History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1946 01

P.01 - Front Cover
The Australasian Radio World

Registered at the G.P.O., Sydney, for transmission by post as a periodical.

Price, 1/-

Vol. 10 - No. 8; Jan.-Feb., 1946

P.03 - Contents Banner
THE AUSTRALASIAN RADIO WORLD

Devoted entirely to Technical Radio

and incorporating

ALL-WAVE ALL-WORLD DX NEWS

VOL. 10 - JANUARY, 1946 - No. 8

P.03 - Publication Notes
PROPRIETOR — A. G. HULL

Manager - DUDLEY L. WALTER

Secretary - Miss E. M. VINCENT

Short-wave Editor — L. J. KEAST

For all Correspondence: City Office — 243 Elizabeth St., Sydney, Phone: MA2325

Office Hours — Weekdays: 10 a.m.-5 p.m. Saturdays: 10 a.m.-12 noon

Victorian Advertising Representative — W. J. LEWIS, 20 Queen St., Melbourne, C1, 'Phone MU5154

Subscription Rates: 6 issues - 5/3; 12 issues - 10/6; 24 issues - £1; Post free to any address.

Service Departments — Back Numbers, 1 /- ea. post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," Elizabeth St., Sydney (Footnote P.36)

P.03 - Contents
CONSTRUCTIONAL —

The Champion Amplifier. . . . 5

Simple Service Oscillator. . . . 7

Home Made Filter Chokes. . . . 17

TECHNICAL —

Cathode Follower Tests. . . . 13

Trends in Set Design. . . . 21

U.S. Radio Newsletter. . . . 22

Principles of Radar. . . . 23

Duplex Speakers for Fidelity. . . . 25

Ham Notes — Calling CQ. . . . 27

SHORTWAVE REVIEW —

Notes From My Diary. . . . 30

New Stations. . . . 33

THE SERVICE PAGES —

Answers. . . . 34

P.03 - Editorial
EDITORIAL

I laughed at a comic drawing in the local paper recently. In the first picture a man was struggling on to the step of an overcrowded bus, m uttering to himself, "There’s lots of room if the people on board would just move up a bit." In the second picture the bus has reached the next stop and this time our hero is muttering, "Surely these silly fools don’t think they can get on this bus; they ought to be able to see that it is overcrowded already." The radio trade is like that, too. You find that many people with a handy knowledge of the radio game change over from amateur to professional status, set themselves up in business and, when firmly established, they take on a high and mighty air of superiority and mutter, "The Government ought to stop people starting up in the radio business unless they are fully qualified." Few people in the radio trade are able to boast that they can pass examinations in every phase of radio theory, but this does not mean that they need be unable to give the public service or make profits. On the contrary, they may be endowed with more commonsense, business acumen and general knowledge than those who have spent the best years of their lives in the cloistered halls of a University. A reasonable amount of healthy competition is likely to be a far better safeguard to the public than any government regulations or examinations. A. G. HULL.

P.27 - Technical - Ham Notes — Calling CQ
HAM NOTES

CALLING CQ!

By Don Knock

P re ss new s fro m G -lan d sa y s th a t it w as d ecid ed, on 2 7 th N o v em b er to re la x D efen ce R e g u la tio n s to allow B ritish su b je cts in E n g la n d to p u rc h ase a n d hold ra d io tr a n s m ittin g eq u ip m en t, an d th a t th e b an on a m a te u r tran sm issio n w ould be lifte d sh o rtly. So by th e tim e these w ords reach “A .R .W .’s” p ress, th e G ’s m ay be on again. A s an y b o d y m ay h e a r fo r th e m ­ selves, U .S.A ., C an ad a, S o u th A m e ric an s a n d o th e rs are in full o ccu p an cy o f 28-29.7 M c/s. 4th D ecem ber, 194S.— M ost m o rn ­ in g s ju s t now th e “ 10-m etre b a n d ” is alive w ith W ’s an d m ixed up w ith th ese a re a few of th e W /J boys, A m erican s in th e arm ies of o ccu p atio n. F ra n k ly, I d o n ’t blam e th ese H a m s fo r seek in g such “ occ u p a tio n a l th e ra p y ,” alth o u g h th e m ode o f o p e ra tio n is defin itely p irac y. I am in trig u e d to n o te th a t q u ite a b it of cro ss-b an d w o rk in g is go in g on betw een W ’s (in U .S.A . on te n ) a n d W ’s (in th e Ja p a n e se a re a on 2 0 ). N o d o u b t all w ill go m e rrily u n til F.C .C. ta k e s a hand. T h e ed ict by W T A, w a rn in g “ th e g a n g ” off 14 M c /s, has n o t ta k e n co m p lete effect, fo r one o r tw o ir ­ rep ressib les a re still to be h e a rd on p h o n e a n d C .W ., w edged in betw een th e irr ita tin g din fro m tele p le x sta ­ tio n s. B o th 14 an d 7 M c /s a re im ­ possible to recognise as p re -w a r a m a te u r ch annels— fo r stra n g e rs are th e re galore. N e w R e g u la tio n s G a z e tte d O n th e 28th N o v em b er, 1945, th e new A u s tra lia n a m a te u r (e x p erim e n ta l) ra d io re g u la tio n s w ere g a z e tte d on th e lines a lre a d y re ­ fe rre d to in th is section of “A .R .W. ” T h ere w ill be few obje c to rs to th e p o w e r ra tin g s of 50 a n d 100 w a tts fo r th e tw o g rad es of licences, b u t th e ra isin g of th e m in im u m age to 18 y e a rs fro m th e p rev io u s fix tu re o f 16 y e a rs is likely to be th e su b je c t o f m uch a rg u ­

m ent. T h ere are p o in ts fo r, b u t m ore a g a in st th e new lim it, a n d it seem s o if-h an d to im ply th a t a y o u n g ste r w ith b ra in s eno u g h to sit fo r a n d p ass th e A .O .C .P. is n e v e rth eless irresp o n sib le to a d eg ree th a t he c a n n o t o p e rate ex p erim e n tal g e a r u n til he tu rn s 18. H e m ay p ass his exam s b rillia n tly p e rh a p s; and th e n is e x p ected to k ick his heels u n til tw o y ears am ble by. In th a t tw o y e a rs he m ay tu r n to o th er fields a n d a p o te n tia lly good m an m ay be lo st to ra d io ’s fu tu re, or, as is m o re likely, he m ay be im pelled to b re a k th e law a n d to o p e rate eq u ip m e n t illicitly. B o th p o ssibilitie s a re d ista s te fu l an d n o t calcu ­ la te d to en co u rag e th e class of s tu ­ dious y o u th th is c o u n try needs fo r h e r f u tu re m anhood. K een y o u th — a m a te u r ra d io — a n d w o rld p eace— can be synonym ous.

T h e N ew F re q u e n c ie s A s th is is w ritte n (D ec. 2nd, 1945), w o rd is o u t a b o u t th e fre ­ q u en cy ch an n els to be a llo tte d to A u s tra lia n a m a teu rs. T h ey a re :—

28-29 50-54 166-170 1345-1525 M c/s. T h ere w ill be sa tis fa c tio n a t least th a t so m e c h an n els a re m ad e av ailable by th o se who h old a u th o rity , b u t also a m easu re o f p e rp le x ity as to th e choice of tw o o f th em. It w as e x p ected in th e first p lace th a t, fo llo w in g decisions by U .S.A .’s F.C .C ., th e p re -w a r 10-m etre band w ould be slig h tly d e h y d ra te d — a t th e H .F. end— 28-29 M c /s as ag ain st th e W ’s 29— 29.7 M c/s, is p e rh ap s no serio u s bone o f co n ten tio n. N ev erth eless, it is a d efinite lo ss to th e A u s tra lia n a m a te u r. T h e new “fiv e-m etre” b a n d fro m 50-54 M c /s c o n fo rm s to A m erican decisions, an d, a lth o u g h it is n o t h arm o n ically re la te d to 28-29 M c /s, it is a b an d w hich m ay pro v e to be v ery u sefu l indeed. T h ere is a p o ssib ility o f in ­ fre q u e n t D X here. N o b o d y sh o u ld g e t th e id ea th a t m o d u la ted oscilla to rs a n d “ sq u eg g er” receiv ers will be a p p ro p ria te. T h is b a n d calls fo r (Continued on next page)

One of the neatest Ham stations we have seen is th is — pre-war G8LP, operated by Geoff Hanley, of Wolverhampton, England. Power was 50 watts and his 20 m. phone reached Australia in fine style. G8LP survived the war and will be looking for VK's again soon.

fu ll C.C. a n d su p erh et. C.W. te c h ­ niq u e as did 56-60 M c /s— th e p r e ­ w a r ban d. U nless sta b le Y F O w ith m u ltip lic atio n is used, c ry stals o u tside th e u su a l ru n o f th in g s w ill be n eeded, fro m 6 to 6.6 M c/s. T he b a n d 166 to 170 M c /s is a puzzle re g a rd in g choice o f allo catio n, fo r th e A m erican a rra n g e m e n t gives th e a m a te u r 140 to 145 M c /s in lieu o f th e p re -w a r “ 2 J-m e tre b a n d .” 166-170 is in clu d ed in a g o v ern ­ m en tal block o f freq u en cies. T h ere m ay be a re aso n fo r th e A u s tra lia n choice, b u t c e rta in it is th a t th is new b a n d w ill com e in fo r p le n ty of use w ith local n etw o rk s.

T ech n iq u e calls fo r ap p lic atio n o f n o n -sta n d a rd valves b u t fo rtu n ­ a te ly “ a co rn s” a n d valves of the 800 a n d 815 ty p e s w ill be av ailable. A e rial d im ensions a re o f co m p actly u se fu l size— a m ere 33 inches, giving a h alf-w av e of 166 M c /s. T h e last b an d, 1345 to 1425 M c /s, w as p ro b ­ ab ly n o t in te n d e d as a jo k e o r an in su rm o u n ta b le o b stacle— b u t th e av erag e a m a te u r can fo rg e t it— u n ­ less he has liv ed w ith R a d a r th ro u g h th e w a r y e a r, a n d has acq u ired R a d a r tech n iq u e ( a n d g e a r). T he sto ry goes th a t 3.5 M c /s (80m ). m a y be re sto re d a b o u t M arch, 1946. A s fo r 7 an d 14 M c //s — th e re is no in d ic a tio n as to th e fu tu re. M ean ­ w hile, licences w ill be issu ed fo r o p e ra tio n on th e new ban d s, a n d we know th a t th re e of th em will com e in fo r p le n ty o f occupancy. ■—D .B .K

P.28 - Technical - New Amateur Regulations
In fo rm a tio n released to th e W ire ­ less In s titu te by th e S u p e rin te n d e n t, W ireless (P .M .G .’s D e p t.), N .S.W ., o u tlin es th e fo llo w in g sa lie n t p o in ts: (1) T h ere will be tw o classes of licences— “ A ” a n d “B ,” w ith th e la tte r e q u iv a len t to th e p re -w a r licence. (2) F ee fo r e ith e r is 2 0 /- p er y e a r a n d does n o t in clu d e re ce p tio n o f b ro a d c a st p ro g ram m es. A n o th e r licence is n eed ed fo r th e la tte r. (3) M inim um age is ra ise d from 16 to 18 y ears. (4 ) A ll p rev io u s licen ce-h o ld ers w ill be eligible fo r a C lass “ B ” licence— an ap p lic atio n fo rm is to be co m p leted — also a “ S ta tu to ry D e cla ratio n of S ecrecy” ! (3) T h e p re se n t A .O .C .P. becom es th e 2nd class g ra d e an d m orse code speed re q u ire m e n t goes fro m 12 to 14 w ords p e r m inute. (6 ) T he first-class A .O .C .P. calls fo r h ig h er know ledge of ra d io and e le ctrica l th e o ry an d m o rse code sp eed is 18 W .P.M. (7 ) A n y p erso n u n d e r 18 y ears o f age w ho has a lre a d y q u alified fo r 2nd class A .O .C .P. w ill be issued w ith th is— b u t w ill n o t b e lic e n s e d u n til r e a c h in g 18 y e a rs ! (8 ) A .O .C .P. exam s (fro m J a n u ­ a ry, 1946) w ill be held on th e sec

ond T u esd ay o f J a n u a ry, A p ril, J u ly a n d O cto b er, b u t it is likely, ow ing to sh o rtn ess of tim e in w hich to m ake a rra n g e m e n ts th a t th e first 1946 exam will be held on 5th F e b ­ ru a ry. E x am fees a re : F irst-c la ss, 1 0 /-; second-class, 7 /6. (9) P o w er ra tin g s: C lass “ B ” m axim um I N P U T to fin a l a n o n e is 5 0 w a tts. C lass “A ” m axim um o u tp u t to final an ode is 100 w atts. (10 T h ere is y e t n o d e c is io n a b o u t frequencies. (11) A ll new licencees m u st serve a p ro b a tio n a ry p e rio d o f 6 m onths, d u rin g w hich th ey are n o t p e rm itte d to use telep h o n y . (12) N o tran sm issio n o f reco rd ed m usic o r e n te rta in m e n t is p e rm itted . (13) H o ld e r o f a first o r secondclass co m m ercial or a ir c r a f t o p e ra ­ t o r ’s tic k e t is e n title d to th e exp e rim e n ta l tic k e t (w h a t g ra d e is no t s ta te d ) . (14) H o ld e r of a b ro a d c a st s ta ­ tio n o p e ra to r’s tic k e t is n o t ene n title d to th e A .O .C .P. w ith o u t ex am in atio n . (15) A n “ A d v iso ry C o m m ittee” w ill o p e ra te in all S ta te s in th e sam e m a n n e r as th e V ig ilan ce C om ­ m ittee fu n c tio n ed prev io u sly.

P.33 - Shortwave Review - New Stations
NEW STATIONS

m in u te s’ P ress R o u n d u p in E n g ­ lish. K C B A, S a n F ra n c is c o , 6.1 7 m c, 4 8 .6 2 m : T his is a new freq u en cy fo r th is o u tle t o f th e C olum bia B ro a d m a stin g S y stem an d carries th e U .S. G o v ern m en t I n te r ­ n a tio n a l In fo rm a tio n S erv ice to J a p a n, K o re a an d S o u th -e ast A sia fro m 7 p.m. till 1 a.m. I t is in p a ra lle l w ith K C B F (9.75m c), K N B A (7.8m c) a n d K R H O (6.12 m e) a n d fo r th e b en efits of th e b ro a d ca st-b an d chasers w ith K S A I, lOlOkc, fro m 7.30-11 p.m. — L .J.K. K G E I, S a n F ra n c is c o : P ro b a b ly b e ­ fo re th is ed itio n reach es read ers, K G E I in tran sm issio n to G uam an d th e P h ilip p in es fro m 7 p.m .- 1 a.m. w ill m ove fro m 9.55mc, 31.41m, to 9.53m c, 31.48m. T his w ill only be lO kc fro m V L W -7, P e rth, an d m ay cause in te rfe re n c e in som e p a r ts o f A u s tra lia , b u t th e m ove aw ay fro m S in g ap o re (9.55m c) w ould be w elcom e.— L .J.K. J I E - 3, T a ih o k u , 9.'395m c, 3 0 .9 4 m : T his s ta tio n in F o rm o sa, once a re g u la r, has been h e a rd again a f te r a lo n g spell. N o t su re of schedule b u t it can be h e a rd m ost n ig h ts if m orse p erm its. W L W S, C in c in n a ti, 15.13m c, 19.83 m : A rth u r C ushen re p o rts : “ W L W S, on 15,130kc, is a new freq u e n c y w ith ‘V oice o f A m erica’ b ro a d ca sts. H e a rd till 6 a.m. T h en signs re -o p en in g a t 6.13 at even b e tte r s tre n g th .” H C IV T, A m b a to , E c u a d o r, 7.00m c, 4 2 .8 6 m : T h is one is re p o rte d by M r. R o g e r L egge, J r ., a n d d o u b tless A rth u r C ushen o r D r. G aden w ill la n d it b e fo re long. I t closes a t 1 p.m. H C 5 E H, C u e n c a , E c u a d o r, 3.9 4 m c, 7 5 .8 8 m : H e re is a n o th e r being h e a rd re g u la rly by M r. L egge, b u t w ill be a “ to u g h y ” in th is co u n ­ try, I th in k. A nyhow, it is on till 2 p.m. a n d som etim es la te r. R a d io B IS S A U, B is sa u , P o rtu g u e s e G u in e a , 7 .0 9 5 m c, 4 2 .2 8 m : H e re is a good catch b y R oger. L egge and th is W est C oast A fric a n should be au d ib le in A u stra lia. L an g u a g e used is P o rtu g u e se a n d schedule is 8-8.30 a.m. T his is ju s t a little la te p e rh a p s fo r th a t c o u n try and th a t freq u en cy, b u t th e tim e sh o u ld su it A rth u r C ushen. R A D IO M A C E IO, A la g o a s , B ra z il, 9 .3 0 m c, 3 2 .2 5 m : R o g e r L egge, J r., also re p o rts th is one. H e a rd in P o rtu g u e se fro m 9-10 a.m. Y N E T, M a sa y a , 7 .1 0 2 m c, 4 2 .2 4 m : T his N ic a ra g u a n sta tio n w ith slogan, “ R ad io M asay a, E m isso ra del P u eb lo ,” acco rd in g to R o g er L egge, o p e ra te s fro m 10.30 a.m. till 1 p.m. Y N B H, M a n a g u a , 7 .0 1 m c, 4 2 .8 0 m : A n o th e r in N ic a ra g u a re p o rte d by R o g e r Legge. “ R ad io P a n - am e ric a ” is h e a rd till 1 p.m. R A D IO M A C A S S A R, M a c a ss a r, 9 .3 7 m c, 3 2 .0 2 m : T his chief to w n a n d p o rt o f Celebes, N e th erlan d s In d ies, is h e ard n ig h tly fro m 7.30. S ig n al stre n g th is f a ir b u t m o d u ­ la tio n is p oor. T he a n n o u n ce r sta te s th e b ro a d c a st is to A u str a lia a n d th a t re p o rts w ould be w elcom ed. F ro m 9 p.m. n ativ e lan g u a g e is used. I am g ra te fu l to E rn Suffolk, o f L o b eth al, S o u th A u s tra lia, fo r first advice of th is sta tio n. I h ad h e a rd th e m several n ig h ts b u t could n o t catch call. M r. Suffolk him self say s it to o k an h o u r o f c o n c e n tra te d lis te n ­ in g to id e n tify it. R A D IO H A N O I, H a n o i, 1 2.135m c, 2 ^ .7 2 m : “ L a V oix de V e tn a n ,” H a n o i, In d o -C h in a, is re p o rte d by M r. L eo E d el as b ein g h eard ’n ig h tly a t fa ir stre n g th, b u t b ad ly d isto rte d. F re n c h a t 10 o’clock a n d new s in E n g lish a t 11. S logan, w av elen g th an d freq u en cy given a t 11, p re ce d in g th e new s. K N B X, S a n F ra n c is c o , 6.06m c, 4 9 .5 0 m : T his freq u e n c y used fo r som e tim e a little w hile ago by K N B I is now h e a rd n ig h tly fro m 8 o’clock as K N B X d ire c te d to th e P h ilip p in es a n d C hina. L a n ­ g u ag es used a re : E n g lish, T ag a - log, M an d a rin an d C antonese. Closes a t m id n ig h t a f te r a 10 R A D IO K U A L A L U M P U R, M a la y P e n in ., 6.0 9 m c, 4 9 .2 1 m : M r. Leo E d el is th e first to re p o rt th is one. H e a rd n ig h tly fro m aro u n d 8.30, b u t o ften sp o ilt by noise. “ T H E V O IC E O F F R E E I N D O ­ N E S I A ” ( L o c a tio n ? ), 15.22m c, 19 .7 1 m : A n o th e r re p o rte d by M r. E d el. H e a rd ev ery n ig h t fro m 9 till 11. V L C -1 0, S h e p p a rto n , 21.6 7 m c, 1 3 .8 4 m : E rn Suffolk re p o rts this new A u s tra lia n tr a n s m itte r as h e a rd on 24th D ecem b er in p a ra lle l w ith V L G -3 in p ro ­ g ram m e to B rita in. H e says sign als of V L C -10 w ere fa ir a t closin g a t 5.25 p.m ., b u t a t 5 o’clock th e y w ere inclin ed to be w eak and flu tte ry. D r. G ad en has since re ­ p o rte d th is one a t sam e tim e one a fte rn o o n.