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Bulletin issued by the Northern \\\ P.O. Box 1010
Branches of the Wireless Institute ! Launceston
1 of Australia, Tasmanian Division Tas. 7250
_ December 1976 q§§b
Vol.6 No.9 \
ered
atGPOHobart
Regist TECEY & ‘kfzg;"
for transmission by post Price 40¢
— as a periodical. Category B. r
MEETINGS
Dec. 10th North West Branch, at the QTH of Jim Davis VK7N.....
Latrobe. (Don't forget, this is a Friday night)
Dec. 1l1lth Northern Branch, BBQ at the QTH of Peter Dowde VK7PD
77 Talbot Rd. (this is not a business meeting)
Jan. 1l1lth North West Branch, Lakins Hall, Ulverstone. 8 p.m.
Jan. 1l4th Northern Branch, S.E.S rooms, Charles St. 8 p.m.
CONTEST
Dec. 11 to Jan 16 ROSS HULL VHF MEMORIAL CONTEST.
As usual there will not be a January issue of QRM, how about
you taking the time normally spent reading QRM to write an article
for a future issue ?
At this time I would like to take the opportunity to thank
_all who have supplied articles and assisted in the production of QRM
this year, a special thanks to Joe Richter for devoting his time
every month to print QRM for us. On behalf of these people and myself
I wish our readers a MERRY CHRISTMAS and a PROSPEROUS NEW YEAR.
John VK7JV
Editor
January 20th Deadline for the February issue of QRM
Page 2 QR M Dec. 1976
Northern Branch notes by Joe VK7JG.
The Northern Branch held its last regular meeting
for the year on the 12th November. There were 33 people present
including several visitors namely, Robin Wooley, Kerry Black,
Martin Harvey, Fred Bail, Greg Whyten and Brian Stevens, the
last three mentioned are VK3's here for the Hamfest. Kerry Black
VK7ZWB, Martin Harvey and Robin Wooley were all accepted as new
members of the Institute at the meeting.
Apologies were received from VK7's, ZWX, ZDA, LZ, ZMC,
AL and ED. Wally had a good excuse for not being at the meeting
as his wife had just presented him with a bouncing baby daughter.
Congratulations Wally and Shirley.
Peter mentioned that VK5 once again won the RD
contest and said that with the present scoring system it is
impossible for VK7 to win even with 100% participation. No doubt
Peter will be looking into the matter before the next contest.
An evening broadcast was discussed and it was
decided to have a tape replay of the Sunday morning broadcast
on repeater 8 on a Wednesday evening.
The meeting finished with a equipment display and
once again it appears that very little construction has taken
place in the Branch as only 4 people displayed home constructed
equipment. Peter VK7PF had his 2 metre FM synthesizer. Bob
VK7ZRF showed a fox hunt receiver, SSB transceiver using the
SL series IC's, a 2 metre power amplifier and a Barlow Wadley
type of receiver. Peter VK7PD an ATV converter and a power
supply using a electric blanket type transformer and a cross
hatch generator. Joe VK7JG shoed his new 2 metre solid state
transverter.
The big event of the month was the Hamfest at
Evandale, this was very well attended with 20 extra people
being present for the Saturday evening meal. As a result of
the excellent catering service by the XYL's with Sue Dowl at
the helm there was food to spare. A special thanks to Sue and
Lindsay Dowl for the way in which the Hamfest was conducted.
Also we must not forget the people who attended the function,
because without them we would not have a Hamfest, Thank you
for attending.
Dont forget the December BBQ at the QTH of Peter
Dowde VK7PD, 77 Talbot Rd on Saturday 1l1lth December, commencing
at 5.30 p.m.. Bring your own meat and mug.
73 till next month
Joe VK7JG
%0 e e de e de e e e ke e ede keok e Sk
Did you know?
That in the recent Novice exam held in Hobart 11 candidates
contested the exam, only 2 of these came from the Hobart area.
That marking for the Novice exam was completed in Hobart
and results were know within 2 weeks. Congratulations to the
"Radio Branch" for a job well done.
That Alan Bourke is now VK7NAB and Jim Davis and Tony Smith
have both passed.
That Norm VK7NR really has sold out everything. Apparently
when the dog was in season recently he wrapped it with a nappy. He
must have sold its chastity belt !
1976 QRM page 3
Dec.
North West Branch notes by LindsayJohnson.
The monthly meeting of the North West Branch was
held in Lakins Hall Ulverstone on Tuesday 9th of November and
was supposed to start at 8 p.m. but someone locked his keys in
his car and naturally everyone became an expert at opening cars,
so the meeting got under way about 8.15 p.m.
The president Ian VK7ZIE and secretary Max VK7MX
were in the chairs. The president welcomed two visitors, Lance
Burton and Kevin Henricks VK7ZAH from the Northern Branch. As
usual there was a good turn out of members with 11 A grade,
7 associate members and 2 visitors. Apologies were received from
VK7's, ZBL, ZKS, ZAT, and ZAQ. The president reminded all of the
next meeting on December 10th, which will be held at the QTH of
Jim Davis at Latrobe, and for all to bring along their YL and or
XYL as well as a plate of supper.
Max VK7MX reported nill for correspondence, but
talked fairly lengthy about the coastal beacon and the Scout
Jamboree held a few weeks ago. It was suggested by Terry VK7TT
that possibly next year instead of Scouts going to the operators
QTH, the operators will have a suitable location picked out and
set up their gear there and have the Scouts come to them. The
meeting was fairly lengthy and finished at 9.30 p.m.
Following the meeting Kevin VK7ZAH gave a very
interesting lecture on the new T.V. translator being installed
up this end of the State, everyone agreed the lecture was very
good, Kevin ably answered all questions put to him by the members.
Tan VK7ZIE thanked Kevin for coming and extended to him an
invitation to come again sometime in the future.
Supper was later served by the Burnie members and all
agreed that Ken VK7KH, Sid VK7SF and Charlie VK7CF would definitely
hold down waitress positions any time they cared to apply.
The evening closed at 11.00 p.m. with the usual
2 metre contacts on the way home.
My apologies to Jim Davis for spelling his name
incorrectly (Davies) sorry OM. Taking pride of place in Jim's
shack at the moment is a beautifully framed award from the
Southern Californian Transmitting Society, this is an award
issued to radio amateurs throughout the world who make two way
contact with any six of their members, Jim was fortunate enough
to obtain this award by receiving signals from that amount while
engaged in two way contacts. He received this special SWL No 1
award, the only one ever issued, and in big print across the
front is written, to Jim Davis No:1 SWL and future VK7 and is
signed by the six members heard.
73 Lindsay Johnson
o e eve Y e Yo o Wk e de T ve e e ke
We_boObed.
In the article by Daniel VK7ZDA "a simple 0-100Hz frequency
meter" on page 10 of the November issue.
Diodes D2 and D4 in the circuit diagram should be inverted.
Page 4 QRM Dec. 1976
DX notes by Col VK7LZ.
Having been away from home more than half the month
I was wondering what I could say about DX and from there to
thinking of defining DX. The normal DX hound would say it was an
amateur station in or at a rare location or country, on the DX
bands which would be considered as from 3.5 to 28 MHz, however
if you were to ask VK7JV if the YJBKM he QSO'ed was DX I'm sure
the answer would be in the affirmative yet the QSO was on the
52 MHz band, again I've QSO'ed VR1l, VR4, VR8, JA, W and KL7
recently on 1.8 MHz and none of these would be acceptable for
DXCC because they were not QSO'ed on the amateur bands specified
namely, 3.5 to 28 MHz.
Although in compiling these notes we normally only
take into account the stations heard on the HF bands, DX really
covers every band used wether it be a KS6 by satellite or a VK4
on 144 MHz, so whatever you operate on be it MF, HF, VHF or UHF
good DX and a Merry Christmas to you all.
Now the happenings of the month as gleaned from our
DX gang and much snooping. Evidently due to problems in the
postal department no QST's have been received for some time,
however it appears that EA9 Rio de Oro, VQ9 Aldabra, VQ9 Desroches,
VQ9 Farquahar, VS9K Kamaran and 824 Saudi Arabia/Irag Neut. Zone
have all been deleted from the DXCC list.
"Break-in" the NZART magazine advises that Campbell
Island will be re activated shortly on 3.5 MHz with a ZL4/A
callsign, the QSL manager will be ZL4NH, also that ZK1BA visits
Manahiki every two or three months and operates as ZK1BA/A, this
is quite a rare one.
VK7BC and VK7JV report that conditions were good for
the World Wide DX contest during the month, 7JV gave me a list
of stations worked and heard and over 60 countries were listed
including VP8, EP, AP, VQ9, EI, VPl, OA4, FC, HB@, 4U and several
other goodies.
VK7AK advises that conditions have improved of late
and that 14 MHz has produced VU's of an evening, also several
European countries have been logged around 11.30Z some nights,
whilst 27 and 28MHz requires watching with 27MHz being quite
busy at times with plenty of stations that shouldn't even be
there. VK7AZ comments likewise and is convinced that conditions
are once again on the up and up and his log seems to prove such
to be the case.
VK7CH finds that CW signals from Southern and Eastern
Europe start to come in on 14MHz at approximately 05.30Z whilst
England and the Northern countries appear at 07.00Z. Charlie has
been working ZS's around 06.00Z and even up to 08.002Z.
Stations listed during the month are as follows,
all times are GMT.
3.5MHz- CW, 13.00Z, Only JA's
7MHZ, CW, 05.30 - DJ@YS
06.00 - 06.30 - YU1BCD, UP2BAO, OKI1BL, LZ2ZX.
06.30 - 07.00 - SP9ICA, SV1DO, CNBAD, DJ@UP/VP2S
07.00 - 07.30 - FOBEX, FWBCO, FK8AI, DJ2BJ, 02110, VP1MPW,
GM6VR, FOBEW, I6BQI.
09.00 - GW3KSQ.
12.00 - CM2HB, VE2BPT, OHORU.
Dec. 1976 Q R M Page 5
7MHz, SSB.
06.00 06.30, DJ9GB, DL8PC, TGOSNE.
0.700 , CT1FrL, DJ3ST, HC1lSO, DJ5VV, OH1lVR, KZ5HP.
07.30 , CT4AT, VR3AR.
14MHz,
CW .
04.30 - 05.00, 4X4JS, UAGLAV.
06.00 , YUINFP,
11.00 - 12.00, AJ3AA, FK8CD, HASBKFB, LZ2KB, KX6RS,
14MHZ, SSB.
04.30 - 05.00, JYOCR, 4Z4GH, SVICT, HC1HV, VR3AK.
05.30 - 06.00, UOSDN, HIBEDC, HIS8CDS.
06.00 - 06.30, OE3NH, SV@WZ (Rhodes)
07.00 , I@FOV.
10.00 , YV4AVJ, ‘
11.30 12.00, 8P7FU, YB@ACB, YB@ACK, P29DW, UA3AAK, C21PS, KG6RL,
3D2GA, GM3GRX, VSS5MC, also VU's and JA's.
13.00 , JYDMB{
21MHz, CW.
10.30 , OHINI, OH1GO, SM4GND, SMS5AKS, AP2TN, also DL's & G's
28 MHz, SSB.
22.00 , KH6 and W's also short skip VK and ZL,
QSL information.
4X4JS via WA2KWP, SV@WZ via OE3NH, 8P7FU via W3HNK,
DJ@UP/VP2S via DJ@GUP, 9M6MU via DJIS8XW, WB4ZKG/KC6 via WA7ZTL.
JY5MB, P.O. Box 299 Amman, Jordan.
KG6RL, Box 189 Saipan, Mariana Islands.
All the best of luck, health and DX untill we make it again
in 49775
Col VK7LZ
dhhkkhhhkhkhhhkhkhkdhdhhdhhdkhx
_This QOSL Business
QSL Bureaux have been with us for so long that they are
probably taken for granted, so a few comments on their operation
and -on QSLs in general may be of interest.
In most countries both inward and outward cards are
handled, one exception being the U.S.A. where 11 different
Bureaux handle inward cards only. On the lst November 1976 the
A.R.R.L. established an outgoing service for their members who
previously had to send their cards direct or through one of
several private forwarding agencies. This will no doubt be
appriciated by the W boys, but we will still have the expense of
sendings to the 11 Bureaux. Untill recently Canadian cards had to
go to their 10 different Bureaux but now a central depot is
operating with a consequent saving in our postage costs.,
I have not seen any recent figures regarding the number
of cards handled in other countries but about three years ago
the total inward through the 11 U.S.A. Bureaux was averaging
over 330,000 per month and Germany's DARC in and out was 15,000
per day. Japan's JARL and the U.S.S.R. CRC must also handle a
huge number. At the other end of the scale VK7 has averaged about
700 a month this year to date, an increase of 100 on last vyear.
These days many DX stations have "OSL Managers"- a friend
Page 6 QR M Dec. 1976
who takes on the QSL chores for him. He would have to be a friend
to take on a job like that voluntarily! This has undoubtedly
meant you'll get cards from stations who otherwise would not
bother sending QSLs or find the job to big for them.
It is of course impossible to forward on all cards immedia-
tely they reach me but as far as possible I try to get them on
their way without too much delay and even two or three for any
particular country are sent within a reasonable time. with an
increase in the number of outward cards the financial side is now
a bit easier and should enable me to get them moving quicker. the
minimum postage for printed matter is 20¢ for 50g. and for this
we can send 13 to 14 cards. The special envelopes cost 2¢ so
unless we have 11 cards we show a loss which is usually the case
as most sendings come within the weight range. However a profit
on larger batches especially to J, U and ZL offsets these losses
and enables us to remain in business.
Inward cards for the North and North West Branches are sent
in bulk to VK7LZ and VK7MZ each month shortly before the respective
Branch meeting dates. Some are collected at the Southern Branch
meeting and a few who have made special arrangements have theirs
sent out periodically. The rest are just cluttering up the files
waiting to be claimed.
Quite a lot of cards are received for non-existent stations
(a packet of 65 from U.S.S.R. today contained 14 of these). No
doubt some are due to difficult conditions, but it surprised me
to find that of 108 of these cards which have not yet gone into
the WPB, 93 showed R5 reports and 39 of them S9. This may indicate
that there are a lot of pirates posing as VK7's overseas or more
likely a large proportion of reports we get are not worth a
bumper. After all R5 means "Perfectly readable" so there should
be no excuse for not copying correctly.
QSLs are a necessity for a number of Awards to provide
proof that the QSO has taken place and for this the following
information is essential; your call sign and that of the station
worked, confirmation of QSO, band and mode, signal report and
date and time (always use GMT). '
Do not expect quick replies to cards sent through Bureaux.
Surface mail is very slow these days, three months from U.S.A.
is usual for instance. There are also inevitable delays at Bureaux
some of whom only send batches at long intervals. For a quick
reply send your card direct with a SAE and IRC for return postage.
Current call books are held here and full QTH may be obtained
from me. And now a few hints for new users of the VK7 Bureau.
Firstly and most important as far as I am concerned is to
keep the size of your card no larger than 5%"X 3%", Not only do
these weigh less but they will fit in a normal sized envelope
and are much easier to pack in bulk. You try and tie up a packet
of say 100 cards when 2 or 3 are oversized. It is hard to make a
good job of it and these 2 or 3 are sure to be damaged.
Cost is 2¢ per card which pays for postage, envelopes and
other incidental expenses. Send some cash with your first lot of
cards and any surplus will be credited to you and used for future
sendings. If you are given any special instructions at time of
QSO put this on the back of your card so I will know where to
send it.
Dec. 1976 QR M Page 7
VHF notes from Kevin VK7ZAH,
6 Mx Band. Since the opening to Japan on the 23rd of October,
quite a number of openings have occurred on this band. Mostly
the openings have been to the Northern VK2 and VK4 areas.
On the 1l4th of November at approximately 22.30%2
the band opened to VK4 and VK2 with very good signal reports
being exchanged. At approx. 02.00Z on the same day YJ8KM was
worked by VK7JV and VK7ZDA. This station was heard at the
Hamfest site but unfortunately no QSO's were made. I believe
YJI8KM listens every lunchtime on 52.050MHz.
To my knowledge the band opened to VK's 2, 4, 5
on the 17th November and to VK's 2, 5 on the 18th November.
Probably the best opening occurred on the 20th and 21st Nov.
On the 20th all States except VK6 were worked and on the 2lst
YJIB8KM was worked by VK7JG as well as VK's 1, 2, 4 as well as
lots of very strong VK5's, on this day we also had the first
opening to ZL with ZL3QK being worked.
I am typing this just after the band has closed
to 2L's 1, 2, 3, 4 and VK2 and 4. (VK7JV 23rd Nov.)
I believe that VK2FT is operating from Lord Howe
Island but he has not been heard to date. Two stations are
active in Darwin these being Trevor VKBZTW and Neil VK8ZCU,
2 Mx band. The openings to date on this band have been few.
The band did open to the Gippsland area on the 1l1lth, 12th,
13th and 14th of November. The most prominent station worked
Tan VK3YJI. Bill VK7AK got his first taste of 2 metre SSB DX
by working Ian. Tony VK7AX must take first prize for the
longest contact on 2 metres SSB when he was talking to VK3YJI
for one hour on the 1llth November. John VK3ZBG was worked from
his portable QTH at Mt.Oberon using an IC202 with attached
whip horizontally polarised.
432MHz band. The only news regarding this band is that VK3AKC
was heard in Launceston on the 12th of November at 5-9+, Ron
was using his pair of 4CX250B's. Winston VK7EM and Ron VK3AKC
exchanged ATV pictures on the same evening.
Thats all the news for this month
73 Kevin VK7ZAH
W e e Wvk Yo v ede ke de e e ke de ke K
Continued from page , This QSL business
Sorting your cards alphabetically and numerically makes
my job a bit easier as does the writing on the back of the card
the call sign of the station it is for.
Let me know if you do not want cards and they can be
destroyed.
Send your cards either to G.P.O. Box 371d, Hobart 7001
or preferably to my home address, 95 Wentworth St., Bellerive
7018 which saves the wife having to carry them home as she
usually clears the box!
Chas. Harrisson VK7CH
QSL Manager
[[[pe—y
Page 8 QRM Dec. 1976
Jpenany
MODIFICATIONS TO IGL FOR 5 CHANNEL OPERATION
AND 7 SEGMENT DISPLAY. by Roy Austen.
vy
1) The circuit has been extended to 5 channels and operates in
the following manner. Plus 5 volts from regulator Q1 is switched
via SW1 to either the scanner or through the 120 Ohm resistor
R34, which drops the voltage to the same value as that which is
-
produced by the scanner, to the common arm of the manual receive
switch. LEDl1 and LED2 indicate the mode selected and while on
scan LED1 will be on while LED2 will pulse on as the scan passes
e
the manual selected channel. On manual only LED2 is on.
2) When a signal is received the mute opens and terminal S is
raised in potential, charging C2 via R8 and D2. This potential
is extended to the multi-vibrator via Q2, turning Q3 on and
mw
stopping the oscillator. Thus the scan is stopped. The potential
from S is also extended to the relay and Cll via D15 operating
remote start of tape recorder and LED3 (mute LED).
[
3) When the signal is removed the mute.shuts and Cl1l discharges
for approximately one second then stops tape and LED3. The value
of C2 was selected so that discharge time is also approximately
n
one second, discharging through the base of Q2, after which the
potential is sufficiently low enough for the multi-vibrator to
start again and the scan is continued.
4) The potential from the channel positions, which is picked up
before resistors R14-R18, is applied through diodes D8-D14 to
the inputs of IC3, which are grounded via resistors R21-R24, this
applies voltage to the segments of the display through resistors
R27-R33, required to give the numbers 1,2,3,4,5, by either the
scan or manual mode.
5) In any of the 5 manual positions, the appropriate transmit
crystal is switched to the modulator diode D1, also voltage via
resistors to the base of the switching transistors Q5-Q9 for
receive selection. In the scan position 5 volts is extended to
the multi-vibrator Q3 and Q4 and to IC's 1 and 2. The multi-
vibrator pulses the counter IC2. The ICl shift register then
turns on each switching transistor in turn to '"search'". For
this to occur the mute must be closed.
6) While in the scan mode any one of the 5 transmit crystals may
be selected manually and used.
7) Audio into the cassette recorder was picked up from the
speaker terminals and fed via R35 to the mike input of the
recorder as no auxilary input was available. Alternatively
audio could be picked up prior to the volume control so that
the volume setting has no effect upon the recorded signal.
CONNECTIONS TO 7 SEG., DISPLAY NSN61L (all anodes common)
Pin Function Pin Function
1 N.C. 10 N.C.
2 Cathode A 11 Cathode D
3 Cathode F 12 Anode
4 Anode 13 Cathode C
5 Cathode E 14 Cathode G
6 Anode 15 Cathode B
7 Cathode DP 16 N.C.
8 N.C. 17 Anode
9 N.C. 18 N.C.
.
b L
NS
CATnonEs
Page 9
waouat vk
7o ANVoLE
Page 10 QR M Dec. 1976
COMPONENT LIST
c1l .0022 Greencap R21 1K
c2 .33 R22 1K
C3 .5 R23 1K
C4 50 uF R24 1K
C5 50 uF R25-33 120
cé Trimmer R34 120
C7 " R35 220
c8 !
Cc9 ! D1 EM401
Cc10 . D2 1N4148
Ccl11 2500 uF D3 OA91
D4 ) n
R1 10K D5 h
R?2 33K D6 !
R3 33K D7 "
R4 33K D8 1N4148
R5 33K D9 !
R6 33K D10 =
R7 120 D11 !
R8 2.2K D12 B
R9 10K D13 !
R10 100K D14 "
R11 1.2K D15 EM404
R12 15K
R13 10K Q1 Regulator LM340T-5
R14 2.2K Q2 2N3565
R15 2.2K Q3 .
R16 2.2K Q4 !
R17 2.2K Q5 2N3564
R18 2.2K Q6 !
R19 1K Q7 "
R20 220 08 !
Q9 B
IC-1 DM 7495
IC-2 = DM 7490 RV1 50K
IC-3 DM 7447 RV2 50K
RV3 50K
RV4 50K
3 - LEDs (your choice) RV5S 50K
1 - NSN61L 2/3" 7 seg. display
1 - 2 pole 5 position switch
SW1 - SPDT mniature switch
1 - ITT P24 A2600 12V relay
WIRING CONNECTIONS ARE AS FOLLOWS.
HT Strap to HT on receiver
R Common arm of manual receive channel switch
T Common arm of transmit switch
XT Strap to X land on exciter
C Strap to C on exciter
S Strap to S on receiver (R-002)
B Strap to B on speech amp
XR Strap to XR on receiver
K + 5 Volt regulated
SC Scan initiate
Dec.1976 QRM Page 11
-15V EXPANDEDSCALE METER by Daniel Apted VK7ZDA.
A SIMPLE 10
The idea was to make a simple 10 - 15V expanded scale
voltmeter using a 0 -1lmA meter giving a linear readout.
The meter can be used to monitor portable, auto or home
batteries or the output of a 12V DC power supply.
The Works. The 723 voltage regulator is set up as a variable
positive voltage regulator giving a stabilised voltage between
its output and the negative line.
The 4.7V zener and the 2N3819 which is set up as a constant
current source produce a stabilised voltage between its output and
the positive line.
The 4K7 trim pot, 1lmA meter and the 1K resistor are actually
a 5V meter with calibration facilities.
With the 5V meter between the output of the 723 and the
junction of the 2N3819 and the 4.7V zener, as the input line
voltage is varied up and down the meter will read the difference
between the sum of the two regulated voltages and the supply line
voltage, when adjusted the sum of the two regulated voltages will
be 10V, therefore the 5V meter is actually working as an expanded
scale meter with zero on the meter equalling 10Volts line input
and 5 volts on the meter equalling 15V line input.
A normal idiot diode and fuse are included to protect the
unit from a reversal in line voltage.
Calibration. Set the:.input line voltage to 10V and adjust VR1
on the 723 regulator for a zero reading on the 1lmA meter, next
set the input line voltage to 15V and adjust VR2 in series with
the meter for a 1lmA reading, each 200uA reading will correspond
to a one volt division, e.g. 200uA = 11V, 400uA = 12V etc.
When calibrated with a good DVM at 10V and 15V it was
found to be within 20mV at all voltages measured over its range.
The completed unit draws approximately 20mA. Fuse kA
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Page 12 QR M Dec. 1976
KEN Ni-Cad Charger, by Adrian Sherrif VK7ZAT.
The following is a simple charger circuit designed to
charge KEN batteries but capable of charging any small Ni-Cad
battery.
The unit uses the 309K, 3 terminal regulator in a
constant current mode. The value of R1* determines output
current, with a 150 Ohm resistor current is about 40-45mA,
ideal for charging Ni-Cads.
Fuse
25omA 1, EM401
o- D
EM 401
o
4oV
o -
O
e
Q1 & Q2 BC1l08 or eq.
D1 zener to set trip
level i.e. 15-16V
The circuit Q1 & Q2 is a voltage sensing circuit. The
value of D1 should be 3-4V higher than the voltage of the battery
pack to be charged. When the connection to the battery pack is
good and they are charging the output voltage is lower than Dl's
conducting point so Q2 turns off, turning on Q1 and the LED.
Tl can be any transformer giving about 2x the voltage
of the battery pack to be charged and a current rating of about
500mA.
My unit was built into a small plastic power terminal
box measuring 100mm x 100mm x 50mm. and a stand to take the KEN
similar to the commercial charger but many other suitable boxes
are available.
e e de d Sk e Bk K de ke e de ke kedede de ke
_IC202 ANTENNA FEED MODIFICATION. copied from VICOM NEWS Sept 1976
(thanks to S.G.McLean VK5ME for this mod.)
It has been noted that some 14mA DC flows in the coaxial
line when on receive if a folded dipole or other closed DC loop
circuit is used. The resulting diode current causes a slight
degradation of the signal to noise ratio.
This can be eliminated by removing the link J14 to the
aerial socket and substituting a mica or disc ceramic capacitor
of 500 to 1000pf. This has no effect on output power.
Vicom News is produced bv VICOM INTERNATIONAL PTY LIMITED,
e —————
| MODERN SOLID STATE CONVERTERS
VHF Modern solid-state, high performance converters
~ GONVERTER
for 28/52/144 MHz bands. Featured in Feb
ruary E.T.l. p.63. '
28 MHZ/ETI707B .. ...t
... $11
KITS 52 MHz/ETI707B ..
144 MHz/ETI1707A
MPE121
These converter kits are simple, easy to construct and align.
® 28/52 MHz (ETI 7078)
This is a tried and proven design and was featured in the January 001
i15sue of ELECTRONICS TODAY INTERNATIONAL. Noise figure 100k 001
on 10 mor 6 m is a little meaningless but this converter produces a
noise figure of around 2 dB. Gain is 20 dB or greater, bandwidth is 3 e % i
MHk2 on 6m, 2 MKz on 10m, spurious responses — 50 dB or better. ‘7k " " "
Choice nf IF frequencies to suit yourself. Please specify 28 MHz or
52 MH. operation. Crystal not supolled Fibreglass p.c. board. Value ] 68D 15p L5 ourt
at . $11 orjust the p.c. board.. . $3.10 001
© 144 MHz (ETI 707A) 02 10p
Natura”y another simple converter. An original 6 UP desi n, this was e an
also featured in the January 1976 issue of ELECTRONICS TODAY 10 Ll q 134 9
INTERNATIONAL. This converter was designed for low noise (3 p g1
dB or better) and low crossmod. performance. Gain is adjustable,
with a maximum of about 20 dB. Bandwidth is also ad)ustab\e
between about 0.5 MHz and more than 1 MHz. Spurious responses \ 10p
are down 50 dB or better. Choice of IF frequencies to suit yourself, .001
No neutralization. Crystal not supplied. Fibreglass p.c. board. What IN L2 220 100K
more could you want for... $14 or p.c. board only ... $3.50
® 432 MHz (6UP-004) 001
The famous design by VK5QZ — now a standard of sorts! improved
p.c. board. This is probably the simplest way to begin on the UHF
bands. A simple and straightforward design that produces good
performance . . . noise fiqure approx. 4 dB, JFET front end, gain of
10-15 dB, IF of 28 MHz or 52 MHz although some constructors
have used 146 MHz successfully for FM net operation. Bandwidth
approx. 4 MHz. Fibreglass p.c. board. Crystal not supplied.
Complete with straightforward instructions. Head for the frontiers
for...$14 or p.c. board only . .. $3.35
® MARKER (6UP-006)
This provides harmonics to 1296 MHz from a 1 MHz crystal or to
432 MHz from a 100 kHz crystal. Can accept crystals to 15 MHz.
Uses 5 transistors. Crystal not supplied. Find the band edge
for. .$7 or p.c. board only . . . $2.55
PACK & POST eon kits is 60c per kit.
SuRcui
end s.a.e. for details on coil components, toroids,baluns & other
kits and components
THE WHAT, WHEREWHOHASSLES & HOW MUCHBOOK
A
(OTHERWISE KNOWN AS “THE AMATEUR'S PINK PAGES™)
i A COMPREHENSIVE COMPENDIUM OF COMPANIES AND COLLEAGUES THAT
b COLLECT CURRENCY FOR COMPONENTS; SELL SOCKETS AND SWITCHES
OR SUCHLIKE FOR CENTS; ARRANGE ARCLIGHTS OR AARDVARKS FOR a paltry
ARDENT AMATEURS; FLOG FT200s AND 4X1000S......cvevereennnes.
in fact, if you have ever wondered where to get something,
$2.50 )
or perhaps where else, then this book is for you. It does +40c Post
not cater only for those who build Tots of gear - even if you
only read about amateur radio, you need this book. It also
tells you where to get the things you like to read!
AMATEUR COMMUNICATIONS
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SEE US FOR A BETTER DEAL, WE SERVICE ALL WE SELL.