QRM
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AMATEUR
TR o
o RADIO
PO Box 1010
LAUNCESTON 7250
Bulletin issued by the Northern
Branches of the Wireless Imstitute
of Australia, Tasmanian Yivision.
’ May 1978
Vol 8, No 2,
Registered for Posting as a
Publication Category B,
OSCAR cHagRT
MEET INGS
May 12 Northern Branch, Clubrooms - 34 Bourke St. 8 pemo
May 11 NorthWest Branch, Lakins Hall, Ulverstone 8 pem,
CONTENTS
Page 2‘,*
Qrm Comment 2 NorthWest Notes 9/10
Northera ®ranch Notes 2/3 Hints and Kinks 1"
For Sals/Misc 3 Quiz ( with prizes ) 12
OSCAR Data 4 RTTY 13
More OSCAR Data/Misc 5 AFSK Keyer ( Simple ) 14
g VHF Notes 6 Northern Bramch Account Data 15
‘ DX Notes 6/7 TV Systems - Fart 2 14
- Co-Axial Comnectors 7 Misc, “tems 17
Simple Gate Dip Oscillator 8 Social Functions ( Ladies ) 18
PCB layout details for March PCB Layout for AFSK Keyer 19
PLL Demodulator 9
t bbete
erbttt
TPtt
OSCAR Y ART
e 4 2-5e (v Ated “7??)
Page 2 QRM May 1978
QRM Cemment
Welcome te ancother issue, We have included a printed circuit beard
layeut fer last menthe PPL demedulater, thanks te Ed, VK7HE., Appreximate cest ef
this prejeect, less power supply is $16.12., An article en an AFSK Keyer is
included in this issue, plus seme ether RITY infermatien,
Beb, VK7ZRF has started a series on test equipment, and featured
this meonth is a GDO, which can be completed in short time, Meters for this
project are available ex stere.
If anyone is interested in state of the art 58TV then printed
circuit beards (produced in Australia) are available for a digital sean convertor,
Similar to the robot device selling at $695.00 US. It can be built for less than
half price. The boards are double sided, 20z copper, plated, and including through
holes., Contacts are gold plated. The boards are available for between $#80 - 90 AUST.
Inquiries to 70CC or 7ZIMM.
As you can probably guess the main job of QRM is to chase around
for articles, and nearly always the same group of people supply these, I'm often
asksd, "What can I write about", Well Brian Lord, VK7ZBL asked for an article on
towers, computations etc, Well that seems like an invitation for Kirby VK7ZKB, who
is a metallurgist to come up with an article., How about it Kirby? Perhaps one of
the eslectrical members can give some practieal hints on wiring radio shacks; how
about articles you have adapted to suil your own situation, and last but not least,
please some information for our "Personality Page", This month's issue will give
you somse idea of what we are after,
Bill Tanner has of ferred a QQEQ/40 to the person who comes up with
the best suggestion for the uss of erystals which are on frequencies of 12,5 and
16 Khz. These crystals are available ex storas,
RTTY Date to remember 17th May - Peter Ackerley of P & T will be along
7pm to give a short discussion on teletype machines in general. In addition he will
have equipment to get your machine into the correct speed etc., We want to get as
many members as possible along - bring your machine ( and loop supply - unless it is
too heavy)., Members from the NW and Southern groups are invited also. Tea and
biscuits after,
P PP
e
NORTHERN BRANCH NOTES Maurice, VK7JU
The Northern Branch meeting was held on Friday 14th April at Burke
Street, clubrooms, 27 people attended, A letter from Bill Tanner was tabled, it
was resolved that suggestions in regard to a storage cabinet be investigated and
put in hand by the Executive as soon as possible.
The Treasurers report and balance shect was tabled by Tonmy VK7TP,
Discussion followsd on the trading loss on last years Branch activities, It was
moved by Brian VK7ZBY that the report be received subjeet to audit., Seconded Ed,
VK7THE.
NORTHEAN BRANCH NOTES (cont.) Mauriece, VK7JU
Peter, VK7PF reported on the funding of WARC 79. Peter requested
that iteas for the igenda of the Federal Convention be sent without delay.
Brian VK7ZBY requested funds be made available to cover such
imber ete for the trestles required for classroom purposes and to
B o
n
plation of storeroom and fitting ot - VOTED $100.00.
o
Volunteers with hand held 2 metre gear are required to ensure
the sucesss of WICEN exerecises on 30th april in the Relbia area. Contact Reg,
VE7:iK for further information. FPHONE 31-2090.
It was agreed that the charge account in the Trading Bank be
transferred to the Equitable Building Society. Moved VK7TP, Seconded VK7HE.
i After the meeting slides were shown by VK7PF. These included
views of MI BARROW and LAUNCESTON.AIRPORT. This was followed by films on
intenna Fundamentals., Jlhanks to VK7ZWX and VK7KK.
I New member to look for:=-
Bob Pearson VKZNFZ (ex Newcastle) and lately residimg George Town
rea, Has been moving into new premises and it should not be too long before Bob
AN
= on the air again, ’
Allan Renton, ex VK4AZ will no doubt be finding the climate here
omswhat different to that of the previous QTH, Proserpine, QLD. Our best wishes
m
o allsn in his new sphere of activities,
cr
73s Maurice,
+ P PPEe
FOR SALE; SHACK « VYK7DA = 31 VALE STREET, LAUNCESTON
PHONEg L4, 6886
2 AT 12V 200 AHR BATT. $36,00 EACH
M LINER 6., 6 METRES SSB $180,00
M LINER 2, 2 METRES SSB $200,00
BELCOM LINER 10, 10 METRES SSB §200,00
SELCOM VF156 EXT VFO FOR 10, 6, 2 METRES $115.00
2 METRES 6C WATT AMP SOLID STATE $60,00
SMALL LATHE METAL AND ACCESS $#400,00
HF TAAPPD DIPOLE 10 - 80 MIDY VN $45.00
LCADED # WARE VERTICAL 27 MHZ $35.00
__'_"———-———-——__———'—m
Cut end of cable even. Remove vinyl jacket 1'/,". ) )
INFC ON CC L
CONNECT
Bare */," of conductors. Tin exposed conductors
and braid.
Slide coupling ring on cable. Screw back shell on
cable. Solder hole should align with conductors as
shown.
Assemble front shell to back sheil. Solder holes in
both front and back shells should align. Solder
braid to shells through solder holes. Solder con-
ductors to contacts. Do not use excessive heat.
For final assembly screw coupling ring on back
shell.
Page 4 QR M May 1978
Tracking OSCAR &
The reference orbit information published in AR and elsewhere’
is the time and location of the first crossing of the equator
northbound for a GNT day. From this data find the nearest time in i)
following list and what follows that is the in range orbit for that
day. eg if ref time is 0106 Z the nearest ime in list is 01052 and
you will find that the first orbit in range of VK7 will be at ACS
1105Z after crossing equator at Ot41 for start of oruit 5 for that
day. ACS means aquisition of signal. 103 loss of signal. i is
equator crossing lcngitude,all degrees west of Greenwich not sast
and West, The first orbit in range will over to the EZast witn satel
going from south to north. The next orbit will be roughly overhead
and the last one out to tne west for the evening passes.Orhits 12
and 13 are morning passes with satellite going from north to south.
eee eetttet et
Crbit W ACS Z 10S Z Ortit WL A0S -2 2F0S 2
Z Z
O 0000 03¢ 0057 0109 0O 0005 OLO 0102 O11L
5 0836 16& 1004 1013 5 0841 169 1007 1019
6 101¢ 1sL 1143 1159 6 1C2L4 195 1147 1204
7 1202 21¢ 1322 133g 7 1207 221 1328 1344
12 2038 34¢ 2136 2152 12 2043% 350 2141 2157
13 2222 01l 231 233l 13 2227 O1 2324 2339
0 0010 L1 0107 0119 0 0015 L3 0112 0O12L
5 O08L6 170 1012 1024 5 0851 172 1017 135
6 1029 196 1152 1208 6 1034 157 1157 1214
7 1212 222 1333 1345 7 1217 2% k353Gl H%
12 2048 351 2146 220 1 2 2053 352 2151 2207
13 2232 017 2329 2 13 2227 016 2334 2 j
0 0020 OLL 025 0OL5 0123 0131
5 0ch6 173% 1021 1035 5 00T 174 1025 10LO
6 1C3% 1S9 1201 1218 6 104L 200 1206 1223
7 1222 224 1343 135G 7 1227 226 1346 1404
o 12 2056 35% 2155 2211 12 2103 355 2200 2216
13 2242 020 33C 2354 13 22L7 020 234 235¢C
O 0030 OL 012 013 0 0C oLo
‘ : 5 08LE 175 1031 1045 5 0911 177 1036 1050
’ 6 1049 201 1211 122¢ 6 1054 202 1216 1233
| <: 7 1232 227 1353 1LO9 7 1237 2286 135¢ 1413
| 12 2108 356 2205 2221 12 2113 357 2210 2226
: 13 2252 022 2349 0004
' 13 2257 023 2254 0006
2 ‘—_‘_—“B‘EG'_U—O
OLO OLS ““LQ“"‘“""’“‘—_L_E00L5
‘O © 5"0"‘"_"£""""' ShUER
| 5 0516 173 10LO 1055 5 0021 179 1045 1100
6 1059 203 1221 1238 6 110L 205 1225 12u3
‘ 7 1242 225 1403 1418 7 12L7 231 1408 1423
11 1935 333 2036 2049 11 1940 334 20L1 2054
| St 12 2118 353 2215 2231 12 2123 000 2220 2236
[ 13 2302 024 2359 0013 12 2307 025 0004 Q016
| ‘ 0 0050 051 0 0055 053
LAY 5 0026 1860 1050 11G5 5 0931 162 1055 1110
| 6 1109 206 1231 12ud & 1114 207 1236 1253
| 7 1252 232 1413 1426 7 1257 233 1417 143
' us 11 1545 335 2046 2059 11 195C 336 2051 2104
| 12 2128 001 2225 2241 12 2133 002 2230 2246
| 13 2312 027 000% 0023 13 2317 026 0014 0027
| O 0100 05 0 0105 O
| 5 U936 163 1100 1145 5 OCSh1 160 1105 1120
_— 6 1119 209 1241 1257 6 112u 210 12u6 1302
71302 234 1L22
11 1555 338 1L36
2054 2109
7 1307 236 1427 AL
11 2000 33S 2055 211L
12 2138 003 2235 2251 12 2143 005 22L6 2256
13 2322 026 0015 0032 12 2327 030 002, 0037
l
I__; May 1978 QRHM Page 5
| 0 0110 056 0 0115 058
I L 0803 160 0%34 0935 L 050k 161 €939 C9LO
5 0¢L46 1865 1110 1125 5 0951 167 1115 1130
& 1129 211 1251 1307 6 1134 212 1256 1312
- 11 2005 340 210L 2119 11 2010 341 20LS 2124
I 12 2146 006 2245 2301 12 2153 007 2250 2306
1% 2 003
2 s 0 0125
I L 0613 162 0943 0L L 0816 163 0SL7 0954
5 0626 185 1112 1136 5 1001 16%¢ 1124 1141
| &5~ 30 =204L- %300 1317 6 1144 215 13205 1322
I 11 2015 343 2114 212¢ 11 2020 344 2119 2134
12 2158 008 2255 2310 12 2203 007 2300 '?16
13 2§u2 Oé& 0039 0051 13 4?u7 5 00LL QEEE CCR6
C 0130 061 O 135 0063 '
L uc23 164 0951 1000 I 0026 166 0956 1005
5 1006 1S90 1129 11L6 5 1011 192 1134 1151
6 1149 216 1310 1327 6 1154 217 1315 1331
11 2025 345 2146 2203 11 2030 346 212¢ 21LL
12 2208 011 2305 @320 12 2213 012 2310 2325
13 C101 13 2357 Q30
v (CleTRE
lol = olgl o ST ST
L 083 167 1000 1010 This data calculatea using
; 1016 193 1141 1156 periocd of 103,23 minutes
& 1155 215 1320 1336 longitude increment 25,89
11 2035 3435 2133 2148 The OSCAR 6-7 tracks can
12;: 2216 013 2315 -:2330 be used on tracking map
13 0002 03 0059 0111 with correction for long.
shift and time along track,
Peter VK7PF
DEF INTTIONS
Sub Zditor.....A person who chases around for suitable articles
for 4BM; often several visits are needed for one article, Usually needs to
decypher to a suitable form for typist. Requires the ability to coerce a
typist into doing the work; a box of chocolates usually does the trick.
Paymeat nil, though if you are lucky you local telephone bill might go up
in eost.
WANTED
One SUB Editor for the Nd coast...Qualifications above.,¥s desperately
need articles from the coast, PLE E E E se,
FOR SALE....VK7JG....PH 443882
SIDEBAND ELECTRONICS SES50T 27 MHZ MODIFIED TO 2 METRE TRANSVERTOR/
DRIVER, COMPLETE /ITH XTALS TO COVER 144 TO 144.5 AND 145.8 TO 146
PRICE, .90 DOLLARS==————- 6 FOOT DISH WITH MOUNTIN® BRACKED,.,.45 DOLLARS
POWYER SUPPLY TRANSFORMER 2500 V PER 3IDE...10 DOLLARS,
ANTED
“NDO NOISE METER==HF AND VHF SIG GEN--TF995 OR SIM
ADVISE ..JOE VK7JG
Page 6 QRM May 1978
FOR SALE:
6 metre transvertor 1 $30.00
Bd, VK7HE
1
Robot model 7 SSTV Monitor
PCB { 3315000
Sanyo Stereo Radiogram Chassis
with FM/AM tuner
Mike mixing +$20.00
KIM 432 MHZ 16 EL YAGI complete
with balun 1 845,00
Joe, VK7JG
Phone - 443882
+ + FF Pt
VHF_NOTES Joe, VK7JG
Surprisingly 6 metres has been open on several occasions during
month, Brian VK7RR reported that he worked JA's and ZL's, Danial VK7DA VK4's
JA's, myself VK4ZKC/M Brisbane. On several evenings CHf TV from Brisbane was
watchable but no stations were worked. I have also been told that a JA worked
into Mexieco; this should be a new world record, and VK4's have worked KHé's,
As you can see the increasing sunspot activity has helped 6 metres this month
R
we should be looking forward to 6000 mile winter 6 metre openings around June/
2 metres has also been usable during the month but it appears th
the VK3's are not particularly interested in operating into VK7, From what Bi
VK7AK reported, sctivity in Melbourne on 144.1 and 144.2 is quite high althoug
we never hear them in VK7, although Kevin, VK7ZAH is able to hear the VK3 beac
most of the time, That's all for this month,
738 Joe
* PP
U S————
DX_NOTES Col, VK7LZ
i St
?
i Whilst DX worked makes for good talking - or writimg its more
!
Al important to know what the future holds in store and this is certainly a much
tougher proposition however to start with we'll live in the past and then move
f .
o CONT INUE
Al ddddd A
RESETVED FOR Y O U R ARTICLE
May 1978 QRM Page 7
DX NOTES (cont) Col, VK7LZ
Conditions generally, although patchy, are still improving day by
days <8 Mhz is now a band worthy of more time as our novices will testify, Allen
VK7NAB and John VK7NJD have been busy and have QSO'ed some exotic DX including
African stations whilst 7AE and 7AK have also had some excellent break throughs
to the dark continent.
21 Mhz - also a busy band and appears to be open almost 24 hours
daily and all econtinents have been worked by VKT's during the month, Some good
South and Central Ameriecan countries keep coming up during our afternoons, mostly
with S7 to 59 signals,
14 Maz - Still living up to its good reputation and T1 and DX on
(oeas Islands was the catch of the month here, Central and South Americans are in
abundance as are Asiatie and Europeans however Africans have besn more noticable
by their absence.
Now for the present, and future.
C31IAC is now operating from Andorra and has been QS0'ed on 14 Maz
SSBe QSL to the REF bureau VR80 is also active., Dave will be on Tuvalu for six
months, QSL, C/- Met, Office, Funafuti, Tuvalu, Central Pacific.
P29J5 still hopes to be active from the Cocas Keeling islands as a
VK9 from the 1st May, or possibly two weeks later.
ZK2, Niue Island, operation from this QTH is due to commence on the
26th May and will be on location until the 9th June,
2L3, Chatham Island -~ Look for this one about the first week in May,
he will be on Chatham for 14 days.
Y11, this country is now active and will have a club station
operating in future,
82/ Saudi Arabia/Iraq neutral zone., According to ZL2HE the DX editor
of "Break-In" a licence has been issued for this country and operation is scheduled
in May or June,
In spite of numerous QSL managers being mentioned for the Clipperton
Island expedition on two occasions members of the expedition have told me to QSL
via HB9MX. (Since writing these notes HB9MX has advised that all cards will be in
transit by the end of May).
m
Cut end of cable even. Remove vinyl jacket 3”. Slide
coupling ring and adapter on cable.
Fan braid slightly and fold back as shown. MORE
CC AXIAL
A
Position adapter to dimension shown. Press braid down v ABLE
over body of adapter and trim to 3%". Bare %" of con- C OMNECT | CNS
ductor. Tin exposed center conductor.
Screw plug sub-assembly on adapter. Solder braid to shell
through solder holes. Use enough heat to create bond of
braid to shell. Solder conductor to contact.
For final assembly, screw coupling ring on plug sub-
assembly.
Page 8 QRM May 1978
SIMPLE RELIABLE GATE=DIP OSCILLATOR Bob, VK7ZRF
This handy piece of test equipment is an adaptation of a circuit
presented some time back in "Ham Radio",
The coil information is modified to suit readily available former
i.ec §" electrical conduit cut into lengths of 14" approx and araldited to old
7 pin plug units (valve type) ax an old computer uwnit from Hobart some years
back,
The modified capacitor is of the type purchased by the branch from
the Department of Transport.
The F.EsT. used in my original was an NF500 but other types may be
more suitable at higher frequencies but the type should not prove eritical.
The meter was the small recorder type stocked by the N.B. equipment store,
In this model the pot was found unnecessary as at low frequencies
gate current gave almost F.S.D. dropping off to less than half scale at the top
end,
A small piece of circuit board can be used to mount the components
by seribing heavily two crossed lines thus making four isolated pads which can
then bs mounted adjacent to the socket and capacitor.
As the current drain is low a small 9V battery is ample and any
friend with access to a frequency counter could help out with calibration.
73's Bob,
PP+t
L1 Former ;" Plastic Concuit.
2.6=EMhz80T, Tap10 33swg
68PF Ql 6-132 Mhz 32T Tap 5 3%swg
123-20 bhz 143T Tap2s 2bswg
30-80 Mhz 55T Tapii 228wg
60-120 Mhz 2iLoop Tap 2 way
186swg
80-210 Mhz Strap 3 x § long
Tap » way
1. Zddystone air veriable
oo ~0
ecuip. store special) cut
own tc 7 fixed & 7moving
ylates, 100 Pk,
&1. N#50C, Mpf102,2D 3019
etc.
( IF ANYONE MuKES UP A SMALL PCB FOR THIS PROJECT VE WiILL )
( UZE 1T IN THIS SPACE NEXT ISTUE THAMNKE )
May 1978 QR M Page 9
MARCH PPL DEMODULATOR
Ed, VK7HE has provided details of a suitable printed circuit bound
layout for the PPL demod - Many thanks, Ed.
TRV Vital StatisticseMJE 340
INAUT Ic 500ma
Veb 3V
Veso 300V
hfes 30=240
equive types 285655, 2N5656
COPPER SIDE
F'Uu.‘&zl’.
Includes a few minor alterations
by Bob,.VK7ZRF,
NORTH WEST NOTES By Jim, VK7NOW
It was pleasing to see a near record attendance of 39 at the recent
monthly meeting, this included several very interested "CB-ers", all studying
for their novigelicence,
At the meeting it was agreed that the APRIL Handbooks would only be
sold to financial members,
Visitors included rPeter Fudge ex VK3ZFP. Peter has now settled in
Ulverstone and is awaiting a change of call sign. Athol Manning, VK7LR also
attended the meeting after a long absence, and brought a large amount of
equipment for the Junk Sale,
The Junk Sale was held after General Business, The many items were
capably auctioned by Graham, VK7ZAQ - So much so that one member complained that
he might take the matter up with the CONSUMER'S rROTECTION, because after paying
50¢ for a good TV chassis, found it had no tube!!!
Page 10 Q R M May 1978
BORTH WEST NCTES (conmt) By Jim, VK7NOW
Please note the forthcoming activities: - Next month : Bob Cropper
VK7BY will give a talk on "Speech Processing" and "SSB", On Tuesday, Jume 13th,
Mr. Ray Groom, Member of rarlisment, will attend the meeting to give a talk,
After the auction, Bob VK7BY showed some most interesting educational
films on VHF, UHF and MICROWAVE ANTENNAE. This was followed by a most historie
film, supplied by Jim, VK7NOW and loaned to him by the National Film Library,
Canberra, It was called "Finding his Voice" and was made, cartoon style by Western
lectric in 1928, It showed the various steps in making a "variable density"
sound track and was one of their very early optical sound films,
SICK LIST
Syd, VK7SF has returned home after a spell in the Burnie General
Hospital. We are all glad to know that old "Sugar Fox" is recuperating nicely.
Also making an appearance at the meeting was Ted Wicks who also is
recovering nicely after an illness,
Jim, VK7NOW reports that recently 10 metres has been wide open to Zs
via short path from around 05302, A net consisting of some VKs and ZS's came up
on 28.400 Mhz. Long path to EBurope has also been good on 10 and 15 metres,
+ P P+
GELSTON COMMUNICATIONS
Specialising in Servicing of Z2-day Radio
Car Radio and Cassette Installation and C.B.
Prop. JOE GELSTON Ph.443882
40 Lavender Grove, LAUNCESTON
PHONE: 44 38&
e
e
a—— ——
-oPte S
4 real timesaver for wrapping traznsformer =nd generator coils
this wooden shuttle simplifies brining the tape throush the
c ntre of the coil. The shuttle is made zypproximately to the
dimensions given and a slight twlst releases a lensth of tape
through t .e slot in either pincers shaped € U e
Short of clamps? Use your ima-lnation and make your oOwna
Strap hinges make the best clamps. A win~ nut, wasner and
roofing bolt provide clamping pressure. A small coil spring
placed over the bolt between the leaves of the hinge will
provide the clamp with self-opening Jja.s.
May 1978 QR M Page 11
S —
T o™
v Ll\s o NIVLN 3 THE RIX-1011
There are five diferent shacks, each with a door of a different.
colour
5
and inhabited by hamsc of different interests, owning
different gear and antennas. L2C a dillerent brew.
MY ¢ VHE
D
P,
ViiL er lives in the shack with the red door.
'
T AT
e
41T AT fanatic owns a Xenwood T. 22C,
;offee is drunk at the shack witnh the creen door,
The DXer drinks tea.
The shack with the green door 1s on She richt of the shack
with the ivory door.
ne yagi owner has a Yaesu T 1015,
My
The trap dipole belongs to the owner of ~he shack with the
vellow door.
23437 Te
Milk
1 is drunk at the midaale 58
The Award Hunter lives in the first shack.
The ham who owns the rhombis live next to “he
»y
ot
=
n
3
D
o
o
[
Ui
( 3
}_
ham who owns the Drake,
The trap dipole belongs to the nam next door to the shaclk where
the Heathkit is owned.
T'he inverted "V" owner drinks oracge Juice.
The RTTY enthusiast owns a trap vertical.
The Awa rd Hunter lives next door to the shack with the blue door.
WHG DRINVES m-
ud :'. i :; :&,:D OGS THL RIY 1011222922222929999
(TBEIRSRISSISSRV AAB R e e sl bl
® 6 &6 o 0 00 00
Send answers to RJIXL
Contest, iecretary
tiorthern “ranch, PO sox
1010 LAUNCESTON 7250
or bring to next meetin ;.
Pirst correct ansver to
the two problems ovencd
at the meeting will reccive
a2 set of Jewelers screw=-
T
g L gilg
L
A m drivers.
o
0,
o>
o A
Page 12
QRM May 1978
May 1978 QR M Page 13
IRTTY RTTY RTTY RTTY RTTY RTTY RTTY RTTY RTTY RTTY RTTY RTTY RTTY
TELZPRINTER EQUIPMENT SPEED CONTROL DATA,...
THE FOLLOWING DATA
SHOULD ASSIST IN OVERCOMING THE OFTeN FRUSTRATING TASK OF GETTING
A PRINTER '’ ON SPEED *’, THIS DATA ONLY RELATES TO GOVERNED
MOTORS, THESz MAY BE EITHER AC OR DC IN EITHER SERIES OR SHUNT
GOVERNED TYPES, THE PARTICULAR MACHINE MUST OF COURSE BE FITTED
WITH THE CORRECT GEARS FOR THE MOTOR TYPE PROVIDED. THIS CAN BE
CONF IRMED BY CHECKING THE MANUAL,
ASSUMING THAT THE MOTOR AND GEAR SET DO MATCH, IT IS A
SIMPLE MATTER TO PAINT THE CORRECT NUMBER OF SEGMENTS ON THE
GOVERNOR RING SO THAT A STROBOSCOPE CAN BE USED TO CHECK THEMOTOR
SPEED, AN EAS ER METHOD 1S TO MARK THE SEGMENTS ONTO A LENGTH OF
WHITE STICKING PLASTER AND THEN FASTER THIS TO THE GOVENOR RING.
THE FOLLOWING FORMULA IS USED TO DETERMINE THE NUMBER OF
SEGMENTS, sueeus
N=F X 120
S
WHERE N NUMBER OF SEGMENTS INTO WHICH CIRCUMFERENCE OF GOVERNOR
SHOULD BE DIVIDED,
F FREQUENCY OF FORK OR STROBING SOURCE,
S SPELD OF MOTOR IN R, P, M,
AS MODEL 15 TELETYPE AND CREeD 7B MACHINES ARE THE MORE COMMON
TYPES ONLY THE DATA FOR THeSE IS LISTED,. OTHERS ON REQUEST,
oV
CREED MODEL 7B 8 TTR 6S
50 BAUDS—-USING 87.6 VPS TUNING FORK,,MOTOR SPEcD 3000 RPM,.
REVS PeR BAUD 60..GOVERNOR SEGMENTS 7 WHITE 7 BLACK..SEGMENT SiZt
25,71 DeGREES.
50 BAUDS—=USING NEON FLASHER ON 50 CYCLES OR 125 CYCLE TUNING FORK,
MOTOR SPEED 3000 RPM..REVS PER BAUD 60,,GOVERNOR SEGMENTS 10 wHITE
10 BLACK, ,SEGMENT SIZE 18 DEGREES,
45,45 BAUDS==USING NEON FLASHER ON 50 CYCLES OR 125 CYCLE TUNING
FORK,.MOTOR SPEED 2727 RPM,.REVS PER BAUD 60.,GOVERNOR SEGMENTS
11 WHITE 11 BLACK,.SEGMENT SIZt 16,36 DEGREES.
TELETYPE MODEL 14 15 19
50 BAUDS=-USING 96,19 VPS FORK, ,MOTOR SPEED 2102.4 RPM (NOMINAL
210C MOTOR),.REVS PER BAUD 46,2,.GOVERNOR SEGMENTS 10 WHITE 10
BLACK,.,
45,45 BAUDS=-USING 87.6 VPS FORK,.,MOTOR SPEED 2308.56 RPM
(NOMINAL 2100 MOTOR)..REVS PER BAUD 46.2..GOVERNOR SEGMENTS 10
WHITE 10 BLACK,
Page 14 QR M May 1978
AF3K Keyer
Herewith the layout for a very simpls and economical PLL keyer, Maleolm,
VK7ZMM has added the transistor andoptoisolator which has improved it no end,
2 fhE #
¥ AR RS
Niged”
4xEML0Y
27~ CNY42
Go MA LOOP
ozosy RA Loof f—@ —r TRANSSR
2 20m collenT
Cry u2
RTTY,.17th MAY,.,Teletype night at the clubroom,.Come along for discussion on loop supplies
How to maintain your machine, and any other questions you may think of, Peter
Ackerley of the PMG will be along. Bring your machine and get it on the correct
speed, We really look forward to a good turaout, flease bring along a plate of
goodies to go with the tea or coffes, REMEMBER 17th MAY.
NEXT MONTH ON RTTYeoswo
LOOP SUPPLIES,. CONZTAMNT CURRENT VARIETY. <0 LOCK
FOR AN EXTRA MJE 340 FOR THIS PURPOSE, .ALSO A LITTLE ON UARTS FOR SPEED
CONVERSION AND REGENERATINN PURPOSES, IF YOU HAVE ANY PARTICULAR REQUIRF=
MENTS FOR RTTY ARTICLESPl THEN LET U™ KNOW.
May 1978 QR M Page 15
NORTHERN BRANCH Y<ARLY ACCOUNT
SALES $4,655.40
LESS COST OF SALES
OPENING STOCK 2,007.44
PLUS PURCHASES 4,935.78
PLUS FREIGHT & CARTAGE IN 23.83
LESS STOCK ON HAND 23/2/78 2,140.14
COST OF GGODS SOLD 4,826.91
GROSS LOSS 171.51
PLUS OTHER INCOME
SUBS 153.00
DIV, REFUNDS 46,50
ADVERTISING INCOME 90.00
Q.R.M. 58.00
SUPPER DONATIONS 18.68
INTEREST 39.39 405.57
LESS EXPENSES
W.I.A. FEDERAL 34.00
Q.R.M. 100.C0O
LICENSE FEES 48.00
PETTY CASH EXPENSES 81.04
(PLUS PETTY CASH EXP.NOT REIMBURSED 3.40
CHEQUE BOOKS 3.20
Q.5.L. BUREAU 11.36
STATIONERY 36.80
FLORAL TRIBUTES 27.00
STATE LIBRARY 1.15 345.95
NET LOSS 111.89
BALANCE SHEET AS AT 28/2/78
LIABILITIES ASSETS
ACCUMULATED FUNDS 3,407.55 STOCK ON HAND 23/2/78 2,140.14
L;B.5. 718.32
LESS CASH FLOAT 20.00
NET LOSS 111.89 PETTY CASH 7.00
ADVANCE TO CLUBROOM 410.20
ACCOUNT(TO BE REFUNDED)
$3,295.66 $3,295.66
CLUBROOM ACCOUNT BALANCE AS AT 28/2/78 950.33
INVESTMENT ACCOUNT 1,533.75
$2,484.08
SUBJECT TO AUDIT.
Page 16
May 1578
o
£
The Telavision System—— Part =
2 MaB At
Maglicolmm TP WNL
VK7ZMM
Let ussxanine the appsarance of a TV siznal with respect to LYime,Tn other
worda let us draw a graph of voltage against time lor a video siznal,
A A
N
Cita e A
Y . v
0 ____if‘j'_m o Ol MM LSl
The first thiaig thatone zould say about this graph is that it does not loow like anyw
thing, Well it's not meant to, You will remember that a TV siznal is made up of
625 lines, Well this is two of those lines, snd white T¥
*f you examine s black
closely you can see the line structure of the picture,
Now let us examine this graph or waveform as we will call it, You may notice
the square pulses that extend downwards. These are norizontal sync pulses, after
tnis there is a flat portion which is called the BACKPORCH. Now the informatinn
starts, The voltage from here on determines the intensity of the picture. The
highest voltageist he highest intensity or brightest sean of that line, The lowest
point that voltage may reach in this part of the waveform is repraseatzd by the
dotted line and is called REFuRuNCE BLACK. Voltage between the max and min are shades
of grey. Now after this video information finishes there is another short flat sechtion
callsd the BACKPORCH which finishes off this line of a TV picture,
There is now another sync pulse as before, This pulse is used to reset the
oscillator of the telsvision sets back to the leftnand side of the picture to a point
just out of view in & normal set. The oscillator then begins another scan of an
electron beam which travels from left to rizht. This beam is used to excite the
phosphorous of the TV tube, which emits light, Brizhtness of the light emitted can be
coantrolliesd by the intensity of this electron beamy, which travels {rom a gun at the
back of the tube, Therefore the voltage of the video signal is used to control this
electron beams intensity, and the intensity of the picture, Thus as the oscillator
scans the electron beam from left to right, the elsctron beam is modulated in inten-
sity by the vcltage of the video information.
Now these two lines of information that we have beental<ing about take 128 mdS
( mizrossconds) or 0,000128 seconds. That means it takes 64 mS for the complation of
one line , or 0,000064 seconds, Not long is it ! Now this means that there must be
1 of these lines every second. Cut with ealeculator ! What do you get ?
0.000064 A number which may sound familiar if you have had much to do with TV's,
It is called line rate and is 15625 lines/Zecond or cycles/second or Herts,
It is the high pitch whistls you mav hear from a telsvieion set,
TEPE PR
bbb b bbb
Fage 4.o...Response to 50 Kz of course !
Page 6.0..VKTTT is of course Terry Tongs..apologiss Terry
MAY 1978
WANTED QRM LPAGE 17
Articles for QRM - techniecal or non technical - § Dstails for our
Personality Page: erosswordss ete: CLOSING DATE 20TH MAY,
L E T e
APRIL PERSONALTITY
VK7JU ; Maurice George Burleigh, "Chook" for short., First licensed in
1938, almost 41 years agoll! Maurice is now retired having spent as he puts it,
"a life time in the electrical industry", He uses a Uniden 2020 and 2 metre FU
mobile to keep in contact with previous workmates and serviee personnel he met
whilst serving 6 years with the RAAF. In between radio contacts Maurice and his
wife Leila (Tem for short) enjoy gardening, Maurice would like to hear (mon -
technical) stories from other members about in and around their "salt mines",
So how about it fellows?
+r P e
NORTHERN BRANCH EQUIFMENT STORE
Business Hours: 19.30 to 20.30 Tuesdays and Thursdays
and monthly meeting nights, at the
Clubrooms.
There are still some assorted items available from a recent tender
purchase. Included are power supplies at $2.50 each and covers,
which make excellent storage trays, at only 10¢ each.
Books. One hundred titles are available through the equipment
store from the Federal Executive Office covering all aspects of
amateur radio and related electronics. Lists may be seen in the
store -« the prices need no comparison!
Major items may be purchased through the store at competitive
prices. Please enquire before purchasing rigs etc.
Enquiries and suggestions (polite) should be directed to
Ian Clements on 82-1188 Extension 237 (Bus) or 44-6588 between
6 - 8 p.m.
DONT FORGET.. INFO NEEDED FOR QURPERSONA ITY
L FPAGW/ITH
E. PHOTO |IF
POSSIBLE..FOR'/'FD COMPLETED TUESTIONMAIRE,
.
VANTED.
oAN ARTICLE ON A SIMPLE SREICH PROCES:O
PAGE 18 WM T 19O
o QOCTIAL FUNCTTI ONS
.adies' Committee
At a meeting held at the home of iirs. Annette Emmett on 29/4/78, a
Ladies' Committee was tentatively formed to try to help organise social
functions for w.I.A, members, their families, and friends., The suggestions
below were put forward by those present at the meeting, i.e. MesdarsSGrant
(convenor), Emmett, Gelston, Hewens and Yeoman.
We would like you to state your first, second and third preference, from
this list, for possible future activities within the 3ranch, and perhaps even, :
suggest others:
swimming for families at Lowbray swimming centre
theatre parties at Princess Theatre (with supper afterwards)
progressive dinners
film afternoons or evenings
soup and sandwich mornings or afternoons
Halloween party
wine and cheese evenings
family outings to Punchbowl Reserve, Trevallyn Dam, etc.
3ingo or card evenings
sports (basketball, carpet bowls, etc.)
river cruises
caparets
lon-.uvn-e..oo-uoe-oun-ol.-o'c-oo'-o.c-a-onooo~c~v-o-9-0-0-.0
2l09‘Ow...l.o’...lhlo.ol'oon.tu.l‘fll05.00'9!0000.90’00030-0-0
3aoooboaco-ounvnooot..oanooooucuooo-ooo-&uoooooooo.oat'concu-
It would be appreciated if you would lend your full support to this
endeavour to improve the social side of Amateur Radio., The response to
this "questionnaire"™ will inform the Committee how much demand there is
for functions.
We would also welcome your comments on the frequency of social
activities -
1. once every month? csescesns
2, " " three months? e
3. " " six months? cereeren
Flease indicate your ideas here too. It is envisaged that any social
activity organised shall not clash with normal events such as Kadio Conventions,
Annual Dinners or Christmas barbecues,
MAY 1978 QRM PAGE 19
he next meeting of the Ladies Committee will be held on Sunday 2lst
May at 3 p.m., Venue is 40 Lavender Grove, the home of Mrs. Phyllis Gelston,
All ladies interested in contributing any ideas are most welcome to attend.
The questionnaire may be sent or handed to the undersigned.
Diane Yeoman (XYL VKTZ3Y)
10 Keid >Street,
ningsmeadows, Launceston.
(telephone 441466)
AFSK keyer ..Double size PCB layoub..These board will be available ex store if you
cannot be bothered doing " your own thimg".
See page 14 for eircuit disgram.
RTTY ENCUDER
TX T XD L€
&-—f—/ |
15T GUNN PTY LTD 50
s
BRISBANE St. LAUNCESTON
Telephone 319333
DOMESTIC & BUILDERS HARDWAKE
" MARINE & PLUMBING SUPPLIES
PAINT & TOOLS
SEDDON PRESS
35a GRANVILLE St. LAUNCESTON 7250
Telephone 316191
FOR ALL YOUR PRINTING
BRUSINESS AND PERSONAL
< A0 M | OSL CARDS
DHe& LS Chillcott & Sons
ALL CLASSES ELECTRICAL INSTALLATIONS AND REPAIRS
INDUSTRIAL AND DOMESTIC MAINTENANCE
SALES AND SERVICE OF ELECTRICAL APPLIANCES
89 CLIVE St., NEWSTEZD, PHONE 311677
AFTER HOURS 444434 or 318659
Athol L awes Electrics
s\t)
135 HOBART Rd., KINGS MEADOWS, PHONE 444710
FOR ALL ELECZTRICAL APPLIANCES, SPECIALISTS 1IN,
HI-F1 SOUND SYSTEMS
CAR RADIO AND STEREC
. oiTTER DEAL, “E SERVICE ALL WE SELL.
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