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TASMANIAN DIVISION
JULY 1965. BOX , 95/J, G-, P. 0. ; HOEART
M 0 V T H L Y B U L 7. E T IN PRICE 6oL.
PHESDENT: Mr. T. Alien TRSA. PURER: Mr. V. P. Dore SECREIAIiY: Mr. K. Spiegel
VK7AL VK7JD VK7KS
Registered a-fc G-*P, 0, , IIoba.—b, foi-' traiismission 'by pos-b as a periodical.
EDITORIAL
An. Editorial is some-thing, to "the bes-fc of my knowledge, -the vKy Bulletin has
never boasted, beforeo
Perhaps -the main inspiration which promp-ted me -bo wri-be this was paj.-t of a
well-known and respec-fce. d Federal PresicLen-b' s Report 'in which he stated, " it is time
we'had a. good lo.ok a-t ourselves ",
I will has-fcily mention this remark could apply -bo all Divisions as well as our
own.. . . _...„..,., . .. ... _. __,.;
Firs-tly, only -two S1. at.es. have fulfilled their mission in reaching the
target, towards their'contri'bution -towards -blie I, T. U» Fund,. One can almost hear -the
re-bor-t ""'/KT'lias " - •'but have we ? Primarily due to ±he over generous suppor-b of the few,
otherwise .we v/oal.d .have .fallen far short o.f •bhe marko
Secondly, all Divisions are now confron-tea v/ith the Annual embarrassment
of pleading for subscripticns wi-th little resul-t 'bu-t lo-fcs of work^ especially in^
regards -to Secretarial duties- Thr-eais Cure made . tc cancell su'bscriptions of "^.AR "
etc», e±c° 18 this ihe "-nswer ? I d.o not thinlc so. Is it. because -the ^ ^» A°^in-..
general has s-fcrived for memlsership in numbers, rather -bhan -fcha-b of q.u.ality ?' Or is i-fc a
sign of the -times and another ex.^jnple of gooct old Australian complacency ?
There could. 'be hundreds cf ansv/ers, however, when we have lost our bands and
the willing horses have died.. of friistr'.ftion and exhaustion it will be -too la, 'te»
T again repeat -the theme, 1i Let us have n good look ai ourselves ."
Tec. VIC7EB»
MEETINGS FOR JULY
July 6 Nor-bli Vfe'stern Zone; Lafcin's Hall, Ulverstoneo 200Q hours.
7 He.ad. ctu. ar ter s General Meeting, 147 Liverpool S-t.., Ho-bar-t. 20-30 hou-rs.
9 Northern Zone.. Adul-fc Ediioa-tion. Cen-bre, 5"t York St., Launceston. 2000 hours.
14 Headq.u. ar'ters V. H F. Group. 2^00 hours,
12 Council .Mee-bingo 193^ hours.
TENDERS s
The following items sre sulsrai-bted for -tender,, The usual condit. ions apply,
•th highest or any -bend-er need nc-fc be accep-bable^
1 Only R» Fo Amp., No 2o Suit No. 22 or :To. 122 , Good appearance^
1 Only No, ^2 Transceiver and. vibrator unit - less phones or speaker, Appesirs in reasonable
conditiono
1 Only 122 Transceiver.. - less pwr» supply, phones and speaker . reasonable condi-fcion.
1 Only AT5 Transmi-t-ber^ Appears in excellen-t conditionc,
Please foreward you tender by ·Tu.ly Council mee-ting,
The mon'thly Bulle'tin of the Wireless Inst. i'tute of Australia
<Tul., -1 6 ^. • Tasmanian Division • ... Pa., e '2o- ,
SUBSCRIPTIOFS s
SuTiscriptions up to and inolu.ding'l8o ^, 65° Acknowledgemen-fcs and -thanks
-bo the .follovang; VKTI.iY^ VKTZ.'i.K:?, VKTKG; VKTCW? VKTGK^ VKTSK; •VK7, OL.§ VETTR; \rEC?ZAL$ "VK7JS;
YK7RK| ¥K?ZW5 ^TZRJ^ ^C7^'^TiVK7'ZAQ$^7BC§-VK7№;'VKTZCR? VKTL'R;, VETLR; VIC7EA; VK7A3;
VK:7LrI', --№:7L35 VK7ZAC? VICYCF;-VETZRF.; VK77,AG; -VKTFH; VETJF^ W.7DV°, '-W.T^°, ZL^O^ VKYSM;
VK7ZAP$..VK7ZGP§, VIC7DJ, VK7GB; VK^ZRG;'V[<:7:ZEC§ VKTJg'; VKT'PJ? %:7CK?, VK.7YL.
Ro Stran-z, D» Porthou.se ^'WoF.'Bowling; S. R« CoopQr^ Ho Jo Biscii"bt$ AoLc •Beatmion-b. FAaI.
Beilelph$ R. J. I'lutton^ RoF, Groom; K» Vi/heeldon^ So Bru. ndle; R. G« Shorthouse; L. Jacobsony
Do Johnstonej RoLo Harwood;•JoE<, Humblej O. L, Jacobsoii^ V/. R. Maxwell 5 G. D. Long^ IToCr Laoey^
13'th. Holiar-fc Scou-fc Group^ T. Bo Berwick^ R.. J. ' Everett; G« Howard; I. F. Ling^ ]i» Stu. tterdo
J.iU'ffiORSE OF THE 1'J-R :
. s' -•:... ;,. : , .
Last' Council meeting we were 'graced with the presenoe of VK7XX«
""Save is'also a keen supporteid of the Scouting moveraen-b and this year has the task of Tseing
the Scou-b Organiser for the Jaiaboree of -the -Air. o The Date is OG-hober l6tho and 1. 7tho . .
Last yo.^ •fcKgrie-Were 22 Radio ^yna'tours par-fcicipating in VE7 - -bhis year we could require •
more,, The same conditions apply •- if you have already been alloca-ted to a cer-fcp. in Sc&ut
Group all you have-, .to do is advise VK7ZZ or VIC7EB -bha-b you will be participa-ting and
make yoiir omn arrangome'n-fcs re site, req.uiremen-ts etco wi-fch the Saoutmn. ster concernedo
If--you-- are no-b- paj'ticipnting thi. s yeiw and h-ave in other yepx's or you woiild like -bo for'
-the first -time. jiis-b let lan or myself know - on the Broadcast-will do» There will be
a job for Associates too, they can help -the Scou-fcs as well as -themselves experience wise.
Let us make the Sthc, Jara'boree the best on record..
H;J'№EST s • ..
This. is fzno-feher nius-b la-fcer in the yenr. It has'tseen suggested -fcha-fc ITovember
27th. and 28.tli. . Would . ALL aecibers and ZOKES please cone foreward with ideas, suggestions
etc» This year- we pr'oposo-fco personally ask msmbers - so have ^-bhp.t idea ready or you
may be asked during the-round up. Ono can hardly 'blaKie the organisers for lack of ideas
if ons cant suiggesT; any. Ge-b your paper and. pencil ready Torn - who knows you could be
kept busy,
PTJBLI CATIONS :
The follov/ing R. S. G. B» publica-fcions are available for order, jus-b drop
Hono See., a line with the necessary and yoa will becoae -fche proud o'>vner of one or all
these fine publications,
Jifflateur Radio Cirou.i'lis...,..,.. ,. o 10/-
8. 8. Bo Eq. u. ipnen-to.... , o, 4/-
oo ... oo. .,
Goraciunica-fcioii Receiverso «. o».. o... 4/-
R«S. G. B. CrAl Sook,, ^ »»,„.„„„«.„.... 6^-
The last raentioned is not a World call book, however has -bhe . listing of ^11 U«K.
Ama-beu. rs sample copies off all the
-
above are being forewarded to the Zoneso
Th© Monthly Bulletin of the wireless In. st. i'tu-be of ^us-tralia.
Jul 1 6 o P&. J 3«
LECTURE ;
The lecture for the for-fchcoaing General Meeting at Headq.uar-bers on July Tth,
will bs deliverecL by lan Cairnduff of Fhillips Eleo-trical. I an sure lan will have a
keen audience as he proposes to talk on equipraen'b and. par-fcs produ. ced. 'by hi s firm. which
could be u-tilised for jiaa-beur Radio*
ROSS HULL I'.IEl.iORI^ V, II, F» CON'IESIL 1 . 64 - 1 6 RESULTS :
.
TROPS? WIENEK
W-3ZSS. R.. V/»' Wilkinson 5787 Poi-n-fcs
AV/^JU) vVINNERS
Section A - Transni'tt. in.g Open
W:2;iSZ R., L» Lear 2240 Points
W13QV B, Ho Ranlcin 108
VK4PU JoD. Pardon 1022 "
VK50L So M. Blytho 266 "
VK6LK G. Jo Kosina 1634
YtCSKK EoAo L'ic^ir'thur 43-12
Section B — Transnii'b'ting, Phone
VK1W E» Penikis 1386 Points
VK2ZFB A.Fo Birch 2220 "
7K3ZER RoW. Wilkinson 57-87 "
VK4ZLG GoH. Lloyd 3338 "
W-^ZSS. C»H. Hutchesscii 4245 "
VK6ZGff A. Lo Har-fcin 2434 "
•VE7ZAH K»J. Her^ricks 1626
VE8ZKD A. Lio Dann 180 "
ZLIMffl DoA. Johns-toa 330 "
ZL2APC H. Bur-bon 340 "
ZL3AA[J J. G. lAiller 950 "
Section. G - Receiving
Y/IA - L2211 RoGc. ATsemc-a-bhy 466 ' oints
WIA - L3138 G. No E?-rl 78
VttA - L5049 D» Doo.ean 1404 "
Full details will appear in July " ^ateur Rad. ie ", It is an-fcicipa-tQd -fchp.1; all
Certifioa-tes will have been Posted. -to those named. R,LOTG beforo the end of Juno.
TiO YOU ???????
1. Adjust your receivsr to maximum sensi-bivity and lis-ben before " belching for-th
on the frequency ?
2^ Turn. cnrrier' wi. thou-fc aodula-tion and proceed -bo pE-ao-bico GV/ with a hammer
on your
on the work bsnch. or worse sound liko Step-toe and Son ga-bh&rins their junk from
-the yard - tha-t is with the modulator on of course.
If the -cap fits wear i-fc - next time it might no-t T-ie in the Bulle-tin but on an official
memora.nduni^
Ths Hprtthly Bulle-fcin of the Mreless Ins-fcitu. -fce o.f-"lus-fcralia<>
July 1;-:6;- • Tasmanian Division . Pa.•e -»
TECm^ICAL
This morL-ths ar-ticls is not a'bou-t a foo-b'ball aatch 'but. something wor-bh seriou.s
considera'fcioh when designing "that nex-b power supply^ La '-bhere is more than enough for
one issue the article shall be serialised like a " who done i-b " so you may have to
wai-t for. next moths biilletin -fco see how you; aigh-b murder -that li-ttle diode - M ( Edo)
lUiLF WA'VE VS. l. 'ULL WATO BY - _R^_ L. .G-un1;her.
A half wave rectifier is a simple way "bo o'bt:?,in d»c>, bu.t it has some drawbacks*
Since load current is always passing-in "-the same direotion -bhrough the secondary winding
of the power t.ransformer, t. he core beGomes sa'burated .at a lower' cu.rren-bo This means -bha-b for
for a gj von load curren-t you need a Mgger -transformer', If you dont increase its size you v/il
will find -fcha-fc voltage regulp-tion will be poor for haavy loads, a.nd the -transformer
may ge-t 'hot,. The amazing fact is -bhat you can ob-tain about 50^ more power from. a
•tr an.gf oraer feeding a 'bridge than a half v/ave rectifier, The cen-tre - WSS& tapped full
wave corifigura-tion is only slightly more efficient than half wave, 'because ciirrent -fchroug'h
each yecon.d. ary half s'bill flows in only one direc'fcion, bu.t it does proviile twice the
ripple frequency and tv/ice 'b,he ou.tput cu.rrent for a given secondary wire»
For light loads it. will not raat'ter mu. ch what configuration. is used, and half wave
is a simple nethod for ge'fc-fcing d., c. from an u.ntapped vnnding; as long aa low carrent
is dravna, reasonable regu.la-bion and. ripple fao-fcor can be obtaine.d. without using -boo g
gigantic a filter condenser. Excellent regula. tion ancL/or ripple reduG-tion can be ob-bained-
by using an addition.a.L transis'boi- regulp.ting staffs of the conven-bion.al emi-tier - foil -
ower design-
Half wave rectifier circuits ou-ght, however, to afford a somewhat greater
safety factor for PIV rating of ^asseous v?lves or silicon diodes ( germanium orsilen -
iura not. as cri-bical )? thp.n would be "the cp. aQ for any full wave circui-t. The reason.
is rather in-fceres'bingo In a full vrave oi. -cGu. it, eit.her -fche whole secondary or- half of
i-t ( depending on circui-b used ) is loaded on eaoh G.ycle9 and this -tends to damp the'
raor-e severe transient overvol-tages that cp.n arise from several causes» In a-half wave
circiii-c; howsvor, the second&yy is altoge'blier- u.nloaded on'half of the cycle, and since
i-t now feeds a hig'h imFedar.ue -fche transient; vol-fcages across i-b can rise to awful levels.
The cure for tlri-s is to uee a somewh.at grea'ter PIV safe'by fao-bor and. better -transient
suppression^ ^For a dioflo in .-. full wave circuit a safety- factor of 1. 5 over the
nominal peak reverse voltago across the diod.e. is iisually (hi ) suffici.ento In a half
wav circuit I shoula. advise. a factor of 2, particularly if a heavy load is -to be drawn.
If a Silicon Controlled Rectifier is used, a safety factor of 2 is minimuni, as far as
I am concerned, because their swi-bching action is -n-clont, and SOB. 's are not cheap,,
TO BE CONTINUED NEXT MONTH.
73
Ted Beard. VK?EB .
for Balls tin Commit-teeo
The Monthly Bulletin of the Tireless of Australia
Jul. 16 . Tasmania Division
V. H. F. Notes.
The Annual General Meeting cf the V. H. F. group was held at tlie Liverpool St
clu'b rooms on -the 19th. May 1965. The following office 'bearers were elec-ted for
•the forthcoming year,
President VK7ZZ
Vice Presidents VK7ZAS, VK7ZMK
Sec/Traasuror VK7TX
S'cast Officers VK7ZJG, VK7LL
News Officer VK7TX
Ac-bivities Comm. VK7ZAX, VK7KZ, VE7ZMK
Research Officer VK7ZAS
V. H. F. SorilDes A. R. VK7ZAQ
Bulletin B. J. RB)DELL
It is no-fced here with interest at the number of VOLUNTEERS??? for
•fche a'bove positions.
The Sunday morning broadcast is now "being relayed in the Hobar-b area on
52 Mc/s and a callback is requested at the conclusion of -the 144 Mc/s roundup,
whioh-c-brings to aind ano-fcher point phaps, -fclie roundup on Sunday mornings and
the chin wag on Sunday nights has been lagging a little the last month or so —
lets see wha-b can be done to rectify -bhis position eh?
The mid - season DX on 52 Mc/s is due to begin early in July so keep
the rig warmed up . a»d. don't forget ynu CTortheim cliaps we would like to hear of
any interesting oppenings (or otherwise) during -this period and at all other
times, the address -to forward any information -bo is
i B. J. Riddell 3 Riawena Rd. Montage Bay Hobar-b.
We also extend congratula-bions to Mike Hooper who has the call sign VK. 'jmC
and Mike can Tse heard and v/orked at the moment on SMetres.
B. JoR.
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