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BULL-
RRl
1.0 ISSULD BY Tir NORTHERN P.0. BOX 1010
BRANCHZS OF THE WIRELESS INSTITUTE LAUNCESTON
OF AUSTRALIA, TAS. DIVISION. TAS 7250
MAY 1975
VOL. 5 No 2
REGISTURED AT GPO HOBART
for transmission by post PRICIL 40c
as 2 periodical, CATEGORY B.
MEETINGS
May 3rd Northern Branch Executive lMeeting
May 10th Ilorthern Branch Civil Defence Rooms
Bourio Street 8 p.m.
May 13th North-wWest Brang? fiLéklnS Hall, Ulverstonec.
a0
May 3rd
& Radio Instructionsl Class Lakins Hall
May 17th Ulverstone 2p.m.
& ,
May 31st
May 10th
& Kings Meadows High School 10 a.m.
May 24th
Contects
May 3rd-4th Bermuda W
May 10th World Telecomm phone
May 11th VWiorked all Britain CW
Mey 17th World Telecomm CW
SUBSC.APTIONS
Subscriptions to the Northern Branch are now due. The
cost this year will be $2.50 as decided by motion at the
last meeting. If you wish to continue getting Q... then
please pay by sending your subscripgtion to P.0. Box 1010
Launceston or by giving it to the treasurcr at the next
mecting.
. A
May 1975 QRM pege 2
Editorial
The announcement last Sunday that the W.Jd.A. broadcast
may soon be originated on the 432 WF3 band in A.T.V. was in-
deed pleasing and it may bring an importent "first" for the
Tasmanien Zone. I, for one, em most pleased to see that
there are still those amongst us that are not "applisnce op-
ereators" and are experimenting with new a2nd old uecthods of
communications as amateurs have a lot to give in thig field.
It ie perhaps worthy of note thet when filling out the app-
lication for an emeteur license one hes to supply details of
the type of experimentaticn that, as en emeteur, one is going
to carry out.
This ennouncement slso indirectly reises ancther quest-
ion: that is on whet band/bands should the broadcast be or-
iginated? There have been in the past comments eos to the
quality of the 80 metre signel when the brosdcest is orig-
inzted on other than this bsnd. 80 metres hes always been
the primary frequency for stetewide brosdcesting =s 1t is the
only frequency used which cen relisbly transiit across the
whole state and the quelity does therefore nezd to be of 2
high standard. On the other hsnd, originating the broedcast
on V.H.F. frequencies coes a2llow Z calls to 2ct 2s origin-
ating stations and thus gives others a2 chance 21t collecting
and giving the news. Different people each week does give
variety to the type of news and audio that one hesrs and
surely this is a good thing but poor quality does reflect
badly on the Institute. One suggestion hss been that 2
calls could originate the brosdcest on 80 metres from the
QTH of full calls and perhaps this sugzestion may merit dis-
cussion by branches and/or council. I have origineted the
broedcast mgself on 2 metres chennel 48 and 2s a result both
fevoureble and unfavourable reports wecre made. Some of
these reports were of 2 conflicting neture as they are on
many callbacks, but, 2s requested in the bulletin, perhaps a
test by the origineting stetion together with relay stations
prior to the broedcest way help to overcome socoue of the
problems reported on by callbeck stations. Any reacer who
feels he/che would like to comment on this or any other
probler only has to senc 2 letter to t.e editor znd it will
be published or perhaps you may feel it is better to discuss
it at your next branch meeting.
Graeme VKTZGG Editor.
Extract from Northern Zone Minutes 11/2/55
"We had much pleesure in welcoming
Mr. Ed Bovis ex G3EXD who is now in Leaunceston".
Ed VKTHE,
May 1975 Q.R.M., 3
Page
Northern Branch
The April umccting of the Northcrn Branch was held on
the 11th at Kings lMeadows High School Present wicre two
visitos Terry Haays and Bill Vu3£X Petcr VKTPL revortcd on
the proolcm oite N.Ww. branch member has been having wnile
operating on 52.525 miz and explained ¥The complex situation
involved,
A Library exinibition on amateur radio has been arranged
at the Launceston Regional Library during the $th - 21st
June inclusive. Norman VKT7IIR is in charge of this and would
figgr iate and equipument including old uwaits which could be
Q
out on display. It is also hoped to have some equipment
operational.
The increase of branch levies was discurred at great
length and finally a wmotion was passed to tae effect that
levies for the ensuing twelve montis would be $2.50. These
ievies are now due and it would be avpreciated if they
could be paid at Tthe next weeting which is to de held at
the Civil Defense rooms in Bourk stirect-members will be able
to exaq1ne the proposed new rooms at first heid. Llembers
nholdingz Northern branch magazines are asked to return theuw
to tie ecretary ag goon as possinle sc that a library
ay be set up to enable gll weuwbers to make use of them.
Joim VK7JV has veen elected clubroouw finance officer
g0, chaps, start diz_ing deep.
The meeting tnen adjurned to enavble sovme most inform-
ative filus to be shown thanks to wally VL7242V,
Hotes as told to VKTZGG by 1d VKTHE
Summary of costs of running the Northern Branch last
financial year as extracted from the Balance sheet.
Repeates. Power Costs: £67
Licence: 125
Call sign VKT7NZ- 512
Cost of runnins QRM- §70
P.0. Box: 8
Hiring of Rooms: © 20
Cost of Suppers: R )
Tctal c219
This does not include fonations to AMSAT etc.
May 1975 QRIL . page
Divisional Annual Genercl loeting lotes
Well, the divisional AGM has come and gone again. It
we.s held this yecr in Leunceston at the Adult Lducation Rooms
in High Strect. ihile 33 abttended some felt there could have
becn greater attendances from the various Branches.
It a .peared everyon was eager to gelt golug so previous
minutes, correspondence, reports and financial statements
were all tabled and accepted.
The Constitution ammendments were passed, also the
Merit Award, with somc minor alterations.
Since the posgition of Patron had fallen vacant, Jack Iiike
VKT7AG was duly electec.
The following Councillors were elected for the ensuing
twelve monthss VKT7AK, XK, PF, 24GJ, FB, ZAQ and ZBY.
Southern mambers were concerned with safekeeping of m=g-
azines thay had accumulated. It was resolved that for any
libreries set up, Council would be the custodian while actual
Branches handled and looked after the books.
Some aged divisional equipment held in the Southern Branch
is to be disposed of except for the TVHZ equipment.
The N.W. representitives agreed to look into their Branch
A.G.:Z. timing to bring it into line with other Branches.
Finally several members praised the c«fforts of the Broad-
cast Officers for the consistency and quality of the broad-
casts.
The members retired at 1700hrs to brace themselves for
the dinner to follow.
I think all who attended the dinner =2t the Village Ifotel
thoroughly enjoyed themselves. Several made use of the dance
floor and the lively orchestra, while one local identity burcst
into the "Gay Gordons" or was it a "Quickstep" or a “"Foxtrot?"
Unfortunately it was on the table, which nearly capsized per-
former and all.
Nevertheless 211 ended well.
73 Bob T2RF.
T.V. TRANSLA.OR FREWUINCIES
Round Hill, Burnie National Channel 4 Commercial Channel 10
Table Cape 1 oh
St. Helens 0 7
Willis Hill Stanley 8 6
Tier Hill Smithton 4 10
A.B.C. BRCADCAST TRANSLATCR FREQUINCIES
Sot. Helens 1570 KHZ
Fingal 1160 KHZ
May 1975 Q.R.Ii. Page: 5
HF nctes for April 1975
Due to the ecarlier sunsets nov with us listening tiwmes
on the higher HF bands have baen scmawhat limited. However,
20m has been reasonably gecod with DX available most days
until about 1100z when wzak CW can be worked. 15m has bean
giving the usual openings to the North and the Americas.
Some wesak signals hevz been heard on 10m from tiwe to
time, and perhaps more calls would prcvide some activity.
40 and 80m have been gocd for DX into all continents after
sunset and around dawn.
On 20m the following have been worked with gcod signals.
BV2 B, 8P64H, FB8YD, 9H3R, LAING, 4Z4HF, KV4AA, plus the
usual burcopean and South Americen statiocns between 0200-1200z.
VI@NWE M/ on HMCS " cootenay" is active in the VS6/JA
area and looking for Vk's after ex. recising with the "Hobart"
etc.
Jack VKT7AG has heard strong signals from zurcpe on 30m
around dusk with the ZL's working thewm with case.
40m has provided good DX especially on CW which with
some searching can still provide WAC each day.
73" VK7BC
These stations have been heard and workef usinglas Frark
Bays) a rather poor G5RY so its obvious 2 sophisticated
gerial is not required to work DX stations(Editor.)
LOOKING BACK.
Extract from Northern Zone Winutes 22 lMar. 1963.
"The President Mr. D. Kelly 7DK then tresented his
report of the years progress and had plezsure in
reporting thzt membership had increased by 6 to 16.
Also that during the year 4 members had geined their
linited AOCP (T. Bevis C. Barnard G.Ranft R. Grant)
and he hoved they would c rry on and pass the code
to gein a full certificate."
LME BRI
The nothern branch is now the Tasmanian ..gent for
VICOM 1INTuiN.TIONLL Pty Ltd. This company through our agency
sells amateur radio equipment to amatecurs, Sece lists
and prices of cquipment elsewhere in this issue and in last
months issue.
May 1975 Q.R.M. Page: 6
LADIES PAGD
Letter via Editor.
Hi G‘irlsg
Pirstly a vote of appreciation for 7 JV John and XYL Joy
for all the work that they did for the last 4 years in putting
together news for the boys.
Secondly, cougratuletions to 7 &GG Graeme, also wishing
you luck.
Thirdly, I wonder what has happened to all of us. We
carried on no end about not having a page of our own in Q.R.IL
As the wives showed an interest in the wonthly news letter,
we asked for a sectiocn for ourselves. Our wish was grantedd
Well, this went well for a very short while, and grad-
ually fizzled. Why? This is International Woman's Year, so
let's put a 1ittle of T.W.Y. into Q.R.}M. and prove that we
are interested when 1t comes to doing a little of the writ-
ten chatter ourselves.
I know a lot of you have young demandins families, and
sometimes we haven't enough hours in the day. Don't show the
O.lls we blow hot and cold, they'll think what” they say about
women is true. Also, there is a new Lditor to help get stur-
ted. There must be some of us with a recipe or two, or maybe
some housc hold hinte, maybe Jjust some plain old news. I'1L
try if 7 2GG will let me, but I can't do it on my own.
Please help.
Cheers and 73's
VK 7 NR's XYL Ann.
LOOKING BACK.
Extract from Northern Zone Minutes 5 Nov 1959.
"A discussion took place as to where the future
meetings be held. Whether now thet the numbers
had increased, to endeavour to find e fixed plece.
No suiteble plece was suggested and taking in
consideration the cost of sore places it was held
over for further discussion. Col Wright sugg-
ested that to ease the burden on the hosts thet a
"Plate" or basket be provided."
PLE..SE HELy FILL THIS LP.CL NEXT MONTH
May 1975 2.R. M. Tacer 7
Dear Iditor. Q.7.N.
VKT7ZGG who ever you are.
For any new ccmers to the world of Amatevr Radio as I
ond many others are and will he, it is very exasperating
listening to Broadcasts, Reading A.R and JRM and seceling
names such as VEK7xYZ Xen and not knowinz really who is being
referred to. I, lile others have been trying since last
Noverber to obtain a call book hit as yet with no sucess.
Terha s a r-w hook 1s not available or I am trying in the
wrong rlace (Terhars "IA is mnot the right placc) bvt as yet
with no sucess in o™tainine a call bhook.
“hat do others think of the idea of including svr-names
with call sisn and christian names in articles. I would
gucgest that it would only he necesgsary to ~ut sur-names on
the first arpearance of namrme in each article. Another
altarrative would he to rrovife an index of all nares in the
magazine. I rrefer the first.
Food for thousht!
Signed
Vk7Z2R21. TBrizn.
P.S. If you have not ecot an up to date call bhook or don't
know who I am then you will pow kncw what I am trying to say.
FOR SALE _ FOR SALY FOR SALE _TOR SALT FOR SAL:
1 Belcom Liner 2 2 metre S.5.8B. Rig
20 watts P.5u.7. Solid state unit with extra crystals.
Price-§230
Danny Arted VK7ZDA Thone I1'ton 316643
65 Broughar St. VWest Launceston 7250
1 “ddystone ®C10 Communications Receiver
Five bhznds covers 540 ke-30mHZ
Transistorised and runs off batteries
Tagily ada ted to A.C. oprerstion. Price :150 o0.n.o0.
Graeme Reardon VK7ZGG Phone L'ton 469455
2 M-ent St Younctown 7250
TOWNSVILLE r.CIFIC FESLIV.I CONTIST
This ycar the contest will be held on Saturday 15th
June 1975 from 0200 GMT to 1400 GMT.
May 1975. Q.1t.M, page 8.
VHFNotes.
The only openings on 6 metres that I have in my Log.
Book occurrcd on Sat. 30th March for about 30 minutes, then
again on .Lpril 1st very bricfly when Kevin worked VK4 4J3B
and I workcd Vk2 4LU in five minutes, signals were very weak
with deep Q3B. On the Saturday opening 1 only received one
5/9 signal report, the others were around the 5/7 mark., In
all, scven VK4's were worked, three of them being new stations
on the air., nctivity has veen very spasmodic but you will
usuglly find most stations have tlheir recelver.tuncd to
52.050 MEZ. So if you intend calling CQ 6 metres try 52.050
forst.
Two metres has provided some activity in the last week
when a large high was present across Bass Strait., iwepeated
contacts to VK3 were not uncomion, we ¢ven had a Vh3 in
Victoria rcply to the callback following the Broaucast,
On 13/4/1975 Kevin VKT74uli worked VK3.4C, VK3ZNJ,
VK3LQi, VK3ZLW, Vi34LY. 1 did not chivck with Danny 74D. but
I am surc he would have worked o fow more stations as well.
73's Until ncxt month.
Joc VETZGI
Sorry thcrce arc no N.+w. branch notcs this month,
Hope to have some for the next issuc of W kil
May 1975 page 9
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et
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.
Standing-Wave Ratio
The standing-wave ratio is an important quantity in
impe dance measurements (g.u.) and particularly in micro
wave measurements (g.u.).at wltra-high frequenciew and abuve,
the moving-probe slotted line is the most commonly used
method of impédance measurement. Unless the impedanceof a
circuit is exactly equal to that of the transmission line
to which it is connected, the transmitted wave is partially
reflected through the transmission line ‘o the generator.
An interfirence pattern is created as a result of the per-
iodic addition and cancellation of the incident and reflect-
ed waves. This is called a standing wave because it is a
gpatially fixed variation of amplitude along the line. An
electrical standing wave is similar to standing waves of
sound in a closed chamber. The ratio of the Voltage peaks
to the voltage valleys is called Voltage Standing Wave
Ratio (V.S.W.R.).
The ratio T of the reflected wave to the incident wave
voltage is related to the loced impedfance and to the =~ .
VoSo’NoR. :-—I".’
Z" 1-T 1+ o 21 8
) =
-— — 0 PV =
2i: AR
T T Fe VoL r
Slotted-line imp dance meters are usually constructed
with a section of transmission line of the desired type of
line (two-wire, coaxial, strip line, ware guide) and desired
Zo, a coupling means to the E field along the direction of
propagation, a moveable probe to sample the T field at ant
point in the line, and a scale to ascirtain the position of
the probe. The probe is set to a point of maximum E, and
then to a point of minimum L. The ratio of B max to L min
is r, the V.3.7.Rs The position of I min is measured as scen
from the relationship between Z and T, Z is readily obtained.
A Smith Chart (ge.u.) is frequently used to facilitate the
det
.rmination of Z from a V.g,.%W.R. measuremnent,
The ware pattern in the slotted section will depend on
the load. If the loed is a short circuit, the standing
wave patterms are as in Pig 1: the voltaze is zero at the
load and a maximum at a positio#k A/4away. The minimum
voltage points repeat every A/2 along the slotted section.
Similarly, the maxima repeat at A\/2 intervals, occuring
at A/4, 3X4, 5M4 along the line starting from the load.
It follows that the voltaze and impedance umimima as well as
thelr maxime are coincidental.
The standing-wave pattern of Fig 2. is obtained with an
open circuit at the load end. This condition is exactly
cpposite to the short-circuit case of Fig 1. It is appar-
ant from these two excmples that placing different load
impedances at the end of tle transmission line produces differ-
ent standing-wave patterns, wiith the voltaze at the load
varying anywhcre between zero and maximum. The dashed lines
4, =% 3 4 =4 and Z.-4, in Fig 3 represent three different
conditioils ©f load” imPedance and the corresponding voltage
values at the load.
May 1975 Goite M, page 10,
1% is not necessary (nor disirable) to measure these
terminal voltages. IFrom the wave-length, 1t is qalme easy
to determine the position of any of these lines in terms
of wave-length by measuring the distance from the load to
the nearest minimum on the standing-wave pattern.
A reflectoumeter measures V.S5.W.R. without providing
information to determine the phace of the load impedance.
Freguently in measur..ements phase is unimportant, as
many devices are specified to have a maximum V.SW.R. with
no limitation on phase. A reflectometer consists of two
directional conplers (q.u.) one sampling the incident wave,
he other sampling the reflected wave. The two out puts
are delected and the ratio determined, either by measure-
ment and computation, or directly by a ratio meter calibr-
ated in T or in V.S.VW.R.
Although the reflectometer method is simple, there are
several importent sources of error. First, the directional
couplers must have a great discrimination between incident
and reflected waves (oalled directivity) in waveguide,
directional couplers commonly have 40db directivity,
correspending to an error of + 0.01 in reflection coeffici=-
ent. Coaxial line directional couplers rarely have direct-
ivity greater than 30 or 35db, which correspond to errors of
+ 0..3 and + 0.02 in T, respectively.
Second, the relative coupling of the incident and reve-
" rse wave couplers must be known accurately. Errors in relat-
ive coupling of 0.2db result in an error in T of 2.3 per cent.
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