aprender

1. Clubs Affiliated to S'rl~IAil
Here IS our lSI 01 groups OIIIloIact to STEIAR together with club callslgn and local 885 where provided
SchoOI/COl/ege Cel/Sign BBS
Ailwyn Community School G7TXA GB70PC
Hollow Lone. Ramsey. Combs.
Allertonshire School
Brompton Road. Northallerton. N Yorks
Ansty Junior School
Eastbrook Road. Alton. Hanls
Antrim Grammar School
Steeple Rood. Antrim
Barnfields Primary School G4LQT/G6BQW
Lansdowne Way. Wildwood. Stafford
Belfast Royal Academy GIOWOO/MII BRA GBlTED
Cliftonville Rood. Belfast
Bishop of Hereford's Bluecoot School
Hampton Dene Rood. Hereford
Bishop's School
Hampton Dene Road. Tupseley. Hereford
Bolton School GXOVUX GB70DM
Corley New Rood. Bolton
Borden School G4LBS
Sillingboume. Kent
Britannia High School
Britan....a Road. Rowley Regis. Warley
Caistor Grammar School GX7TWV GB7HUL
Caistor. Lincoln
Castle House School
Chetwynd End. Newport. Shropshire
Christ The King
Stanford Road. Southport. Merseyside
Clifton High School
College Road. Clifton. Bristol
Caine Park High School G4CPS GB7PWY
Venables Avenue. Coine. Lancs
Cranleigh School
Horseshoe Lane. Cranleigh. Surrey
Denton Pari< Middle SchOol GOIOQ
Linhope Rood. West Denton. Newcastle uopn Iyne
Dollar Academy GSOSNG
Dollar. Scotland
Eton College MXIBEC GB7WIR
Eton. Windsor. Berks
Fitzalan High School
Lawrenny Avenue Leckwith
Framlingham College MOCBB GB7MXM
Woodbridge. Suffolk
George Watson's College
Colintan Road. Edinburgh
Gresham's School G3PXO GB7TLH
Cromer Road. Holt. Norfolk
Haileybury College
Hertford Herts
Harrogate Ladies' College GOHCA
Clarence Drive. Harrogate. N Yor1<s
Hartismere High School'
Castleton Way. Eye. Suffolk
Heather Grove First School
Haworth Road. Heaton. Bradford
Holswarthy Community College
Victoria Hill. Holsworthy
lichen College
Middle Road. Bit1eme. Southampton
SChool/College CeUslgn BBS
John Hanson Community School GXORBL GB7SDN
Croye Close. Andover. Hanls
Kesgrave High School
Ipswich
King Edward VI School
Biry St Edmunds
King Edward's School GX4SKE.GX8ZKE GB7SUT
EdgbOston Pari< Rood. Birmingham
Lancing College GOVSI
Sussex
Looe School G6RLS
Sunrising East Looe. Comwall
Ludtord CE Primary School
Magna Mile. Ludford. lincOlnshire
Mariengymnasium Warendorf DFOSTT
Warendorf. Germany
Oakbonk School GOWNE GB7KLY
Oakworth Road. Keighley. West Yorl<shire
Richmond School GXORYS GB7CYM
Darlington Road. Richmond. N Yorl<s
Ridge Danyers College GOVRC
Hibbert Lane. Marple. Stockport
Rishworth School GXOSQA
RishworthSowerby Bridge. W Yor1<s
Royal Grammar School Newcastle MXI CIH@GB7MSF
Eskdale Terrace. Newcastle-upon-Tyna
Rushey Mood School G4RMS GBlNLH
Melton Road. Leicester
Ryelands Middle School
Prestbury Rood. Duslon. Northompton
Scarborough College G3LCG
Filey Road. Scarborough. N Yor1<s
Sir William I?obertson High School G4WRS
Welbourne. Lincoln
St Lawrence College
Ramsgate. Kent
Stromness Academy
Garson. Stromness. Or1<ney
Swaminarayan School
260 Brentfield RoadNoosden London
The Bishop of Herford's Bluecoat School
Hampton Dean Road. Tupstey. Hereford
The James Young'High School
Quentin Rise. Dedridge Livingston
Underwood C.E. P~mary School
Underwood. Nolls
UniverSity of Plymouth GOUOP
Sec & EE. The Smeaton Buildlng.Drake Circus. Plymoulh
University of Wales Swansea GW3UWS
Singleton Pari<. Swansea
Ursuline College GX7UPG GX7Y1Jt-I
Westgate on Sea. Kent
West Kent College
Brook Street. Tonbridge
Wigan Deanery HIgh School GOTWD
Frog tone. Wogan. Lancs
Yeavil College
Goidcroft Campus Mudford Rood. Yeavil
Ysgol Syr Thomas Jones
Almwch Anglesey

2. Schools across the country arc experiencing the difference RM's softwa re,
systems and services can make to teaching and learning.
If you wam to know how RM can make a difference in your school,
call us on 01235 826868.
Or visit our web site at www.rm.com
I~~
Contents
From the Editor's desk 2
Chairman's Channel 3
Project Excalibur 4
The G3RJV Six-Pack 5
Committee
Patron
Lady Plowden DBE, G6PHY
Chairman
Anthony Vlnters GOWFG
Vice Chairman
Alan Wright GOKRU
Secretary
Mike Wade G80GO
Treasurer
Gordon Siddle G7TBX
Course Organiser I Editor
Hilary Claytonsmith G4JKS RSGB President
Committee
Richard Constantine G3UGF
Derek Morrison-Smith G7VBY
Philip Northmore G4KMM
Richard Horton G3XWH RSGB Council Member
'Office' Contact Details:
Richard Horton G3XWH 7 Carlton Road, Harrogate, North Yorkshire.
HG12QG
G3XWH@GB7CYM, Internet g3xwh@amsat.org
Fax 01423 871027
Email: stelar@hlc.org.uk

3. From the Editor's Desk.
Hilary Claytonsmith G4JKS
2 Falcon Drive
Hartford
Huntingdon PE18 7LP
I have just been thinking of the New
Year ahead and how external influences
will affect amateur radio. The hobby
will be under pressure in the years to
come, not overtly so but in a subtle way.
Outside influences are at work in the
form ofE uropean Dil-ectives, car manu­
facturers and large business conglomer­
ates. The RSGB is always alert to any­
thing, which m ay pose a threat. You
may remember when thl! EMC Directive
carne on the scene how the Sociely made
sure that home brew amateur radio
equipment was exempt from its require­
ments. The issue ofkits remained a grey
area. I took this up with theDTI and got
their agreement that radio kits assem­
bled for use by radio amateurs would
also be exempt so the creative aspects of
kit making survived. 1998 saw the draft
Radio and Telecommunications 'rermi­
nal Equipment Directive appear out of
Europe and again we fought to get Ama­
teur Radio equipment made by Ama­
teurs exempt. 'r his was agreed Lo but
again kils were not included. Mter much
lobbyingby Europeanradio societies led
by the RSGB and the Belgian Radio
SocieL
y, an amendment has been ac­
cepted and now kits a nd home brew
equipment have been saved from legis­
lation's r~d tape.
Another enjoyable part of Amateur
Radio is operating mobile. This is done
for muny rellsons, including gettingaway
from cBusmginterference to neighbours'
'rve etc,avoiding annoying the family or
helping io occupy the time on long jour­
neys. Those of you with new cars will
realise how hi-tech they are compared to
those of years ago. Many things are
microprocessor con trolled automatic
braking systems, engine management
systems and air bags are becomingstand­
ard. Manufadurel:S are acuiely aware
that these features are susceptible toRF
and so limits have been laid down as to
how much power you can transmit in­
your car. Some say 3 watts, others 100
watts. The powercan varydependingon
!.he band in use. The handbook should
be read carefully, as failing to follow the
guidelines may mean your Warranty is
invalidated; worse still, your insurance
may be affected if you make a claim.
Most sensible amateurs would not con­
sider using high power in a moving car,
but the choice was there, now there is
little chOice. It still makes me cringe
when I see at foreign rallies, manufac­
turers selling tKW amplifiersfor mobile
operation.
The Internet has taken offin a bigway
and there is a race on to see who can
deliver this facility the fastest to the
end-user with the least inconvenience.
One company has been trialling Internet
over power lines on frequencies of 2.9
and 5. 1 MHz. Unfortunately, under­
ground cables seem toleak and the emis·
sions produced would cause the noise
floor to rise to a level where communlca·
tions on the lower HF bands would be
virtually impossible. Amateur trans­
missions may also interfere with PLT
(Power Line Telecommunications) as
they also may do with other systems
coming on line, such as ADSL which
delivers Internet access over standard
telephone lines. The RSGB EMC Com­
mittee is actively involved in trying to
make sure that if such a system is al­
lowed to go ahead, any unwanted emis­
sions are kept. to a mimmum.
With all this advancement in commu­
nications techniques takin~ placo arou nd
us we must present ourselves as a stronJ,(
force and to this end we must try to
increase our numbers so that we arc nOl
marginalised. We must use our bands
as much as possible, especially at VHF
and UHF as well as microwaves a s there
are others waiting in the wings with
eyes on our bits of the spectrum with
large sums ofmoneyin hand. Thephrase
"use or lose" is more pertinent today
than it has ever been.
S'f ElAll's way ofraising the numbers
is by training up science leachers so that
armed with a pass in lhe RAE they can
go back t.o t.heir schools and inspire the
next generation to take up alld enjoy
a mateur radio. The next 'crash course'
.'or teachers runs from April 6tb to 91;h.
Ifyou k now of any school which does not
yet have an Amateur Radio presence
pleasepersuadeone science teacher from
that school to enrol for the course and
help bring another school into the fold.
A New Year resolution could be that
each one ofyou could introduce just one
other person to the hobby to make sure
we are still alive and transmitting into
the next millennium.
RALLIES
21st February - Sandown Exhibition
Centre, Esher Surrey. Entrance free to
under-l4B. Lectures and trade stands.
10.30 a m - 5pm
IS/14th March -London Amateur Radio
and Computer Show, Lee Valley Lei­
sure Centre, Picketts Lock Lane, Ed­
monton, from 10 am. Tel 01923 893929
21st March -NORBECKRally, Norbeck
CastleExhibition Centre,Blackpool. De­
tails from Peter 0151 630 5790
Chairman's Channel
My first task in this new year is t{)
wish all the members ofS'rEUB a very
happy new year. 1998 closed on an ex­
pectant note. Mter much discussion ,
paperwork and yet more discussion, the
application for STEIAR to become a
charity waS submitted to the Charity
Commission at the end of November.
Finally a letter was received just after
Christmas to say that our application
had been successful. STlilAR is now
officially recognised as being of charita­
ble status. The reason for seeking to be
a charityis simplyt hat it will make fund
raising for our wor k easier. We hope
that we can attract financial support in
order to fw ther our efforts in educating
teachers and youn g people in Amateur

4. Radio and the benefits it can bring to the
teaching of Science and Technology in
schools. The course that we r un each
year at Easter, is provided free ofcharge
in order to attract as many tea.chers as
we can. Naturally this operatlOn costs
several thousands pounds to stage and
STEIA.ll h as to find a way of funding
tills. But this is only the start, as the
years go by I hope that S'fEIAR will
inaugurate other initiatives to bring
Amateur Radio into school. What moti­
vates all those involved with STlUAIl is
the knowledge that radio commuruca·
tions are going to playa very importAnt
part in the next century. Exploring
what radio can do whilst at school and
being given the chance to use it is an
important educational experience that
all young people have the right to expect.
S'fEIAB has also had one-ofits memo
bers elevated to that exalted position,
President of the Radio Society of Great
Britain. Hilary Claytonsmith who has
done much valuable work forSTEIAB is
now the occupierofthat illustriouschair.
Prior to our Annual General Meeting I
had the opportunity to look around the
walls of the presidents room in RSGB
headquarters and take a look at photo­
graphs of previous presidents. I was
struck by the list of radio pioneers who
had held that position over the years.
H ilary must indeed be very proud of her
achievement and deservedly so. I feel
sure that you wil1 be pleased that the
person at the top has not only a sound
knowledge of Amateur Radio but is also
involved with education and appreci·
ates the joys and tribulations ofbringing
Radio into the school community. Fi·
nally I must also congratulate Richard
Horton, who I consider to be the found­
ing father of STEIAB for being elected
onto the RSGB council. Again it is sat­
isfying to know that he is keenly aware
of the objects of our organisation and
hopefully can further our aims within
the wider world of Amateur Radio. He
has an important role to play in making
those who make the decisions that affect
our hobby aware of the issues within
education. With our new found charita­
ble status and two influential people
within ilie national organisa.tion who
are sympathetic to our cause, the future
for STEIAR looks bright as we head
towards the new mIllennium.
Project Excalibur
Bill Fenton G3XZF
As 1 write This, 1 am also listening to
a favourite recordby 'MPeople' . "Search
for the hero..."
Ifyou know the record, you will know
the lyrics . I hope you can ftnd some
heroes to enjoy Amateur Radio! I am
proud to have been a Radio Amateudor
30 years and made many friends all over
the world. I have a better appreciation
of geography and international activi­
ties; my initial knowledge of '0 Level'
French has helped me to enjoy several
visits to France and lots more conversa­
tions in French via Amateur Radio.
The Amateur Radio community is a11­
embracing. It can be a passport to a
career in engineering, design, research,
broadcasting etc.
Industry will need new recruits and if
Amateur Radio plant s the seeds now,
the crop ofengineers it produces will be
a rich harvest.
World Amateur Radio Day, Saturday
18th September, could be the opportu­
nity to present Amateur Radio to your
students and teachers if the school club
can operate a special event station. Per·
haps you can invite visitors from adja·
cent schools to see how Amateur Radio
works as well as school governors, the
local newspaper,local radio stationet aI.
This event could be the ch ance to obtain
positive publicity in order to encourage
newcomers into the hobby by demon·
strating the tangible benefits of Ama­
teur Radio.
Doyou know ofany companies, local or
national, who would be useful guests,
esp.
ecially those whowill need engineers
in the future and can be persuaded to
provide financial support to assist stu·
dents to study for the Radio Amateurs'
Examination?
Consider inviting your local member
of parliament, has your school any fa·
mous students? Try to set up a QSO
with your twin town. I would like to see
the event becoming an explosion of ac·
tivity; the fallout could be the next
generation of Radio Amateurs!
From the Shack of G3RJV
In this issue, George has kindly agreed to our printing details of his Six­
Pack, six simple but most useful circuits which are built on circuit boards
which 'snap off' as individuals from a single board.
For those who prefer to have the boards pre-fabricated and with a pack of
components, Kanga Products have been supplying kits for the Six-Pack at
very reasonable cost
Telephone I Fax them on 01303 891106 I 0870 0568608 (e-mail
sales@kanga.demon.co.uk)for latest details on availability I prices.

5. Six~Pack 1 ~ The Plug and Play Transmitter
~}ANTDMl
~}REttID
BAND VC1' C2 C3 R1 RFC L1 L2 I
3.5 120p 100p 220p 39 25uH 43tT50·2 6t
7.0 120p 100p None
- ~ 1~ _ ~T50.2 5t
10.1 60p 47p Nono 47 1~~ 35tTS0-6 _ 41 - I
14.0 60p 33p none 47 15uH 271 TliO-6 ~I
The PlugandPlay Transmitteris a re-workingoftheW7Z01 UniversalTransmitterto
include several newfeatures:
.. ABetter Lowpass Filter -following the W3NQN constants
.. Full Break-inChange Overcircuit
• AVXO (Variable CrystalOscillatoras the RFsource
ThewholetransmitterbuildsOD to oneboard with input/outputsocketsand yields 1
wattofRFoutputon these1ectedband.Values aregiven forfourpopularamateurbands.
The constructor merelychoosesthevalues from the bandtablefor thepreferred band.
Adjust VC2 for thebest compromise between transmit and receive.
+l2V
I
oI I 777I I 777I I ~71 I
IiI¢Ofl-:O~l'i O~ 0,," Oa
~vU 8 ~Ol 0rzQl3 ~
~~g~- [}. ~ 11111 ~
.>0 coD Y..rL
PLUG &,PLAY TRANSMITTER
CRYSTAL
(with ~ , Lv IF u.ad)
, Murata Smm Ceramic Trimmers [120p • Black, 60p - Brown]
Wind L2 over the 'VC1 end" of the L1 winding. L1 occupl.. "/. clrcumlo...nc. of co....
VALUES FOR THE PLUG AND PLAY TRANSMITIER LOWPASS FILTER
Band C4,7 C5.6 Wire
MHz
L3.5 L4 Core
pF pF swg
turns turns
3.5 4TO 1200 25 27 T37·2
7.0 270 680 19 21 T37-6
560
10.1 270 19 20 T37·6
14.0 ' 180 390 16 17 T37-6
Note: Wire gauge Is not critical.
Use size to cOmfortabl~ fill the core about thr&O-quart~1! of full cl_rcumfereil~
28
26
26
24
r--'
VALUES FOR CHANGE-OVER BREAK·IN SYSTEM
COMPONENT 3.5 7.0 10.1 14.0
VC2 Trimmer 120pF 120llF 35pF 3SpF
C8 Disk 47pF 47pF 47pF NOT USED
L6: FT37·61 22 turns 141ums 11 turns 11 turns
Experiment with a wider swing VXO. DJ1ZB Introduced the Idea
Y:ID, 0'placing two inductors physically next to each other to
Increase the VXO swing using mutual Inductance between the
~ two Inductors. The Inductors are placed as shown on the letL
ElCperimental Values to Try:
3.5MHz . 39 + 39uH 7MHz • 39 + 33uH
10.1 - 22 + 15uH 14MHz -15 + 15uH
These are just suggestions - try your own values.

6. Six-Pack 2 - The Quick receiver
, O+9U
OSCI1
I
ANTDINA
lUll1
::). ~
.-. ~
OSC~
110191" ..-/./".,
01
lu
e.B8~~O
L.UlTCIt -;J;fVtpl l 4' i llr
• II
II
II
II
Dl/D2 =
IN'! L-18 or
Tl is 8 turns trifilarwound on FT37-61 Core
The quick receiver board was born ofnecessity. Some time ago I was in needofa test
receiver to listen to some SSB signal generated at 9MHz. At that time ldid nothave a
receiver which covered 9MHz so decided to build one for myself.
The circuit is simple and basic: a passive mixer formed by Dl and D2 feeds an audio
pre-amplifier TRI . Tomakea receiver the boardrequires aoscillatorsignaland anaudio
amplifier. Most people have a small utility audio amplifier and a signal generator to
completethereceiver.Theboardrequires abouthalfavoltofsignalinjection intoTl and
about 80dB ofaudioamplification afterTRI. Thereis noinput tuningalthough thiscould
be added at the antenna input port.
Theboardis easytobuild. Uyou go wrong,itwill be windingLI. Trifilar transformers
are easy ... on the second one. Lightly twist together three lengths ofenamelled wire
(about 8 twists to the inch will do) and wind them on the coreas one winding. The dot
marks the "start" end ofeach winding. Join them in the circuit exactly as shown. Get
it wrong and it won't work!
Although theboard was built for one specific purpose, it has remained a usefulpiece
oftest equipment as wellas a stand-by receiver for odd frequencies not covered by my
other equipment.
How to use the Quick Receiver Board.
ANTDNt I..-uT
V
IRECEIVER IIDARD ~RUDIO RI1PLlrIER FQI
SIONFL GENERATOR
*
loseI
~ .up
I
01 ~]..1'47a( A
~
[] i:ILI­ ~
Tl D2 + D . 881
. IJ j08TRl 0°0.11
-c:J­ 0.... 471(
1-7 .81
QUICK RECEIUER +9y

7. ___
Want toadd aBandpass Filter to the input? This willgive slittleselectivity and make
it more like a conventional receiver. The circuit below tunes from about 3 to 15MHz
andisinserledbetween thesntennaand theantennainputon theQuickReceiverBoard.
Ituses a surplustwo-gangpolyvaricon tuningcapacitorculled from a transistorAM radio.
Ifyou want to add any more features - you might as well build a proper receiver!
The Suggested Bandpass Filter
SpS
Ta R8ce iuet'"
Soard
rr'08l 1
AntentWI = St
L2
~
I
Ll
over b...
04='
L2 • ...at LED
Dual Gang L3 • ..at
Pal WV.,..i con Bot.h on
T31-2
Six-Pack 3 - LED Standing Wave Indicator
F"ROM
--4111---....
TX
--fIlm­
--tII:m- TO
-{III}­ .10
--fIlm-
ANT
201(
LED SWR
9 . 1 ThebasiccircuitisthatofaResistive
SWR Bridge. The three 50 ohm resis­
t tors, with the antenna load, form the
o ~8· arms of a Wheatstone Bridge circuit.
;,.~1N91" Whentheimpedanceoftheloadreaches
around 50 and an four arms of the
bridgeareequal, thevoltageacrossthe
bridge will null.
The Superbright LED is remarkable in
that it will still glow when dissipating
currents of 10 microamps or less. As the
antennais tuned for minimumVSWR, the
Superbright LED win extinguish. The
preset provides a sensitivity control and
the indicator will work with signal to be-
LEO SW
R MONITOR IO~~;~!~tchout.thecircuitaftertuning
sa = 2)(198 HI up and before transmitting.

8. Six-Pack 4 - A Diode Probe
Thebeginneratradioconstructionsometimes assumesthattheywill haveto invest
heavily in test equipment. Most QRPprojects canbe builtwith the minimum oftest
equipment. Thebasicneedisan analogueYOM. DigitalYaMs arenicebutmost times
we are more interested in changes in readingrather than fmite readings. The next
essential forRFworkisa diode probe. Anyonewhobuysoneoftheseshouldbeashamed
-it isJust a "crystalradio ona stick".
ThecircuitshowsabasicpeakreadingdiodeprobeforRF signaltracingandmeasurmg.
Itwould bepossibletoadda seriesresistancetoget a RMS readingprobebutthevoltages
in QRP RFworkare usuallyqwte lowand usuallythepurposeoftheprobeisto acljust
RFlevelsin circuits.
A sharp pointed wiremakes aprobeand a crocodile (or alligator!)clip is the ground
connection. The leadsbetween theprobeand the YOM mustbescreened to avoidRF
pick-up. ThePCBprovidestopandbottomscreenpanelstoattach tothemainPCBusing
stand-offpillarsorextrabolts.
Attach the probes to an antenna and the output to some headphones and you will
pr obably hearyourfavourite local broadcaststationl
IN111e Scr
e 1 -c:::J
PROBE ~.J.
-b- ot" l NS1.. OUT JTo-M
IN
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-
Z
0
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CLIP _
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CD CD
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LEAD
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.,
~
.tar
PROBE
Six-Pack 5 - A Voltage Monitor
::>
~ In ~
::>
~ roI ~ m ~ ....
i IS) .... .... .... ... .... ....
....
.... "
- - -
~ ~
18 X LED
SET HIGH
l'UiU
15 I' 13
12 UOLT MONITOR
o1fK1
LM391~
, 5 6
12 11
7 8
18
8
SET~
tau
+
SlFPLY

9. TheIndicatorusesan LM3914Dot/BarDisplayDriverChip. TheLM3914 lights up
totenLEDs (in theBarmode) oroneoflOLEDs(intheDotmode)inresponsetoaninput
Voltage. Thechipcontainsavoltagedividerand 10comparatorsthatturn oninsequence
as theinputvolt8gerises.Thereis aninternalreferencevoltagesourcethatcan beused
11 X LED
~-~-~--l
1 U13914N
iIK2J­
~
~ @
K7
L0L4
lJOLMON
+GND~
tosethigh and lowreferencepointsontwopinsateitherendofthevoltagedividerchain
to adjustthe rangeofmeasurement.
Thebattery(orsupply)beingmonitoredprovidestheoperatingvoltage. TheLM3914
operates with any supplyvoltage from 3 to 18volts. Apresetpotentiometerfeeds the
i.nputtopin5. Thisisused to setthe highestreadingpoint. Anotherpresetcontrolsets
the lowreadingvoltageusingtheinternalreferencevoltage.
Pins 1to 10feed the LEDs. ItispossibletoobtainBarLEDswith 10 LEDsmounted
in a row but thisindicatorusesindividual LEDs. I used red orgreen accordingto the
desirabilityofthevoltage:11.5to 13.5voltsaregreenand thevoltagesahoveandbelow
arered. The green representstheprobablysafetymarginforusing12voltequipment.
All the LEDs may bered and set into a panel marked to indicatevoltage.
Settingup issimple. The leftpresetcontro)setsthehighvoltageandtherightpreset
sets the)owvoltagereadings.
Avariable powersupply is useful. Connect themonitorto thepowersupplyandplace
a voltmeteracross lhcsomesupply. Begin with a centrevoltage (say 12volts)and adjust
thepresets toread the volt.oge indicutedon thevo)lm~ter. Thenreducethevoltageto
about 10volts and ad.Jusl t.he preset until the bottomLED lights. Increasethevoltage
to about 14.5 voltsand adjust the probets until tho top LED lights. Thisprocessmay
haveto berepeated to bringtbe monitor to cuvl!rthc dl'/iired range.

10. J
Six-Pack 6 - XCheck - Surplus Crystal Checker
C(lJ(f£R
OUTPUT
l:Tt~) t~~
-=-su.
TRllTR2 = 9C182
CRYSTAL CHECKER
01/2 .. 0A91 or ~ GIl Diode
CRYSTAL
CHECKER
~
Quartzcrystaloscillators arecommon­
place in the QRP world.
This is a little pocket tester for those
surpluscrystalssometimesseen atama­
teurradio events. Theavid constructoris
always lookingfor good deals andmoney
saving. Itdoes pay to search around the
smaUer tables and pick up inexpensive
crystals, Eveniftheyarenotonanamateur
band,somecrystalswillmixwithanother
frequency to hita desired band.
Butdo those surplus crystals work? Is
thefrequencywhatis written onthecase?
Thislittlecircuitissimple to use. Sim­
ply attach to crystalto the clip leads and
press thebutton.
IftheLEDglows- thecrystalis oscillat­
ing.ltalsohasafacilityformeasuringthe
frequency0 funknowncrystals.
The circuitisverysimple.
TI, a genericNPNsilicontransistor,is
configured as a Colpitts Oscillator. The
capacativefeedback network in the
base circuitischosen to allow oscilla­
tionovera wide range offrequencies.
Prototypes of this oscillator have
worked to beyond 20MHz.
The oscillatoroutputistakenfrom
theemitterofTl viaa lOOOpFcapaci­
tor. A small value capacitor (56pF)
couPlesthissignaltoanoptionalsocket
foradigitalfrequencymeter. Aphono,
oraUnilarsocketmaybe addedto the
case to provide output to a digital
frequencycounter.
Two diodes rectify the signal and
produceaDCvoltageon thebaseofT2.
CRYSTAL
680 I
-Q;
T2 functions as aDC am­
plifierwithanLEDinthe
collector. IfTIisoscillat­
ing, T2 will conduct and
theLEDwillglow. Agood
~
"l.-f" TRl
..rn:n... 0
~
~.eel
Y -D­
[J
01 56
D2 n ~
...
-0­
9910
TR2
crystal produces output
from the LED.
Myprototypewasbuilt
in a smallslopingfronted
case wit.h
OUNTER enough
C spnce to in­
clude u 9­
volt PP3
bnt.tery.
LED 'rhccrystal
-----....-- connection
I
+
XCHECK
lcndscomcoutofthefront
ofthe box and are termi­
nated withcrocodile (alll­
gator)clips. TbeLEDpro­
trudes through the front
panelandthepushswitch
is on the endofthe box.

11. PRINTED CIRCUIT BOARDS Copper Side Slightly enlarged
Individual boards snap off from the large board.
TT
(I) ....
.... :x:
)(r1
Ie')
-OW
:D~
o~
~c
The G3RJV Six Pack Parts List
PLUG and PLAY TRANSMIITER
(with 40m band pack selection)
2 X 220R 1 X 4.7K I X 10K 1 x 39R
I X 47pF 1 X lOOpF 2 x 270pF
2 x 680pF 4 X O.lIlF
1 x 120pF plus 1 X 120pF Trimmers
4 X IN4148 I x 151lH RFC
1 X 2N2222 I X 2N3866
2 X PHONO 1 X 3.5mm SKT
I x T50/2 3 X T37/6 I X FT37/61
I X WIRE I X HEATSINK
QUICK RECEIVER
I X 47R I X 47K I X 470K
2 X InF 2X IOnF 2 X IIlF
I X BC 182 or 2N2222 2 X IN4148 or IN914
I X 100llH RF Choke 1 X FT37/61
3 X PHONO SKTS WIRE Battery Clip
The LED SWR BRIDGE
6 X I OOR, I WATT I X lK 1 X 20KPreset
2 X O.l IlF 1 X 1N4148 or IN914
I X SUPERBRITE LED
The DIODE ~ROBE
2 X O.11lF2 X IN4148 or IN914 1 X CROC CLIP
The VOLTAGE MONITOR
I X 1.2K 1 X 4.7K
2 X 4.7K Presets ] 0 X LI£D'H
I XLM3914
The CRYSTAL CHECKER
I X IOOR I X IK I X39K
1 X 56pF I X 150pF I X 680pF
2X InF
2 XBC182 2 X OA91 (or similar Germanium)
lXPTM 1 X LED Battery Clip

12. THE G3RJV SIX-P
ACK - A NOTE ON LED USE
PP3 9v.
~ I I ~-
390
afaf I~Ano~
I
e
LED
LEOs for the Six-Pack
TheSix-Packkitsaresupplied withtwo
stripscontainingLEDs. This isto reduce
thecostofthekits. Itiseasyto removethe
LEDs from the strip and use them in the
circuits
WHICHWAYROUNO?
Thecorrect voltagepolarity on an LED
is essential to make it light. This circuit
shows bow to test which way round the
LED is mounted in the circuits. Use a 9
volt PP3 battery with a 390 ohm resistor
jnseries. Theanode is thepositive side. If
you want to test the LED with a 12 volt
source, use a 560 ohm resistor. Want it
easier than that? Holdthe strip ofLEDs
with the yellow one second from theleft
end. TheanodesideofeachLEDisnowleft
lead.
Communicatel
'fhl:! S'I'IUAU net is held each Wednesday in term time and
normally begins at 13.00 p.m. and continues until at least
13.30 p.m. (local time, i.e. BST or GMT as appropriate). It is
hoped that GB2SR from Harrogate will be on to act as 'net
control'. At the present state of the sunspot cycle it is
anticipated that we shall check 80m first and if not open, to
QSY to 40m. If both bands are closed but 20m is open, time
may be best used by a change to this band, even ifwe cannot
hear each other within the UK!
The S'I'I~LL'U frequencies on the HF bands are:­
80m 3.770 MHz
40m 7.048 MHz
20m 14.165 MHz
15m 21.287 MHz
10m 28.428 MHz
± QRM
Format for AMRED contributions
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formats e.g. TIF files.
Deadlines for the next two issues
.unum Vol. 6.3 1tI.th April 1. ~199
A~lRlm Vol. 7.1 14thAu~us' 199!)
A~IIUD is published by GaXWH and
printed by Wednesday Press Ltd. South­
end-on-Sea. Essex. SS2 SSE
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All material in JUIRIm is copyright
The Author / S'I'I~IAIl. On written
request, permission will normally be
granted to include sections ofthe maga­
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