SKM C450i24093017010
Recognised text
Text below was produced by optical character recognition and may contain errors. Check it against the original.
11^ w.M:yis JMll. iy.li
Of AViiaALJA
TASMANIAN DIVISION
JATO^Y -1.966 BOX 85U, &. P. O., • HOEART
M_0 N TH L Y BULLETIN PRICE 6d.
PRESIDENT: Mr. T. Alien T№&STO^: Mr. V. F. Dore SECRETARY: Mr. K. Spiegel
VK/AL . VK7JD VK7KS
Registered a-b &. P. 0., Hobar-fc, for -transmission by post as a periodical.
EDITORIAL
Another New Year is with. us and with the Suraner months.. DX seeas a little
more proainen-fc on -the HP Bands "» likewise VHP - extremely good oontac-bs .Taeing made
from mobiliB installa-tions. . This would seem n good way to s'tart •bhe New Year - -the
activity, new fields, new bands and for the lucky ones, now e^uipaen'b»
As kids we usod to endeavour -bo turn over a new leaf - now-acLiilts, we; gi vs a sigh
of relief after "the nad coniaercialised ru.sh of Xnas, and relax, or try to^ remeaber
the harmonics are on holidays* Instaad of jus-b coping vd-th QRI,'l and QRIT as we know i-t,
with a rare one popping up I gone'fciaes have "bo 'battle thru. girlish-screaas -to liear
wha-t the other chap is saying - narvelous for -bhe concentra-bion and pa-t. ience - just
what doesnt our ho.b'by teach us ?
Kow I h.?,v© -to finish this Editorial off - -the XYL wnn-bs soaethi'nfl- donB«"
See you next month
Ted VK7EB.
MEETINGS FOR JI-JST31SI. s.
JJiNUARY 5 .Eeadquar-fcerg General Meeting, 147 Liverpool S-t*, Ho'ba.r-t, 2000 hours.
14 Hor-fchern Zone, Adult Education Centre, 51' York St., Lalinceston, 2000 hours.,
17 Council Meeting, Hobar-t. 1930 hours.
19 Headquarters V> H. F. Groupo 2000 hours.
Overmodulation does not help get -that rc?j"e DX - i-fc frightens theo away T3u.t
it can attrao-b -the wrath of your aaateur nei^i'bours plus -bhe RI I ^0% nodulation
properly raa-fcohed is far better in effect -than over 100^ improperly matched. Remera'ber
impedance inatching is about one of the nost important factors in designins efficient
equipment — try i-b sone 'bime - then you. will work those rare ones»
T'he Wireless.. In:s. -t;i-bul-fce--o. f ^.us-trali. a'.Hon-bhly ••Biill. e'tin,:,
Januar'"1 . 66- t . '' '• '''• Tasniauian-I^vi'EftQri: . • • .. :... -..-——•""""""" ' Pa 3
T.EGSaiQ^tL ':":" . "bx;,.Gr:6.g...John;s'tffrL"" Part 2<>'
One poin-fc to watch-.when' gs-fc.-ting -bhe -12AT7 'bo mi^ is -tlie ampli-bude of the
injection vpl-bag? - rau. ch..less vol-fcage is'required he're than for a pentode. If 'bhe osc
illato'r'voltage ±s too hi.gh. all 'sorts of spurious: res^ result with near zero
ou.-feput»"ill'o real trouble should be oncoiin-bered. with -bhe RF stage stability provided
•fche centre spigot of . the. .valve •sQokQt'a'nd the shield ( pin 9 ) are earthed, properly.
If -bhis'i d.oos;no.1; iio 'tho job then it may 'be necessary •to inser-t; . a .. neutralising coil in
place of the 33 ohm resistor betv/eeq pins ,1 and 8, this was not heoessary in. my own 32
" ''. * '•
case» :"-" '
ITov/ just becau.se the circu.i-b 3. riclad.es';,-thGOsoill<?.tor oirouit shown dont -bhink
for a minute th3t''i:'':aa'::^00^ satisfied wi.-bb. -iffc- I IiavQ-spent a week"stabilising it -fcc
^.
the point,. whQr. g. it will-• hoi "d .. zero 'beat with a crys-fcal osoiUator-'for 5 to 10 ainu-bes
'^
-but'as this is not adeg. uate.. staMlity" for ^B.rcppy. (....,"araeh^^ ',).. we-do"o'oasid. er
—fcha-(;.. ther-e xs roora f.dr'impro'vea'erit here, mog-b" likely in terms of a Vackar circui-t
(. ..o.r use Q."xt al'oscillator and -tune the IF - Sd.)
As a parting sally, if you think your receiving set up is pretty good in -fcerms of
sensitivity and noise figure try this eagy test on it« R.enioye- the ari-fcenna and replace
it with a resistor, equal to :-the receivers ircpiit impedance,; if the receiver noise
•pe-aks up when "the RF.. Gir,oui'ts are 'tuned "bhroiigh resonance then you can say your
reoeiver has high sensj. -t.ivi'by. At- this stage, if -the noiSG (i. e. internal noise )
is say 6d"b down ( i. Oc 4:1 ) on -bha-t heard with. the antenna oonnQOted then yoii can
say that'your r-eoeivQr has-. an. 'acoep-fcablQ noise figure ^ as well» Both '•these tests havo
boen tried. 'on -the . fron-t . end ; de scribed, an.d on 'both counts things-measure up.
Vfeen we 'bu.ild a no.ise, gon^ra-tor. -bhough, we'll endGavour to. measure -thG performance in
db stylo' and present the figiires as the final clu.o<,
For -the be.nefit of any fell-om associa.'tes who may wish •to have a orack at a beastie t±
like this liu-fc desire raorG infomation. on how to go about it I nay be contacted
sometiaes at hone - phone 82416 (• no-c ye-fc you dont - he's down with the penguines
for about a year - Ed. ) • "
T'hank you. G-ceg for a very in-beresting -bopic - for those. who ar. e . interested' I used
the like new mixer in my. -. SSB. transceiver where it is very sa-fcisf.ac-tory, WJCV used
the Eiame circ^ui-b in -the transai-fc-fcer' '• sec'bion of his . S8B rig and. was q.ai-fce pleased
v/ith -the'perforaanco, ospeoially in-regards to its isolation •capa.'bilities which is
a very good point to considero )
73 until next raon-bh
Ted Beard W.1EB.
for -bhe Bulletin. Co.nmiitteeo
The Monthly Bulle-fcin of the V/ireless Ins-fci-fcu-be of Aus-fcralia
Januar-; i 6 Tasmanian Division Pa-'.-e 2.
NEW YEAR GREETINGS :
Your President and Council extend Best Vishes to all members of
the Division and their fanulies. May 1966 -bring toe-fc-fcer con-tac-fcs, bet-ter etiitipmen-b,
more members and less electrical noise - hio
HEAD UAATERS GEIT.ERAL MEETIKG :
The lecture intended for -the January meeting of the
Division shall be delivered by "VE:7№, I.iiles McGinniss. I hav@ 'been -bold. that -the text
is a mys-tery bu-t i-t will be in-fceres-ting.. Surely it isnt about GO - Carts 1'ffi. les ???????
GOKGRATULATIONS ETC.
I mast have hammered Greg Jolms-ton a li-t-ble -boo mach on the technical
article - first up Greg topped -the State in the R. D. Listeners Sec-tion m th a reeilly F B
score ( oongra-bulations Greg ) second, he flees to Macquarie Islai-id. and now I hear he has
gone for a swim doivn -there - well - as long as you don't start following a pre-fc-ty little
penguin around; then I will really start -to worry ( never mind the penguin. ).
Seriously, -fche call sign is YICOLII, so keep a look out on 20 chaps
APOLO&IES
I wish to apologise for a late Bulletin fhis month chaps, what with Xmas - -fche
spirit and All that I mus-t confess I delayed the bloke wot, does "bhe handle turnin&-
and those wot do the wrapping - promise it wont happen again - Ed«.
FOR S^E
1 Only Geloso G222-TR Transmi-t-ter condition as new, incorpora-fcing the 4/104 WO
plus modulator - only ISraonths old, 60 watts fone 5 75 wa-b+. s ow.
Original cost £1. 40 - owner will aocep-t £50.
A bonus is also offered at no extra cost to the lucky purchaser- which is
One only Seloso M59 Dynamic 1,'iike complete wi-bh zipper carrying case»
Interested persons to contact Athol Elliot-fc, WJZV direc-t, At hoi' s address is :-
11 Turru.ng S-bo, Gooee, Bu-rnie, N. V/. Tasraaiiiao
The following is not to be consider d an ad. ver'tisemen'b Taut as two people have
prospered, one of them myself, I feel that -the information should Tse passed ono
There is available on the mainland adu. al vernier dial - 6:1 and 36s1 raoveraent;
cos-fc 32/- plus postage - inner dial 2" d,iaa» ou-ter dial 1-g-". The dial is made by
Jackson Bros», England, and is soiaewhat the same in appea-rance as "the Swan 350 diali
I believe -bha-t DX is still rife on -the VHF Bands -• just a li-t-tle tip - remem'ber you
arent the only one who vyants to work it so keep your overs short, dont overmod. ula'fce,
and remember the ama-fceur code - to concliide, I dont wish to sound •too -bhingo with
these tips of mine 'but I seriously suggest the are adhered to as they are based on
authentic obgerva'bions - mu. oh 'be'bter from me than. froin another source*
RnnURL. inOEH—EEB.
SUBSCRIBE ±o -the E<SJrPM$!NT BXGHAKQ^ . BULLETIN. P. 0., Box 177., Sandy -Bay, Tasmania
^— The EEB is a technical periodical of a casual type, published as a hobby by
the San^y-Bay'Basement Iia^orat cries, and . fea-turin^ in-bere-sting arbioles and
effective advertisements. Sub.scid.ption still 3/« per year. Bound copjy of Vol.
I, 12/6. each, availabl1§?l& January 196uS.. No more individual back-issues available,
ANNUffl INDEX of -fchc EEB. Volume 1» 1965 probably.
№.. Month Page. Itejm gfl. * Month, Paee Item
Silicon Con-fcrolled ReoAi- 10 7 1 Moi'e baclc-Tsiased diodes.
fiers, Part I. Fundamental. 6 Semiconductors Reference, !.
1+ 1 Use of reversed diades. 7 Tape Recording, Part V.
4 SCR, II:Simple pmr supply, ll s+9 3 Back-biased diodes (concl.)
3 2 1 SOR, Ills Transients. 6 Bibliography, Part II.
4 2+ 1 SCR, IV* Transients. 7 Volume Compression, I. and II
4' Did you know? (Lab perils) 14 Tape Recording, Part VI
2 SCR, V»Bffioa-en-t control. 17. Puzszle.
4 Did you know?(More perils) 12 10 2 Fluoresoen-fc poiner?
3+ 1 Protecting SORs by diodes. 3 Pseudo-'bunnel t'ransistoiis I
1 How to avoid Baked Ham, 4 Volume Compression (adden»)
5 Tape Reaoiriing, Parfe I. 5 Practical transist. ignition,
1 Articles planned, maybe. 7 Answer to Puzzle.
2 PIV safety facrtors. 13 11 2 How to buy technical books*
4 Pseudo-tunnel Diodes. 2 A practical Transistorised
5 Tape Recording, Par-b ll. Ignition System, Part. II.
6 Protec-fcing electric traujis. 5 Puzzle Postscript.
7 Peak curren'fcs in diodes* 5 Tetrode Transistors, Part I.
1 EBB Explored 14 1s- 2 Transistor Ign. Part III,
3 SCR, VI t A prac-tical\aria- 4 Reversing battery polarity.
ble-phase voltage control 4 Reference Lis^. part III.
system with inherent 5 Tetrode Transistors, Pt. II.
voltage regulation. Nice. 10 Annual Index, ie, -this.
5
SCR, VII'. Uses of y^Q. 10 Field Effect Transistors.
6 Tape Recording, III7
1 Train pro-fceo-tion, again* riease note that advertisements appear
3 More Laboratory Perils I in each issue, -though we have not
4 Tape Recording, IV. listed them here. We have found -bhem
5 High curren-fc power sup- -to toe amazingly effective, and all this
plies, and heat sinks* from a circulation which has only now.
Semiannual Index. reached 200 I Tell your friends about us.
+++
PI^D ™BGI TRANSIS OR& * are now ayail&ble in Aus-traH. a. It is rathey startling to con-
s.ideL'?he P^STib^^'!:y ?f runrlinf a loudspeaker directly from a crystal pickup, wi-th orOy
one ^tage of amplifioation, or to design a -transistor vol-tme-fcer as on^ vaould'a valve ^'•
voltme-fcer. Bu-fc the enthusiastic experimenter is emphatically to be pautione. d thafc a
device with an input impedance oflO15 ohms has one serious liability —If the input
oircui-b is allowed to remain comple-bely open, i-fc can accumulate enough s-fca-tio electric
potential -to destroy -fche transis-bor t Therefore keep the transistor's leads shorted
unli:L. read^ 'to ins't;all» and ensure -tha-t -the input is always shunted by some resistance
I\irther details can be obtained from -the manufacturer's specifications,
2 : oe : a= : es 8 Bea =" _ a
imi o