QRM
Recognised text
Text below was produced by optical character recognition and may contain errors. Check it against the original.
Amateur
Radio MARCH 1985
News
S——
o—3_no
Issued by the Tasmanian Division of
ro——
the Wireless Institute of Australia
iM m—
| .
Radiotorial (Conmunent
For the first time in many months, the Editor is apologising
because some contributions have had to be held over until April.
Thirgs are definitely improving - did you notice that the November
editorial, reprinted last month, had to be squeezed down to a much
smaller size? This time it's gone altogether! With a little bit
of luck and some well-kept promises, we may be able to increase
the nurter of pages to twelve.
Som.. of the comments in our pages may well be worth further
discus.ion and we would like more letters to publicise members’
opinions on the topics raised.
It is encouraging to know that regular practical working
sessions dare in progress on the Southern Branch's Activity Centre
in 'ewtown Rood, Hobart. Reports on this will be included in
eacn issue of "QRM", as will any inform.tion received from the
Nerth West on the activities of the Penguin centre. Suggestions
are -lready flowing in, mainly to ask that certain items be
piogremmed in "as a first priority”. The most popular request
seems .o be for the opportunity to build as much amateur test
eqigment as possible - a request worthy of early consideration.
VK7 JK.
/
SO _YCU WANT TO CONTACT THE EDITOR?
riis name is John Rogers. His callsign is VK7JK. His telephone
number s 002,2934C2. His address is:
1, Darville Court,
Blackman's Bay,
Hobart, 7152.
And when you lose your copy of QRM, remember he's O n&k. When
he is at ..ome, the Zm rig is normully running and listening to
Repeater 2.
e
- The Edi*ar’s deadline for copy for the Apri: issuc of "QRM"
vs Fu.dvy, 29th, March. Friday, 29th. March. FhIDAY, Zz%th. MARCH.
e oo
AWARDS, by Bob, VK7NAI.
NZART 1985 CONFERENCE AWARD.
This year's Conference Award sponsored by the NZART has
appropriately been called "The Garden City Award" as this year's
conference takes place in Christchurch, on the south island.
Contacts for the Award are required to be worked between 1st
February and 30th April.
The Award is earned on a points basis system, with the basic
Award requiring 50 points and the Merit Award requiring 100.
Points are earned as follows:
For working Branch stations ZL3AC, ZL3AF, ZL3RR, and
ZL3VV - 10 points each station.
Members of Branches 01, 05, 56, 68 - 5 points each.
All other NZART members - 1 point each.
If the station you have worked has registered for the Conference
and can give you the receipt number, then you can claim an extra
3 points.
At least 2 Branch stations must be worked and claimed.
Applications with the normal details certified and posted
before 15th May 1985 to be forwarded together with 32 of any
currency and posted to:
Garden City Conference Award,
P.0. Box 29040,
Fendalton,
Christchurch,
New Zealand.
TASMANIAN DEVIL AWARD.
It has been suggested that I should put down on paper some
tips that may make the Tasmanian Devil Net operate a little more
smoothly, so here goes:
1. Before you check in to the Net, it is advisable to have
on your desk, a scratch pad for making notes.
2. On this pad, write down station call signs as they check in,
on me side of the pad.
3. When you first hear them working a station, note down the
following against the call sign:
NAME LOCATION SIGNAL REPORT
4, The Regulations require you only to identify your station
at the commencement of a contact and each 10 minutes thereafter
until the end of the contact, when 6nce again call signs must be
exchanged. Therefore a contact fot “the Award should go something
like this: A
Initial call - VK7XYZ this is VK7ABC. Your signals 5 by 9
into Hobart this evening. Name is John. Nice to work you
for the first time. OveT.
Response should be: - ‘Fine, John. Thanks for the 5 by 9.
Your signals are also 5 by 9. Over.
Next response: - Thanks for your report, Peter. Hope to
work you again soon. Bye for now. VK7XYZ VK7ABC.
(Eonfinued}
5. If you think you may be called, make o note on the pad.
The Net Controller will call each station in turn by call sign
and usually also by name. Other details can be obtained by
listening to them working other stations.
I hope this article may assist some of you in the operation
of most nets, not only the Tasmanian Devil Net.
Dloc, VIUWL, OUES ALL MATREMATICAL.
Thanks, Bill, for your very kind remark about "QRM". With
your permission, I may print it in the next issue, along with the
brain-boggling teaser you enclosed. Meanwhile, I give below
the solution to the centre(?) fed antenna problem which, Bill says,
is fair Dinkum! ;&
£ O
"
20 e,
A 120m. F B
In triangle ADB, %% = %g Thus EF = DiéAF
: .. DB,AF = AC.FB
In triangle ACB, EF = FB _ AC.FB
AC 2B Thus EF = —AB
Thus AF = AC.FB = 80.FB = 4FB AF + FB = AB
DB 20
<. AB = 5FB i.e. FB = AB = 120 = 24
D 5
From 2nd statement above, EF = AC.FB = 80.24 = 16 metres.
AB 120
(Absolutely unbeatable, that is! - Ed.)
FOR SALE.
IC2A with soft cover, belt clip. $200. Superboard Computer
in commercial case, multi-voltage power supply. Dabug 3 operating
system, expanded memory, stacks of information, $200.
Contact Peter VK/PF, 181, Punchbowl Road, Launceston, 7250. 003.43018
LIAISON OFFICER FOR "QRM":
Things are beginning to move at last! The Editor, and, I'm
sure all interested readers, will be delighted to know that
BOB VK7NAI
has been elected Liaison Officer for "QRM" at the A.G.M. of the
Northern Branch. Already he has contributed to our magazine, as
you can see from other pages in this issve. Thank you, Bob, for
your support, and I hope northern members support YOU in your
ligison operations! Is it possible that this initiative from
the north will result in similar moves in other areas?
NORTHERN BRANCH NOTES BY BOB VK7 NATI.
The Annual General Meeting of the Branch was held on Friday,
8th February with 25 members attending.
The following were elected Officers of the Branch for the
ensuing twelve months:
President: Mike ... VK7 ZWW.
Vice-President and Club Room Manager: Bill ... VK7AV.
Secretary: Byron ... VK7BD.
Treasurer: Leon ... VK7NHG.
Broodcast and Liaison Officer: Bob ... VK7NATI.
QSL Manager and Historian: Col ... VK7 LZ.
WICEN Co-ordinator: Ken ... VK7KKV.
Publications and Stores: Malcolm e VK7MA.
A General Meeting followed, and Peter, VK7PF, showed slides
taken on his recent trip to Zimbabwe and to the AMSAT meetings in
the USA and England. Unfortunately, a film Peter took in the
USA and on the early part of his tour of Europe went missing along
with o suitcase in Paris. (I know how you feel, Peter. I once had
a Pentax camera and a complete film stolen from my car in that
same city - Ed.).
, The next meeting of the Branch will be held at the Alanvale
Division of TAFE at 7.30 p.m. on Friday 8th March, as a tour of
the College and its facilities has been arranged for that night.
We would like a good turn-up to the meeting, and members' XYL's
and visitors from other Branches would be most welcome.
LETTERS TO THE EDITOR.
Congratulations for a fine magazine.
So much for the bouquets - now for criticism. Some years ago,
before I ever thought I would become an amateur and join the W.I.A.,
I can recall "QRM" being posted out to members.
I have been a member of the W.I.A. for ten months now and I
have attended nearly every monthly meeting of the North Branch in
that time. I have also been listening to the Sunday morning
broadcasts for the past four years.
One thing strikes me quite plainly and that is, like most
organisations, you see the same faces at meetings and hear the
same voices meeting after meeting and broadcast after broadcast.
You, the Editor, complain about the amount of information and
articles that are not being forwarded for inclusion in "QRM".
Perhaps the reason for lack of articles is because this magazine
is not reaching the full membership of the W.I.A., but only the
small fraction that attends the meetings. Perhaps consideration
should once again be given to the posting to all members of our
magazine. Apparently, registration of a publication with Australia
Post is now a lot easier, and postage would amount to about 12 cents
per copy.
If this expense does not seem justified, perhaps an approach to
Federal Office might result in the inclusion of "QRM" with the
Tasmanian mailing of "A.R.". I wonder 3f a separate subscription
for "QRM" might not be such a bad idea.
Relatively new Novice.
THE TAMAR VALLEY AWARD - REVISED RULES.
The Northern Branch of the W.I.A., Tasmanian Division, has
instituted o new award. The purpose of this award is to
encourage all amateurs to make contact with amateurs resident in
the Tamar Valley Region of Northern Tasmania. Short wave listeners
may also qualify for the award in the usual manner.
You may qualify for the award in any of the following sections and
you may qualify for more than one award.
SECTION 1: OPEN: By the use of any combination of bands and modes
available to the applicant. (Split banding is
permitted but cross banding is not except between NAOCP and ALOCP
holders).
SECTION 2: - HF ONLY: By the use of any combination of bands up
to 30 MHz available to the applicant.
SECTION 3: - VHF/UHF/SHF: As for Section 2 but above 30 MHz.
SECTION 4: - SINGLE BAND: Any one band of those available.
SECTION 5: - SINGLE MODE: Any one of those available.
SECTION 6: - ALL NOVICE: Contact with Novice only (including “K"
calls below 30 MHz).
SECTION 7: - REPEATER: Via in-band repeaters. ~
SECTION 8: - SATELLITE: Via amateur satdlites. Cross banding to
HF allowed if permitted under licence term
SECTION 9: - SWL'ing: For short wave listeners.
Section 4 and 5 may be combined with other sections.
Applicants must earn twenty points to qualify for the award.
Stations can be worked only once for each award.
Points are earned as follows:
CALL AREA ON HF ON VHF /UHF /SHF —
Tasmania 1 point 2 points
(20 stations) (10 stations)
Australia 2 points 4 points
(10 stations) (5 stations)
All others 4 points 10 points
(5 stations) (2 stations)
Stations in the following municipalities (shires) are eligible
as contacts for the award:
City of Launceston Lilydale
Beaconsfield St. Leonards
Evandale Westbury
George Town
Applications in the form of log extracts should show the applicant’:
Name, Callsign, Section applied for, Callsign of the station
contacted,Date, Time, Band or frequency, Mode and Municipality.
Claims are to be made by the applicant only. Spot checks may be
made with stations in VK7 for confirmation. QSL CARDS ARE NOT
REQUIRED. Only contacts made after 1st. September 1984 are eligible
as claims, and applications for the award should be made to:
The Awards Manager, PO Box 168, Launceston, Tas. 7250.
A fee of 82 or five IRC's should accompany the claim.
Directional Antennas with Closely-Spaced
Elements
By John D. Kraus,* W8JK
(This article is taken from the January issue of "QST" 1938 and
is submitted by Holger, VK7KI - see notes at end) :
ONE of the simplest and most efficient length and fed at the center. The cross-over feeds
radiators used on short waves is the the two radiators 180 degrees out of phase. The
horizontal half-wave antenna.! Offhand feeders connect on at the middle of the cross-over.
it might not appear that two such antennas would The radiation from the antenna is maximum in
make a good radiating system, if placed parallel both directions broadside and minimum off the
to each other a small fraction of a wavelength ends. The gain in both directions broadside is as
apart and fed with currents 180 degrees out of much as or more than in the one preferred direc-
phase. It is true, however, that this arrangement tion when a half-wave radiator is used with a
forms a simple and very compact directional reflector one-quarter wavelength behind. Dimen-
antenna. sions are given for fundamental operation in the
Fig. 1 is a sketch of two half-wave radiators 14-Mc. band. The antenna is actually a multi-
oriented in the horizontal plane as described and band affair, giving approximately the same
placed high above the ground. The spacing may horizontal bi-directional pattern on 28 Me. as on
be a small fraction of a wavelength. If the wires 14 Mec., or on any frequency between these two
bands. When used on 56 Mec. the horizontal
Minimum
pattern has four lobes. For fundamental opera-
Minimum
tion on 28 Me. the dimensions of Fig. 2-A should
be halved. This smaller array would have about
——» the same bi-directional pattern on hoth 28 and
Maximum
Maximum 56 Me.
An antenna of about the same size as the one
of Fig. 2-A is shown in Fig. 2-B. This antenna is
end-, instead of center-fed. An array having two
)4"/01001 sections, which uses four half-wave elements, is
shown in Fig. 2-C. It is 62 feet long. The array
FIG. 1—TWO HALF-WAVE ANTENNAS CLOSELY
SPACED AND WITH CURRENTS 180 DEGREES OUT of Fig. 2-D has 4 sections or 8 half-wave elements
OF PHASE and is 112 feet long. The antennas of Fig. 2-B,
. The arrows indicate the directions in which radiation C, and D have the bi-directional pattern only on
is a maximum and a minimum.
their fundamental frequency—14 Mec. in this case.
When operated on 28 Mec. their horizontal pat-
are not placed too close together, the pair will terns will have four main lobes. For fundamental
radiate the same power as would a single half- operation on 28 Mec. the dimensions should, of
wave antenna with the same input. But, because course, be halved.
of the close-spacing and out-of-phase currents,
the direction in which the radiation takes place CONSTRUCTION
is profoundly altered. G. H. Brown? was the To make one of these antennas as a unit so that
first to point out the advantages of using such it may be supported between two poles it is
close spacing. convenient to use spreaders, which, for a 14-Mec.
As indicated by the arrows in Fig. 1, the radia- antenna, are about 9 feet long. These may be
tion from the pair is very small—theoretically either of bamboo or 1- by l-inch strips of wood.
zero—off the ends and also vertically. The A suggested arrangement for a two-section
radiation horizontally broadside is a maximum antenna is given in Fig. 3. Since the antenna
and is considerably greater than from a single bears a striking resemblance to one of the ‘T’ or
half-wave antenna fed with the same power. flat-top types popular a decade or two ago, it is
Fig. 2 shows the close spacing idea applied to called a “flat-top beam.” 3
a number of practical directive antenna systems. The cross-over at the middle of the flat-top
The type of Fig. 2-A is 32 feet long. It has two is made by using two 6-inch feeder-spreader
half-wave radiators spaced one-eighth wave- insulators, one placed horizontally at the center
*Arlington Blvd., Ann Arbor, Mich. and the other vertically half-way between the
! An excellent treatment of the characteristics of horizon- center and one end of the wooden spreader. The
tal antennas has been given by George Grammer, QST,
Nov., 1936, and March, 1937.
two-wire feed line comes up from below and con-
2G. H. Brown, “Directional Antennas,” Proc. I.R.E., 3J, D. Kraus, “Small But Effective Flat-top Beam,”
Jan,, 1937, Radio, March and June, 1937.
nects on to the cross-over at the hori-
zontal center insulator. In order to
get greater separation at the cross-
over, the insulators may be made
longer by fastening two 6-inch feeder e 0
spreaders end-to-end. The wire
Jo center
length at the cross-over is of neces- of flat-top
sity a few inches more than the spac-
ing. Thus, the wire length at the Feeders
connect here C
cross-over of a 14-Mec. antenna (8
feet 8 inches spacing) may be abou
8 feet 11 inches. ' 32,
The line used to support the long
600 ohmline "¢Shortjng wire
wooden spreaders at each end of the
12’
flat-top should preferably be of rope.
In case a 4-section flat-top is used, a Feeders
method of accomplishing the addi- connect her ‘
tional cross-overs is indicated by
dotted lines in Fig. 3. One vertical 266" 26 6" - 266" ; 26'6"
feeder-spreader insulator is used at
the middle of the long wooden spreader. The FIG.2—FOURTYPESFORUSEIN THE 14-MC. BAND
recommended spacing lengthwise between the A and B are single-section types, C a 2-section, and D a
4-section. For fundamental operation on 28 Mc. the
sections of the flat-top is about 2 feet. dimensions should be halved. Approximate dimensions
for a matching stub to feed the 2-section antenna of C
are given in E.
FEEDING
The main characteristics of a flat-top direc- center of the cross-over in the flat-top as shown in
tional antenna are the closely-spaced elements, Fig. 3. The approximate dimensions for a stub
about one-eighth wavelength apart, and currents to feed the antenna of Fig. 2-C is indicated in Fig.
180 degrees out of phase. All the elements are 2-E. With more sections the 600-ohm line will
driven. The spacing is not critical but one-eighth connect farther from, and with fewer sections
wavelength seems to be about optimum when closer to, the shorting wire on the stub.
180-degree phasing is used, and is recommended. Where the line is not over a wavelength or two
The mutual coupling between closely spaced long, the Zepp type of feed is very practical. It is
out-of-phase wires is such that the impedance at also convenient if one expects to use the same
the center of the half-wave elements becomes flat-top beam on a number of bands. For example,
quite small and, inversely, quite large at the ends. the antenna of Fig. 2-A may be series fed at the
Accordingly, the current flowing at voltage nodes transmitter on 14 Me. and parallel fed on 28 Mec.
is very high. The feeders in this case would be either one-half
The dimensions are not critical and the values or one wavelength long, approximately, since
of Fig. 2 are recommended for use on any fre- this antenna is fed at a current loop (voltage
quency in the 14-Mec. band. Compensation is node) on 14 Mec. A matching stub for this antenna
made for any small variations when the antenna would also be either one-half or one wavelength
is tuned up. long on 14 Mec. and about 8 feet either longer or
Either Zepp feeders or a matching stub and shorter on 28 Mc. The other antennas, Figs. 2-B,
600-ohm line can be used to feed the antennas. C, and D, are all fed close to current nodes as
The Zepp feeders or the stub connect at the used on 14 Mec. so that matching stubs to feed
Beam them should be
|
either one-quarter
or three-quarter
wavelengths long.
Feeder -spreader. It is often con-
I/nsuvlators \/ i Feeders come uyp from
below and connect here venient to use a
three-quarter wave-
length stub as one
T~ Jnsulators —/ J \ Wooder spreader may be able to ad-
just it from the
Beam ground after the
FIG. 3—TOP VIEW SHOWING CONSTRUCTION OF antenna has been pulled up into place. It is ad-
A 2-SECTION ANTENNA WHICH IS POPULARLY visable to use good 6-inch spreader-insulators
TERMED A “FLAT-TOP” BEAM throughout the stub and 600-ohm line.
Method of making cross-over if extra sections are In adjusting the stub the antenna is shock-
added is shown by dotted lines at left. excited from another antenna or from an r.f. line
(continued).
The copies of this newsletter will be distributed to WIA
members at Branch meetings and to other interested subscribers
by post at purely nominal cost. Anyone who would wish to take up
this offer, please contact the Editor on 002,293402.
coupled loosely to it. The shorting wire on the antenna (see Fig. 2-A). The maximum radiation
stub is then adjusted for a maximum of current is broadside and the minimum is off the ends of
through the short. The transmission line is next the antenna. The radiation is 3 db down at an
connected on the stub a foot or two above the angle of about 35 degrees off the center line of the
short and adjusted up or down the stub until the beam (broadside). At 70 degrees the signal is over
20 db down, representing a front-to-side signal
power ratio of well over 100 to 1. The relative
field strength is plotted in decibels, the minimum
signal observed being taken as 0 db.
The power gain of a single-section flat-top
compared to a single half-wave antenna is over
4 db. When used on its second harmonic the gain
RELATIVE FIELD STRENGTH
FIG. 4—COMPUTED RADIATION CHARACTERIS-
TICS IN THE VERTICAL PLANE FOR A SINGLE
HALF-WAVE ANTENNA (DASHED) AND A 2-SEC-
TION FLAT-TOP (SOLID) BOTH AT A HEIGHT OF
THREE-EIGHTHS WAVELENGTH ABOVE
GROUND
standing waves along the transmission line are a
minimum. A sensitive r.f. current meter (0-200
ma.) equipped with a single turn loop and an
insulated hook can be used to slide along one
side of the transmission line, so that readings may
be made quickly at four or five points along the
line spaced about an eighth wavelength apart. FIG. 5—MEASURED HORIZONTAL RADIATION
Insulation of the antenna and feeders from the PATTERN OF SINGLE-SECTION FLAT-TOP AN-
transmitter plate supply voltages is, of course, TENNA
important in any installation. The relative field strength is plotted in decibels.
PERFORMANCE is about 6 db. The horizontal radiation as meas-
Because of the out-of-phase currents, the ver- ured from a 2-section flat-top (Fig. 2-C) is only
tical radiation from the flat-top antenna ap- slightly narrower, the signal being 3 db down at
proaches zero. As a result, the maximum radia- about 30 degrees off the center. Thus, a 2-section
tion in the vertical plane is lowered to a smaller flat-top puts out a very satisfactory signal over
vertical angle. In Fig. 4 the vertical radiation an angle of about 60 degrees in each direction
characteristics of a single half-wave antenna broadside, and a usable signal over an even
(dashed curve) and a 2-section or 4-element flat- wider angle. The null off the ends, however, is
top antenna (solid curve) are compared for a very pronounced. Three 2-section antennas
height in both cases of three-eighths wavelength arranged at angles of 120 degrees with respect to
above ground. The plane in which the radiation each other should give good coverage over 360
is shown is at right angles to the antennas. The degrees. The gain of a 2-section flat-top is over
relative field strength is plotted in arbitrary 6 db. A 4-section array would have over 8 db gain
units, and the curves are calculated on the basis and a still narrower pattern than the 2-section
of the same power to both antennas. Perfectly type.
conducting ground is assumed, but with hori- y‘f)\ pair of double-Zepp antennas, one stacked
zontal antennas and the height being considered one-half wavelength above the other, is a familiar
the patterns for ordinary ground would probably bi-directional array of 4 elements. In many cases,
be quite similar. especially where the lower double-Zepp is not
It is apparent from Fig. 4 that the radiation very high off the ground, a 2-section flat-top
maximum is lowered from about 43 degrees in the should give somewhat improved performance,
case of the half-wave antenna to about 32 degrees that is, if the flat-top is placed at the same height
for the flat-top. The maximum gain of the flat- as the upper double-Zepp of the pair. A 2-section
top over the half-wave does not occur at these flat-top should also give more gain over a much
angles, however, but rather at lower ones—15 wider horizontal angle than 4 co-linear half-wave
degrees and less. It is these low angles which are antennas in phase and at the same height above
frequently the most effective in long distance ground.
communication. The effect of lowering the vertical The small dimensions of the flat-top antenna
angle of maximum radiation from a flat-top beam make it suitable for use in many locations.
is most pronounced at heights up to a half wave- Through the use of close-spacing the gain is
length or so above ground. At greater heights the exceptionally good for an array of its size.
angle of the lowest lobe becomes nearly the same
as that for a single half-wave antenna. For 14-Mec.
DX a height of three-quarters to one wavelength
above ground seems worth while. (Se.e nokes on
Although much of the gain comes through
vertical directivity, the horizontal gain is also
next [:aae,.),
important. This depends mainly on the number
of sections used. Fig. § shows the measured
horizontal radiation pattern for a single-section
The version that I made up is the 25m. long beam, as Section C,
page 16 of "A.R." for September 1984. Using the measurements
from the "QST" article, that gives 40 feet per element and 2 feet
spacing in the centre, giving an overall length of 82 feet, which
is 25 metres.
For the end and centre wire supports, I used 45 x 20 mm. pine,
and had to use an additional rope from the centre of the end
supports to the apex of the rope triangle. The open wire feeder
is 1 mm. encmelled wire and spaced 55 mm. using 6 mm. quad.
The A.T.U. is a Z-match and a noise bridge is used as a match to
the transmitter.
Other references:
1. A combination driven array, page 142 ARRL Antenna Book,
13th. Edition.
. Wire antennas, "A.R", September 1984, page 12.
B~ wnN
Flat Top, RSGB Handbook, 4th Edition, page 13/58.
End Fire Arrays, 1983 Radio Amateurs' Handbook, page 20/9.
Holger, VK7KI.
SOUTHERN BRANCH A.G.M. ELECTION OF OFFICERS.
The following office bearers were elected unopposed:
a) President: Russ Pitman, VK7ZRP.
b) Secretary: Arthur Hinsley, VK7GH.
c) Treasurer: Phil Lovett, VK7BZ.
d) Equipment Officer: John Holbrook, VK7ZJH.
e) Broadcast Officer: Deferred to next meeting.
f) WICEN Co-ordinator: Anthony Tulk, VK7ZTA.
g) Repeater 2 Co-ordinator: Anthony Tulk, VK7ZTA.
h) Membership Officer: Deferred to next meeting.
i) QSL Officer: "Sandy™ Powell, VK7FL.
j) Vice-Presid
Pttt et
ent: Barry Riseley, VK7KAD.
HOBART AMATEURS TAKE PART IN REGATTA. Alan VK7ZAR.
On Saturday at dawn - well, 7.30 a.m. anyway - five amateurs
set off to make their contribution to the communications of
Hobart Regatta. They were Shayne VK7BX, Anthony VK7ZTA, Alan VK7ZAR,
Kevan VK7KV and Warren VK7CV, and from all reports, they achieved
excellent results.
First, there was the P.A. commentary primarily on the rowing
and swimming events, using 2 metres from the water. This was very
well-received, with crystal clear communications. On Saturday
afternoon, VK/RR and VK/KJ went aeronautical mobile and followed
the Bruny and Wedge Island races from the air. They provided a
number of position reports for relay to the public on the foreshore.
On Tuesday, basically the same procedures were carried out.
Warren reported from the water for the swimmers and Alan for the
rowing, while Sue Cure, Warren's daughter played her part from
the foreshore. On air interviews were included, and when Warren
came ashore, a number of people thanked him, saying that it was
the first time they had ever known what was happening in the
swimming events. Alan reported a similar reaction - the State
Rowing Council were most intrigued by what was done from the
water, and it seems this may become a regular event on our calendar.
The Athletics Board also expressed great interest.
The equipment used consisted mainly of IC2A's handhelds and
a 251 base station for patching. Shayne was concerned with the
patching and, as always, did a very "professional" job.
Monitors AGC~-HM=-123
HM-123A 12" DIAGONAL SCREEN / TEXT DISPLAY MONITOR
Designed for use with advanced level small business or scientific computer systems. This high
performance data display monitor features an anti-reflective and dark tinted viewing screen,
computer matched appearance and high resolution graphics and text display. With 5 x 7 input
character, monitor resolution and computer compatible scanning provide a displayed capability
of 24 lines and 80 characters.
FEATURES
*
High resolution crisp, clear.
*
Anti-reflective, dark tinted,
75 square inch screen.
80 characters x 24 lines
display capability.
Attractive, computer
matched styling.
Textured high impact
plastic front panel and
metal housing.
* 80 Column and 40 column
switchable.
* All controls on the back,
except power lamp switch.
SPECIFICATION
* CRT:12",90', 635R
display standard phosphor
P31.
Resolution:
Centre 1000 lines
Corner 900 lines
* Video response: 10Hz-
22MHz (within 3db)
Power consumption:
DC12V, 1.1A
* Dim (mm): 308W x 266H x
333D (mm)
* N. Weight (Kgs): 6.8kgs/set
Package: Freight package:
16.7 cuft/78.2kgs/8 sets/one
carton.
AVAILABLE FROM GEORGE HARVEY ELECTRIC PTY. LTD.
| 76, York St., 162-4, Argyle St.
Launceston, 7250 Hobert, 7000,
1 003.316533 002.342233 |
PRILE © 1ST - AMATEUR PRODUCTS ‘ IC OM 1st October 14984
MODEL DESCRIPTION R.R.P.
—_— ; o
UHF
IC 45SA 430MHz/FM/10w syn. 12/v/mic. "395.00
IC 47A 430MHz /FM/25u syn. 12v. mic. 498.00
IC 430A 430MHz multi-mode syn. MBL. 6839.00
Portable
IC 4E 430MHz syn. HT, Nicad & Charger 338.00
ICO4A 430MHz syn. HT, Nicad & Charger 385.00
1.2GHz Mobile
IC 120 1260-1300MHz 1w. Mobile 6939.00
6 METER
Portable
IC 505 6m multi-mode, portable syn. 1-10w. XCVR. 443.00
FM unit EX248 Option.
ATTENDANT ACCESSORIES
, AMPLIFIERS
IC 2KL/PS 10-160m solid state liner 701/720A/730/ 1,748.00
740/745A/751A
IC mu1 10w Mobile Liner for IC2R 395.00
IcMm.12 10w Solid State Liner for IC 120 450.00
HF _ANTENNA TUNERS
(701/720R/730/740/745R/751A)
IC AT100 Auto Antenna Tuner 100W 493.00
IC ATS00 Auto Antenna Tuner 500U 620.00
SPEAKERS
IC sSP3 Base Station Speaker 659.00
IC SP4 Remote Speaker for Mobile 29.00
IC sPs Remote Speaker for Mobile 30.00
IC sP10 Remote Speaker for Mobile 39.00
POWER SUPPLIES
IC PS1S 12v Power Supply 720A/730/740/ 215.00
T45A/751A
OBTAINABLE HOBBY ELECTRONICS Phone:
FROM: 477 Nelson Road, Mount Nelson,
HOBART, Tasmania. (002) 23 6751
HAMFEST NEWS
We are now able to confirm the Montrose Bay Yacht Club as
the venue for TARC 85.
These excellent facilities are located just north of Hobart o»
the shores of the beautiful blue Derwent. Ample car parking 13
available and the site lends itself to the relatively easy
erection of aerials.
As we intend to try to arrange a special rate with a local m te&’
for block booking, your accommodation arrangements should be
given some thought now.
HAMFEST FORMAT
The Hamfest will be run over the Saturday and Sunday of the Qucen's
Birthday Long Weekend in June (i.e. 8th and 9th).
Saturday will be a WIA members day and will include the histe-ical
Blinking Billy re-enactment and other amateur related act’vities.
There will be an ox or pig or some other poor unfortunate aaimai
or part thereof roasted by way of social activity at the Mountrcse
Bay Yacht Club that evening (that is the Saturday eveni.g).
Sunday will be an open to the public day with a view towards
attracting interest generally in our hobby.
Success or failure will depend entirely upon you.
Please read the inside back cover of the last QRM newslecter
we listed there our requirements for your assistance. Vvaen w2..
you let us know the role you intend to play????