonbiased newss ervice . We ll, althOughthey haven t req uest ed us to do so . we are here10 askyo u to lend them a hand financially.

Like m ost nonprofits o tm e type , the y la ce acon sta nt batt le in making end s meet i n order toprovide their valuab le se rvice. So whaddya say?Let's help the m sta rt out the new millennium onso lid footing by making as la rge a c ontributionas you ca n to: Newsline Supp ort Fund , Post f -fice Box 6609 37 , Arcadia CA 91066. Be sure to

mention that you 're a 73 rea de r, too , so we canshow them h ow much our folks care about theARS.

They'll than k you , we ll than k you , and so willbelieve rs in a free press e verywhere . .. Pleasedo it toda y, while you 're thinking about it.

8/10/2019 73 Mag - Sept 1999

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V T R O N I S l i sHigh.pe rlo nn ance electronic Icifs fun to build and use

In spe c t lind d o.. n lo ad o u r m a n ul ll ~ fru m :

http://www.vectronics.co m

Cr y st : lII n d io s et K lt lets yourelive the ex perien ce o f early radiopionee rs. Th is ba by re ally works

Wind yo ur own induc tor . wire up the ea r liest rad io circuit wi thout so l

, de ring a th ing an d listen to themagic of rad io that needs n o powc r. Put up anant enna, co nnect a gr ound. S tations co me inamazing ly lou d and cle ar . Incl udes ant enn a wir e.sens itive ea rph one. I / .x 5,,6 {, in. Simpl e , killlevel . Or der VE C- 12 IK . 519 .95 .

Sh ur t wave R ecefver Kitlet sC W '\ I em un_ Ke\ er Ki t stores 512 . . ._ . yo u listen to the wor ld chara ct ers in fou r 128 charact er non - volatile EEPROM messag e mem o- . Covers 75 i80 , 49. 40 . 30, 31 .n es . Co ) Qf I efltil l? QS O s by j us t 20. 25 . 22. 19 , 17, 16 . 15 and 13 Meter bands .

oItl' p1 l ssil1g memory message buttons . Exp lor e A \ t . SSn . C W, ~ V tV RTT Y an d Pac ketTru e sinewave sidc toa e wi th soft ri se and fal l lime signals . Vernier red uct ion drive . smoo th regen era-elimina tes hars h keyclicks . Has a ll features o f lio n co ntrol, Rf stage. in cludes a ll me ta l cabine t.VEe 0 1 e w K K 11 6'1 5 1 S I 2 earpho ne j ack s . Use 9V ba ttery . 2 /:x7 x 6 in ,' - K eyer II . . ,, Il l. imp e Intermediate skill in-el. VE C- I02K, 5 ~ 9 ~ .skiIJ level. Or der VEC U I K. 569 .95.

H i~ h. pe r f o r m a ce 2 M eter t,lRP l rwrxm .,.,.AitsjorlJl j -I4JJ4Y]tI.U P ream p Ki t pulls weak signa ls Great introd uct ion to QRP , the hot tes t and fastes t

out o f no ise . So lves three rIX:ep . growing act ivitie s in ham rad io.tion prob lems _. boos ts signa ls usin g a I -d El nors e With this tiny I r ( ms cl i~ t r you 'l lfigur e mic rowave transistor, provides razor-s harp disco ve r what tho usands o f Q Rrba ndpass filter ing , elim inates unwa nted elec trica l en thusi ast s a lread y know - younoises w ith buill-in ba lun . Us es 9-14 volt s DC , don ' t need a $10 00 rad io to ge tTiny ) '/' x3x ) in , fits in any Sill' bo Interm d ial f on the a ir and c omm u nica teskill level . Ord er VE C- 14n2 DK . S59.95. AI . .Ll _ It wo rldwi de. A ll it ta kes is so me

simple ci rcui try using l es s en e rgy t ha n a pen -ligh t2/6110 \I t''It r F \ 1 R ecet ver Kits let you bulb You get VX O freque nc y c o ntrol . broad -tu nc into th e world o f ha m rad io . Cat c h bande d tra nsmitter ci rcuitry, so li d o ne Wall p lusall th e action Each covers th e entire F \ 1 outp ut, sh a pe d keying. .3 uV sens itivity. d irectsub-ba nd an d runs o ff you r 9 vol t banery , co nversio n rece iver . Incl udes crystal fo r p o pular

Plu g in s pe ak er o r head p hon es for loud cl e ar Q Rr calling frequency . 1 1 14 141.5 1 in. /I1t( l mt dialereceptio n. I 1.. 4 d in . int ermed iat e skill level . skill level. Order \ E C .1 3 80 K ( l l Meters ). n :c-Or der V EC -1002K (2 Meters ). \ E C I OO6K {6 1340K (40 Metcrs). VE C-13 30 K (3 0 Meters ),\{ el ers ). n :C - IOI OK l lO \ 1eters ). SJ.& .95 each , VE C .1 3 20 K (20 Mete rs) 559 .9 5 ea c h. = 2 .\ l el e r .\ l on itor Ki t rece ives 14 + 148 Su p er C W Audi o Filte r Kit g ives you;-l:: l : . Ml-lz. Lo w no ise . high gain RF preamp

:. . . gives you excellent 0 .1 uV se nsi tiv ity. three bandwid ths: 80 , 110. 180 Hz, EightAir variable tuning capacit o r has 8: I red uction, po les g ives supe r steep sk ins w ith noDu al co nversi o n super he t provides selec tivity a nd ri ng ing. Pu ll C W QSO s o ut o f terrib lestability. A utomat icall y e lim ina tes sq ue lch ta ils, QR M Plugs into phone jack to dri ve phones . QR M

I down 60 dB one octave fro m c enter freque ncyRuilt-in spe ak e r, squelch , tone, vol um e centre s. (7 50 Hz) for RO li z band w idth . Imp roves SIN ratio19' 1. in. telescopic whi p . 9V battery, 2x4 /. x,4 in, 15 dB, Use 9 V batte rv. I / .x4 x 3 11 in. Simple .ikilJInter mediat e skilt teve t. Ord er Vf:C - I (14K, $79 .95 . tevet. Ord er n :C-1I20K. SI9 .95 ,

5 WaU 2 M l, tl, r F .'\1 t ra n sm il t e r K it letsvc u tran smi t voic e a nd da ta _ AF S K da ta A.'\I Radio Tra n smi ll e r Ki t lets you set up your(up 10 1200 baud) an d FSK da ta (u p 10 0 w11 A \ I station an d broad cas t cr y stal9600 bau d) . J um pe r se lect reactance or clea r p rogrammin g from yo ur studi o wi thdirec t F ~ fmod u la to rs , Reli ab le Motorola you as the d isc joc key or ta lk show host .

~ B f tran sm itter IC an d PA transi stor . Crys tal Play mu sic from CD pl ayer . t ape d ec k or d oth er sourc e . Choose cl ea r frequency fro m 53 Q.-

controlled (x8 freq uency m ultiplicatio n}, ........ Be 1750 KH L Standard line level o r mic rop honesp u rs and harmo nics . Use 12 1 4 VOC . L5 am ps .5-p in D l~ microphone jack . I / .x 4 f . x5 1. in. inpu t. Easy CD, tape dec k o r m ike mixers coo-

I Onl ...... ..., ncct. Aud io level adjustmen t. l / .x 4 x3 1t inches.Difficull skill teve . er ' T C 1lO1K, ~ Y >. = - Sim pl e skil l 1( Vf /. Orde r n :C-1290K , 529.95. i - a d l~ I- . \ 1 HBlItl l '1 Cha rge r Kilsa fely quick charge s expens ive batt eri es - The GIAl\ T Book of ......- no overch arg ing _. manv in less than an EI . Proi I I

, hou r. HTs , cell phones , camc orders , lap ectron tc rojects, ,, 0 um e .top com pu ters. I a ndles I to 12 ce lls . Charg ing I~ T h e G IAN T P r o j e ~t book ~n d u d e s 19SL1tuS LED s. Disc harge b ef ore charge fu nc tion UO'lk of e X ~ h n g kits on this pa g e . Hasreco nd itions b atterie s. A lso re moves me mory E1ectr.,nic building ups, co mplete partse ffect. Runs o n 12. 15 V DC . 1 1 ,,4 1. x5 1 inch e s. Pro jhort y,ave rece iver s a t a specs. sc he ma tics, cabinet lay-push o f a bunon . Choose tw o I M Hz Volume l ou t a nd mu ch , m Jch more ,ba nds betw ee-n 3 and 22 MHz . Popu lar 13. Great schoo l pro j ect book o r16. 19. 25. 3 1. 4 1. 49 and 60 \I eters inte r gi ft for you r fa \ OI1te ha m .

na tiona l r o a d c3 ~t bands . OnIo lf bypass . S E O rd e r n :C. I90 I . 5 19 .9 'i.60216 11 mixe r-oscillato r IC and runed inp ut circu it. Use 9 V bancry. 1 /.x4x3 j, in. Il1rermediate

skill lt \ e l. Order n :C- IOIK, 527.95.

Full featured el l Kever Kit, S] 4'.1lYF:C- 2 01 K. the be st e lectronic keye r ba rgai n in h am r a di o Sen dbea utifu l so und ing Mo rse Cod e. Self-co mpletin g dot- da she s and dOId ash me mory forgi ve t imi ng err ors -- ma ke s se ndi ng CW easy a nd

accu rate. Fro nt pan el vol ume/speed (3-65 wpm ) co ntrols. Weightadjusts 25-75% . Sidct one (300 - 100 0 Hz) has LM J 86 au dio amp forexternal speake r/phones . Selec t Iambic A or R, fully automa tic orsemi -auto bu g mode . Tu ne mo d e for lun ing r ig. RF proo f. Slee pMode battery saver, Usc 9V battery. 1'l.x4x 3'1> in. Simp le skill level.

~ . . . ; - . : ~_ , : _ ~ _VE OC O-O O ~~ ~ _._ ._ ~~ O ~M t lI ;nyi ........., wp 100/ .Ito .....). VEe10/KC. 14.\ irn aft Recefver Kit tunes entire voiceaircraft ban d 11 8- 1) 6 MHz . Picks up airtraffi c 100 miles 3 \\0'3)'. Track p rogress o fincom ing/ou tgo ing traffi c in you r area.

gai n advanced w eather informa tion, and disco ve rho\l, . the Xarional Ai r Traffi c System reall y works .Great way 10 learn a bou t a\ ia tion . Use 9 V battery.Drwese xternal speake r/phones . 1'loX4:d 'h in.lnterm e diate s kill level . Ord er \ F.C -I J I K. 5 2 9 9 ~

20130 /40/80 :\-Ietf r Receiver Ki t s givehigh perf orm ance Covers enur e ba n d

or tailo r to cov er des ired pon ion . Co pyCW /SSB /A M . NE60 2J 6 12 mi xer-o scillator, LM3116 high g ain a udio am pli fier. 1 I.x4 I. x5 /. in, Mod er at e s killl en l, O rder VE C 1120K(20 Mete rs),VE C- 1130K (30 Meters), V EC- 114 0K(40 Meters ). VE C-1180K (1l0 Met ers ], $29.95 ea .

20/30 /40 /8 0 :\ h ' ler QR P C W trans mitte r K its have variable crystal o scillatortun ing. front pan e l swnc h se lects I o f 2crystals. I crysta l incl uded . Transmit an d

Receive switc h. C onnect rece iver, I' / . x4x3 h in .Intermediate skill level . Order VE C 122 0K (20\ k ters). \ T. C - I2 J OK (3 0 Met ers ). \ EC 1 l4 0K(40 Meters) . VEC -12 80K ( SO \ k t ersl. 529 .95 ea .

Tunabl e SS8fC W .-\udio fil t r Ki t hassharp jour po le pea k an d notch fillers.Zero in wit h freque ncy control & adj ustbandwid th for best response. Tune fre

que ncy from 3 00-3000 Hz. Notch is an outstanding 50 dR. I Wa tt a mplifie r. Spe aker /P hone jack s.12 VDC at 300 rnA. I /. x4 1. x5 /. in. Interme dia teskill level. Or der Vf:C-H41 K . 53U 5 .

I i - , r r ol li r ~ Co mpreh l Iu i l f S (l/der b f :Ct un.e lin d Ki t is the be st home study solder

ing course a vailab le Includestheory. quizzes , PC board tools .sa f ety. techniques and m ateria ls .

Get professiona l sol dering skills and a fun blinking LED p roject . Gets you read y for th rou ghhole PC boardassembly a nd repai r. Simple. .\

slillln-e1 . Order V C I 500K . 5 29.95. i ~

Super C W fil te r lamplifier Ki t has pow .erfu l I wall audio am plifier 10 OO\ 'es pea ker. 8 poles ac tive IC filteri ng u se scascad ed low -Q stag es. 3 bandwidths:

80 .110 . 180 Hz . Center frequency: 750 Hz. Up to15 dB. Usc 918 VDC , 300 rnA rnax. I /.x4 ,,3 110 . Simple s kill level . O rder VEC -82 I K. $29.95 .

Super SSB Audi. ) Fil te r Ki t improvesrea dabilit y with 8 pol es. opt imize s audi oban dwidth , red uces SSB splatter. low, hipitched inter fe rence. h iss , s ta tic cr a shes .

background n o ise. Use 9V hall erv. I ' /.x 4x, 3 /, in.Simple sk il l fn el. Ord er n :C- 8 30K . 51 9.95 .

10141210 1440 I l i l l .o\\ .. :o i Prt lImpKits so up up your am e nna system.Helps pull in we ak signals . Wori;..s won

ders for scann er or hamba nd rec e-ivCT_ Gi vesgr eaI IO\\'. no ise perf on n ance an d immun ity fro mdama ging electrostat ic discharge. 1 '11 f, in. Simpleskillinoel . Or de r \ 'E C-I 402K ( 1014 MHz ),n :c1422K (210 '.1Hz) \ T C I-U-llo: (.$oW r..fHl'). 51795.

/ V,. l tm ics kiu t eatu rr.:l p m {N sional / Al l m l t a l ('liSt S for mo st ki t s. S I4. 9 5, / Or d er Toll-Free 80 0-363-2922q u u f rp oX gfa ss C hm , rJ wir ~o l d e r m a~ k Add C for cas e to model #. Examp le: VEC Fa x : ~ 6 0I ) 323- 6551 ' T l

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umwr 1 on YO FH tJ r; card

P Key P KeyThis s imple C W keyer is a g reat wa y 1 learn about P I s

Vladimir A . S krypn ik UY5 DJP ravdinska 58

Kharki v - 107Ukraine - 310 107

[uy 5dj@yahoo .co m]

Algorithm of simpl e ke ye r p rogram

si ng le PI C micr ocontr o llcr , a lon g w itha very few di screte co mpo nents to acco mpli sh input/output f unctio ns. be liesthe latent po wer of the program store dwithin th e P IC.

Th e m ain c ha lle nge for thc P IC d esigner is to cr eate a p ro gr am to imp lement the proj ec t idea . Th is i s a da u nting i rst-time task- at leas t it see ms so hefo re yo u begin yo ur study of microco ntrollers . I have fo und t hat t he be s t wayto s tudy is learning -by -d oing . To begi nw ith . a ll you need for your home lesso ns is Dav id Benson ' s hook (seeNo tes at end o f a rt icl e ). Th is e asy- tou nde rs tand man ua l wi ll intro d uce youto PIC mi croco ntr ollers fro m the inside .Ste pping f rom page to p age . yo u will acquire incre as ing abilit y by learning towrite s im ple pr ogram s and then check-ing th em with the :vtP LA B m edi a ( seeNo tes).

Do yo u reca ll th is ph ra se: T hese simp le proje c ts s ho uldw he t yo ur ap pe tite to lea rn

more about the litt le P IC microco ntrollers yo u sec so freq uently ? Thi s co m

m ent preced ed t he articl e U sing P ICMic rocom rol lers in A mateur RadioProj ect s . hy Joh n H an sen W2F S. inthe O ctob er 1995 issu e o f Q T Th ispredic tion w as ce rta inly tru e fo r me Before reading t ha t article . I wa s not a tall fam ilia r with PIC m icroc on trollers .To me . they were terra inc ognita Butthe a rticle e ncouraged me to beg inlea rnin g a bout PI Cs by e xperi me n tingw ith p rogram min g and by produc ing

m y fi rst pro j ect s. T his a rticle is a direc tre su lt o f John Ha nsen s predi c tion .PI C microcomrollcrs . a new ge nera

tion of e lectronic co mpo nen ts. pr ovideus wit h fasc inat ing p o ssibiliti e s o fel imi nating ea rly- on ra th er large nu mbers o f d isc re te cle me nts by uti li zin gthe powe r o f pro gr ammi ng to pro videneeded fu nctio ns. Th e large p rinted Let s review how an ordinary k eyerci rcuit hoard . wit h its mu ltiple cc nduc - wo r ks. Le t' s assume tha t the keyerstors perfo rming func tional co nnection s ou tp ut i s co nnec ted t o the tra nsmit te rbe twe en part s of sc he m ati cs. is s up- keyin g ci rcuitry. In puts a re co nnecte dplanted by an in vis ible program stored in to the left a nd r ig ht contac ts of th ememory inside a s ing le, sma ll chip. Th e kcy e padd le. No rma lly. t h e kcy cr issmall size o f a c irc uit b oard co nta ini ng a in the idl e co nd itio n: T he o ut pu t is10 73 Ama te u r Rad io od y September 1 999

ope n ( or high) a nd t he tran s mill er isno t ac ti va ted. W hen the op er a to rpresses the padd le h andle to the 0 0 con tac t. t he o utpu t becom es active anddrive s e ith er a re la y or a tra nsi st o r con

nec ting the ke yi ng circ uit to g rounda nd th e transmi tter s tarts sendi ng a or se cod e dot. T he kcyc r supplies t heappropr ia te leng th of the dot. a s wel la s a pause in seq ue nce. Th e d uration so f both th e do t an d the pau se arc equal.Wh e n the paddle return s to the n eutralpo s ition . the ke yer . on ce agai n . assu m es the id le c ondition. If the padd leis pre ssed and hel d in the Do l position . the k cy cr per for ms a pr eci se se

tie s of dot s and p au ses. Th e same i s truewhe n the operato r pre sses the paddleto the Da sh po sit ion . How eve r. thele ngth of a d ash is thr ee time s longe rthan t he lengt h o f a do l.

Fo r min g pr ecise dots. da shes. andpa uses. as descr ibed ab ov e , w ill be acco mpli shed by t he PIC s pr o gra m . an da coh e rent m icrocontroll c r prog ra mm ust have a coh e ren t plan : s uch a p lanis ge ne ra lly ca lle d an a lgor ithm . F ig. 1dep ict s the a lgo rithm f or ou r proje c tkcycr. R eferring to Fig. 1, k eep i n m indthat the mic roc ontrollcr . PICI 6FS4 . has5 lines o f po rt A a nd H line s of port B .

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ss

ST ART ~A2 l0W?J ~

- lEACH PORT IS NPUT RA3lQW?

l AO< PORT OUTPUT O rPORT RBI PORT

HIGH HIGH

MAKE PO RTBLOW

GIN l OAD DeLAY lOAD DLAYCONSTANT CONSTANT

It>I11AlJZECOU NTERS

SOUNOON SOUND QI II

I PORTRB3 PORTRB3

m m

A O O A ~ .. oearm ~

PORTRBl PORT ,. ,ow, , lOW lOW

PAUSE

lOAD DElAYCONST ANT

OOOM PI ETE?

~

Fig . I . Opera tio n algo rithm fo r the PI C co m lled keye

to m a ke t hem ready fo r the nex t opera - run thi s loo p until Y e s (a do t o r da s htio n. T he k cycr prog ram now sc qucn- pad dle co ntact closu re) occu r s on o netia ll y c heck s to de te r min e if th e do t or of the co mp ar iso n rho mb s .

d ash padd le co nta ct s a re cl os ed or not. Let s c o ns ider w hat will ha ppenF irs t. i t c heck s the d ot inp ut. If port w he n the d o t is p re ss ed a nd t he ke yc rlin e RA2 is low , th e prog ram wi ll ca ll heg in s forming th e d urati on o f th e d otthe subro utin e Do l. Th i s is depict ed m ark to ke y the tran s mitter . Fir st. weby th e right compari son rh om b corne r ha ve to make the ke yi ng o utput po rtm ar ked wi th Yes . If n ot , R A2 i s s till l in e RB I go high. T hi s wi ll ca u se t heh igh, w hich mea ns th at the do t p addle tran smitte r co nnec ted to the ke yer toc o n ta c t wa s no t cl osed . a nd t he p ro - s ta rt tra nsmittin g a dol.gr a m will go to c hec k th e stat us o f the T he ne x t box on th e alg o ri th m diu -d ash in put. If the da sh pad dl e co nt ac t gram tel l s us th at we ha ve to load th eis pre ss ed to mak e po rt RA 31 0w (yes). d ela y co nstant int o th e c o unt e r. Aft erthe program w ill c a ll s ubrou t in e tha t . the p ro g ram w ill s ta rt to ge nera te Das h t o for m a dash . no t (t he dash a sou nd p ul se se q ue nc e to o per a te th epaddle conta ct no t cl osed) , it w ill re turn m onitor in g b uz zer .to the begi nnin g poi nt and co nt inue to T he nex t rhom b is for de c rea si ng the

A ny l ine of po rt A or B can be u sed aei ther a n inp ut or a n o utput. In th iproject. w e w i II co nn ec t the do t andda s h paddle cont ac ts to the port Ai nes , w hi c h wi ll fun ct ion as inputsKcy er o utput a nd pi cz o buzz er for a ud io m on itoring will he co n ne cte d t opor t B as o utput s.

No w, let s ex a min e the o pe r a tion u lgori thm di ag ram . Fig, l All wo rki ngsteps are ma rked w it h rectangu larbo xe s . B ox S ta rt is the poin t w herehe program wi ll ac tu a lly sta rt to ru n

Wh en s upp ly vo lt age is a pp lied t o thekey er , t he fi rs t step in th e pr ogr am is tonstruc t a ll por t A lines to fun ct ion a snp ut s. In t he next ste ps. all lin es of

po rt B a rc instruct ed to fun ct ion a sou tputs, a nd the y a lso ar e s witc hed tonormal low o ut put level s. U p to thi spo int. th e p rogr am ha s o n ly prep ar edhe PIC mi c roc o ntroll cr , But co ntinung from thi s poi nt. the program willegin to run in th e nor m a l id le o pera

ion o f th e kc yer. Th is is m a rk ed by th ea be l B E G IN o n the d iagram .

Let m e di gress a hi t from the a lgoithm d iagr am an d e xp lai n h ow certai no t. da sh . or pa use du ratio ns w ill ocu r in th e keyc r o pe ra tion. PI C m icroo nt ro llers a c t b y s te pp ing und er int er

a l cl oc k p ulse s. Every s te p is c all edut as a cy cle . Eac h co mmand in struc

ion ha s some q uantity o f in st ru ct ionycles . I w ill not desc rib e ea ch o ne. orow man y c ycl es it w i ll requ ire . I o nl y

wa n t to poi nt out th at in o rde r to p rouc e a certai n le ngth o f d o t. we need toalcu la te ho w m an y instr uc tion cy cleshe m icr ocomrcll cr w ill usc for proid ing th e op era tion . a nd how m an y todd fo r d el ay ing cycle s to es ta b li sh t he

ro per re lat ions hip bet wee n tra ns mitng speed a nd M orse c ode el e me nts.

De lay d urati on depend s up o n th e del ayo nsta n ts we w ill inco rporate in to th erog ram . Th er e are th ree diff er ent c o nta n ts used : o ne e ac h for t he dot . da sh,nd pa us e . T here a rc th ree cou nte rsomina ted in th e fil e re gi ster s int e rnal

mem o ry ar ea . To provid e the desir edelay. the co ns ta nts wi ll he pu t in to

h ei r ap pr o pri a te co unter s.But l et s now return to th e a lgo -

thm . Th e box clo se st to th e BEG INbe l is initialization of the co unters.

nit iali za tio n m ea n s to cl ea r co un ters73 m t e u ad io t e v S e pt e mber 1999 11

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However , if bit 2 of port A is low, thenext executed instruction will be call.Thi s means call the Dot subroutine.

In the first s ubroutine , the lin e labeled as dot, bit 1 of the port B is setto I . This high level will act ivate thetransmitter 's keying circu itry t o starttransmitt ing a dot. The next two program lines load decimal value 12(the d elay consta nt) in to counter 1.Following this step, the program be -gins to generate signal s for the buzzer.Instruction b sf sets to 1 bi t 3 ofport B. you remember, previouslywe made all port bits low . Now RB3goes high and the buzze r produces on eclick. But in the nex t step instruc tion, bcf ma k es this output low , causing anew click. A fas t repetition rate tran s

forms the clicks into a tone .Instruc tion decfs z decrements

counter I co ntents by o ne un it a ndcompare s the res ult with zero . Untilzero ha s been reached, the in struction goto loop s to the label rptdot toproduce new clicks , and contin ues todecrement the coun ter until the contentof the counter becomes zero- thenth e following instruc tion bcf willmake RB I low. The do t is now overan d the transmitter no longer transmitsRF energy .

Bu t sub ro utine D o t isn't over. Instruction call will execu te a nothersubroutin e, Pa us e . Th is begin s byloading decimal valu e 14 (delay constant) to counter 2. The nex t instructiondecrements this counter until the delayis complete and the coun te r is clear .Note tha t ou tput port lines RB 1 andRB3 are no t used in thi s sub ro utine.We do no t need to e ither key the tr an smitter or prod uce sound. We only needto ge t a standard length pa use eq ual tothe length of on e do t . The pa use fo r theaudio signa l is controlled by co unter 2and a much large r delay cons tant.

When subroutine Pause is over ,instruction return returns us to subroutine Dot. Bu t the last instruct ionhere a lso is r eturn, and the programgoes back to the Dot portion. Fromthere the program j umps to the po int

labeled BEG IN to initialize co untersagain , an d starts c hecking which contact on the paddle is being pr essed .

Subrout ine D as h is the same as73 Amateur Radio Today Septe mber 1 999 13

n assembly language program

The assembly la nguage program fore keyer is presented in Table 1. Asmb ler sof tware wil l examine thi sogram and ignore all line s beginningom the semicolon. Other s performsemb ly so urce code . Th i s par t will

assemb led by MPASM , the co mler inc luded into the MPLAB inteated development e nv ironment fromcroch ip . The assembler will conrt readable text files into hexadecial code for programming the PICcrocontroller .The lin e beg inning with the words t informs the as sembler what typea P IC microcontroller i s used . The

xt line determine s the type of inter

l clock o scillator built in to the d ece . In this case, it is an RC-typecilla tor.The nex t five lines a rc eq ua ti ngatements which ass ign h exadecimaldresses to file regi sters in the PICemory area . The line with OR G (orin) d efines the addres s in memoryhere the program code start s.The line with the label start in thest col umn of the program will teachport A lines t o func tion as inputs b y

ad ing hexadecimal FF (or binary11 1111 into a special tristate regi s. Actually, this ins truction onlyeds five T s , becau se port A has

ve input/output lines (named asAG--RA 4) in this type of PIC. Therere , the three l 's i n the left F arenc tionally superfluou s. In like manr, the program will teach all port Bes to functio n as outputs by loadingxadecimal 00 (binary equivalent is o o into this regis ter. The Port

register is also cleared, w hich meansw leve l statements for each of th eght ou t pu t line s RBQ--RB7.The label BEGIN show s the po inthere delay counte rs are cleared .hen all three counters are ready, theogram begins the Dot portion .re the program checks for the low

vel at the input port RA2 . Electrilly, this point is wired to the dot conct o f the paddle . bit 2 of port A isgh (paddle is not pre ssed to do t) incordance with the instruction goto,'e program goes to the Dash portion.

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o f course . is tru e on ly fo r th e b uzzer s

- se rsv IN UI OUT ton e. not for th e s ignal s he ar d from

O76L05

1 yo ur s ta tio n he adph on es Yo ur trans-j Q 'OOnf GNO ee lvcr u se s ot her m et hod s 10 ge l aSPEED 2SV 2SV m onit or ing tone .,

CONTROL ,Co nstr uc t ion

RI ~U2 Th e kcy cr w as bu i lt o n a 30 x 35 mm

P C16F84 R3

4 .7K - : R4 g lass -e poxy sing le-s ide d PC board5K 14 10K 10KR2 4 w n 0ORA 2 , / . (se e Fig . 3 ). yo u n o t icc my nam e

~K16

QSC' RA32

~ la nd ca lls ig n , yo u will u nde rs ta n d wh ym et r ic si zes we re ci t ed . C usto mary

C DOT E ng lis h d im ension s a rc a pp roxi ma te ly15n f ,1 ,L. l x 1-3/8 inche s . I am n o t fa mili arl\-

v wit h co m pa ni es o ut side of th e Ukra ine;J.. SI.5 tha t produce c us to m board s in sma ll

LS I , , , 4 7 < qu antiti es. However . I think i t is nor-mv mal pra c tice for ra d io a ma teurs 10m m ake their ow n hoa rd s.V

KEYING Th e assemble d h o ard can be 10 -TO sta lle d into al m os t an y t ra nsce ive r.

0 1 TRANSM m L imi tati o ns w ill b e e ithe r no t e no ug h

2N2 222 room in i ts ca se (w hic h se e ms inc red-

Iib le ) o r so me s pec ific fea ture o f th ekeyi ng c irc u it ry suc h as key ing w it h

Fig . 1. Schemati c of the simpl e PI C C\V k eyer. Unl ess other wise spec ified. re sistors are hi gh s in k current o r h igh voltage ab o ve1/4 lV 5 tolerance. c a rton c omposition or fi lm unit s. Appropriate eq uivalent parts groun d . In thi s situa tion. tran s istor Q Ifrom Di gi Key KJcall he subs tituted as shown in Tabl e s ho u ld he used to drive a sm a ll re lay

w ith open contacts. D on t forge t to in

sub ro ut i ne D o t: It IS followed b y spe ed varies from a pproxi ma tely 5 wp m elu de a s m a ll sili co n di od e across the

subro utine Pa use -, a s we ll. T he o nl y to ove r 30 . To m ak e a m or e na rro w rel a y co i l 10 man age t he in d u ct ive

d iffer e nce is in d el a y cons tan t va lue . spe ed ra nge , yo u may usc a h ig her spike when th e rel ay co il is de-e nc r-Th e decim al e quivale nt is 37, w hich va lu e of R2. g izc d (a nd , of c o u rse . d o e nsure tha t

mak e s the d ash d uration a lm os t th ree S ig na l fro m pi n 7 o f U 2 is us e d forti mes large r t ha n the do t or pa use . k eyi n g th e tra n smitt er . Q I fun ction s as I Part s List Ibipo lar swi tc h to key th e tr an sm i tter ICircui t descrip tion k ey ing c ir c uit ry . Wh en po rt RB I goe s IDes ignation Part

Refer to the sche matic di a gr am . Fig . hi g h it tu rns Q I o n , th ereby co n nect - I51 Any type CW key er paddle2 . The cir cuit is power ed from + 5 V ing the co llector network to grou nd .

Cl , C3 Ie sistor R5 is fo r limi ti ng base cu rrent. 10 IlF, 25 V electrolytic orvolt ag e regu lator U I . Ca paci to rs C I tantalum (OK P5148-ND)a nd C3 p ro vide clear DC . an d C 2 is for The pi czc b uzzer ; connec ted t o p in 9 ,

suppr es s io n of inc o mi ng RF energy m onitors the transmitted Morse code C2 , C4 Ce ramic (C2: OK P4924 -

fro m th e tra nsmitter . text. Th e re is a noth er u nu sual func tionNO; C4 : OK P4905 NO)

T he k eye r it se lf is mi cr ocont roll er o f the b uzzer. Yo u w i ll n o tice th a t the L51 Piezo buzzer element ( OK

U 2. Resis to r R I k eeps t he reset inpu t buzzer ' s p itch is re la te d t o th e cloc k P9924 -ND)

o n pi n 4 h igh . R esisto rs R 3 and R4 ar c spe e d o f th e mi c ro co ntroll cr . W hen th e APl 25 k pote ntiometer O Kp ull -up r esis to rs for inp ut s R A2 and o pera tor va ries th e M or se t ra ns m iss ion CT2266ND)

RA 3. Th ey p ro vide hig h idle level a t sp e e d b y ro tat ing th e k n ob o n RP I , it Ul 78105 small 5 V positiveth e p add le 's do l a nd da sh co n tac ts . w ill a lso v ary th e so u nd pi tch . At first regulator OK NJM78l05 Note tha t I do not s pecify lef t or right th is m ay see m li ke a di sa dva ntage . b ut NO)

c o ntacts o n the padd le beca use th a t is a the po s itive effec t of this is to m ake i t U2 P1C16F 84 microcontr oller Iatter of th e operator s ta ste . po ssi bl e 10 e stimate des ired Morse (OK PIC16 F84-Q4/P-ND)O nboard compo ne nts R2 a nd C4 10 - spe ed ju st by li s teni ng to t he p itc h of 0 1 2N222 or an y general

gc thcr wit h o uthoa rd po ten tio meter the ton e . T he low er th e ton e of o ne do t .purpose NPN s iliconRP I arc the RC ci rcuitry fo r the intern a l the lo we r th e M or se s pe e d . No nee d to trans istor (OK

cl ock os c illator , With the component ov e rload t he ba nd wi th a se rie s of dot s PN2222ADICT. NOva lues sh ow n he re . the tr a n smittin g t o c h eck the tr an smittin g speed. Th is , T bl e 2. Parts li st.14 73 Amateu r Radio Today Septe mber 1999

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g . 3 a . P keyer prin ted ci r uit board. component s ide.

:\'ote s

a m us ing t he si m p le se rial port prog ramme r , w hic h wa s in cl u ded (al on g w i tha d et a i led __de s c ripti on and opera li ngproc ed ur e) in W2FS s articl e .

SAVE 47%on 12 months o f 73

Only 24 .9 7Ca ll 800-2747373

I . D a vid Ben son , Easy PIC n . ABeginn e r ' s G ui de t o U s ing PI C 16/ 17Microc o nt r ollcr s. Ve rsio n 3.0 , SquareI Electr onics, 1997 .

2 . Availa ble ar lht tp .z/ ww wmic rochip.co m ].

3 . Availab le at [ httpv /hom ey.s wipnct .sel -w 5 3783]. l

T his s im p le keycr is a n exam p le o fga ining know led ge and sk i lls by se lfstud y. expe rime n tation, and co ns truction n d yo u e nd up with a very usefulstat io n accessory as we ll An d, o fco urse , like most amate ur rad io projects ,the pro ject itse lf is ripe f o r fu r ther impro ve ment s and m odi fic at io ns. K eep inm ind th at th e p rogram descr ibed inthis s ho rt a rt icle utilize s only a verys m a ll p art of PIC l6FS4 capab ili ties .

In clo sing , I wo uld li ke to ex pre ssm y hea rties t grati tude to m y friendD ave Evis on W7 D E for his valuablere m ar ks an d c om m e nts .

Summa ry

73 Amateur Radio roaev Se ptember 1999 15

GND

+9 -15 V

RP

MP L A B so ftware . T hi s is the best e nviro nme nt fo r desi gn an d de bugg ingyo ur p ro g ram s. T hi s so f tware can b eob ta in ed fr ee f ro m the Microc hi p Websi te ( see Not es). T he a sse mbler co mpi ler MP AS l\ is i ncl uded in MP L ABan d also supplied se pa rat e ly It may beused to o bt ai n s ou rce file s fo r the pr ogram me r , h ut I pre fer to us e the whol eM PLA B p ackage . On the W e h s ite,yo u w ill al so fi nd a ma nual fo r thene we st ve rsi o n of MP LAB , w ith d e

tailed ex p la nation s on ho w to workwi th [his software .T he re sults of yo ur work in M PL A B

wi ll h e a fi le wi th ex tension .hex. Itsho uld he u sed in pro gra mm ing sof tw are PIX ( se e N ot e s , not e 3 ). A ls o,you w ill n e ed the p rog ra m m er it self. I

R3 R U2 R2Dot -i I-

Do shR4

C 3

CU1

GND RXMTR

0Buz.

C

e po larity i s co rrect and t he diod e iso t D C co nduct ive when the r elay coil

e nergize d .It is w ise to in stall the key er bo ardrect ly onto the key e r p addle assem

ly. T his w ill ensure the shortest p osble input wi re s, an d kee p it awa yo m strong RF fi e ld s . A m etal e ncloure to further sh ie ld a gainst RF engy in your shack i s a lso a w ise id ea .he acco mpanying pho to reve als that

m y keycr is a n im provis ation (whi ch in

he U kra ine is standard pr oc e d ure d ueo the cos t o f li vi ng and scarc i ty of

man ufactured elec tronic pa rts) . It ismou nted on an old -fa sh ioned telep hone

olarize d relay mo dified as a paddle.u t thi s is also t he ama teur radi o tradio n . a nd I m su re yo u wi ll co nj u re upo ur o wn uniqu e impr ovisa tio ns .

rogramming

UY iDJ PI C ke er

ig . h . P IC key er primed circuit board ,olde r ing side . Photo A . H b osed key er

Fi rst o f a ll, yo u h a ve to wo rk wi thour asse mb le r p rogram in M icrochip's

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Numl r on your dbsck ClIrd

Y Portable Po \Vh at e mergency will you need to handle?

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pot entially c ritical p or t ion o f th e antennafor easy dup lication . co nvenience . andimproved lo ng-term stab ility (no tape toco m e unra veled ) .

O n the J -po le co uple r P C bo ar d . the

o u te rm o s t U is a ct ually th e co ld e ndof th e q uart e r- wa ve mat chi ng sec t io n.In side it is t he lin k cou p li ng loop a nddon ut pa ds to m o unt t he se ries t unin gcapacitor (3.5-: O p F. Mou ser : -l-AA0: 2

o r eq uivalent) . Pad s are a ls o p ro v idedto insta ll a small fix ed ca pacitor in pa rall e l wit h the t rimm er j ust in c ase t heo ne yo u usc is too sma ll i n va lue. Th erem a ining small pad is fo r RG -5 8 o req uivalent) co a x ce nte r co nd ucto r : th etwo la rge r pad s nea rby acc ep t pigt ailsfrom the co ax shield. one on e ac h si deof the co a x. T he t w o iso lat ed p ads ar cdr ill ed out to provi de ho le s for coaxstrai n re lief. Usc a nyl o n t ie-Vral' orsma ll m ag net wir e wrapped a ro und th ecoa x a nd thro ug h these hol es to sec ure itto the PC boa rd . No w yo ur co nnect ions

CI C_1101 _ 1

L :r:= r ; = = ==== ;;1 === ==._ - _ I=_ iJ .

most handhclds . m aximum po wer tran sfer a lways occ urs whe n the sou rce andload im pedance s are m atched . Besides.hi gh VSWR nag s at m e. eve n w he nov e ra l l r esu lt s see m to he sat isfac tory .

T he a pproach taken in thi s a nte nn ais so o ld . it mig ht be co ns id ered no ve l.I was br ow si ng th rough an ear ly radiohook a nd n oti ced in a diag ram that aha lf -w a ve Z epp e lin ante nna (the orig inal J-p ole ) used link co up ling be twee nth e trans mitt er and the quart er -wavemat ching sec tion (which f eed s the halfwave ra diator) . Ah a Link co upling ... Iha ven 't see n th at tried . so here i t is Itai ves fuJI ba nd co vcra ee on : me ters.- -wit h VS WR less than l .Sc--vcry br oa d .

- I ) ' f irst att em p t at const ruct ion u sedordi nary hoo ku p wire for the link andp las tic tape to ho ld it in p lace at theshort ed e nd of t he matc h ing sec tion . Itworked lin e but. rea lizing the diffi -c ult y of des cr ibi ng how to do it. I dec ide d to use a PC board to fre ez e thi s

Por : -mct er portable usc . I lik eth e id ea o f h aving a full- sizeroll-up ant enn a avail able fo r

si tuatio ns wh ere c o mmunication n ece ssi ty outweighs th e com p act convenience

of the usua l ru bber- fl ex ante nna. So metim e s . we nee d to ge t o ut be tte rR oll it up a nd a n ante nna like thi s willfi t pe rfectly in your Y: K e merge ncyprep a redn ess kit

T he portab le . flexible J-pol e is not ane w idea : l ve see n se ve ra l ov er th epast d ecad e or so and tri ed most ofth em u t w ith mi xed results . Th cvdid r adiate a fter a fashion . b ut VSWRwas mu ch high er tha n e xpected. and

band cove rage was narro w o r th e c oaxtap poi nt for a d ec e nt match wa s ve ryp icky and d iffi cul t to mov e. Wh i lemo der at e VS \VR can he t oler at ed hy

Photo A . Y2K portable l pote alllell/lacoile d li p a nd ready T go. Fig . J Portabl e l pole a l l elll G fo r 2 meters16 73 mateur R a d io Tod ay Sep tember 1999

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TV DOwn ConvertersO ~(I t w ~ -lid rM i t )UooeI ATV_3 (420 -450)(Ga AS - FET) $.49 l5'$69 95

Model ATV

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YA E S U

T5-S70D GFull Featured HF Base

5 Model Inc l ude s 6 meters

TH-D7AFM Du al Ban de r AP RS a nd9600 Baud m e B uitt-in

Cont inued on JX,lge 36

so mewhat-c-es pc cia lly th e di stancefrom the coupler to the ga p--so youm ay have to experiment .

yo u re tempted to pu sh th is antenna into a p iec e of PV C tubin g withen d ca p f or u se as a fixed station antenna, it will work u t not with thedi m en sion s given. Fo r use inside a 1in c h-i.d. PV C tube with a wall thickness o f 1/8 inc h, you can make theco upler - to-gap di stance -7/8 in chesan d shorte n the radiator to 34-3/4inch es . Ad just the l ink tuning capacito r for bes t SWR wi th as m uc h of theantenna as possible inserted in thetube . an d then push in the re st.

T he antenna ca n be supported withinthe tube by dri ll ing the wal l appruximate ly 18 inche s do w n from the topa nd in se rting an i nsulative pin orsma ll -d iame te r rod through on e of th e

ai r secti o ns of the ladde rline. Se a l theholes to keep the rain out. Keep inm ind thai th is antenna w as de signedfor typ ical handhe ld transceiver powerle v el s . Though it sho w ed no evidenc eo f R F h ea ti ng in th e trimm er ca p acitor with a watt tran sce iver. I doubtif it w ould handle a wh ol e lot m or eth an th at. If yo ur power needs areg reater than the to walt level, I su gg es tyo u s ubs tit ute a mi ca compre ss ion

trimmer like the A R e a 401 i f you c anfind o ne .

Photo B A ntenna de tail

VX-5R5 11441430 MHzHeavy Du ty FAfHa ndh e ld

FTl

HFI6Id12W430MHzSUptN Compact

Transceiver

te-748100 Wa tt HFI6 M12AfTra nsceive r

O

Ameritron AD Bencher Butternut AfFJC us hc ra ft D ia mo nd MAHA AstronK an tr on jc s L ar se n M ir ag e L ak ev ie w

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te-2800H = =

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located 2 miles south llie PATurnpike t oil 2 on R12nM,T,F U W,TH 9-8 Sa/9 3

measure 12-7 /8 inche s back to ward thesam e end. cu t the l ine . a nd r em ov e 1/4inch of insulati on from each w ire .Co n nect thi s en d of th e l ine t o the largepads at the open e nd o f the o uter U onthe co u p le r PC board . Th e d istance between the se pad conne ctions and thebeg inning of the g ap should be 12 5 /8inches .

From the other side of th e ga p, m ea

sure out 37-5 /8 in ches and cu t theladder line a t tha t point. Remove 1/2inch of ins ul a tion fro m each s ide of theline an d bend the wires at ri gh t anglesso that they touch ea ch other . So lde rthem togethe r. Th i s make s t he rad iatorj us t over 37 inche s long , an d co nnecting the two wires fattens it con side rably for broad band performance . Forsuspending thi s antenna verti cally , attach string . shoe lace . o r small ro pe o f a

length that will s ui t yo ur n ee d s.With th e antenna han g ing i n a clear

area. adju st th e lin k t uning ca pac ito rfor m inimum VSWR whi le tran smitting in th e m iddle o f th e band . Reflected po we r sh ou ld go d ow n to ze r oor nearly so , and V SW R at th e b andedges sho uld n ot ri s e mu ch be yon d1.3 to 1 at lea s t th at wa s th e case inse veral uni ts bu il t and te sted he re .

Other types of parall el cond uctor

transmissi on line . ev en 1V twinl ea d ,sho uld w or k with th is co upler PCboard, but difference s in pro pagation velocity will likel y c han ge the dimensi on s

18 73 Amate ur Rad io Toda Sept ember 1999

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Defogging MicrostripsAll intro to nticrost ripline f ilters

Ji m Kocsis WA9P Y53180 Flicker Lan e

So u th Bend IN 4663 7

This artic le describes mic rosti pli ne filters. The y per form thesa me fu nction s as LC c ircui ts

but do n , loo k a nything like ty picalines . r II show yo u h ow to de sign a ndma ke yo ur own . I retrac ed m y s teps as

was trying to d e ve lop o ne . s o youw ould n t was te lim e and m ake theame mi s takes I did . Let s try to re

mo ve s ome o f the fo g su rrounding t hiso pic .

I nee ded an input fi lter fo r a mi crowave downc on vert er tha t I b uilt. Itran s la tes microwave frequ encie s to

VHF. With out a fi lter at th e R F inp ut.he s ign al wa s no isy be cau se the c on

vcrte r com bi ne d both the desir ed signal a nd th e ima ge noi se in the outp ut Ihad see n mi cro stripli nc filt ers in cornmercia equ ipm ent. but ha d no ideahow to d es ign th em o r how theywo rked. Th e filt er I d esi gned pro vides

oise free s ign als. wh erea s before th eigna l wa s co vered w ith so m uch no isehat it was usel ess .

Th e se fi lter s can be u sed i n eq uipmen t for the +t o. 90 . a nd 12 96 ~

am ban d s a nd t he 1691 \ IHz wea therat e llit e band (my a pplicatio n) . Th ey

rc use f ul a t h igher frequ en cies if testq uipme nt i s a va i la ble tha t can goi gh er .

T heo ry

Micro stripline fi lter s can co ns is t o fseve ra l gro unde d 1 /4 -wavel eng th - long

ectio ns of pri nted ci rcuit t rack on

do uble- s id ed PC boa rd. Se e Ph ot os A

a nd T he e nergy in o ne el ement i sc oupled into the next c leme nt d ue tothe ir cl o se proximi ty. T hey re sonat e at

Pl wt o A F romle ft filt er s I 2 an d 3

on e freq uen cy . j ust like a 1/4 - wa e antcnnu . T he lo ss throu gh the fi lt er is determ ined by the spaci ng between theeleme nts and th e n umber of e leme nt s.Th e ba ndwidt h decre ases (get s sharperor nar r ower ) as the spaci ng be tweencle me nts is in cr ea sed . a nd th e lo ss

Co nt inu e d on p ag e

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Photo fl . From /elf. filters I 6 f itter 5 afte r trim] and 7.

b oard insul ating ma terial a ffec t s th e velocity fa ct or becaus e it has a diele ctricc ons tan t d iffe re n t fro m tha t o f air. T hi sma k e s the line s s horte r tha n th eyw ou ld h e i f th e d iele ct r ic w as ai r .

In this art icle. I ll di sc uss t wo confi guration s of micro s tr ipliue filte rs:comb an d in tcrdi gital. In a comb c on

fi g uration . all t he lin es a rc g ro un de d atthe same e nd. In an imerdig iral c o nfigurati o n. th e g ro u nded e nd s al t e rna te . I ob t a ined g re at e r loss w ith ac o mb confi gura tion . T he g rap h s di sc ussed la ter will dem onstra te th ish igh er lo ss.

Development an d design

T he fir st thin g I a lways d o w he ns tarti ng a n ew co ncept is to go o ver al lm yoId Issu es o f 73 Mag a ine, HamRa dio QST an d th e AURL Handbooks.

I a lso ge t RF Design at wo rk a nd k e epa fi le o f articl es tha t I think I m ig h tne ed 111 th e futur e . A fter spe nd i ngma n y ho urs se arching for in fo rma t iono n niicrostriplinc fi lter s. I found o neb rief a rt icl e In /-/ //1/ Radio Ref. I) ,o ne pa g e in the A RRL U HF an d Micro-

Th ere is a th ird typ e of c o n fig urat io nthat I d id no t try. It u se s 1/4-wave l in esg roun de d a t th e input/ output an d 112wav e floating l ines fo r th e im c rm cdiat e lines . Se c Fig. I . I d on t kn owwh et h er thi s typ e ha s ot he r desi rablec h a racter istics. Se e R ef. 3 for furth e rd ct aiIs .

Th e actual li nes s ho u ld he 50 o h msimp edan ce . because that pr o vides ag ood ma t c h to ot h e r de v ices the LN A .m ixe r, ctc. . Th e input a nd o ut pu t tracksho uld al so be 50 o h ms im p edan ce .Fo r O.06 2-in cb g lass e p ox y hoa r d , a 50o h m lin e is u. f On -inc h w ide. Th e 50o h ms is det ermined h y th e lin e w id tha nd th e type an d thickn es s o f s ubs t ra te .A g ood articl e on d etermin ing th e impe d an ce o f va rio us t hi ck n esse s. s ubs tra t es , an d l in e wi dths wa s refer en ced

b y ma n y ot he r a rt icles . Se e Ref . I . T oob tain the d esi red 50 o hm im p ed ance,the in pu t a nd o u tp ut ta ps s hou ld h eabo ut 1/3 o f th e w ay up fr om theg round e nd.

.,

Defogging Mi crostripsco ntinuedIrom pane

In cr ea se s as t he spa c ing is increased. Co mp a re Fi gs. 3 a nd 4. )

T he a mo u nt o f loss yo u c an to lerat ea nd th e ban dwidth yo u requi re d e te rm ines the s pac ing. Y o u c an ad d I11 m ccl ements an d ge t a sha rp e r filter c urve s teeper sides o n the filt er res po nse:co mpare F igs. 3 and 5 1. hut mor e boardspace is re quire d . yo u w arn lo ts o frejec tion fa r fro m the pas sband an d awi de pass han d . you m ay have to s tagge r tun c th e cleme nts. ma ki n g e ac he lement reso nate at a s ligh tly differentfreq uen c y. T he re is no o ne til l e r c onfigura tion numbe r of cle ments and spacing)th at i s cor r ec t for eve ry a ppli ca tion.

S ince th e 1/4 -\ av e lines wc H ca ll

th em lin es i nstead of PC track s ) a rec on struct ed above a g ro u nd p la ne . th e

.

.

j1:25

.

. -Fig . I . Typical PC board rtwori: or jloaril/g I .?-Il (/\'c design.

20 73 Amateur Radio Today. Septembe r 1999

4Fi/:. 2. F requency response curve o itter I. 3- pole . . / )O spacing ccnuh ClJlljiglln/fiol1.

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an d Microw ave Ex per imen te rs H andboo k listed a n exam ple of a fil ter bu td idn t pro vide much de sig n info nn ation . The be sr gu idelin es I was able coo htain cam e fro m Chuck H ougbton.He sk etc hed o ut some no tes in answerto que st ions I po sed and s aid I wo uldhave to e xperiment w ith the design .The handwritin g was o n th e wa ll Itwas time to s top re adi ng and startmak ing som e filters

W here I wo rk . we u se DOX (Desig no f Experime nt) and Tag uchi m eth odswh erein wc vary o ne (or mo re)pa rameter (s at a ti me to see t he e ffectsof ea ch change on a given d esi gn . Using these tech nique s to de velop th e requ ired fil ter. I would have to vary the

..

-

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Fig. 6. Freq uency response ( I I I 1 e o itt r 5. i-pote. ./ ) ) spacin g, interdigital cOl/figuratiol1.

180 0150. .5 50 ..

T he o nly c hange t o be made a t thi spo in t was to c hange Fi g. 7 so that the cleme nts we re mo r e fully e ngaged withthe c orr ec t len gth . T he fi nished fi lterperf orm ance is shoe vn in 8. Whil ethe fi nal d esign d oc s ha ve m ore losstha n I th ou a ht m v rccc i vcr c ould tol er -o a te. i t a ctually wo rk e d fin e as-is fo r m ya pplication. La ter I ll di scuss how tored uce th e loss o f the filter . I f y o u mu s tc ha nge the len gth o f a filt er cl em en t as igni fic ant am ount to ge t i t exac tly on

frequen cy . d o n t forget 10 m o ve th e inpu t an d o ut pu t l ines to 1/3 th e d ist ancefro m t he gr o u nd e nd. T his w ill r e tai nth e 50 o h m i nput / output imp edan ces.

Fi Iter line le ng t hs f or the fr equ enciesI test ed a rc a s follow s : 45 0 M Hz3.625 in ch es : 1400 M Hz - I .OO inch ;an d 169 1 M Hz O.XS inch es.

Mak ing th e filte r s

To co m pose th e f ilter art work I usedth e Pa intbrush s o ft w a re tha t c omesw it h Windo ws 3 . 1, W in95. an d Wi nN T. You w ill h av e to t urn o n th e coor-din at es (X . Y ) to pr o vide in f ormati ono n the p osi tion a mi d im en s ion s o f th efilt er c lemen ts. U se z oom so y o u ca nsee e ac h g r id sq ua re. You should a lsoha ve th e g ri dlincs turn e d o n. T his softw are w ill g ive yo u O.O I- inch r esolution. w h ich is ade q u ate f or th is ty pe offilt er w ork an d mo st o the r PC a rtw or k

yo u ma y need.Se lec t bl ack fo r t he co lo r. then beginclickin e alon e the o utline o f t he trac k0yo u need. Ar t er this usc fill ( the ic on

660 1460

,

..

1350

I

.

.

.

. .

.ee

.es

giv en spa cing a nd n um b er of cl em en ts .In Fi g . .j. the line s we re pl ac ed farthera p a rt. N o te t h at the los s at th e pa ss f req uency is ve ry h igh - 17 dB ). In F ig. 5the numb er of e leme nts was incre ase dfrom 3 to 5 . Thi s c hange pr o vid eds tee pe r si des. indica ti ng mo r e a ttenuatio n o f und e s i red fr eq u en cies .

F ig. 6 show s a filt er that ha s th ep ro p er s pac ing . It s a n im erdig hal co nfigurat ion and w as purpo se ly ma de toolong so that it could he trimm ed to reso

nate at the d esir ed freq ue ncy 1 691M Hz) . Aft er trimmi ng , not ice i n PhotoBfb) that th e cle me nts ar e no lo ng erfu lly e nga ge d . Th is sh ow ed up as mo rea tte n uatio n than I t hought sho uld b epr es en t (- 10 dl i }, a lt houg h th e c u rveh ad t he cor re ct shape.

M ,. ..

.as

25

Photo C. Ot OI I I I n l (d S MA COlll1ectors.

spa cing. try b oth im c rdigital a nd c om bco nfig ur at io ns. and va r y the n umber o fc le me nts un til I obt ain ed the d esi re db andwidt h a nd loss.

I beg un by b uildin g a filt er tha t Icould e as i ly t est and a na lyze w it h o urcom me rcial ge nerato r. Bo th th e freq uen cy and leve l ca n be se t ac curately.T he fi rs t fil te r I b uilt re sonat ed ata round 4 50 :\1H z. we ll wi thin therange o f bot h the s pectrum a nalyzera nd the co m merci al s ig na l g en er a to r. Ip lott ed th e dat a s howi ng th e pcrforman cc of e ach fil ter a fter it was built . Imad e m o re filters tha t h ad d ifferen tsp acin g. a di ffer ent c on fig urat ion . an da diff e re n t number o f cle me nts. P lo ts

o f fil ter pe r fo rma nce vs. fil ter ty pe ar es ho w n in Figs. 2 throu g h 8. See a lsoPhotos A, R, and C.

Flgs. 2 an d 3 s how th e dif feren ce h et \vcc n co m o a nd int cr d igital c on fi gur ali on s. Co mh fi lter s ha ve ab out 3 dBmo re los s than in tcrdi gu al ti ller s fo r a

F iR 5. Freouencv response ( I I / W o fittcr i. 5 po/e ux spacing interdigital coefiguratton.22 73 Amateur Radio Today Sep te mber 1999

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After prin ting the tr a ck onto the speci al medi a. use a co mm on cl oth ingiron t o tran sfer it to doubl e- sidedco pperclad board . I ve used both litepaper-based an d th e blue plasti c film

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Fig . H F Il. qllt IlCy response curve of fil ter 7. 5-/ e J x r spac ing interd igitul co nfiguration.

Summary and other ch ang es

As yo u ca n see . I bui lt a lo t of filte rs.By ke eping cha racte ristics th a t helpedpe rfo rm a nc e (O.10 0- inc h instea d of5116 spac ing, u sing an irucrdig ita l instead o f co m b config ur atio n) and discardi ng on e s tha t hurt pe r form anc e. I\vas ab le to ge t cl ose to the de si redhand wi d th and loss.

Yo u will n eed access to a spe c trumana lyzer a nd a y at a mi nim um . yo u d on ' t o wn an anal yz er . perh ap s abro adca st e ng ine e r a t a loc al TV /F Ms ta tion (h o pe f ully a ham ) ca n let youusc t he irs . Th e v o is ad eq u at e forth e hom e ex perimenter . Of co urse. ag en er a tor is e asi er to use .

Th ese filte rs a re not mad e for tran s

mitt ing appli cat ion s . I don ' t kn ow howm uch po wer th ey c an ha nd le. since m yapplic ation was fo r rece iv ing . I didn ' tha v e a ny eq ui p m ent to mea sure SW R ,

ma d e using Exc el softw are and data Irecor ded ma nua lly.

Th e HI' gen e ra to r I used on l y go e sup to I I00 ~ 1 z I nee ded a II Iter th a top e rat es a t 169 1 : vlH z, an d I need ed totest it we ll above 1691 Ml'lz . To te stab o ve M l l z, I use d a POS -2000v o fro m ~ i ni i r e ui ts (Ref . 6 ) . T he

v o costs $20 (pl us handlin g/ shippin g )and covers 1300 M Hz to 2lXXl ~ t lwith about 15 milliwatt s out p ut po w er .T he y ma k e ver y good . ru gg ed v o s.T hey arc a ll 50 ohm o utp ut impedan ceand co ve r freq uen cie s fro m 10 M H / . to2 ) x) MH z. O btain the data s hee t thatco vers the unit yo u usc . T he y are tun edo ve r th e ran ge w it h a pot as sh o wn inFi g . 10.

You ll also need to design a simp le c irc uit hoard for this g enerator; Th ev o 's pin s arc a ll o n 0 . 100 c en ters. sothe layout is very s imp le. I rec ommendgelli ng a co py of th e ir R / I DesignersHa ndbook a nd VCO De signers Ha ndbook. Sec Ref. 6. Th ey have ex tensivea nd very usefu l theory a nd practi ca l desig n and c onstruc tion information onvariou s type s of micro wave componen ts.

I used SMA- ty pe co n ne c to r s toco uple s igna ls in a nd o ut of the fi lters .I bo ught u se d o nes at a ha m fes t for S I

each. N ew on es cost S Io. T hey mo unton the edg e of the bo ar d as shown inPh otos e a nd D .

B OO750100650

Testing th e filt ers

.1550 .

inc

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1- - -

1300 1350

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type s. and p re f er the latter, I useS cu l ; h 13 ~ Super 13+ e lect rical tapeas a resis t for the gro und p lane. Hand lethe hoa rd very carefully when attaching the tape . Th e track re sist on the fille r s ide ca ll co me off if yo u sc ra tc h ittoo ha rd . r used c tcham f rom RadioShack that I heate d w ith a 100 ....ut tspo tligh t held abo ut l inches abo ve asma ll pl a stic tray. Plea se d O l/ po ur th eused c tcha m down the d ra in It wi ll eat

meta l (it a le the c op per from you r hoa rd.rig ht ). so m ust he di..card ed p roperly a ta hazar dou s mater ia l han dli ng s tat ion .

To ground the on e e nd of eac h filte r elcmcru. I drilled a small ho le (O.04 4 inchdi amete r ). pushed a small wire through .he m the wi re o ve r on both s ides. and so ldered it on bot h sides. Ma ke sure tha tyo u arc drilling all ho les the sa me distance from the ungrou nded e nd. or e lsethe line s wi ll he a diff e rent ph ysical andelectricallengt h. thus s poil in g the s ha pemd perf orm ance o f the filt e r,

I don t kn o w ho w cl o se the e nd o fea c h e le me nt can get to the edg e o f thehoa rd be fore filt er performan ce sta rtsto suffe r I use d a minimum 1/2 in chspa cing a ll a ro u nd t he ho ard .

C o nne ct yo ur s ig na l gene ra tor to thespe c tru m a na lyz er and adj us t the le ve lof the gene rator (i f you rs is adj us table)unt il the disp lay rea d s nea r ly fu ll sca leso y o u ca n u se the fu ll ra n ge of theana lyze r. T hen in se rt t he fi lter to heteste d in lin e be tw een the a na lyz e r a ndge ne rato r. Vary the freq ue ncy fro m thelowes t to the hig hest frequ en c y o f interest. Th e lowe st s hou ld he well h e1 \ v the i mag e frequen cy o f yo urcon verte r if yo u are buildin g a low sid cinj ec tion co nver ter .

T he range ov e r whic h yo u tes t thefi lter sho uld includ e a ll freque nciesyou want to rej ec t and pass. In mycase . I wan ted to pa ss 169 1 ~ 1 l an dreject 141 6 M H z, since 141 6 M H z isthe i mage o f 169 1 M H z. Th e imagefreque nc y is tw o ti me s the IF low er th anthe frequen cy yo u want to rece ive . [M y

IF ;s 137.5 169 1 - (2 x 137.5) =14 16 .] Plo t the freq uency vs. Jev e l o utpu t e ve ry 25 ~ z (m or e o r less. depend ing up o n wha t kind of resolut ionyou need on your filt er 's perf ormance) .

No te tha t th e lev e l wi tho ut the fi lterin lin e is the start ing le vel . All t he d atapoint s w ith th e fi lter in line a rc bel owthe s ta rt ing lev e l (negative d B ). Th efi lte r ide ally wo uld ha ve no los s dB )a t the c enter freque nc y and lo ts o f lo ss

-40 dB or m ore) aw ay from th e ce nterfreq ue ncy. Pl ot the da t a poi nts youto o k us ing ax i s scale s as s ho w n in

Fig . 9. Pri me r scaling t est patter n. Figs. 2- 8 . Th e pl ot s shown he re v.-ere24 7 mate ur Rad Tod ay Septembe r 1999

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Ph oto o p view of SMA co nnec to r s

so I coul dn ' t de termine the inpu t a ndou tp ut im pe d a nces. Th e y ma y bes light ly d if ferent from 50 ohms and ma ybe reactive (c apacitive or inductive) .

Tu n ing cap aci t ors ca