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I^£....,,,i/V/./:?£L.. E.SS,, /:NS, I/, I. U, TF
OF AUSTRALIA
TASMANIAN DIVISION
BOX 8 U G. P. O. HOEART.
J^XJACT 19'63 MONTHII--BULLETIN Price 6d
PRESIDENT . ' TREASURER SEGEETABI
Mr. T. Alien. .VK7AL Mr. G. IIarri sson VIC7GH Mr. K. MLllin •VK. TKA
.
Regis'bered at G. P. O., Eobarfc, for -bransiiiission by. pos'fc as a peri.odical*
GENERAL^ MEETING.
The next general nee-fcing wiU be held in the Club Room on IEDNESDM,
1st January 1963 at 2000 hours. A lecture is being arranged. • - ......
NORTHERN Z0№.'
The nexb aee-fcing ^dll "be held at 73 George St,,, Launces'bon, on FEIDAX
11-fch January 1963 at 2000 hours. There is iiaportant "business •bo discuss &nd all
members of the Zone'are asked to nake a. special efforti •bo be present* •-
NORTH ^STEEN ZOME;. ••
I have no-b received ary inforraat'ion as t-o when the next meeting -uill be
held, but a. s the usual nigh-fc is New Year's Day it nigh-b be-a good-idea to check
up bofore going along on -bhgt date, .
COUNCIL №;ESING. •
The next Council Ifeeting •will. be held on. IONDAZ., 21s"b January a'fc the
residence of Mr. C. Harrisson VK7CH, 38 GibUn St., Lena h Valley,
LIBRAEC
The Library Sub-Coiac.u.ttee have,, done a good job in renovating the book
case and are now ready for business, tie have some new publications on order, but
would particularly like -bo have handbooks on surplus gear to build i.q? a reference
library* It aryone has any •bha'b they •would care -bo donate to the D^yision it
would be nuch appreciated.
R. D. CONTEST.
Gongratula'fcions •bo -the TC6 Di'vlsion in •uimung -bhis yearTs contest, I'm
afraid that we did not pu-t up a veiy irapressive perforraance,. bu-fc wLll do bet-ber
next year. And cerfcaiiily the -b-uo nor'fchern Zones put i-b all over the South -fchis
•bine.
IIAMFEST.
Mr, L. Jensen VK7LJ has veiy ki.ndly presen-bed -fche lastitu-fce -ui-fch an
enlarged copy of a pho-bograph of all the licensed gnateurs a-b -bhe Hamfest, and
has Veiy genorously offered -bo supply us with 6-g-" x 4i-" prints at cost, aUL .
profit to go -bo Club funds, If you would like one send 2s/6d (plus pos'fcage)
to the Secre-fcaiy by January 21st. This is an excellent photo of wha-fc is
cerbainly the larges-b group of YKPs ever assembled -boge-bher*
NEW №№ERS.
We welcome Joy: BatcKler WTSCL back a g a neafaer, and are also pleased to
have Messrs, J. R» Gimley and P. <T. GOQG as new associate meiabers,
NOISE
Enclosed •w. th -this Bulle-bin is a Noise Repor-b Fom. Anyone troubled
wLth electrical in-fcerference (and few of us aren't) are asked to complete this
fora and forvrard it to I4r. E. Beard, 148 Derwont, Ave., Lindisfame, or to the
Secre-fcazy* The Noise sub-eoiiuaittee will then collate the infonaation and pass
it on to -bhe right quarters*
Page L
The Wireless Ins'fci'bu-be of Australia* Tasmanian Division*
January 1963
Page 2
CRYSTAL ETCHING.
The anaonium bifluoride is now -bo hand and those who' ordered can collect
at the nexfc meeting. Cost is 4-s/- each. There is still some available if anyone
else is interested a'b this price, but bring along a small plastic container
please.
PORTABLE OPERATION,
Most of •the YK7 cry s'fcal contrbited porfcable/inobile rigs have c37S"bals on
359Q kc/s and this has become more or less the standard frequency for portable
.
wrking. It is expected thg-b several 's-bations vdll be active during -the next
couple of mon-bhs, so keep a lookout on that frequency. Weather and other
clrcums-fcances permi-fcting VK7GH, -with YKTKA as assistant op., will.be mobile' '
marine froa the'South Wes't and Port Davey for a couple of weelcs from Chris'fciuas,
and^would -welcome con'fcac-bs» . Regular sked times are 0800, 1200 and 1800 hours on
either 3515 (c. w. ) or 3590 (phone). I hear -bha-b VECT^ will also be spending, a
few weeks at his country residence at Bond Bay, Port D^vey, in Januaiy and will
have his portable alongo
R. S. G. B . HANDBOOK. • , '
The order'has been despatched for thesebooks, and to simplify ma'fc'fcers
two copi.es -uill be posted direct froa London to the members mentioned below and
it would be appreciated if -fchqy .would pass on the extra copy to the other member
shown. Tho ss whose naEies:^o., not appear on this list wi.il repeive -fcheirs 'by pos'fc*.
Addressed to: , Extra co for :
Alien, '&.A. Secre-baiy
Beard, E. Aschman, G«
Berxy, D. McGinniss, M.
Brown, J. Johns, D. H.
Connor, T. Spiegel, C.
Oordell, L. Hancock, H»
D'Emden, G. Pieniacki, F.
Dore, V, F. Kelly, K. :M.
Edwrds., L. W. •Jensen, L« . R.
R«K.
Emme-fc-fc, Rogers, R»
Fri-fch, P. D, Self.
Kelly'., D. H. E^rne, A, E»
Macey, J.E. Self
MUlin, K. E.. Libraiy,
MorrisTy^ A. H. Secre-taiy
Nichoi s, I. Secretaiy
Tanner, W. E. Frith, 'P. D.
Wilson, R.K. Durld. n, L.
CONTINUED USE OF 0- 2 Me s BAND
Federal Executive ad-vlse -bhat condi-fcional use of this segment until
December 31 1963 has been granted ty the Department, subject -bo -bhe condi-bion
that the band wi.il be vacated at the expiratimn of U days notice at any -fcimB
before. the 31 Decenber 1963 if found desirable,
The a'fc'fcention of gmateu.rs is dra-un to the possibility of second harmonics
of signals from stations operating on the ,50-52 mc/s band causing in-fierference
•bo reception of •television" programs in Channels 4 and 5 (94-101 mc/s and 101-108
nc/s respectively). '. In the event of such, interference being caused it may become
necessary to review the position a-b short notice,:
OPERATING FROGEDUBEg.
Reports fron obse]"vers on the ama'beur bands indicate a general
deterioration of the standard of operating among aniateurs generalty, ^his
includes failure -bo announce call signs v[th±n specified periods?, "use of "10/4"
code which is not recognised in this country, and the general bahavlour is below
the standard expected of ama-beursa
Council urges every ac'tive raeniber to take a good look at his operating
procedure,. and to do Ms bit -bQ brxng about an all rpund improvement.
The Wireless .'Institute of ,AustraIi.a» I&smanian Division,
Janua.ry 1963 Page 3
TEGH NIGAL.
•Facts on Feedlines. -by G. G. ' Jobnston •B, Sc.
At one'stage or another every person wi.th a serious in-beres-fc in radio is
confronted with the problem of "fcsw to match their feedline into their new
antenna". Most handbooks provide data on input impedances of various •types of
an-fce. nnae bu-b few,. unfortunately, give de-fcails of feedline s'beyond saying •that
coax. of x 6&m. s charac-beris'bic irapedance'is necessary. As aany have found tihe
cost of purchase of this "x ohms" fe'edline is often out of propor-fcion m.-th that
of -the project in hand. It is in an a-b-bempt to alleviate the woriy_and distress
symp-fcons so often seen upon such a discovery whether made \y the XIL or CM himself,
that this short note is being writ-ben. Perhaps i'b w3. il assist you -bo'use -bha'b
piece of nondescript coax. you have in your junkbox to good effec-fc*
The conductors of a feeder cable possess distributed self-resistance
(R, ohms per metre), self inductance (L, henries per metre), shunt capacitance
(G, farads per metre) and shun-b conductance (G, mhos per me-bre. ). Thus -fche
equivalent circuit of a feeder cable may be considered as being represented 'fcy
the circuit below ;
R L R L
l>— •v"/\'j'-r'- ^~:/:'№s'^-~ -A/S'^. 'V" -!'^^'r;^'~
Zp '; I.
1 ^i ^c
->
t tc 5^. Tl
-"
Zo G
•-v\' ^./^yrY'-,-^, :„— ]„„.„„. /v^yy^.____., />,-^'
R L
The feeder exhibits a characteristic impedance of (Zo) ohms at P when the
termination at Q is also of Zo okas iapedance. Thus when input and outpu-b _,_
impedances (i. e. at P and Q respectively) are ma-bched -bhen Zo a J R lus i W c
•which approxLma te s closely to '^LC at R. F.
Since the physical dimensions of the feeder, govern the magnituda of L and
G these dimensions •will also govern i-bs characteristic impedance (Zo),
Charac-beris-fcic impedances of tvo popular types of feeder may be simply determined
by -the formulae showi below i
(a) Twin. lead unshielded
276 _s
i\ Zo = log.10 r
) ,
/K"
->' r^-
.
K 3 1 for air, 2. 3 for polyethylene
(b) Coaxial.
Zo = 138
/- 7" ^T- 10^0-^
; is
v
K s 1 for air, 2. 3 for polyethylene
1 Generally speaking coasdal cable covers "bhe range 50 -bo 250 ohms and tmja
lead 200 - 500 ohms. " Tw devices for matching a feeder with an impedance somewhere
in -bhis range -bo the desired output impedance are :
(a) x -wave transforaer. The procec'ure here is •bo insert a •^ wave section of
cable of inpeJance Zo, <n ^/ZqZo between the feeder of impedance Zo and -the
desired ou'fcpu'b of impedance Zq.
(b) "S-fcub match"
When x = ^- -tan s/~ZQ/ZO metres or fee-b from our feedpoint
Zx comprises R a Zo paralleled Ty a reactance plus/minus i X A stub is teed in
at t,M.s point x and stub length end hence reactance is adjusoed ("by a shorbing
bar) -bo cancel -the plus/rainui i S on -the Une a-b x. A standing wave indica-bor
is invaluable here.
Of the two methods the iirst is the easiest to my niind as it is likely
•bo work "first up" T^ithou-fc hours of adjustraent.
The Wireless Ins-fci-bu-be of-Australia • Tasmanian Division,
January 1963 Page 4
FEDERAL COUITCILLOR. . , ....
As one only nomination, -was yeceived, froia Mr, E. . J. Cruise VK7EJ, the
retiring Federal ;. Go'uiLcil.lor, he is declared re-elected unopposed,
GALL^OCK^
"These are not obtainable through the Division this year, but. they are
available through newsagents. The Avalon Newsagency, Elizabeth St., Hobart,
have a. limited supply but as s-fcooks cannot be. replenished best get in early if
you. want one»
DISPOSALS. .. '
"The first 'shipniont'from -the Victorian Division has been nearly all sold,
Another,, lot has sines been received and a further list •will be inclu.ded wLth next
mo.nth's BaLletin. . • • •• •
G;LUB ROOM FUND. •
Don'-b forge-b we still want scrap copper, brass and lead also rags.
These can all be sold quite profitably to holp -bhe fund along*
REGEIH'S.
'Receipts on hand ; 609 G. Ranft. 618 R. Jones* 20 R. 14. Barker. 47 A. Hubbard
FEDERAL CONVENTION,
You are ireainded that i-bens for the Agenda should be foi'uarded to the
Federal Councillor as soon as possible,
On behalf of the President and Council I ^rould like to take -this
opportunity of ashing 'all nenbers, their -wives and. faiailies, a vezy happy
ChrLstmas, and good health and happiness in -the coming year.
73
C» Harrisson VK70H
for Bulletin Corami'b'fcee
WIRELESS INSTITUTE OF AUSTRALIA
Tasinanian. Di-vlsion
NOISE REPORT FOR II
Name • . . . . . Gall Sign (if any)
Address * . . .
Date on which the noise •was last heard . Tine
GS№RAL DESCRIPTION OF NOISE
IfflEN IS NOISE HEARD? (a) Continuously ...... (b) Interrai-cten-bly . . . .
If noise is in-benait-bently heard is it heard s
(a) Frequently ...... Occasionally ..,... » Rarely
(b) In fine weather ....... . wfc weather . , . . . wLndy weather
or in what particular conditions
(c) In day time . . . . night time . . . . . week days
week ends ....... any ·bir.ie . . •
or at, what par-fcicular tine
FREQUENCIES ON IJHICH THS NOISE IS HEARD (Give strength)
On Broadcast band , . . .. Onl. 3 GIC/S . . .. . . on 3. 5 . .. . •on7mc.
on 14 me on 28 me . . • . on 56 me .. . . on 144 me « . •
NATURE
Does the noise appear to be associa-fced with ro-fcating inachinery?
Or does it appear to be associated with leakage of electricity over insulators
transformers etc?
№iat high voltage AC feeders or -fcransfonaers are located near you? (Attach
sketch)
c n a o
AREA AFFECTED. Over wha-fc area can the noise be heard? (Show on sketch)
Names and addresses of others who are affected ^r the noise
B • •
» * « • » 0
SUSPECTED SOURCE OF NOISE
Wia-b evidence have you to substantiate thLs suspicion? »
AM OTIiER RELEVANT INFOBI-'IA.TION (e. g. tests made, results etc « • • •
Signed
Re-bum this form -bo Mr. E. Beard, U8 Derwent, Ave., Lindisfame, or to the
Secretary, Box 851J G. P. 0., Hobart.
12/62