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Amateur
Radio ook September 1985
News
Issued by the Tasmanian Division of
the Wireless Institute of Australia
Radiotorial (omment.
In this issue of "QRM" we include a complete list of monthly
broadcast responsibilities for the WIA branches in Tasmania through
to March 1986. And this brings to the fore, once again, the subject
of the quality of our Sunday morning broadcasts. With the linking of
Tepeaters on 2m., it is perfectly possible for contributors to take
part from different areas of the state. With the setting-up of tele-
type equipment, it should be possible for hard copy to be transferred
to the broadcast area for the use of the originator. For those who
adre diffident about coming over "live" on the broadcast, it is quite
possible to pre-record a contribution and play it over the air on cue.
Implementing all these possibilities would ease the load on the
originator of the broadcast, provide a variety of voices and probably
a0 greater range of more up-to-the-minute news. Technically, all the
right facilities are available for a really lively, interesting
weekly bulletin. What is lacking? Well, the fact is that the great
majority of amateurs do nothing towards preparing an effective news
service. The whole set-up revolves around a few people whose efforts,
week after week, receive congratulatory lip-service on the call-back.
But, let danything go wrong..... .+ Where are the offers of support then?
The broadcast is - or should be- o vital part of amateur contacts
across the state, and yet, quite often events that are published more
than once on the broadcast, are not supported because many amateurs
never bothered to listen and so were unaware of the function. Why
don't we ALL listen, unless of course circumstances make it quite
impossible? Is it because we aren't making the content interesting
enough to attract listeners? 1Is it because there isn't enough local
news? Is it because we just don't feel involved? Whatever it is,
some State-wide action seems justified, and for this to happen, it
must come from Divisional level. How about a lead from Council? -
a conference at some mutually agreed centre, to include those concerned
with the technical side (repeater links, transmission relays), and
those compiling the news and sitting in front of the microphone.
We MIGHT get to the point where we can say (with some apologies to "The
Investigators” on TV) "Can you afford NOT to listen?"
7T
SOUTHERN BRANCH - CHANGE OF VENUE.
Due to a change in the policy of the State Emergency Service,
it has become necessary to find a new meeting place for the
W.I.A, Southern Branch in Hobart. From Wednesday, September 4th,
the Branch will meet at the Elizabeth Matriculation College in
Elizabeth Street, on the corner of Warwick Street. The time
remains the same - 8.15 p.m. Parking is available in the streets
around the College and the meeting room itself is approached from
the Elizabeth Street entrance - the first room on the left along
the corridor. After the September meeting, it will be possible to
work out in more detail the general organisation, such as the
set-up for Executive meetings.
Our thanks are due to the S.E.S. for their acceptance of our
meetings in the past, and it is to be hoped that the present
amicable relations will continue into the future.
Who's into Gigahertz??
If YOU are into this area of our hobby, you may like to know
that VK7ZAL (Bob) is building 10GHz gear aond 1is keen to hear
from anyone who is interested in the same. He is QTHR and listens
on the 2m. repeater about 7 p.m. on weekdays.
Social Evening.
Those of us who went to the TARC weekend and enjoyed the dinner
at the Masonic Club in Macquarie Street, will be pleased to hear
that on September 14th., there will be another informal occasion
at the same venue, 7.30 p.m. Members and friends are welcome.
Just ring the Club, book the number of places that you require (Ph.235231)
and all will be organised. September is a cabaret night, so the set-
up will be the same as that of the TARC weekend. Any further
questionssttentac¥s oy VRK/BUYCQTHRS
Nevicesahd Mo¥se ' THoimihg CoUTses.
Starting this month, it is hoped to open a Novice Course to
prepare for the examination in February 1986 and meetings will be
held at the Activity Centre, Newtown Road, Hobart,
Morse training will be held as a separate course for the
benefit of "Z" call holders wishing to upgrade.
Details of times and dates will be circulated as soon as the
level of response is known. Anyone interested in either of the two
courses is asked to contact Rai VK7VV. He is QTHR, often is heard
on Repeater 2 and his phone number is {(002)
Similar courses are running in the N.W. - and it is encouraging
to know that support is forthcoming in different parts of the
Division. "QRM" would appreciate information on how the schemes are
progressing.
TION
FORTHIS
ALARA's CONTRIBU MONTH.
As o result of the recent A.G.M., we have some new office bearers,
one of whom is Laura, VK7NYL, who becomes=the new VK7 State
Representative. She would like to hear from any YL's who are interested
in joining our Association. Helene is now serving her third and last
-year as President, so it is pleasing to have two office bearers from
VK7 on the Committee.
In view of the recent RD Contest, we thought the following would
be very appropriate.
CONTEST, by Joy, VK2EBKX.
"CQ Contest,..CO Contest",
Over every band,
Paper lying everywhere, YCQ iContEst, n6QContestl,
Pen clutched in my hand. Hunched up in my chair;
My list of members is somewhere here,
I wish I knew just where.
There's a strange look on the 0.M's face,
(Can't think why that should be!)
He says, "How long before the end
Of this insanity?" "I'm pretty handy as you know.
To get a meal I'm able.
But I don't know where to put it
'Cos there's no room on the table".
"Hey, mum," yells son,"Where is my shirt
I can't fimdl iiigE all™,
"Look among that heap of ironing
In the basket in the hall". "C@ Contest, CO Contest',
Past the fifty mark.
(Better go and feed the chooks
"CO Contest. LU Confest) Before. it.ogets fop:.dark!)
Way into the night.
(Did I bring the washing in?
I can't remember quite). "CQ Contest, CQ Contest",
Must be off my head!
Wonder why the lights are out?
"CQ Contest, CO Contest", Think all have gone to bed!
Getting laryngitis!
(Must get a can of flyspray -
Get the mossies 'fore they bite us! )
"CQ Contest, CQ Contest",
Into it once more.
Must be getting writer's cramp,
Time's up - the contest's over; My fingers are quite sore.
Try and organise the log;
Check the points and ad my score up.
(Better go and feed the dog). Now to set it all out neatly.
Post off with a stamp or two.
People ask, "Why do you do it?"
Well - I really wish I knew!
ALARA's THOUGHT FOR THE MONTH (& perhaps the YEAK, too!)
There are three kinds of people in the world:
Those who make things happen.
Those who watch things happen.
Those who ask, "What happened?"
Which group are you in??
SO _YOU WANT TO CONTACT THE EDITOR?
READ TS,
. ... .RE2D THin.
.....READ THIS!. .. READ THIS.
Hey, what's going on? Well, your usual Editor thought unless
he specially drew your attention to this paragraph, you wouldn't
bother to read it - see the Editorial, The fact is that the Editor
won't be available for the next couple of months - he's doing a
marathon swim round waterlogged Britain. SO - please send all that
copy to Peter, VK7ZPK, QTHR and tel. no. 438791 (002). He also
joins in on 2m., most afternoons., Let him have your news, articles,
comments and letters, and double the size of QRM before your
rugged-up and wellie-booted Editor returns.
WOULD ALL ASPIRING CONTRIBUTORS TO QRM PLEASE NOTE THAT THE
CLOSING DATE FOR COPY FOR THE OCTOBER.ISSUE: IS, FRIDAY:s 27 the SEPTA
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 wishes to take up this offer,
please cantact the Editor.
A HOME BREW CAPACITANCE METER,
by Ian, VK7ZBQ
Following the Editor's comments in the August Editorial about
the vagaries of marking components Ian has submitted the design
given below. If you have any problems in construction, please call
him on 951865. Thanks, Ian - it's good to get a positive response
to a QRM request.
Vero board can be used for this project and all wiring must be
short and rigid, especially round the test terminals. The accuracy
of this instrument is that of the meter movement, so be wary of
low cost Toiwanese meters which are sometimes very non-linear -
e.g. 29V ISH byt o'ftten 5% mid-scale!! A large scale meter is an
advantage, enabling a minimum capacitance of 1pF to be read on the
100pF range. A flat mounting (no holes) taut band movement is
available from VK7ZBQ for $23.00 (2% F.S.D.) to Club members only.
Size: 86 % 75 x 14.6 mn. > NexT PAGE.
Must be [%
M 100K 0K
'0;( 9{6\/
B9 reguiated
bK]
242 ' VQA_
] 100n
2N2bk6
| /(ZNboz'fl
] 5 , )
o 3
Fee | L€ [ 1
bettes e lookg 100k
Vkz. ‘VQa
If using a 109uA meter, use 100K pot for VRIT.
RO
e TRP MR TOnF 4., 100nF 5. V»F Foab.
Note: Rl - use IMa.pot to find 500Hz +10%, then replace with the
correctveflod” % resistor.
Calibrate with VR1 on range 3 or 4 (10nF or 100nF) wusing a 10nF or
100nF 1% capacitor (see VK7ZBQ if you want to borrow one of these).
Ranges 1 and 2 are calibrated with VR2 and VR3 using 100pF and y&F
Vicaopde itors,
VR4 is used to zero the meter on ranges 1 and 2. Use 1% resistors
throughout for long term stability, and GOOD QUALITY SEMICONDUCTORS!
TASMANIAN DIVISION OF W.I.A.
VK7WI BROADCAST ROSTER.
August 1985 - Northwest Branch.
September 1985 - Southern Branch.
October 1985 - Northern Branch.
November 1985 - Northwest Branch.
December 1985 - Southern Branch.
January 1986 - Northern Branch.
February 1986 - Northwest Branch.
March 1986 - Southern Branch.
Issued by VK7 Divisional Broadcast Officer,
Dat i VLTI
SUPPRESSION FUMDAMENTALS
~ INTRODUCTION
Vehicular electrical systems have long been Technological advances in electronics have
recognized as major sources of radio fre- enabled U.S. vehicle manufacturers to
quency interference (RFI). appreciably reduce RFI levels, thus provid-
RFI problems can be further compounded ing satisfactory reception on installed AM
by adding to these totals the countless mil- and FM receivers. Solid state circuitry in
lions of industrial, recreational, farm and breakerless ignition systems, voltage regu-
garden equipment engines currently in use. ~lation, electrical system and accessories,
and the use of non-radiating cables and
The growth rate in the use of mobile com- wires are but two facets that have contrib-
munications has been dynamic in recent uted heavily to the success of RFI control.
years. The rapidly expanding use of high fre-
quency equipment plus the extension of the The suppression techniques and equipment
usable portion of the radio spectrum make it
currently used by U.S. manufacturers have
imperative that adequate RFI suppression brought RFI to within a standard set by the
is established. SAE for external receivers. Amateur radio,
citizen band, police and fire services, and
The vast numbers of communication units marine communication systems may,
involved, the low transmitting powers, the however, require additional measures
extremely high receiver sensitivities and beyond the basic suppression methods
their proximity to interference sources, in used by the vehicle manufacturer.
Minimum interference achieved
themselves, combine to create a wide-
spread and sometimes severe RF| problem. by proper suppression techniques will
improve reception and extend operating
distances.
| PRELIMINARY PROGEDURES
Two fundamental approaches are used in suppressing BONDING
radio frequency interference.
Bonding provides a common ground for radio inter-
ference signals. It keeps the interference generated
1. Reduce the strength of the interference from each
by the ignition and charging systems from traveling
individual source as much as possible.
throughout the vehicle, reduces intercoupling, and
prevents re-radiation. It also minimizes RF| radiation
2. Confine the interference . . . make the engine com- from the vehicle by connecting the metal parts together
partment an efficient shield box. to form an effective shield.
Basic components and techniques used in RFI sup-
pression include capacitors, bonding, routing of wir- ROUTING OF WIRING
ing and suppressors in the high voltage circuit. Vehicle wiring must be carefully routed to avoid trans-
fer of interference from one circuit to another, particu-
CAPACITORS larly from the high voltage ignition cables.
A capacitor will, in effect, pass alternating current but
block the flow of direct current. Since interference is HIGH VOLTAGE SUPPRESSORS
an alternating or impulse signal, a capacitor will by-
Resistors in various forms are used in the high voltage
pass most of it to ground without affecting the direct
ignition circuit to reduce the level of radiated inter-
current circuit. Conventional bypass capacitors are
ference. This subject is of utmost importance because
satisfactory for broadcast-band suppression, but they
the ignition system is by far the greatest offender.
are not very effective at higher frequencies. Communi-
cations frequencies up into the UHF range make the Various types of suppressor resistors have been
use of coaxial capacitors necessary.
manufactured. Some are separate components for
use at the distributor towers or spark plug terminals.
CONVENTIONAL BYPASS CAPACITOR
They have often been moulded into the distributor
rotor, towers, and even the center contact button.
They are used to some extent as original equipment
or European vehicles, but are available in the United
COAXIAL CAPACITOR States mainly as service items.
INSTRUMENTS
When installing or servicing two-way radio equipment,
- Install a .5 mfd. capacitor at the battery terminal of
these procedures will help to insure quiet operation.
the voltage limiter . .. ortry a.1 mfd. radio-type pigtail
1. Check to see if all suppression components speci- capacitor directly across the limiter terminals. A stub-
fied by the vehicle manufacturer are still in place. born case may require a hash choke in series with the,
The resistor cables may have been replaced with battery lead.
non-resistor types. A bonding strap may have been
lost. a tooth-type lockwasher may be missing or a
connection may be loose. Make sure all of the com-
ponents are in good condition. Broken resistor
cables or corroded bonds will not help suppress
RFI, but may very likely make it worse.
2. If the engine has not been tuned recently, have it HASH CHOKE
done by a qualified ignition serviceman. Include R
>
N~ ‘
new spark plugs, breaker points, and condenser. ;hl 7O BATTERY
The engine must be in top operating condition to
guarantee optimum radio performance.
BONDING
3. Connect the radio directly to the battery. Do not
tap into the accessory-ignition switch because Add bonding in suspected areas. Unfofiunately, the
intercoupling between the car's electrical system is often no better than a cut-and-try proposition.
and the radio circuit may cause interference. Experience is the best teacher in chobsing bondipq
locations for maximum effectiveness. Location 1s
4. Route low voltage wires away from the ignition
sometimes highly critical, and a few inches either way
system . . . keep all suspectedcircuits separated.
Dress the wires against grounded metal areas can make the difference between good results and
where possible . .. do not bundle them. If a prob- none at all. Bonding kits are often furnished by the
lem persists whereoriginal wiring is bundled, try radio manufacturers. Follow their directions carefully.
connecting that circuit with a separate wire outside Typical bonding locations are:
the bundle. . Corners of engine to frame
=
W OoOONNMNUBEWN
5. Make certain the antenna lead-in shield is grounded . Exhaust pipe to frame and engine
at both ends. Insulation should be inspected, and . Both sides of hood
all connections must be clean and tight. . Both sides of trunk lid
. Coil and distributor to engine and fire wall
Here are three ohmmeter checks you should make . Air cleaner to engine block
on an antenna: . Battery ground to frame
. Tail pipe to frame ‘
. Steering column, oil gauge and other lines when
they pass through firewall
10. Front and rear bumper supports
11. Radiator to supports
INTERNAL-
EXTERNAL
TOOTH TYPE
LOCKWASHER
(a) On lowest scale, touch probes to antenna rod
and center contact of plug. Resistance should be a
fraction of an ohm. (b) On highest scale, touch HEAVY
’ SELF-TAPPING ™
probes to antenna rod and vehicle ground. You
should read open circuit on most antennas. Some
EXISTING SCREW
high gain antennas with built-in matching trans- AND LOCKWASHER
formers will be short-circuited. (c) On lowest scale.
touch probes to outside of antenna plug and vehicle In general, any adjacent metal parts which are sepa-
gound. It should measure zero resistance. rated by mastic or paint must be connected together
electrically.
(To be continued)
eAttt St ee e e ee
WANTED !
Does anyone have the October 1983 copy of "Amateur Radio" (U.K.)
either for sale or loan? Please contact the Editor.
A SHOCKING INTEKLUDE .
A conversation recently heard between two amateurs in anothe
r state
outlined some of the effects of static electricity in antennae
.
One operator had worn a welding glove while making the necess
ary
protective arrangements, but still felt g "tingling" in
his fingers
while manipulating the co-ax connectors, Here is an idea from
Tom VK5TL which might be of use in preventing further
problems on
this score,
The antennae have been terminated in a small box fitt
ed with co-ax
connectors plus two terminals as shown:
To Long'Wire Verti
Antenng
The Box end ot Fhe | Bad-in Co-ax to the shock's oper
ations area is
left lying well clear when the antennae are not in use.
An earth
wire leads to the box. A short length of suitable wire fitted with
battery style clips on each end, and suitable plugs
in the middle,
(4mm banana plugs fit nicely into 50239 centre pins
) enables direct
earthing of the antennae.
At the first suggestion of an electrical storm,
real or forecast,
fitting takes place as follows: one clip to the earth te
rminal, the
other to the long wire antenna terminal, and the plugs are
inserted
into the co-ax sockets which lead to the vertical an
tennae, This
Prevents any build-up of static electricity - Tom ho
pes!!
Care should be taken to ensure that the earth end of
the Storm Ground
Lead is connected before touching anything else,
Remember this is by comparison a static trickle discha
rger, as a
direct hit by lightning would probably cause ante
nnae and earth wire
to disintegrate or atomise!
(From the S.A, W.I. Journal, June 1985)
e ee e ettt e eo
SNIPPETS
.,
OV TRACY, B.O0 0w 362, NIS.W. .20/ ase running continuous Morse
transmissions on 3.699KHz using 15 watts output
with a crystal
locked Tx. They would appreciate listener reaction,
The Customs 2% Tax is now consolidated so long as
transmitters
brought into the country are useable only on amateu
r bands. You should
be able to bring in items from overseas without
difficulty but
consult "Information Leaflet for Tourists no. R.83/1
60",
'
rflO8 BY =) e
HLil'e TRONIC
477 NELSON ROAD,
MT. NELSON 7007
Telephone (002) 23 6751
SPECIFICATION
PREQUEKCY COVERAGE:
150KHz ~ 29.999MHz
118MHz - 173.999MHz"*
FREQUENCY RESSU
100Hz (Digital Readout)
PREQUERNCY STABIITY:
<+ 300Hz in 30 mins after 1 min on
< 50Hz in 30 mins after warm up
KODES OF RECEPTION:
AM, CW, FM NB, SSB (LSB/USB)
A3E, A1A, G3E, J3E
BB/ (J@@IA'ME ¢
2.7KHz @ -6dB, 8.0KHz @ -50dB
Qenoval Coverage oyboard
7o (GSE) namow
Continuous coverage from 150KHz to 30MHz. A 12 button keyboard is fitted as standard 12.5KHz @ -6dB, SOKHZ @ -40dB
Two speed spin tuned VFO plus keyboard plus allowing quick accurate changes of frequency AR}(ASEH3E) (stenderd/narrew]):
computer interface control. and band (MHz and KHz pregrammed 6.0KHz @ -6dB, 15KHz @ -50dB
individually). The keyboard also has nine 2.7KHz @ -GdB 8KHz @ -50dB
Al mode control buttons to allow rapid changes from
The FRG8800 demodulates SSB (USB & LSB) memory to VFO, memory to memory and VFO to SENSITIVITY:
CW, AM (Wide and Narrow) and FM narrow as memory. Memory channels can aiso be recalled $SB/OW (JSE/ATA) @ 10dB S + N/N:
standard. This, complemented by an all mode at the turn of a knob, ideal for storing <0.4uV into 50 ohm, 1.50-30MHz
squelchr, produces the most practical receiver calling/working channels or broadcast <3.0uV into 500 ohms 0.15-1.6MHz
available. The FM narrow is useful for 10M, CB reception. <1.0uV into 50 ohms, 118-174MHz*
and for VHF with the optional VHF convertor The keyboard is complemented by an opto-
coupled, two speed, VFO drive: fast for rapid P4(G3B) @20¢B & + Rl
flemory : . tuning of a band or slow for accurately tuning in <1.0uY into 50 chms, 1.60-800H=
The FRG8800 comes fully equipped with twelve a signal. In addition a fine tune control <2.0uV it 50 chmae, 118-1748H="
memories programmed and scanned at the compensates for drift in the received signal.
touch of a single button. Any of the memory The dial can be electronically locked ARd (A3E) @ 10dB S + N/N:
channels will accept a frequency within the preventing accidental change in frequency. <4.0uV into 50 ohms 1.60-30MHz
whole range of the receiver including the VHF <3.0uV into 500 ohms, 0.15-1.6MHz
range (with the optional VHF unit). The mode is <10uV into 50 ohms 118-174MHz*
also stored in the memory eliminating the Clockftimer
need for inconvenient manual mode change, Dual accurate 12 hour clocks, with AM/PM CH SENSITIVITY:
when hopping from one memory to the next. indicators are ideal for log keeping (GMT/ $8B/CW (JIE/A1A):
Local). The clock uses the main digital display - <2uV, 1.60-30.0MHz
Solectivity & Sensitivity and features full back-up facilities in the event <4uV, 118-174MHz"*
Four filters are fitted as standard (SSB/CW, of a mains failure or disconnection. The timer
AM, AM-NAR and FM-NAR) with bandwidths can activate the receiver or tape recorder via FM (G3IE):
chosen for optimum performance, these the relay contacts provided. A snooze facility <0.5uV, 1.6-30.0MHz
combined with switchable AGC and variable allows up to 59 minutes of listening. <1.0uv, 118-174MHz*
tone -control provides maximum enjoyment
AR (A3E):
despite today's crowded bands.
High input sensitivities are obtained by the VHF Converter (optional) <2uV, 1.60-30.0MHz
latest in RF stages, making the most of The FRV8800 extends coverage te include <4uV, 118-174MHz"
inefficient aerials and difficult locations, and a 118-174MHz all within the main frame, thereby AUBIO OUTPUT:
continuously variable RF attenuator control allowing monitoring of; PMR, marine and air
overcomes problems encountered with very bands, as well as 2M. 1.4W in 8 ohms internal @ 10% T.H.D.
powerful stations. The FRGB8800 is operated as before via the 4-16 ohms external speaker/phones
keyboard or VFO, and the memory still holds Constant level line output (recorder)
LCD i any frequency and mode. The actual VHF POWER REQUIRERIENTS:
The back-lit green LCD display incorporates frequency is displayed on the main LCD to a
easy to read 'any angle’ 10mm digits. resolution of 100Hz.
100/120 220/24V @ 50/60Hz
A twelve function display indicates the 35VA Rx, 5VA standby
transceiver's status at a glance, It includes 12vDC (nommal)
memory channel number, mode, and Workdwide 1A Rx, 0.020A standby
tfrequency to a resolution of 100Hz. Also At 6.1Kg (excluding convertor) the FRG8800 is DIMENSIONS 5%0 octions):
included is a two dimensional LCD, graphical ideal for taking on any trip. The power supply is 235/270 D, mm
SIMPO and 'S’ meter, which is conventionally easily adjustable from 240-220 VAC to 110-120V,
335/350 W, 120/130 H,
calibrated at 1-5 and 0-9, +20dB, +40dB, ~60dB 50/60Hz mains and 12VDC operation is available Weight 6. 1/6.3Kg (w/o c/w VHF unit)
respectively. -as an option * OPTIONAL UNIT
WANTED
: Qe E1/ or TS1200. o7 F5 000,
Please contact the address above.
VC)L;UME ‘TXA nx DUP T
: - POWER DUPLEX SELCALL
BASE BASE
STATION STATION1
VEHICLE VEHICLE R SECE
e
e
iy eainiutb e BASE
WAREHOUSE o STATION 2
VEHICLE VEHICLE VEHICLE VEHICLE
BUSINESS PRIVATE
X470 X470
wherever you drive, work, live...
TX470...THE ULTIMATE IN TWO-WAY RADIO
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brings you your own high quality, Electrophone Interference Shield ...
professional communication system. giving you crystal clear reception.
The TX470 has been-especially Reception that is free of
designed for Australia’s harsh interference from motor ignition,
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communication company. fransmissions.
AVAILABLE FROM GEORGE HARVEY ELECTRIC PTY, LTD,
W °. York S5t. 162-4, Argyle St.
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