QRM
Recognised text
Text below was produced by optical character recognition and may contain errors. Check it against the original.
Bulletin issued by the Northern P.0. Box 1010
Branches of the Wireless Institute Launceston
of Australia, Tasmanian Division Tas. 7250
November 1976
Vol.6 No.8
Registered at GPO Hobart
for transmission by post Price 40¢
as a periodical, Category B.
MEETINGS w
Nov. 9th North West Branch, Lakins Hall, Ulverstone. 8 p.m.
Nov. 12th Northern Branch. S.E.S. rooms, Charles St. 8 p.m.
Y.R.C.S. MEETINGS
Nov. 13th Kings Meadows High School, 10 a.m.
27th
A.0.C.P. Classes
Nov. 8th Kings Meadows High School
. 15th
2ond Block X B, room 35
" 29th CWw at 7.30 p.m.
Dec.
"
6th Radio
i Theory 8 p.m.
_CONTESTS_
Nov. 6&7th RSGB 7MHz phone
Nov. 27/28th CQ WW DX Cw
Dec, 11lth - Jan. 16th Ross Hull VHF Memorial
NOV. 13/14th VK7 HAMFEST AT EVANDALE
Nov. 22nd QRM deadline
Page 2 Q.R.M. Nov. 1976
NORTHERN BRANCHNOTES, by Joe VK7JG,
The last Northern Branch meeting was very well attended
with 34 people present, this included 2 visitors, namely Ian
Clemments and our guest speaker Professor R.H.Thorpe, chairman
of The Australian Consumer Association. Apologies were received
from VK7NR and VK7AK,
The meeting adjourned after about 30 minutes to hear the
lecture by professor Thorpe and continued again at 21.35 to
discuss general business,
Two new members were accepted by the Branch they were
Ian Clemments and Alan Bourke. Alan passed his telegraphy and
regulations for the Novice license at the last exam and will
be sitting for his theory next month. Ian is a student at the
AQCP classes and is sitting for his AOLCP next February. Best
of luck to both of you.
The next Northern Branch meeting is to be an equipment
display night, so bring along your newly aquired piece of
equipment or something that you have constructed. The display
will only be as good as you make it !
The Christmas meeting will be in the form of a B.B.Q.
at the QTH of Peter Dowde VK7PD, 77 Talbot Rd. starting at
5 p.m. on the 1llth December.
Lindsay VK7ZLD reported that Hamfest arrangements were
well in hand, Bob VK7ZRF has designed a fox hunt receiver and
to date two have been built and used successfully, this was at
a trial fox hunt held on Friday 22nd when about 10 people used
equipment ranging from the above mentioned receiver to IC202
SSB 2m transceivers.,
Catering arrangements are being capably handled by
Sue Dowl (Mrs VK7ZLD), if you can help Sue by making caseroles,
desserts etc. please phone Sue on 444690. Any expenses incurred
in making any such items will be reimbursed.
Congratulations go to Lionel Hillard in being successful
at the last AOCP exam, Lionel now holds the call VK7HL,
Professor Thorpe's lecture on the role of the Consumer
Council was very well received, a number of Choice magazines
were given away and almost everyone took home a cumulative
index covering from April 1960 up to September 1975, with this
you can see what type of merchandise Choice examines, One point
of interest raised was that of the cost of living, to calculate
present day cost of an item take it's price of 20 years ago,
multiply by 10 and covert to Dollars, try it on a few things
it's not far out.
A New Years Eve Dinner Dance is to be held at the Town
House Motel, anyone interested in going please contact Brian
Yeoman VK7ZBY, phone 918218 before the next Northern Branch
meeting, cost is $6.00 for a 3 course meal and $7.00 for a
4 course.
73 Till next month, Joe VK7JG
November 1976 Q.R.M. Page 3
NOTES FROM THE NORTH WEST BRANCH, by Lindsay Johnson,
The monthly meeting was held in Lakins Hall Ulverstone
on Tuesday the 12th October and commenced at 8.10 p.m. The
President Ian VK7ZIE and the Secretary Max VK7TMX were in the
chairs. The meeting opened with apologies being received from
VK7's, TT, ZAQ, ZKC,CF and ZBL, The minutes were read and
confirmed. The correspondence was then read by Max, these were
quite numerous and took up a lot of time. The treasurer reported
a very sound bank balance and I quote $358,00. The equipment
officer, Adrian VK7ZAT had quite an assortment of gear for sale,
this included, ARRL handbooks, AM FM radio boards, switches,
gauges etc. Winston VK7EM reports a bit of beacon trouble a
blown fuse, also a valve went haywire but this has since been
rectified.
Following next months meeting Bob VK7ZJS has something
or is working on something for the after meeting talk,
The president reminded all of the coming Hamfest at Evandale
on the 13th and l4th of November, also that the AGM will be
held on the 2nd of April 1977 in Hobart. The December meeting
here in the North West will be held at the Latrobe QTH of Jim
Davies, don't forget to bring along the XYL and make this one
a bumper meeting.
There was a very good turn out of members and visitors,
with a total of 23, (10 grade A and 10 associates and 3 visitors)
The meeting closed at 9.05 p.m.. Following the meeting Jim Davies
entertained us all with a very fine and interesting 1% hours of
movies, including some of the olden days when they were termed
as the flicks, after seeing them we all understand why, they
were in very good order for their age. This was only a sample
of Jim's collection. Following the films supper was served
very efficiently by the Devonport and Ulverstone members, the
evening finished off at 11.00 p.m.
In answer to many letters and phone calls I have received
recently, asking if I knew or would find out why, when a certain
Devonport member comes on 2 metres, there is a very distinct
sound of heavy breathing, This has been very hard to pinpoint,
but as I am a very dedicated listener I can now report that I
have found out. After listening to this Devonport member on
2 metres mobile a few weeks ago returning from Hobart. He came
on and said he was approaching Perth where he and his XYL were
going to have a big steak dinner. OK that's fine, but later on
he comes on air again with a terrible back ground noise and
complaining he couldn't hear a bit of what the other fellow
was saying, so he says, oh well I will just have to pull up
and give her a bottle of water or something. So this is how
we discovered the truth behind the heavy breathing, the recent
arrival must eat, if nothing else but water, why not the
microphone. My apologies to his XYL, we know it's not her fault,
she is just onother very understanding XYL.
73 Lindsay Johnson
It has been suggested that the December meeting at the QTH
of Jim Davies should be held on a Friday or Saturday, this
will be an item for discussion at the next meeting so please
be there if vou want to express your view on this.
Page 4 Q.R.M, Nov, 1976
JOTTINGS FROM THE DX BANDS, by Col VK7LZ.
It appears that the most active stations around
Launceston lately have been VK7's BC and HE and judging by the
QSL's that have gone to the bureau its been a successful
operation, Congratulations also to VK7HL, Licnel was heard
working SM3PZ on the long path one evening, so it looks as
though we have another keen DXer coming up.
Conditions are still fairly good considering the low
sunspot activity, if one delves into the noise and does plenty
of listening.
1.8 MHz:; has been very noisy and consequently the normal good
period of the equinox has been lost.
3.5 MHz; this band also has had more than its share of QRN so
little listening was done and therefore nothing to report.
7 MHz; can be full of surprises and is well worth watching
particularly on CW from 05.30Z. A glance through the stations
heard list may give you a surprise.
14 MHz; also comes to life at odd times with Europeans coming
in long path around 10.,30Z also HL, JA, KR6, VS6, 9M2, UA9 and
UA@ etc. during our evenings local time. JW7FD on Bear Island
advises that he is quite active around 14,225 MHz and was QSO'ed
here at 12.17Z although he had been S9 from 11.30Z., TF5TP has
also been heard on 14.225MHz at 11.30Z together with WB4ZKG/KC6
Pig Island which counts as the Western Carolines for DXCC,
Evidently the Yasme Foundation have gone "walkabout"
again as I QSO'ed them from the Virgin Islands on 7 MHz C.W.
This team really move around so the Caribbean area would be
worth watching in the next few weeks.
21 MHz; all I've heard has been JA's and as they belong to
VK7BC I have kept well away.
The following list of stations heard (all at workable
strength) over the last 4 weeks includes 61 countries and all
continents so DX can still be interesting.
1.8 MHz; C.W. - WI1HGT, W1PBW, W6PBV, ZL and VK,
SSB., - VK's and ZL's.
7 MHZ; C.W. - CN8AD, CO2HT, DJ6ZM, DL8AN, DL8BL, DK8NG, DL8NF,
DJZUP, DM3XBB, DM2DEO, EA's, F3NB, F6CGU, F9BB,
G4DUW, G6Z0, G6FB, GM6RV, HB@NL, HC2SL, HM2JN,
HISNQG, I3GNQ, JA's, LA2B, JTPOAQ, LZ2ZX, OK3BDE,
07Z3Y, PAPRE, SM@CCE, SP6CTY, SP2AJO, SV1DO,UK1AAA,
VE3DZV, VP1MPW, VP1FOC, VS6BB, W's, YO3RF, YU3DBC,
4H1EL, W6KG/AJ3,
SSB. - CT2BS, CT4AT, DJ9GB, FSII, F6BII, FOSEX, G3CLW,
GW4NZ, HB9AWW, HK4BXE, I1DFS, ON4LJ, XF3A.
14 MHZ; C.W. - JA,UAg, W, HLO,
SSB. - BV2B, CROAJ, DJOGD, DUIREX, DU6BG, EA3ANW,
EA3AMS, EA3JO, EA8JJ, F3EG, Fo'EX, HC2CF, HL9TO,
HLOWP, I4GKJ, I@AAF, IT9ZNW, JABAYN, JW7FD,KG6RT,
KJ6DL, KG6RL, KC4AAA, KAGJH, LABNH, LX1RG, OHl1AA,
OHB8TI, PA@GMW, P29RJ, SM3PZ, TF5TP, UK9AAN,
UK@gYA2A, UAOVB, UK5BE, UR2QD, VK9JA, VR1AA, VR3AK,
VR4DH, VR4DN, VS6BE, W's, YU2RTT, 4Z4GH, 4Z47ZH,
9M2SS, 9M6SN, 9M6EMU, OVINR, WB4ZKG/KC6,.
Nov. 1976 QR M Page 5
21 MHz: C.W. & SSB, Only JA's heard here.
QSL information; CT4AT via W1YRC, FOSBEX via F6AUS
JW7FD via LASNW, KG6RT via W6IAE
WB4ZKG/KC6 via WA7ZTL, SM6MU via DJI8XW
HI8BNQG, P.O. Box 1157 Santo Domingo, Dominican Republic.
VR4DN, P.O. Box 81 Guadalcanal B.S.I.
W6KG/AJ3, via Yasme Foundation. P.O. Box 2025 Castro Valley,
California 94546,
A QSL received back in 1934 showed a cat walking along
the top of a paling fence followed by five kittens and the
caption read " You've gotta make calls to get results", this
still applies however you can also get very good results by
careful and methodical listening and you save a lot of power
too.
73 Till next month, Col VK7LZ
VHF NOTES, by Kevin VK7ZAH,
To my knowledge no 6 metre openings have occurred
during the month. The only DX type contacts I had on 6 metres
was with Mike VK7MC at Park Beach, Joe VK7JG works Mike quite
successfully. I understand there is very little hope of any
VK9's being active this DX season.
On the 2 metre band there is little more to report than
on 6 metres. Early in October VK7RR and others visited the Ch2
repeater site on Mt.Wellington to check the repeater equipment
after the winter period. During their investigations a loose
coax connector was found on the TX aerial feeder. After this
was repaired I am once more able to read the repeater at my
QTH. I haven't heard how work is progressing on the North West
repeater but I understand there are several busy people trying
to overcome the problems.
On the lower part of the 2 metre band (SSB) interest
appears to be increasing. Tony VK7AX went out portable with his
IC202 and % wave whip, he was able to read my SSB signals from
two high spots in Ulverstone, but due to his low power (3 Watts
P.E.P.) I was not able to read him. I believe VK7ZIE has a
IC202 on order so it looks like Tony will have somebody to
talk to on SSB. Mike VK7TMC at Park Beach gave me a report of
R5 - S6 on 2 metres SSB and I was able to read his 20W P.E.P.
signal. Brian VK7RR running his FT221 (15W P.E.P.) was also
worked with some difficulty, I was using my ringo antenna at
the time. At the same time as Brian was being worked Winston
VK7EM called on the repeater to say he was also reading me.
Further tests with Winston showed that he was able to read me
with my beam pointed to VK3,
Several VK3's have been worked during the month, the most
consistent being Ron VK3AKC who can be worked just about every
night. For those interested in listening Ron calls at 20,30 hrs
nearly every night on 144,070 MHz., The VK3 beacon on 144,700 MHz
can be heard most nights.
Page 6 QRM Nov. 1976
VHF notes continued
I heard a whisper that the Devonport 2 metre beacon is
to be moved to the repeater site at Ulverstone, this move I
know will please our friends in VK3 and VK5 who regularly
complain that signals have to be at least 20db over S9 before
the beacon can be heard.
Now for news on the 432 MHz band. The beacon at Ulver-
stone failed the other week but was quickly restored to normal
by Winston VK7EM, Ron VK3AKC rang Winston to tell him it was off
the air. On the 27th September Ian VK3YJI was hearing the beacon
at very good strength and piped it over repeater 8, Daniel VK7ZDA
has resurrected his 432 MHz transverter after dropping a hammer
upon it and can get into Oscar with 1 Watt output. In Hobart
432 MHz SSB seems to be the in thing with VK7AZ and VK7ZAK
recently purchasing rigs for this band with the main purpose
to work through Oscar.
That is all the news I have for you this month, I hope
that next month I will be able to report about the DX which has
been worked on 2 and 6 metres.
STOP PRESS
On Saturday 23rd October the 6 metre band opened at
about midday to Northern VK4. Signals were generally poor but
several stations were worked. At approximately 04.00Z John VK7JV
heard JH1ECU calling CQ, John called him on the frequency with
the result that a VK4 answered him. Kevin VK7ZAH listened on
52,050 MHz and heard a JA working a VK3, after the QSO with the
VK3 finished Kevin called the JA and had a contact with him.
From then on for about an hour a lot of JA's were heard, some
very weak and difficult to read. The total number of JA's
worked were, VK7JV - 9, VK7JG - 5 and VK7ZAH - 5,
It is believed that this is the first JA opening to
VK7 since about 1968 when a number of JA's were worked with
AM equipment.
Athol Johnson Memorial Contest.
Only 9 logs were received and congratulations go to
Malcolm VK7ZMM who had the top scoring log of 160 points.
Some bearings and distances that may be of interest.
These are centred on Launceston.
Location Bearing in degrees Distance in km
from true North
Norfolk Isl. 60 2329
Lord Howe Isl. 48 1529
Sydney 24 914
Brisbane 21 1642
Papua & New Guinea 0 3549
Melbourne 335 443
Christmas Isl. 298 5305
Perth 281 2963
Hobart 175 162
Mc Quarie Isl. 153
1700
Nov. 1976 QRM Page 7
A SIMPLE DIRECT READING CAPACITANCE METER F — 1pF,
Trevor Briggs VK7TB
I'm sure at some stage all of us mad fiddlers
of electronics have wished they had the facility of a reasonably
accurate capacitance meter or bridge. The problem of measuring
capacitance of low value has always been a bit of "hit & miss",
at least when associated with amateur fiddling.
On reading an article by WA5SNZ published in that very
good technical magazine "HAM RADIO", I decided it was time to
give this simple circuit a go, the idea looked excellent and
so were the final results.
Theory:; since the readout is a D.C, meter, it is desirable that
there be a linear relationship between the capacitance to be
measured and the D.C. output of the measuring circuit. It so
happens that the average D.C. value of a pulse waveform has a
direct linear relationship to the duty cycle of that waveform.
Duty cycle can be defined as the ratio of pulse width to the
time between the beginning of each pulse.
T1
D.C. value = T2
........ DC.value
T
The width of the pulse (T1l) can be made directly
proportional to the value of the capacitor under test by the
use of a monostable multivibrator arrangement, using a NE555
timing I.C. This means that the pulse width is directly prop-
ortional to the timing capacitor, enabling a linear direct
reading to result,
The circuit by WAS5SNZ needed some rethinking to enable
some locally available components to be used. It is important
to note that for the ranges of capacitance values to be measured
the frequency of the trigger oscillator is quite critical, if
not reasonably accurate, it will cause errors at the top end of
the lower ranges. The trigger circuit should operate at a
frequency of 500 Hz and have a pulse duration of 1 uS. As the
reference is obtained from the power supply a regulated D.C.
source is a must,
Operation: Set the range switch to 100pF, with no capacitor
connected to the test terminals adjust the zero knob for a
meter reading of zero, the zero pot is necessary to balance
out the stray capacitance of pins 6 & 7 of the NE555 and the
switch wiring etc., you will find that the stray C will only
have to be balanced out on the 100 and 1000pF ranges. Now
connect a 100pF,5% mica capacitor to the test terminals and
adjust the 10K calibration trimpot for a full scale meter
reading of 1 mA. This completes the calibration. Since A.C is
not applied to the capacitor under test, polarized capacitors
may be tested but care should be taken that the negative lead
of the capacitor is connected to the grounded test terminal.
Page 8 Q R M Nov. 1976
Capacitance Ranges.
Range Switch Resistor Capacitance Range
10 M 0 - 100 pF
1M 0 - 1000pF
100 K 0 - 0,01urF
10 K 0 - 0.1 uF
1 K 0 - 1.0 uF
Any attempts to modify the circuit so that it will
measure capacitors larger than 1 uF should be done by lowering
the trigger frequency. Resistors in the range switch should not
have values less than 1 K,
Since the D.C. voltage across the capacitor under test
reaches a value approximately two thirds that of the power
supply voltage, any capacitor to be measured should have a
voltage rating of at least 8 Volts.,
The unit performs extremely well and has very good
accuracy, (depending mainly on the size of the meter scale)
and is simple to construct for only a few dollars worth of
components.
IN264 6 £cio8
|€ooflz Osc, |
"— TRIGeER CiRcw
T —"
o-ImA
——— o ——— — - —— - — - — — — ———— ——
We need articles, hints or bits of information to f£ill spaces
about this size every month. This month it has taken a lot of
my time to find bits and pieces for 4 pages, I managed 3.
Can you help to £ill a space for future issues ?
John VK7JV, Editor
Nov. 1976 QR M Page 9
Extending the range of the FRG7 receiver down to 200KHzZ,
by Peter Frith VK7PF
The FRG7 will work down to this low frequency but is
limited by the pre-selector tuning range. Even if the pre-
selector could be made to tune it would require frequent re-
peaking while tuning.
What I have done is to make the input circuit broad-
band, this introduces some problems but these can be solved.
Modification; This is done in such a way that the receiver
can be restored to normal at any time. I have made use of the
ATT switch to make the 500 - 600KHz band broad banded when the
ATT switch is in the LOCAL position. The receiver behaves
normally in the NORMAL or DX position.
Procedure; On the ATT switch nearest the chassis under the
blue coax will be found a 10 Ohm resistor, disconnect the
earth end or easier still cut the earth end of the resistor
at its top. Connect a 1000pF capacitor from the top of the
resistor to the fixed plates of the rear section of the pre-
select gang. To tune down below 500KHz just leave the pre-
select tuning at 500KHz and put the ATT switch to LOCAL,
If broadcast signals cause interference to wanted
signals a trap is required. The problem can be due to mixing
in the mixer, in my case a spurious on 300KHz was found to
be due to 7EX 1010KHz minus 7NT 710KHz. I used a transistor
radio 455 KHz IF transformer with the tuning capacitor replaced
with 100pF to resonate on 1010KHz . Tune into spurious then
tune trap to remove the spurious.
s000 PF
i
|
1
1
: > | LocaL pw sTATION
=+ ; rwopF | | TRAF
v
{
lj::j |
What can be heard on these frequencies ? Many NDB (non direct-.
ional beacon) used for aircraft and ship navigation, all with
MCW idents and many with continuous weather information.
Location Call Frequency
Nile NIE 230KHz
Launceston LT 242KHz (weather)
Devonport DV 281KHz (weather)
Flinders Isl. FI 296KHz
Wynyard WY 302KHz (weather)
Ship to shore, 400 to 500KHz MCW.
Page 10 QR M Nov. 1976
A SIMPLE O - 100Hz FREQUENCY METER, by Daniel Apted VK7ZDA,
The idea was to make a simple 0-100Hz frequency meter
using a O0-1lmA meter and a linear readout.
The meter can be used to monitor the mains, portable
or fixed generating plants and D.C. to A.C. invertors. The
construction can be left to the builder so lets deal with
the electrics only.
The 240V A.C. is applied to the input via a 100K, 2W
resistor and is clipped to produce a 18.7V approximately
square wave pulses by the zener diode. The pulses are fed via
a capacitor to the bridge rectifier and the meter, with the
meter current being directly proportional to the size of the
capacitor and the pulse frequency, therefor the value of the
capacitor is reasonably important in obtaining the desired
meter range of 0 - 100Hz.
I used the 50Hz mains to calibrate the frequency
meter, the unit is connected directly across the mains and
the 4K7 Ohm calibration pot is adjusted to give a half scale
reading of 0.5mA which corresponds to 50Hz.
J8NF
/8V zZener
Mains Failure Indicator for Digital Clocks. by John VK7JV,
As my digital clock hasn't any form of indication to show
that the mains has failed and therefore the time shown is
inaccurate, we devised this little circuit.
An LED will light, indicating the mains has failed. After
resetting the time you will also need to reset the SCR to
extinguish the LED. The value of Rl will depend on the supply
rail voltage, R1 should be calculated for about 15mA,
crobDl
Nov. 1976 QRM Page 11
Lights on reminder, by Wally Morphett VK7ZWX,
light switch 12v
1A fuse
side lights
tail lights
head lights
solid state buzzer
4IAF|e from Dick Smith p/1
, p.75 of 76/77 catalogue
door switch
l
To drive safely in foggy condions, its usual to turn on
either parking lights or full headlights.
The"lights on reminder" gives an audible warning to the
motorist that the lights are still on when attempting to get
out of the car.
Coding of Green-cap capacitors
Value in uF Numbers on capacitor
022 mmmmmeee 2a224
el e 2alo4
0082 el 2a823
068 o 2a683
0056 e 2a563
60l o 2al03
0068 mmm e 2a682
0047 e 2a472
00039 mmm 2a392
0012 e 2al22
Page 12 QR M Nov. 1976
FOR _SALE FOR SALE FOR_SALE FOR_SALE FOR SALE FOR SALE
Shack clearing sale at Norm Richardson VK7NR, 11 Fort St.
Phone 272928.
Belcom Liner, 6 metre AM - SSB transceiver, 18W PEP $200.00
Ham M, Mark 5 heavy duty rotator $130.00
Hansen, FS5 S.W.R. bridge $ 21.00
50 Watt, 2 metre power amplifier, 12 Volt $ 30.00
Dual 6 -2 metre beam, Hy Gain. 4 el on 6m,16 el on 2m $ 20.00
20 foot pipe mast $ 10.00
Kyoritsu, S.W.R. bridge (needs new 100 uA meter) $ 10.00
Assorted large meters each $ 2.50
Sony, reel to reel tape recorder with alc $ 40.00
Light dimmer switch $ 3.00
Various microphones from $ 3.00
Ex Army head set, 2000 Ohms $ 2.00
DM111, 50K Hi impedance microphone and stand (new) $ 15.00
BLY90 transistors, 2 only each $ 10.00
BLY88a transistors, 2 only each § 5.00
6 way channel change switch with sockets etc. $ 4.00
Valves, 6/40 new each $ 12.00
" 3/20 new each $ 9.00
" 6SJ6, P.A. valves for FT101l, FT200 etc.each $ 6.00
" 6883B (12V, 6146) new 2 only each $ 3.00
6/40 sockets new each $ 2.00
20K Ohms per volt multimeter, very good, glass broken $ 3.00
230Volt A.C., 10 Amp relay (2 change overs) $ 2.00
Home brew, 2 metre transverter 6/40 valve with rough
power supply 800 Volt the lot $ 15.00
Nova Tech, Pilot 2, needs attention (dropped) $ 5.00
Amateur Radio magazines in 12 month bundles P.O.A,
ARRL handbooks 1970 and 1972 each $ 3.00
ARRL, VHF manual $ 2.50
ARRL, SSB handbook $ 2.50
Many other items, to many to list come up and make
a fair offer.
e 3 e e e e o o e Ak eo o eok eok eok
Galaxy 5, Mrk 2, 5 band SSB transceiver with heavy duty
power supply, very good unit, would also suit Z call for
transverting to 6m or 2m SSB. $300.00
can be seen at the QTH of John VK7JV Sint o °
Wo o e S g Ve ev W ok v e K e e e W ok
CH, FREQUENCY USE CH. FREQUENCY USE
37 145.850 Ch. A 50 146.500 simplex
41 146.050 repeater 1 53 146.650 repeater 1
42 146.100 input 2 54 146.700 output 2
43 146.150 " 3 55 146.750 ! 3
44 146.200 " 4 56 146.800 " 4
45 146.250 ! 5 57 146.850 " 5
46 146.300 " 6 58 146.900 ! 6
47 146.350 " 7 59 146.950 " 7
48 146.400 " 8 60 147.000 " 8
40 146.000 Ch. B
COMMUNICATIGNS
COMPONENTS AND KITS
from
AMATEUR (¢ IUNICATIONS
ADVANCEMENTS
P.0. BOX 57, ROZELLE 2039
45W TWO METRE BOOSTER AMP.
This kit was featured in the April issue
of Electronics Today International page
86 It delivers. 35-45W output from
about 10W drive on a 13 6V supply. It
features the 2N6084 diode changeover
switching, simple construction
only
$26.50 ! 5o re THE LS.STARRE 7"
24 e 4
Heatsink . .. ....$250 su«s‘ 4 \ll.'1 il
+60c P&P
The 45/W, two metre RF power amplifier. The 2N6084 transistor is visible in the centre of the
p.c. board. The mica compression trimmers located on the right hand side are for tuning the input, those
on the left for tuning the output. The printed inductances are readily visible. The two quarter wave coax
lines are visible at the top. They may be coiledup as shown or conveniently arranged in some other way.
Note that the components are soldered on the copper side of the printed circuit board.
‘RF POWER TRANSISTORS SPECIAL CAPACITORS FOR RF
APPLICATIONS
“8 We are proud to present these premium These are suitable for RF tuned curcuit «— metal-clad
quality RF power transistors by C.7.C DC blocking and bypass applicaions to
They are rated to withstand infinite several gigahertz at power levels to mica’'s
VSWR at all phase angles and are suit- many hundreds of watts. Silver-mica ELEENCO trimmers for RF
able for use in class AB or C circuits up construction rated at 350V DCW. Exten-
to 220MHz from a 12,5V supply The sively used in high power solid state RF
pover uses_ to 500MHz
set of three is suitable for a three stage power amplifiers T=60PF cveoo 75;
2W to 40W power amplifier . 1-10 11up Values stocked 35—160PF L 75¢
1-4 Sup 22-62pF $1.85$1.75 33pF, 47pF 25-280pF ... 95¢
B3-12 5W out $56.70 $4.80 68-250pF $1 95 $1.85 68, 82, 100,
B12-12 15Wout $7.70 $7.10 150, 200 Other types for RF power
B40-12 40W out ¢£17.50 $17 20 270-500pF $2.20 $2.10 300, 470 te 20CMH2z, suit HF uses
or $30 the set
POST AND PACKING 4-28DpF ..ue.. S50¢
BM70-12typically 8OWoutat 146MHz
from 9-12W drive at 65% collector 30c fof 10 or less, 80c for more than ten lO—llOpF ®% 00 50¢
efficiency $46.50 10-1 6OPF coee 50#
We also stock the popular 2N6084
made by both Motorola and SSS for
§ P& P:200/5 or less,
only ..$16.75 40¢ up to 20, 60¢ for more
or for 10 or more ..$16.00
POST & PACKING is 20c for a single also stock VITRAl
_‘v1 Vee-j*_r_'____NPO_’___g_g}‘a_chip
_____L__&__mic
cap's
device. 40c for up to five, 60c for i These are suitable for RF applications well into the
more
I microvwave region. Sta ndard EL?2 series in values between
g 1pF and 1000pF stoc eds S izes below B820pF: 2x1,3x1.3mm,
1820 1000 pF: 2.3xL.571.3%mm . All 50 VDOW,
ONLY MtK P &Py 20¢ any guantity
U GUINNE R AR,
50 BRISBANE ST. LAUNCESTON
Telephone 222 51
DOMESTIC & BUILDERS HARDWARE
MARINE & PLUMBING SUPPLIES
PAINT & TOOLS
SEDDON PRESS
35a GRANVILLE ST. LAUNCESTON 7250
Telephone 31 61 91
FOR ALL YOUR PRINTING
BUSINESS AND PERSONAL
QSL CARDS
NORWINDS
ELECTRICAL ENGINEERS
SPECIALISING IN MOTOR REWINDING AND ASSOCIATED WORK
27 SUNCREST PLACE, RAVENSWOOD et
TELEPHONE 391515
Athol Lawes Electrics
135 HOBART ROAD, KINGS MEADOWS, PHONE 444710
FOR ALL ELECTRICAL APPLIANCES, SPECIALISTS IN,
HI-FI SOUND SYSTEMS
CAR RADIO AND STEREO
SEE US FOR A BETTER DEAL, WE SERVICE ALL WE SELL.