QRM

1980sDocument1982QRM 1982

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AMATEUR
RADIO
NEWS JUNE 1982

Issued by Tasmanian Division of Wireless Institute Aust:
i Registered by Austraha Post Publication No! TBH0043.
133 Gordons Hill Road,
Lindisfarne, 7015.

cietkl
COPYPRINTING T o600
M.G. & L.E. COOK

Ny
FOR LOW COST MULTIPLE COPIES OF:
(PRINTED COPIES)

3
Newsletters, Price Lists, Stock Sheets, Time Sheets, Letterheads,

et
advertising Notices, Minutes of Meetings and general office forms etc.

IF IT CAN BE COPIED WE CAN GIVE YOU MULTIPLE

N E
COPIES BY THE OFFSET DUPLICATING PROCESS
ALSO PERSONALISED Q.S.L. CARDS CAN BE SET UP AND PRINTED

TN
Please feel free to ask fora PRICE LIST

A b b
BETA

A
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ELECTRONICS

ke L
SN
131 Bathurst Street Hobart Tasmania 7000

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Telephone (002) 348232

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FOR ALL ELECTRONIC SALES AND SERVICE:

Low, low prices for components;
PL259 PLUGS now $1.20 RESISTORS from .4¢

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RG58 COAX now .45¢ mt, CAPACITORS from .14¢

2
Ma
WALKMAN Headphone Cassette $69.95||4 Band Stereo Radio

2 2
AM WALKMAN Headphone $16.95|/Cassette, AMSS Searcher
AM/FM WALKMAN Headphone $39.95||System, Metal tape, LED
SONIC Car Cassette; 20 W per indicators; TU-4300
channel, LED VU meter $95.00 only $199

2
i)

The first issue of the new look QRM produced by
o

the Southern Branch in April was well received,
judging by the resultant comments and letters.
Riiiimsmsmm——mnpmee—m—m—eg
e

Production was advanced to ensure that the
magazine was available at TARC and it was dist-
ributed to members when they registered.

TARC, which was held at the Lea Scout Camp just
south of Hobart, was very successful despite
the rather damp and muddy conditions outside the
hall. Various workshops were conducted over the
weekend with the Annual General Meeting being
held on Saturday afternoon. The Saturday evening
rneal consisted of a pig and lamb roast with a
o

very comprehensive side salad provided by the
Southern Branch and WAGS. Over 70 people were in
MR

the hall at one stage on Saturday evening. The
TARC committee and WAGS are to be congratulated
for their efforts in ensuring that TARC was a
success.,

The response to our request for articles was,
far in excess of our expectations. Unfortunate-
ly some contributions have had to be edited in
this issue due to space / cost factors. Please
do not be discouraged if your article does not
appear this time as many have been held over for
use in further issues. A decision was made by
the QRM committee NOT to print Branch minutes
from meetings as it is 0ld news to the interest-
ed members - they were at the meetings!

4¢ Keep the articles coming,as well as your
.14¢ compliments and criticisms, we welcome them
all. Remember, the success of QRM depends on
your input.
archer
e, LED 'QRM', P.O. BOX 123, SANDY BAY. 7005,
D0
DIVISIONAL NEWS
The main topic for discussion at present is the situation

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S ()=
which has developed as a result of applications to Local
Councils for permission to erect antenna towers.
The general feeling of Council is one of deep concern that
if Local Councils, or rather neighbouring residents through
Appeals Boards, succeed in preventing the Amateur from
erecting a suitable antenna support structure at his or her

1
residence, then a severe if not crippling limitation will
have been imposed on amateur activity.

b
NY
In Hobart there are currently two cases being considered
by Planning Appeals Boards, and while reports to date paint

1)
quite gloomy pictures of anticipated outcomes, recent
developments in both cases have altered the situation to
give quite strong hopes to both applicants.
Reliable reports indicate that other Municipal and Town
Councils are waiting for the outcome of the Hobart cases

“m
before stating their own policies on this matter.
There have been cases in South Australia and New South Wales
which have seen amateurs being forced to take their cases to
the Supreme Court - a very costly exercise.
Policy formulated at the recent Federal Convention will see
the Institute embark on an extensive promotional campaign
Australia-wide designed to educate the public and perhaps
avoid the need for costly legal battles in order that an
amateur may erect a tower.

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A Special General Meeting of the Division has been called to
discuss this problem and formulate a course of action for
this state.
Notice of Motion has been given by Council to make a call on

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all members to establish a Support Fund which will be used
where necessary in this campaign, whether it be for
promotion or as a last resort, court action.

M
PN
L.J. Cherry.
Divisional President
NOTICE OF SPECIAL GENERAL MEETING
You are hereby advised that, on direction of the Council, a
Special General Meeting of the Tasmanian Division of the
Wireless Institute of Australia is to be held on Saturday,
June 26th, 1982, at the Kings Meadows High School,
Launceston, commencing at 1.00 P.M.

AGENDA

1. Open Meeting
2. Apologies
3. Report on developments interstate with regard to antenna
tower installation by the Federal Councillor, Mr. R. Fudge.
4. Report on legal implications by the Divisional Legal
Officer, Mr. P. Corby.
5. Notice of Motion.
Moved - Mr. P. Fudge, Seconded - Mr. K. Kirkman
"That under the terms of article 83 of the Articles of
Association, a call of $10.00 per member be made for the
establishment of a Divisional Support Fund to be used if
or when the need arises."
6. Close of Meeting
PPT e KK 3K K IH I e KI 3K F K I KK KKK KRN HHH NN X

PROXY VOTES shall be delivered to the Registered Office of
the Division - 22 Karoola Road, Lindisfarne, 7015 - no later
than 1.00 P.M. on Friday, June 25th, 1982, and shall take
the following form:-
I..........a member of the Institute hereby appoint Mr.......
also a member of the Institute to act for 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......
on the..........
Signature.........Withess..eeeeesee
I that we record the passing of

NEHD
two widely known fellow amateurs,
TERRY CONNOR VK7CT passed away on April 3rd. 1982
IAN NICHOLS VK7ZZ passed away on May 3rd. 1982
Both these men contributed a great deal to amateur
radio in Tasmania, thus we feel it is appropriate to

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relate some of their activities and achievements.

H MO <dSSNoO EsE
Terry obtained his licence in June 193%6 whilst
living in the village of Rokeby. Having no commercial
power, his power supply was a 6v car battery charged
by a car generator driven by an old Douglas motor bike
engine with one cylinder removed. The antenna was a
'Hertz', H.T. for the mopa transmitter came from a
'‘Carter' genemotor driven by a 6 v battery. Receiver
was a two tube (0-V-I). Operation was mainly C.W. but
some Work was done on 'loop' modulation.
An auto-electrician, Terry joined the Signal Corps
prior to the war and on the outbreak of hostilities

N ~+ 40 OO0
joined the A.I.F., serving in the Middle East and
later in New Guinea. He achieved the rank of Captain.
After the war he returned to City Motors as manager of
the auto=electrical department. Later he manager the
Huonville Branch for 11 years. In 1960, Terry returned
to Hobart where he joined the firm of H.M.Bamford &
Sons. During this period he became a regular member of

-
the 'Sewing Circle',
After retiring, he and Adelene toured Europe, and
England (of course), where he met many of his fellow

~
amateurs and was honoured to be entertained by the
R.S.&.Bq
Terry served as Divisional president in 1968 & 69
and at other times as both Treasurer and Vice President.
He was awarded Life Membership in 1966,
Apart from his involvement with the W.I.A., Terry
will be fondly remembered by many for his tutoring of
A.0.C.,P. classes which he did for many years.

Ian Nichols was accidently blinded at the age of
five but he made a remarkable adaption to cope with
this disadvantage - his activities ranging from house
painting to cricket,
continued.
b
Ian's memory was so remarkable and his perception so
acute, that amongst other achievements he obtained
two degrees; Batchelor of Arts and Batchelor of Law.
The latter part of his working life was spent at the
Zinc Works.
In 1958, Ian passed the full examination for the
A.0.C.P. and after that the world became his oyster.
He was active on all bands from 160 metres to 70 cm,
and by 1979 he had worked 271 countries and had W.A.S.
on 14, 21, and 28 Mhz. The number of his contacts was
shown by the piles of QSL cards which were handled for
him. The outwards cards, Ian typed himself. Although
he used phone when appropriate, his true love was C.W.
very often in the early hours of the morning. He was
always willing to assist candidates studying to pass
morse code.
Despite his 'on-air' activities, Ian was deeply
engaged in Institute affairs. For many years he was
a member of the executive council and its legal
adviser, Amongst other offices, he was for some time
the Federal Councillor and was Vice President for
three terms. Finally he served two terms as President
and was elected a Life Member in 1981,
Although it is hard to imagine how he found the
time, Jan was also an active church member and a busy
worker for the welfare of other blind people.
Still relatively young when he passed away (58 yrs),
he had certainly lived a full life., Ian is survived
by his wife and a family of five.

Terry and Ian will be missed both on and
ent. off the air, not only by the many amateurs
who knew them, but by people in all walks
of life,

Compiled by VK7NWR and VK7BJ respectively.

T.
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SA THE GURDRAMT MALL. INCO
LAUNCESTON, "HL‘G it ubs
‘P,0. BOX 328. FHOME(O@3)317073. New
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TRANSCEIVER. . ¥ 7522 . 2 TRAHSCEIVER. . FS5S=29 . B
EXPE
ICOM-IC25R~2SW M FM-MOEBILE PRESL-FTE2ER-EM FM/SSE~16W Refu
TRAHSCEIYER. . F 382 . BB TRAMSCEIVER. . ¥4 832 . B3 New
Life
TRESU-FT29GR~-2M FMASSE-F./'T YAESU-FTE9OR~eM FMA/SSE-F/T Subs
TRAMSCEIVER. . F 3825 . OB 1"~"-'PH':‘F‘EI'ER.. $3&5 . A6

KEMWODD-TR7EBG-21 18W-MOBILE rh4u9uu TRS408-78CM-MOBILE QRM
TRAMSCEIVER. . #3222. @2 T:Q”VEEIsEF CEITZ L a0 Fed.
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SFECIAL KEHHOUD-TSE00-248%-6 10N Post
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TRAMZCEIVER. . F322 .B VK7W
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YAESU-FRG77@@-ALL MODECIAC FMI-RECEIVER-15GKHZ 70 “Gnﬁk. Cat.

KEHWIOD~F €86-AMA/SSE- 2MHZ TO ZBMHZI-RECCIVER, Bank
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HATIOHAL-RF 310@-TO 3BMHZ AM/SSE-28 J 163MHZ FHRE’IEVEF Dick
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SOHY-ICF 2081-iSCKHZ TO ZBMAZ AMSSSE-TE TO 1BEMHZ-FM-RECEIVER... SURE
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KENWOOD-PS 30-FPUMER SUFPLY.....¢civvvven . F1ES5 . B2
KENWOOD-DFC 23@-FREGUENCY COMTROLER.......$225. 98 This
MIRAGE-E168 2M 18K IM SOW QUT.RX PREAMP...¥225 . 9@ audi
MIRAGE-B23 2M 2W IM 38W OUT.IDEAL FOR HAND HELDS.. $1 12 .98
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TASMANIAN DIVISION W.I.A.
Statement of Income and Expenaifure to 21[2[82.
INCO _
Subs from Federal Exec. 1667.18
New member Subscriptions. 1007.20
Donations from Life Members 69.50
Sale of Reguletion Handbooks 188,00
Bank Interest 13.21
Sth Branch contrib. to
Deed of Indemnity 214.50
Balance of CYRS account 40,56
3200.15 3200,15
EXPENDITURE
Refunds of Sub Excess 195.26
New Subs to Fed. Executive 669.20
Life Member Subs to Fed., Exec, 72'00

Subs to branches Nth. 109.50
Sth, 216,67
N/W 161.00
QRM costs paid to Fed. Exec. 225.70
Fed. Subs Dues 257.10
Devil Certificates/ mailing tubes 103.05
Post Office Box 16.00
VK7WI / Repeater Licences 60.00
Stamp Duty re Fed. Councillors 15.00
Call Book Supplements 7.60
Repair A.J. Trophy 23.60
Cat. B Registration 20,00
AMP Insurance Policies 342.43
Bank Charges/ stamp duty 12.50
Divisional Travel Expenses 50.00
Dick Smith Grant to Branches 498,00
3054.70
SURPLUS 145.45
ASSETS
Bank A/C 508.26
Cash on hand 5.75
Video Tape 25.00
539.01

This statement was checked and found in order by the
auditor on 8/3/82.

q.
VHF NOTES
Pape
52 MHZ. 31.3.82 - Six metres was open to VK5 with 80 m
with VK5 ZRY, ZLJ, MJ and RO being worked. The usual not
stations were heard on during the opening, those being able
VK7 JG, ZPK, KXA, ZOT. The band closed at approx. need
10.00, hit
Ian, VK7ZIF reports good openings on 6 over the past Each
month with VK7KMA heard on the 17th. April, also w'I.

having worked into most call areas of JA and the usual "Net
VK stations., Cont
An aurora on Sunday, April 15th. gave rise to several Send
VK3 stations being worked. Awar
Allan, VKT7ZAR has also been active on 6 from his Canb
island retreat on Bruny, having worked VK4, 3, and Here
JA 7, 8, also some VK7 in Launceston. hous
Joe, VK7JG worked W5hJJ after a call on 52.050; this DX W
may be a state distance record for Joe.
No ¢
432 MHZ. There nas been an increase in activity on
Maur
/{C Cm. in Hobart with the purchase by several stations
of tranceivers, some of the stations active on 435 FM
are VK7 GD, TC, ZAR, RR, HK and on 432 SSB VK7 JG, ZQOT,
41¥, ZTA,
Anotner note from Joe VK7JG is that the Northern 70cm.
repeater is operational on a manned basis at Joe's
place. They are still looking at possible sites for
the device. It's input freq. is 433.625 and output
freq. 438.625. The output power is 10 watts and it
will be operating under the call of VK7RAB.
David Chadderton VK7Z0T

lopK OvT Fok TAL Dum3
Cop OV THE CORNER
"PAPERCHASING" by VK7NHA Les.

Paperchasing is more and more becoming a fun pastime on
80 metres and all other bands for that matter. For the
not so serious award hunter, there are many awards avail-
able in Australia, the beauby of these being you don't
need QSL cards and they are not costly, so they don't
hit the o0ld wallet where it hurts,
Each issue I will supply information on TWO awards.
W.I1.A. VK1 AWARD:
‘Net freq. 3.570 Sundays 10.30 Z (after evening broadcast)
Contacts: 20 required. Cost: $2
Send log data: date, time, freq, callsign & RST to;
Awards Manager, wW.1.A. (A.C.T. Div.), P.O. Box 46,
Canberra, A.C,T. 2600, e
Here is an award for the sometimes forgotten lady of the
house.
DX WIDOWS AWARD:
No contacts needed. Send first name of XYL and $2 to
on Maurice Batt, R.S.D. Rokewood Junction, Viec. 3351.
ions
FM

GELSTON COMMUNICATIONS PTY. LTD.
Z0T,

Ocm.
40 Lavender Grove, - TWO WAY RADIO SALES AND SERVICE -
Launceston.
PRE STOCKTAKE SPECIALS: Voo "B
AT AV,

120T IC 290A 2M Multi mode transceiver. $499
2Metre Handi-talkie telescopic antenna,
10 db improvement over rubber duckie. $ 39
WILLIS Ul0 10 watt UHF Transceivers.
(VKTRAB approved & awaiting final installation)
Get on 43%2 FM tomorrow!

Large quantity of Video Tape recorder
Control Modules $ A4ea.
Lots of other goodies, transceivers etc. suitable
for parts - MUST CLEAR.
P.O. Box 1311, Launceston: Phone (003)443882
REPEATERS

A repeater is a 'black-box', normally situated at an elevated
site, which receives a signal and re-transmits the information
contained in that signal on another frequency, 600 kHz higher.
Operation of a repeater is 'full-duplex', i.e. the transmitter
and receiver are in operation simultaneously. Compare this
vith an ordinary transceiver where either the transmitter or
the receiver (never both) is in use at any time - the antenna
is switched via a changeover relay (or electronic switch) to
the unit in use. If you like, a repeater antenna system is
'frequency-division multiplexed' (FDM), and an ordinary
transceiver is 'time-division multiplexed' (TDM).

In a transceiver, interaction between Tx and Rx does not occur
because only one is on at a time; but in a repeater, extensive
measures are necessary to prevent the transmitted signal, or
any sidebands of the transmitted signal, from affecting the
performance of the receiver - whether this be by overloading
(blocking), on-frequency noise or the generation of inter-
modulation products.

TWO ANTENNAE

One method of preventing interaction between the transmitter
and receiver in a repeater is to use two separate antennae,
physically separated to provide a degree of electrical (RF)
isolation. Vertical separation is more effective than
horizontal separation, on a 'dB/metre' basis. In the case
of the Mt. Wellington repeater, two antennae are currently
in use, with a vertical separation of approximately 43 metres.
Additional isolation is required, in the form of narrow band-
pass filters (cavity resonators) in both transmitter and
receiver feeders. One cavity in front of the receiver also
incorporates a bandstop response (notch) on the transmitter
frequency.
The tvo-antennae arrangement means that the radiation
pattern available to the transmitter is different from
that available to the receiver, resulting in some areas
vhere the repeater can be 'heard but not worked', and
vice versa.

An advantage of the two-antennae arrangement is that the
receiver antenna can be fitted with a low-noise mast-head
pre-amplifier, to overcome the cable loss (about 4 dB to
the upper antenna). This can result in an improvement in
the system sensitivity, in the absence of too much on-
frequency RF noise.

DIPLEXER

A diplexer provides an alternative to having two separate
antennae. It provides a method of sharing one antenna and
sive one feeder between the transmitter and receiver.
SINCLE ANTENNA
AND FEEDER

There are several types of diplexer, but all share the
following characteristics:

(1) lov loss between transmitter and antenna
ports at the transmit frequency (<2 dB);
(ii) lowv loss betweenantenna and receiver ports
at the receive frequency (<1.5 dB);
(iii) good isolation (high loss) between transmitter
and receiver ports at both the transmit and
receive frequencies (about 85 dB at each frequency).

13.
—— e - —eeee e ——— e —

Characteristics (i) and (ii) are obviously necessary for
operation. If we had a perfect transmitter, which did
not produce any output except on its designated frequency,
and a perfect receiver, which did not respond to any RF

S &
energy outside of its receive passband, then (i) and (ii)
would be sufficient. Unfortunately, our equipment,
although very good, is less than perfect : the transmitter

o~
does generate some noise on the receive frequency (perhaps
as much as 110 dB below the carrier power), and the
receiver can be overloaded by too great a signal on the

=
transmit frequency (say anything greater than a power level
of -15 dBm, or about 50 mV - possibly as high as ¢ dBm, 220 mV).

-"T
For a 50 W transmitter then,’the isolation required must
reduce 50 W (+47 dBm) to -15 dBm, i.e. 62 dB on the transmit
frequency.

The transmitter noise level is 110 dB below 50 W, i.e.
-63 dBm. Now a signal level of 1 yV into 50 represents
-107 dBm. Thus 44 dB of isolation on the receive freguency
is required to reduce the transmitter noise to 1 uV, and
64 dB to reduce it to 0.1 uV. (For interest, the D.0.C.

M o
specification RB 207 requires emissions removed by 50 kHz

£
or more from the carrier frequency to be not greater than

*h(Y
2.5 uW, i.e. - 24 dBm; obviously equipment which just met
this specification at 600 kHz would not be suitable for use
.

() bde M
in a repeater!).

Consequently, characteristic (iii) of the diplexer is very
important.

¢
A prominent commercial diplexer uses cavity resonators,

O T
configured as band-stop filters, and is known as a Notch
Diplexer.

M0
Antenng

NN
-—

cesorator
acteh cn ;'R; notch On P((

Iy
For exgmple, the AEA model 6D4-145 provides'
85 dB of
isolation in both transmit and receive logs (at fRry and
f1x respectively), with a loss of 1.2 dB in both legs.
- aS

Note that the notch diplexer provides no bandpass filtering,
and additional bandpass filters will be required at
congested (RF-wise) sites.

Other elements used to make up diplexers include circulators,
vhich may be either ferrite devices, or constructed from
precisely cut coaxial cable - the hybrid ring, or so-called
'rat-race' circulator,
Antenna,

Tx Rx

The circulator provides low loss between any two ports in
the direction of the arrow, i.e. Tx~antenpa, antenna to Rx,
vith high loss (25-30 dB) between adjacent ports counter-
clockvise, i.e. Rx-antenna, Tx-Rx. Further notch or bandpass
filters are required in the Tx and Rx legs to make up the
remainder of the isolation required. Note that any deterioration
in the VSWR seen at the antenna port (e.g. due to ice build-up
on the antenna) will reduce the Tx-Rx isolation.

SYSTEM CONSIDERATIONS

Although it often 'goes against the grain' to consider intro-
ducing an extra 2 dB or so of loss into any system, consider-
ation of a diplexer versus two antennae must take all factors
into account. Cost factors to consider are :

(i) the capital cost of a diplexer;
——

(ii) the maintenance cost of an extra antenna and
feeder in an exposed situation;
—

(iii) the rental for an extra antenna (not charged
at present, but a possibility in future).

/5
A straightforward economic comparison has shoun that,
assuming a lifetime of 20 years for the diplexer (not
unreasonable for a piece of static equipment), and
assuming that each antenna and feeder may have to be
replaced every 5 years (certainly not unreasonable for
Mt. Wellington), the present value of the total costs
are $2161 if a diplexer is used, and $2044 if two antennae
are maintained. This accounts for material only - no
account is taken of time and effort to install the
replacement items.

Performance considerations are :

(1) the extended range due to 2 dB less loss
in the feeder;
(ii) the uniform Tx and Rx coverage in the case
of a single antenna;
(iii) the greater reliability when only one antenna
and feeder has to be maintained.

ANDREW BOON
VK7AN

Southern Branch : NOTICE OF MOTION

At the April meeting a motion was moved by Andrew, VK7AW
and seconded by Harvey, VK7HK that :

"The Southern Branch commit $1600 and
freight to purchase a diplexer for
repeater 2".

This motion will again be put to the Southern Branch
meeting on 2 June 1982.
*QTOL FATHITIIE ‘TIIWIS HOHITH
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1¢298Y 2
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S3JIAH3S OJINOHLO313 J
HOBBY ELECTRONICS
IN 83 Carella Street

STOCK Howrah 7018
Ph. 476674
(At 22/5/82)

H.¥. TRANCEIVERS: 2 METRE TRANSCEIVERS:
TS 130S $550 C22A $170 UsedJ
FT-7 $380 IC214A $150 Used.
FT 101B $350 KEN.H/held KP202 $110 Used.
HW-7 Heathkit $ 85 IC202E $175 Used.
ROTATORS2
POWER SUPPLIES:
FP 301 20 amp $120 CROWN CAR 24 $ 99 New.
PS 30 20 amp $180 CDE Big Talk $ 99 New,
HK-4 2 amp § 35 EMOTATOR 103 LBX $180 New.

OTHER NEW EQUIPMENT:
AT 230 Coupler $195 ICMB6 22S Mount
LSG 16 Sig. Gen. $145 ICMBS 701 Mount
ICSM2 701 Mic. §$ 45 ICFA2 2M Ducky (IC2A)
MC10 Kenwood Mic$ 23 SS-2 2M S/steel 3Wave
MC3SS n " $ 31
6JS6 Valve

P
YETA Yaesu Mic & 18 6KD6 Valve
ICBP4 IC2A Pack $ 10 6146B Valve
ICDC1 IC2A Pack & 20 12BY7A Valve
ICLC3 Case IC2A $ 8.80 7360 Valve (Used?)
PL 259 Acme .50¢ C32-25 Reducers

YK 88 CN 270 Hz Filter TS 530S etc. $ 53
FRG-7 DIG. DISPLAY - 3 Segment $ 79
T 25 25 W Dummy 3-500 Mhz,. $ 16
XTALS Ref. last QRM (GTX 3325) $ 3
TH3 JNR. BEAM 20-15-10 Metrs. $320
USED:
ROBOT SSTV Fast to Slow $600
LOGIC PROBLEM
These playing cards are in a pile, omne on top of
another, face down. There is a 3, an 8, a 10 and
a Jack and each one is of a different suit.

. The bottom card is a club.
. The next-to-the~bottom
card is the highest value.
. The club is not the lowest
eard in value,
The 8 is one of the red cards.
The card directly under the
diamond is higher than a 9.
. The spade sits directly on
top of the heart.

Issup)
not from Sydney
(37, Canoerra (5), or Perth (7) so he must be fron
Melbourne, and is running 400W (5).
The yagi is Peter's (1). The rhombic is 30W so it
can't be Jim‘s who runs 150W (6) or Mike's who we
know runs 400W. Nor is it Tom's from Hobart (2) so
it must be Bill's and it is he who has a rhombi
and 30W °
Peter is not from Canberra (1) so he must be from
Sydney which leaves Canberra as Jim's home and 150W
output. Peter from Sydney hasn't 80W (3) so he must
have 200w which leaves Tom from Hobart with 80W.
Jim doesn't have avertical (6) and nor does Mike (3)
sothat must be Tom's antenna, As Mike hasn't got the
G5RV (7) he must have the quad and the GS5RV must
belong to Jim.
iNAME LOCATION ANTENNA OUTPUT

Perth Rhombic
Canberra G5RV
Hobart Vertical
Sydney Yagi
Melbourne Quad
VHF PRE-AMPS. vk7zan
J310 preamp was developed by VK7ZDF for radio tele-
scope use and adopted for 2 metre use, firstly for the
Hobart repeater. This preamp was a two stage device
with 12 Volts A.C. fed up the cable to power the preamp.
A single stage design (see detail) is now in use in
a lot of 2 metre FM equipment,
VK7ZJG took the design and by changing the LC ratios
on the input and output eoil produced an excellent 6
metre design (see detail) and a number are in service
in 6 metre equipment.
Setting up the preamp is simple - connect the amp
in line with your receiver but do not power up the amp
at this stage. Firstly tune the output coil while
listening to a weak signal. The peak will be quite
sharp. With a 50 Ohm termination connected to the input
of the amp, again receiving a weak signal, tune the
input coil for best signal. Power up the amp and re-
peak the coil for best signal to noise ratio. The tun-
ing will be quite broad. If no peak is found, adjust
the coil by either stretching or cramping the winding.
The preamp has limited gain but excellent signal to
noise ratio and will improve even the best of receivers.
Older valve receivers will not benefit to the same
extent but it certainly will improve them as well,
although a two stage design would provide more gain,
The circuit has also been adopted for commercial
use on 4 metres with great success.
While a board is not necessary, the layout shown
will give excellent results.
David, VK7ZOT reports success on 6 Metres using
TISS 88 Fet and others could be used with some variat-
ions in performance,

by A. Ruthven,
ore
ZHIN 8¥1-P1l *SI9
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€8 SS'L *3
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GEORGE

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HARVEY While
ELECTRIC inte:

Pty. Ltd. form
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reco:
Tigr.

who |
for .
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tect.
of el

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WTCPN Soldering station bell
of g
A transformer powered soldering station, complete with a low TRADE PRICE Naza
voltage, temperature controlled soldering pencil. The special flas
Weller “closed loop™ method of controlling maximum tip
temperature is employed, thereby protecting temperature $69 and
sensitive components while the grounded tip protects voltage
and current sensitive components. The soldering pencil features TAX EXEMPT Wale
stainless steel heater construction, a non-burning silicon rubber byx t
cord and a large selection of iron plated tips in sizes from .8mm EX STOCK shel
diameter to 6mm diameter with a choice of tip temperature of
DELIVERY: duri
600°F / 315°C, 700°F / 370°C and 800°F / 430°C.
A redesigned transformer case features an impact-resistant noryl and
for durability and protection against accidental damage, a quick than
connect/disconnect plug for the soldering iron, extra large with
wiping sponge, tip tray to store extra tips, plus a improved off-on most
switch with a long-life neon indicator light, a nan-heat sinking
soldering pencil holder, and a 2m flexible 3-wire cord.
The soldering iron is normally provided with a PTA7 ~1.6mm
screwdriver 700°F/370°C tip.
Furt
futu
162-164 ARGYLE STREET, HOBART. TEL. 242233

While reading a 1956 issue of A.R. I came across an
interesting item which is as follows;
Man's first contact with electricity was in the
form of lightning, and fear of this phenomenon is
still widespread in modern times. Some of the oldest
records of this were found in the ruined cities of
Tigris and Euphrates dating back to 3000 B.C.
In France there was a superstition that people
who had been struck by lightning and recovered had
for 40 days the power of curing all kinds of diseases
by touching the body of the afflicted person. It is
also recorded that during this period they touched
his pocket as well. In Europe and England it was,
for many centuries, the general practice from the
time of Charlemagne to supplement prayers for pro-
tection against lightning and by the vigorous ringing
of church bells to ward off the demons of the air.
It was reported in 1874 that in 33 years light-
ning had struck 386 church towers and had killed 103
bell ringers at the ropes. In 1769 one hundred tons
of gun powder in the vaults of the church of St.
Nazaire in Brescia were exploded by a lightning
flash. The explosion destroyed one sixth of the city
and killed 3000 people.
During the early stage of settlement, New South
Wales met with misfortune when several sheep arriving
by the first fleet, were killed by lightning while
sheltering under a tree during a storm. In Australia,
during 5 years, (1946-1951) lightning killed 19 men
and 2 women., Many more people are struck by lightning
than are killed. On one occasion a church was struck
with 300 people in it; one hundred were injured and
most made unconscious, but only six were killed.

by PMaurice Potter VKT7SA

Furtoner articles of a similar nature will appear in
future issues of QRM,

3.
FOR SALE
KENWOOD TS-820:
TS 820: Good condition. D.C. Converter, C.W. Filter,
Noise cancelling mike. $750 VKTNWR 444089.
oy
Very
KENWOOD TS-%ZOS;
in mint condition. Complete new MC-10 mike.
-
usec
Original carton and manuals, An "on air" test if
necessary. Used on the 80 Metre relay. Resonably priced
incl
sol¢
Cash $475 (Licence holders only). Jim VK70W. Phone
Phone (004) 26 1520. ed 1
base
YAESU FRDX-400§FLDX-400:
Transm er/ receiver; Receiver covers 160-2NMet.
$95
with full 10 Metre coverage, the new 10 Mhz. band and
ir
an FM demodulator.
. Transmitter covers 80-10 Metres and is currently
modified to novice power but can be converted to full
power if required. Price $400 ono.
Contact VKT7NOX (002)439948 or VK7MM (004)254526.
YAESU FT 620B:
etre transceiver 50-54 Mhz. USB, LSB, AM, CW.
V.F.0.: 240 V AC or 12 V DC operation. 20 W PEP output
with U310 Rx pre-amp, xtal calibrator and two fixed
§hannels installed. Mic. and handbook. Good condition.
320.
MR 154 - A.W.A, 52,525 Mhz. Carphone - valve. Handbook
included. $25.
H.B, 6 & 2 Metre Linear Amplifiers combined in one unit,
separate 6/40 valves for each band. Drive required 2-3
watts, Carrier operated relay or manual contral, 750 V

=
Hd
o
power supply for above in separate box and several spare
6/40 valves - condition unknown. $180 ono. the lot.
John VK72ZJG (002) 438114.

KENWOOD TS 820S:
ransceliver in immaculate order, spare finals
and driver. Original packing and manual. $725 ono.
Peter Vince VK7PV Ph. 446132 (Home) 348507 (Bus.)Hbt.
THORN CCI COLOUR CAMERA:
As new .
Shane Burgess VK7BX Ph. (002) 296884,
24
FOR_ SALE

-%Qﬂgggggi Superboard II with power supply in alumin-
um box. Dabug II monitor, 8 K ram, misc. extras.
Very little use. $350 ono.
B§2¥ EEMODULATOR; ETI design, bar led tuning, variable
: shi uning, power supply in aluminium case. Can be
mike. used with above computer. Unpopulated modulator pcb
included. $60. Will sell separately if computer
ced sold first.
L0METRE TRANCEIVER: Sideband SE 502, factory convert-
ed to 10 metres, 28.300 to 28.600 Mhz. 240 V operated
base station. In original box with operating manual.
$95 ono.
Net. SPEAKER%: Home brew 2.5 cu.ft. 2 way. 10 inch woofer,
inc ome tweeter. Ideal for rumpus room. $50.
Phone Ron - VK7RM - (002) 232808 QTHR.
ntly XA BTh oSe itaNs
1 :
00 »*BMORY BOAR - 3 only - 16K each board - $160 ea,
VK7ZTA - Anthony Tulk 20 Athleen Ave., Lenah Valley.
PHONE 282366

, CW. Wanted to Buy
ut _
e
A
Teletype Machine-~ Preferably a Model 15 and
preferably in working condition.
Sok Contact Andrew Perkins VK7ZAP on Repeater 3
or Ph, 004 351099 - P.0. Box 209, Somerset 7322.
unit, ip e i o e
2=3% PHONE PATCH to suit FT 101E in good condition.
oV Please write giving particulars and price to;
spare Mr. A. Snowdall, P.0. Box 90, Ballarat, Vic 3350.

SOLUTION TO LOGIC PROBLEM (This Issue)

1s Card A Three of Spades.
: Card B Eight of Hearts.
bt. | Card C Jack of Diamonds.
Card D Ten of Clubs.
NOTES FROM OUR NORTHERN SCRIBE - Robin Harwood VK7RH.

Our meeting in June will be on the 11lth. of the
month, and our Annual Auction will be held. It is
at the Kings Meadows High School upstairs at the
end of the corridor in the Sewing Room at 7.45p.m,
In July we are planning a tour of the local TNT9
studio complex.
On the weekend of June 12th. to 14th., there will
be a major WICEN exercise to help provide communic-
ations for the Police and SES, as well as other
groups allied with Search & Rescue, Field Headquart-
ers will be at Storeys Creek. The club call, VK7NB
will be used. Communications will be primarily on
2 metres on 146,.5 simplex and on the proposed Snow
Hill Repeater on Channel 6900. I also believe that
there will be a portable repeater also on standby.

S
There is also the provision of a 1link bpack to Police
Headquarters via VK7ZGA who will relay Repeater 6

A
onto a 52Mhz. frequency, and also for the station at
Police Headquarters to communicate directly with
the field via this 6 metre link to Repeater 6. This
exercise will be continuous for 60 hours and will
be monitoring all the channels in operation, so
there will be a need to keep accurate loggings.
We were very saddened to hear of the deaths of
Terry Connor VK7CT and Ian Nichols VK7ZZ. The
sympathy of the Northern Branch is extended to their
families at this time. They will certainly be missed
on the air,
Until next time, 73. VKTRH.
vee kbt
e e e eA e
I
(
!
When purchasing items from our advertisers please I
remember to mention that you saw their ad. in i
QRM as it is their advertising which keeps your
magazine going. i
(
£
e

TASMANIAN ELECTRONIC SUPPLIES erv. uro.
INCORPORATING N.S. ELECTRONICS (TAS.)

P.O. BOX 206,
TELEPHONE: 44 1337 BELLERIVE,
TASMANIA 7018.

NATIONAL SEMICONDUCTOR DISTRIBUTOR
Stocking the following integrated circuits-
Data Acquisition A/D D/A, TTL, CMOS, LS also HYBRID,
Linear, Regulators, Microprocessors CPU (all types),
PERIPHERAL, MOS/LSI, Timers, Clocks, & Memory Products
Semi-conductors plus Diodes, Zeners, Rectifiers,
Bridge Rectifiers, SCR, Triacs.
Transistors - Small Signal, Power Switching.
RF Transistors - Motorola.
Capacitors - full range.
Connectors - computer related.
2ir Crystals - lmeg. - lébmeg.
sed
Data Books.
I.C. Sockets - Solder and wire wrap 8-40 pin.
Microcomputer boards BLC.
Opto-electronics - Displays, LCD, LEDs, Couplers.
Transducers - Temperature and pressure.
Resistors - carbon, metal film,
Relays.
VMOS Power Fets.
COMPREHENSIVE STOCK HELD IN HOBART - OVERNIGHT
SERVICE ON STOCK ITEMS - NON STOCK ITEMS 48 HRS.

27.
QSL BUREAU NOTES
Points to remember when preparing QSL cards;

-Wnen logging in UTC (GMT) remember that the date does
not alter until 10.00a.m. local time (lla.m. Daylight
Saving Time).
- To be accepted for awards a QSL card must indicate
that a QSO has actually taken place. Many VK7 cards
do not meet this requirement, so it is suggested that
when having new ones printed, they show the words
'confirming two way QSO ' or similar.
- Please sort your cards alphabetically, by prefixes,
before handing them in to the QSL Bureau. Those for
U.S.A. and Australia into call areas and all the U.S.A
prefixes sorted together under 'W'.

When having cards printed, do not choose
a heavyweight type of card and make sure
they are no larger than 140 x 86mm - the
size of the box drawn around this item.
Outward cards larger than this will not
be accepted. They weigh more, do not fit
in a standard size envelope and will not
pack easily in bulk with others, result-
ing in damage to your card.
The charge for outward cards is 2c each
(non-members 6¢). Sheets of 100 stickers
are available from branches, QSL officers
and the Bureau for $2 and one of these
stickers must be affixed to each outward
card, except those from members for other
VK stations as these are handled free of
charge.