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BULLETIN ISSUED BY THE FCRTHERN Z0FES OF THE
WIRELESS INSTITUTE OF AUSTRALTA TASUSIIA DIVISICE
MARCH /
VoL, 1 NO.10.
REGISTERED AT G.P.O.HOBART
for transmission by post as
a Periodical, CATEGORY B, -
"GOODBYE TO 1971"
Well it's time for the A,G.li, for 1972 in the Tasmanian Division of Wireless
Institute and also in the Northern Zone,
During 1971 successful functions were held, firstly the A,G.}, and Dinner
in Launceston was attended by approximately seventy people; also the "ew Type"
Hamfest was held at Evendale, this two day get-together was attended by over
one hundred people including visitors from Victoria, New South Weles and America,
Thanks must go to the girls in the kitchen and the organisers Kevin, Reg. and
Brian VK7ZBY, .
Other functions were held at National Park and Port Sorell, National Park
is not the best place for radio communications, but it is very good for picnics,
talking etc., North and North West members and families enjoyed the fox hunts,
picenic and cricket match ete, at Port Sorell,
Monthly meetings in Launceston were very well attended during the year,
averaging well over thirty members per meeting, Many interesting lectures were
heard during the year and members also benefited from auctions of equipment and
sale of new components at special prices, Thanks rmust go to Kevin VK7ZAH for all
the work he has done running the equipment store, thanks also to Judith for
nutting vp with the visitors and phone calls associated with ccuipment sales,
Thanks must go also to Rey VK7KX for his work as Secretary and organising
throughout the past year, OQur thanks elso to John VK7JV for all the work he
has done during the ycar; he has been a Councillor which has meant travelling to
and from He%art at night every month during the year at his own expense, general
organising in the Northern Zonc, selling cquipment, and editing (ORM, I think this
is more than any one man should have to do. Thanks to Joy for her assistance,
Thanks also to Col VK7LZ for his work as (OSL Menager and advice he has given
during the year,
Our greatest achievement for the year in my opinion was the cstablishing
of a fully licenced MM Repeater on Mt. Barrow; this has helped to bring operators
together in our own area and State also during opcenings in Victoria and South
Australia, Our thanks for this mighty job must go to Peter VK7PF snd Beb VK7ZRF,
Thenks also to all the other members who helpcd to meke the W,I.A, "go" in
Tessie in '71, and to all the others - make surc you have more than twelve copies
of AR, to remind you that you were a member of the W.I,A, for 1972,
VK7ZLD.,
Fe FFF RN RIHK
COMING EVENTS
HARCH 17 AUAL GENERAL MEETING OF THE NORTHER! ZONE
' THE AUDITORIUM OF RADIC 7LA, QUADRANT, LAUNCESTON,
MARCH 7 NORTH WEST ZONE MEETINVG AT LAKIN'S HALL, ULVERSTONE,
F36 IR
RHA
W sWp. wie
BULLETIN OF NORTHERN ZCNES W,I,A, TAS. MARCH, 197%.
PAGE 2,
NORTHERY ZCNE NOTES
The February mecting was attended by 24 Members, After the minutes were
read and confirmed then the meeting adjourned for the sale of the remainder of
Len 7BQ's equinment and was reconvened,
Disappointment was expressed in the roll up for the recent Fox Hunt; it
was suggested that this was mainly due to holidays and that there would be
rore participation later in the year,
Meeting venues were discusscd and it was resolved to use the York Strect
\WE.B. rooms rether than the Teacher's Centre or the High St, premises on a
different night.
Peter 7PF veported on repeater activity and requested that contacts be
kept short and that no duplex operation bec wndertsken, Some discussion took
place on the running and maintainance cost of the repeater and it was resolved
to open a fund for this purpose. Uscrs of the repeater are rcquested to donatc
to this fimd,
The next meeting will be the Annual General and will be held on the 17th
March in. the Auditorium of Radio 7LA in the Quadrant, Leunceston, After the
nceting Rex 7RB will present his lecture on Audio and distortion end give a
deronstration of Hi Fi using a couple of 50 Watt Audio modules,
FH PR KKK
There will be no clection for Councillors of the W.I,A. this yecar - which
is a bit of a disappointment, However, the Northern Zores have a 2nd Councillor
this year - Bill 7AK -~ congratulations Billl
3N AHHH
Rob 7RH now has a G5RV up and can be heard on all bands using en FT200.
J IR
Sone news from Col VKCJV:
The trip to Casey was very calm and took 9% days which is a new record.
Shortly after arrivel they had a storm with winds of up to 115 m,p.h. taking
down the 20 meter beam a ZL special, This has been put back on its perch
and is operating as good as ever and can often be heard on 14.120 MHz, around
22,00 TASTIME, Col tells me that Casey is only 5 miles by land from the Wilkes
station, Col has sent some 70 colour slides home of his trip over and the
asey which we will bring to a future mceting for viewing,
RNN
YVCNI'E, the lady with the typcwriter is rost upsct, she had a previous
engagenent for the Port Sorcll weekend and was unablc to go up to do some
'sniffing! she said!
SR ISK
2 METER SXEDS between VK3 and VK6
IFORMATICON recceived from STEVE VK3AKR indicates that skeds are kept every
night starting on 20M 14.130 at 2300 EAST between VK3, AKR and ALK and VKé's,
AB, SS, BE, XY, WA, ZED and ZFY, When recady the group 0SY's to 2 mcters,
calling is done in 5 minute intervals as follows: VK3's calling every odd
5 min,, VK6's calling cvery cven 5 min,, cach having 2-5 min, calls,
NORTH.. WEST ZONE NCTES
The February meeting was fairly well attended and routine matters were
dealt with, Some time was devoted to the Port Screll field day on the 27th
which will be over when you read this,
| At the close.of business, Ken 7KH showed somc rost interesting colour
slides, taken during his rccent stay in Japan, It was evident that some J.A,
Harms really advertisc their conncetion with Radio, Call signs printed on the
side of cars dwarfed Joe's effort into insignificancec|
We have had some very good V.H,F, onenings here, Too good in fact as Mt,
Barrow end BGLR2 repeaters werc getting tangled, At times onc was not surc how
or where the signel was arriving, All active members on 2 meters made contacts
with VK3, On onc occasion the bend was open for nearly threc days, There have
alsc been openings on 6 meters so .the V.H.F. boys have been well pleascd,
The WX has been hot and humid and this scems to faveur conditions for openings,
On the weckend 12-13th Feb, Tony 7AX :nd Herold 7MZ set up carp on the top
of Barren Hill lookout ncar Prcston, beight about 1,000 feet, end workcd the
Wationel Field day contest,
Tony made an exciting start by stepping onto a broken bottle, resulting in
2 dash back to Ulverstone and surgery, Undaunted, he rcturmned to thc site and
corried on, Morc exciterint at bedtime with scorpions scuttling round the tent,
Frustration when a rcsistor open circuited in the two meter rig, more when the '
30 Amp, soldering iron flattcnded a battery, nasty words when a pair of leads
were applicd back to front, and really harsh words when the petrol driven charger
£ave ui) the gtost. Things became so despcrate that a battery was fitted into
Grahan's (7ZGS) car and his XYL Suc went for a drive.about to put some herbs
into the battcry,
Determination paid off as the boys worked VK7 and VK3 on 2M, and VK2, VK7
and VK3 on 6M, Horold also made contocts on h.f, Cuite a few visitors and helpcrs
turned up including XYL's Rescmary, Sue, Lucy, Glen and Lyn, 7X did an excellent
job by boiling the biliy. The wholec stunt was voted a huge success]
Two of cur associates face the music...cr.., the cxeminer shortly and we
will await rcsults with bated breath, Good luck chaps!
Congratulations to our ncw Ccuncillors and to our old Fuderal Councillor, Hi,
"cod on yer TED, ™X,
PILGE 4,
MMATEUR TELEVISION (A, T,V,)(PART 6,)
L—-)/z —
is
T L FEEDER
Fig 1
?)g 2
L FEEDER
75
Fi¢ 3
AERTALS
Bandwidth again is the dominent factor in the design of acrials for A.T,V.
work, As can be appreciated, it is a waste of time having a transmitter or
converter with en excellent frequency respense and coupling it to an antenna
with a narrow bandwidth,
Long mlticlerment yagis therefore arc not generally used for T,V, work unless
certain design precautions have been taken, The simplest aerial teo use for
cross town contacts, is the humble dipole x/2 as in Fig, 1. For those interested
I have built the collinear as in Fig, 2, (rultiple dipoles in phase) but have
not yet nut it to the test,
The antenna shown in Fig, 3 is known as the corner rcflcector and can give
approx, 12Db of gain, Fisures 2 and 3 can be uscd for longer contacts and the
dinensions can be extracted from R, S.G,
23,
This completecs this short scries of articles on A, T,V, for thc present,
I would like to point ocut that most of the ground I have covered, is how I
rysclf interpret same, If some of the statements put forward do not agree
with anyone, please let me know - better still, why not print it in C,R.IL
For those intercsted in persuing this interesting phase of amateur activities,
I suggcst you become a member of the "Dritish Amatcur Television Club, "
Subscription is $2,00 per annum, Mcmbers receive a cuarterly magazine "COLTVM,
nostage included,
Write to:-
THE MEMBERSHIP SECRETARY,
BRITISH AMATEUR TELEVISION CLUB,
MR, NICHOLAS SALMON,
#CODBOLDS",
MAGDALE! LAVER,
Nr, ONGAR,
ESSEX. U.K.
I must anologise for not having the list of refcrence articles on A, T, V.,
rcady, however I will endeaveur to have them nrinted in the ncar future,
TONY, VK7AX/T,
AMSAT - OSCAR — C,
This is now thc name given to the satellite that is hoped
launched in Jvly, A-0-B has not been scrapped but changes hawe beq
neces.sary (:iuc to & reduction in available launch wecight,
/a0
C will rost likely consist ofs
(1) Amsat 145.9 to 2.5 MHz linear translator (see QR for Dce.)
(2) The VK ccrmand systen
(3) A rorse tclemetry with output on 20,45 VMHz
(4) A code storc
(5) Solar powered with one year life
The morse telemetry and code store has not bem given mich publicity
so here arc some details:
Telemetry
I-Icasfirements made in the satellitc arc converted from analog to
digital form thencc into moree code, A sample of this might be received -
H1 171 118 129 156
248 200 297 214
363 377 324 380 HT,
The first figure indicates the line number and the start and finish
of a sequence by HI,
Codc Store
This has been designed to store from five to ten words of a rorse
nessage, This is broadcast continuously, until re-programmed, and can
be used to pass on orbitel informetion, repcater status ctc,
It is belicved that the teleretry and code storc will be both
on the one frecuency,
VK7PF,
I3 AN
WANTED TO BUY:
STEVE 7ZSF requircs a Signel Generator in rcasonablc condition, Please
give deteils with price,
Fe RN
A
7 Ausio =
. AMPLiFie R
cl Ll
G
RT inpPur
FRom Lasr 2]
¥
LF Srage C
L3 D L=k
The triple tumed discrizinator was an early forerunncer ofthe modern M
detsctor, It is seidom uszd "to'.’.f:-‘;-,', but it is moeful iL(d,g;'d.e“ng the operation
of the more complex Foster - Cccley discriminator, ©1 is Inductively coupled
to coils L2 and L3 and the threcz“'o phyeically arranged on a forner, so that an
equal distributicn of energy will cocure, L1 and CL arve tuned to the carrier
frequency (e.g. 0.z LeC2 ie Guncd to a frequency lower than L1C1, end L3C3
to a higher frequency than L.b?o Note there are two sccondary circuits containing
scparate diodes and load resistors, The D.C. voltages developed across these load
resistors are of opposite polairity; emsequeatly, the net wvoltage taken from the
output termingis AB will be the q,,ff‘erence between the voltage across R1 and the
wltage across R2, If the apnlicd frequency varies from a point below the
resonant frecuency of L202 to a point above it, the curve of the wol*age across
R1 with respect to the freguency appears as cuxve 1. Maximin voltage is produced
across R1 at the resonent fraquency of L2C2. ‘“he voltage falls off above and
below this frequency, The wltage across R2 possesses a similar characteristic
cxeept that its peaking point is at another frequency., The polarity of the DC
voltage across R1 is opposite to that across 2, so the curve of the woltage
across R2 with respect to {irequency can be placed as curve II, The woltage
at terminals AB is equal to the wcltage across R1, plus the opposite - polarity
voltage across R2.
AMPLtT1y &“-
_THe ResultanT S CuRVE
10.9 MHz
FINEQUENC y
AtiPliTuoe
" - CENTRE 77?5’62-&15"()1
2,7 M-
TREVOR 7TB
Q. R. M.
DULLETIN OF NORTHERN ZONES W. I, A, TAS, MARCH, 1972,
PAGE 7.
MCBILE HINTS
Imition, gencrator, altermator and other noises that creep into the receiver
are not always the fault of the vehicle, When they are, it is sometimes irpossible
to clean up the vehicle, But the following can bc tried; material required:
Braid from old co-arial ceble and a handful of assortcd self tadping scrcws,
Try bonding the following: bonnet to bulkhead, radiator to front grill, front
grill to carthed battery terminal, exhaust pipc both front and rear to car
body, engine to chassis, To prevent creaks and groans from body panels
rubbing together, the manufacturers often apply a "omic" boetween panel joints,
this is not very good for clectricel bending but cen be overcore by driving
self tepping screws through adjacent panels, in concealed places naturally;
ORY in the receiver when switches arc opcrated can be ceused by faulty and or
dirty battery tcrminals, Try scraping bright the inside of the terminal
and the cutside of the battery post. Connect up end then vaseline the
tecrminals, Do not vascline the battery nost before connecting the battery
lug., Cuorbon ignition leads are CK if in good order, if not fit a suppressor,
Fire type L3 are very good.
Aternators, generators, distributors, coils, windscrcen washcrs and
other nodse producing devices can usually be quictened with a hend full of
capaciters, Bcnd the antenna carth lugs securely and filter the input power
lead,
Noturally the rcduction of ™ceise" is rore noticeable in AM covipment,
gy
FEHR oAKN
AERIAL
Mo®ile | —J0 PF
If you don't like drilling holes in your vehicle, then try the above
gimick, In “leacc of the Breodcast acrial fit a VHF typc for the band you
work on and install the above gadget to split the antenna between the Mchile
rig and B.C, Receciver, L1, for 2 metres 4 turms 3/8" c¢iam, spaced. 6 lctres
10 turns 3/8" clesc wound, To edjust, plug a power meter between antenna
end splitter and adjust Ci for maxirmum indicated power output. Inscrtion
loss of Tx is negligable, Inscrticr loss on Broadcast recceiver can be high
enough to loosc distant stations, If this is a problem, inscrt a 100PF(apnrox)
variable capacitor at X and adjust for best volume on a weak E.C. Station,
This is the only snag with this splitter but it's better than a car full
of hcles, TR,
333633
3¢
2 METRES 8 WHIP AGATN
COIL., Wind about 11 tums 14 gauge enarcl wire spaced over
4", For best results rount in centre of car rcof,
ADJUSTING, Meke surc Transmitter outout is tumed to 50 OHm,
, Adjust coil spacing for best S,W.R., If this cannot be obtaincd
4,73/4 to a recasonable valuc say 1 1:5 then a slight adjustrent to the
whip length is in order, If scrc sort of power reter is on
hand then it should be installcd between the antenna end trans-
. mitter and the whip length further adjusted for maxirum forward
Lo power, This may not coincide with the best S.W.R. Experience
/2 has shown that the whip usually turns out shorter in practice
:% “ then theory statcs,
TR,
LSV L ALY VL AVUGLVLLLLELAY OVAdow W LA A L8 Mal Vii C
11
Ne¢te to full members of the Wireless Institute
It is expected that the agenda of the Annual
General Meeting to be held in Hobart on March 18 will contain
. iteps of concern to Northern members. Members who cannot
s attend are urged to exercise their vote by proxy.
Items 67 and70 ¢f nur Articles of Association
state;
67. The instrument appoimting a proxy shall be in writing
under the hand c¢f the appointer and shall be deposited at the
registered office of the Institute at least 24 hours before
the time appointed for the meetingee.eeve.e
70 But the powers of a proxy may be limited to such
extent as the member giving it may think fit. A statement
detailing such limitations, if any, shall be presented at
the same time as and attached to the ProxXy eveeeeccves
NOTE It is assumed that the registeréd office of the
Institute is 147 Biverpool St., Hobart.
Proxy form
Il LU N I I I B I I I T I IR IR L N B A N a member Of the Insti‘tute
hereby appoint Mr also a Member of
the Institute to act fér me as my proxy and in my name to do
all things which I myself being present could do at the
meeting of the Institute to be held at
® ® 0 00 0 0% 80000
te e
on the @ @ ® 0 08 ¢ 20 ° 9 80 9B PSR L e e
: Signatwe‘.llO'.‘..l.5..l.I’O0lwitnees.......'.'....O..
P} T 8 9 Q@ % 0 0% 0 8OO 0P 0O OO NSO PSPPI S S L T SN ST F O IPP PO YOO NS eSO 0N E e
Northern Zone, Full members
The Meeting on March 17 will be the Annual Meeting of
the Zone, O0ffice bearers to be elected include, President,
Vice-Rresident, Secretary, Treasurer,
Nominationa are called for these positions and the forms
below should be in the hands of the Secretary prior to the
meeting.
........‘...I.......l...l.‘..l....C..CI......‘......‘.O‘.....'......'.l...l
I hereby nominate ...seeeveecessessessees for the
pOSition of.......oo.oo.o......
Proposer.&.a.u..nb-nololoo.‘.
Seconder......o.oolocoootcl'.'
I hereby accept nomination ...ieeecceocerscsccsccscce
€ 4 0 0 0 0 9P PR OSSO P OO0 NSNS P NS E 0O TOOO e PO ERPO NSO SREY S SE0NYENEe s Se s
I hereby nominate .s.veeecceseecesceeseese Lot the
-
Position Ofseeeveeeceseoncenece
PropOSEresececsssssssccssccnse
Seconder.ceeececccrssocessccsne
Ihereby accept nomination L NI 2RI I I I I I I I L 2