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September 2011
IN THIS ISSUE
Meeting Program
Club News
Future Meetings & Events
Members News
Technical Snippetts
Notice Board - Wanted and For Sale
News from other Clubs
Meeting and Event Diary:
02 Sep
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M
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Junk Box Antennas by Martin M1MRB
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06 Nov
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R
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Kempton Park Radio & Electronics Rally
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07 Oct
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M
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'Military Radio Equipment for the Amateur' by Dennis Noe M0NDJ
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20 Nov
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R
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CATS Bazaar
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04 Nov
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M
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An Evening of Short Talks
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02 Dec
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M
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Christmas Social
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E = External event, M = club meeting, R = Rally, T = Training course
Our next Foundation training course will
commence on 24th September 2011
Dear Reader
Recent Event News
5th August 2011 - Summer Barbecue
We welcomed two guests and a number of members to this event. Chicken and sausages were served with a mixed salad followed by cheesecake and chocolate gateau.
Future Club Meetings and Events
2nd September - Junk Box Antennas by Martin Butler M1MRB
Martin wites:
With many new amateurs joining our hobby, a large number of questions about getting on the air are often asked. While their licence only allows them to use black box equipment, some antennas are easily made and you can get great results without opening you cheque book for the radio dealer.
The main point of this talk is to allow new amateurs the knowledge to build their own antennas and to remind old armatures of the simpler times. It should also be a discussion starter and may result in becoming a club constructional evening.
The talk will contain many pictures and construction ideas as well as some examples to look at on the day.
4th September 2011 - The Kent House Flower and Vegetable Show
We will be manning a stand at this event with a live radio station. Help would be appreciated to erect the station, talk to visitors, operate the radio equipment and take it all down at the end of the event.
If you can provide an hour or two please contact Bob or Victor - contact details in the next section.
The event takes place from 10:00 - 14:15 at Kent House Leisure Gardens and the main entrance to the site is between 91 & 93 Kent House Road, opposite Woodbastwick Road, Sydenham, SE26.
Tea, coffee, snacks and lunches are available on site and plants are available for purchase. Club member Peter's grapevine is worth a look as something over fifty feet in length.
Foundation Training Course 2011
Our next Foundation training course will take place on four Saturday mornings - 24th September, 1st Oct, 8th Oct and 15th Oct with the revision session and examination on 22nd Oct.
A copy of the Foundation Licence Now! book will be provided. If you would like to join this course please contact:
There are some minor changes to the Foundation syllabus that commenced on 1st July 2011 and the new pass mark is now 19 out of 26.
Members News
Nothing forthcoming this month.
Club Meeting Place
We have been advised by All Saint Church that they propose to close the Parish Meeting rooms towards the end of this year as part of the main church building has been redeveloped into a meeting room with a new kitchen, toilet and an additional smaller meeting room at the other end of the church. Your committee is considering the new facilities and will report back to members by the next meeting.
Technical Snippetts
Our Treasurer Colin M0XED has sent in two articles for this newsletter:
a) More power from your Solder Sucker
Attempting to change two resistors in my KX1 QRP CW set in order to increase the output power with a 9v supply from 2 to about 4 watts, I was frustrated yet again by the apparent lack of `suck' from my (admittedly cheap) Maplin solder sucker.
I expect that many of us will be familiar with this particular model, which requires diligent cleaning to keep it in any sort of order. But try as I might, I could not get it to remove the solder from the pads, despite cranking the iron up to 400c.
In some desperation, I took the solder sucker apart to see if anything could be done (pic 1). On inspection, it was clear that the O ring washers are a rather loose fit on the plunger, which means that they are not necessarily in good contact with the sides of the plunger tube. This results in the the efficiency of the device being compromised.
I removed the O ring washers (pic 2) for inspection. They appeared in good order, not worn, and therefore replacing them would not help. Instead I tried winding a strip of insulating tape approximately 2mm wide and 6 cm long into each of the slots in the plunger where the O rings fit, in order to make them sit tighter against the outer tube, and reassembled the sucker.
I am pleased to report that `sucking power' is greatly enhanced, and I was able to clear the pads without further problems. Members may wish to give this simple modification a try.
b) The FOXX-3 QRP CW Transceiver
The original FOXX transceiver was designed by George Burt GM3OXX, with the circuit being published in the 1983 summer SPRAT. Built on a piece of 2" by 2" pcb (available at that time for 85 pence from GQRP Club sales) it incorporated the novel idea of the PA transistor doubling as the detector. Ever since then, amateurs have been modifying and refining this original idea.
Related designs include the Micro 80 (courtesy of Oleg `Mr QRP' Borodin RV3GM) (Sprat Autumn 1992), and a whole range of Pixies (originally a Californian version of the Micro 80), of which there are at least six different versions.
George GM3OXX subsequently modified his original design to include a 7 element LPF. Then, in the 1999 Spring edition of SPRAT Derek Alexander G4GVM published a design for the FOXX-3 which included automatic transmit/receive changeover, a muting circuit to minimise changeover `thump', a sidetone oscillator in place of the original `click' sidetone and audio amplification.
This classic is once again in production and may be purchased in kit form from www.kanga-products.co.uk for the sum of £29.95 plus postage and packaging. It is available with crystals for the 80m, 40m, 30m or 20m bands.
Dennis G6YBC at Kanga, has kindly given permission for me to reproduce here some details of the circuits and operation. Kanga offer a generous discount for orders of more than 5 kits. It would make a suitable project for intermediate candidates or indeed for any amateur wishing to make a start with home construction.
The kit is well packed and includes all necessary components plus fibreglass pcb. A separate morse key may be used or alternatively a board mounted `key' is provided. The completed board fits inside an ALTOIDS mint tin, now available from Marks and Spencer.
Outstandingly clear instructions are provided, and it is very simple to assemble, requiring only a couple of hours work. So in one evening you can have a neat little QRP transceiver with an output of about 1W which will fit in your pocket and the satisfaction of knowing that you have made it yourself.
The transceiver operates from any 9v - 14v supply and draws approximately 250mA on TX.
It is a direct conversion receiver with limited selectivity and sensitivity. However, enterprising amateurs can make further refinements such as adding an RX BPF to mitigate breakthrough.
Audio Amplification
Audio amplification is provided by an LM386 chip. There are separate inputs for RX audio and the transmit sidetone. During transmission, RX audio is muted. Output is sufficient for low impedance personal stereo type headphones.
Keying Circuit
Keying is via transistor TR2. Depressing the key turns TR2 on which energises the changeover relay which in turn removes the positive supply feed to the crystal oscillator via the RX offset control and disconnects the PA / detector transistor from the volume control. TR1 turns on, energising the 12v rail, which applies power to the crystal oscillator and the PA transistor and the sidetone oscillator. The voltage across the relay coil turns on TR3 to mute the audio amplifiers input. When the key is released between dits and dahs, the crystal oscillator and sidetone oscillator stop running, but the relay is held open by capacitor C13. If the key remains released for about ½ second the relay switches back to receive. The time can be adjusted by altering the value of R6. Capacitor C15 holds the muting transistor on until the relay contacts have changed over.
Sidetone Circuit
The sidetone is provided by phase shift audio oscillator TR4 fed from the keyed 12v line via a volume control to the LM386 audio amplifier.
Crystal Oscilllator
The crystal oscillator is fed from the keyed 12v line via a 1N4148 diode (D4). About 4 kHz of frequency variation on 40m is possible using the 5.5 to 65pF trimmer (TC1). During receive, the oscillator is fed via variable resistor (VR3) which permits an offset of a few hundred herz to generate an audible beat note.
Drive to the PA transistor is controlled by R17, which should be chosen on test to give an output of between 800 - 1,000 mW.
I always use a small solar panel and battery with an output of approximately 9v for my QRP rigs, so I set it up with a 100 Ohm resistor to give just under 1 Watt output. Good enough for QRPp.
PA and LPF
A seven element LPF is included. The attached photo shows the clean output signal with little evidence of harmonic distortion. Kanga's own tests show harmonics better than 46dB below carrier level.
FOXX-3 TX Output Waveform
Thank you Colin - Ed.
c) Emails and Email Addresses
Following a recent request, all email addresses in this newsletter have been changed into the form:
Fred at xyz.com
so that they cannot be machine read online. Please change the at to @ when using each email address. To prevent additional spam problems all newsletters are emailed BCC (blind copy) so that the recipients email list is not visible.
All PC users should ensure that their security software (antivirus, anti-spyware and firewall) are kept up to date. There are many seemingly harmless web sites harbouring malware that could damage your PC or send your email address book to spammers.
PC users should NEVER download or run an attachment that is an executable program unless they are absolutley certain of its origin. A number of ISPs (but not all) will not allow attachment of executable files to emails.
Notice Board - Wanted and For Sale
The Notice Board is for all club members to use so if you have one or more items that you wish to buy or sell then please send in the details. The current list of items may be viewed at: http://www.g3oou.co.uk/ in the "Notice Board - Wanted and For Sale" section.
Wanted:
SWL club member looking for a VHF multimode receiver covering at least 144-146MHz. Contact Victor on 020 8653 2946 or Bob on 01737 552170.
For Sale:
 Pye Westminster 4m transceiver. Including crystals for Channel 10 ie Tx 51.310, Rx 50.810, in good condition £30 ono.
 Kenpro 2M hand-held FM Transceiver KT22 including battery but no charger, in good condition £30 ono.
Contact Victor G1PKS on 020 8653 2946.
JAB Electronic Components, PO Box 5774, Birmingham, B44 8PJ supply a wide range of electronic components and can be contacted on 0121 682 7045 or by email at: jabdog at blueyonder.co.uk
73
 G3OOU
Diary of External Events
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18 Sep - Belgium Amateur Radio & Computer Rally
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Hall 'Lotto Mons Expo', Mons, 50km south of Brussels, access direct from motorway. Opens 09.00, Talk In via repeaters 145.600MHz & 430.325MHz. 4000m², international. Details Michel, ON7FI, on int'l +32 64 849 596, michel.dewyngaert at skynet.be
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30 Sep & 1 Oct - National Hamfest
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Brought to you by the RSGB in association with the Lincoln Short Wave Club. George Stephenson Pavilion, Newark and Nottinghamshire Showground, Lincoln Road, Winthorpe, Newark NG24 2NY (close to junction of A1/A46/A17). Morse proficiency tests on demand, RSGB Bookstall, RSGB Services & Committees.
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7-9 Oct - RSGB Convention
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Horwood House, Little Horwood, near Milton Keynes. Full convention programme with lectures for all interests and all levels of technicality
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06 Nov - Kempton Park Radio & Electronics Rally
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Kempton Park racecourse, Staines Road East, Sunbury on Thames, Middlesex TW16 5AQ. OT 10.00. TS, FM, DF, free CP, RSGB, LEC, TI S22 (V44). Paul, M0CJX, 08451 650 351, email: info at radiofairs.co.uk, website: www.radiofairs.co.uk
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20 Nov - CATS Bazaar 10am - 1pm
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1st Coulsdon Scout HQ, rear of Council Car Park, Lion Green Road, Coulsdon, Surrey. 10.00-13.00, £1, Details Glenn, G4FVL, email: chairman at catsradio.org.
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News from other Clubs
Club Secretaries - please send your meeting programs to Bob G3OOU. Our newsletter is now published during the third week of each month and closes for editorial input at the end of the second week. Due to differing publication dates and short lead times it is sometimes difficult to include other clubs' specific events although we will endeavour to do so if advised in time.
Chelmsford Amateur Rado Society (CARS)
Secretary Martyn Medcalf G1EFL Tel: 01245-469008. First Tuesday of each month at MASC, Beehive Lane, Great Baddow, Chelmsford, CM2 9RX. Essex. UK. Web: www.g0mwt.org.uk
06 Sep
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Programming your modern VHF/UHF rig
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04 Oct
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Annual General Meeting
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Coulsdon (CATS) 2nd Monday every month, 8pm at St Swithun's Church Hall, Grovelands Road, Purley. Contact: Steve Beal G3WZK on 01883 620730 or secretary at catsradio.org
12 Sep
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CATS Equipment Sale
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10 Oct
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Radio In The Scouting Movement by G6CJR and M0NDJ
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14 Nov
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CATS quiz: Quizmasters Steve (G7SYO) and Wendy
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Dorking & District Radio Society
Meetings at the Friends' Meeting House, Butterhill, South Street, Dorking RH4 2LE starting at 7.45pm.
27 Sep
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The STEPPIR antenna, Rob Barter M0ZAF
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25 Oct
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Software Defined Radio, Olof Lundberg G0CKV
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Echelford Amateur Radio Society
Meets on 2nd and 4th Thursday of each month.
Phone for details.
Mitcham & District Amateur Radio Society
Secretary: Mike Knott G0WCR, 76 New Barnes Avenue, Mitcham, Surrey, CR4 1LF.
Tel: 020 8764 4716
Phone for details
Reigate Amateur Transmitting Society
Secretary: Tim Trew G8JXV
Tel: 01293 775278. Email:
Meeting on 3rd Thursday of each month, 7:30pm at RNIB Redhill College, Philanthrophic Road, Redhill.
South East Essex Amateur Radio Society (SEARS) ContactDave G4UVJ on: 01268 697978,
Meetings: 8pm 2nd Weds each month at: 31 Feeches Road,Southend on Sea SS2 6TE (temporary location which may change for each meeting - please see web site).
14 Sep
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Home Brew Antennas by Dave G4UVJ
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12 Oct
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Talk by Philip G8LHW on Power Supplies
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09 Nov
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AGM
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14 Dec
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Christmas Social Night
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Surrey Radio Contact Club (SRCC)
1st. and 3rd. Mondays every Month (unless Bank Holidays) 7.30 for 7.45pm at Trinity School, Shirley Park, Croydon, CR9 7AT. Contact John Kennedy G3MCX on 020 8688 3322 or
05 Sep
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Radio Fox Hunting Terry G4CDY
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03 Oct
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Autumn Surplus Equipment Sale
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Sutton & Cheam RS. 3rd Thursday every month, 8pm at Sutton United FC, The Borough Sports Ground, Gander Green Lane, Sutton. Contact John Puttock G0BWV on 020 8644 9945 or email info at scrs.org.uk Web: http://scrs.org.uk/
15 Sep
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'Repairing Vintage Radios' by Dave Smith MØSXD
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20 Oct
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`Noise Eliminating Products' by Graham Somerville M3ZGS of BHI Limited
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Wimbledon. 2nd and last Friday every month, 8pm at Martin Way Methodist Church, Buckleigh Avenue, Merton Park, SW19 9JZ
Contact Jim Bell, M0CON on 020 8874 7456
Web site: http://www.gx3wim.org.uk
09 Sep
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Summer Camp Retrospective
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28 Oct
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AGM
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25 Nov
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Surplus Equipment Sale
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Items For Sale
Sensible bids are invited to Bob G3OOU for the following items that are for sale from three radio shacks:
a) A few remaining items from the shack of Eddie G4KBY:
Description
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Price
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Description
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Price
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Telequipment Model 43 dual beam oscilloscope - working but needs a good clean as very dusty inside.
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£5
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1 bag of pre-packed ICs, 1 bag of RS Components prepacked, 1 bag of identified ICs and transistors
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£5
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2 two-way data transfer switch box - useful painted project box
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£2
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Sangamo Weston E772 1000 ohms per voltanalyser with leads.
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£5
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3 way data transfer switch box - useful painted project box
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£2
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Original HRO receiver printed manual with an S Meter conversion article.
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£5
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15W soldering iron, mains powered
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£1
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25W soldering iron, mains powered
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£1
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Pye fist microphone with 5pin connector
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£2
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A Future Electronics transistor tester FTC 401
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£5 the lot
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1mA FSD meter with 3 inch dial
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£1 each
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b) The following items are from the shack of Ron G8OTG:
Description
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Price
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Description
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Price
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Advance Signal Generator SG62B
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£30
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5 Way coaxial switch with SO239 sockets - 4 outputs plus ground position
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£7.50
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FT290 + manual
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£100
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Kenwood SP120 loudspeaker enclosure
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£25
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6 way coaxial switch - four outputs plus open and ground positions, SO239 sockets
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£10
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Microwave Modules digital frequency counter with short aerial
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£25
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Trio 9130 2m multimode
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£75
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Soldering iron base and spring - less soldering iron and sponge
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£5
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Crystal calibrator on a PCB with 1MHz crystal
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£5
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Bosch mobile radio with fist mic - amateur band frequencies not yet established
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£20
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Active ATU - requires external DC supply
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£10
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Complete 230V Soldering Iron station
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£25
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Icom IC-240
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£80
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Yaesu FT-225 RD transceiver
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£80
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Yaesu speaker/microphone YM-49
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£10
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Thandar battery oscilloscope SC110 with brief manual
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£25
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Nova mobile radio
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£10
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Diamond DSV3000 12V 25A PSU
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£25
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Mains Bench PSU with 12V output
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£10
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Kenwood PS-30 DC PSU
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£30
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ARRL Handbooks - 1976 and 1988 editions
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£5 each
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Colinear vertical aerial with white weatherproof outer cover for 6m and 2m, other bands not yet known
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£15
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AM Radio Techniques by G3VA
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£5
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RSGB VHF Manual
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£5
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9 Q-Max chassis punches
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£5 each
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2 gang 500pF standard varable capacitor
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£4
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Heathkit RF Probe
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£5
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c) The following items are from Trevor's shack:
Description
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Price
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Description
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Price
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Yaesu FT-707 HF multimode solid state transceiver with matching FP-707 power supply. Covers 3.5-30MHz ham bands incl WARC with CW, SSB and AM.
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£150
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Q-Max chassis punches in ?. 1, 1?
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£5 each with an Allen key, £4 without
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Marconi TF2437 100MHz counter timer
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£50
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Project box, unused, in good condition approx 7" x 7" x 11" wide
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£5
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Marconi TF2103 AF oscillator
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£30
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Project box, unused, in good condition approx 4" x 5" x 6"
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£2
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Datong D70 battery powered Morse tutor
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£25
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PX3 small unused project box
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£1
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Ex Army Morse key
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£5
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Box of assorted variable capacitors
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£3 each
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Small hand held hand powered drill
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£2
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Avo Universal Multimeter - looks like a model 7
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Box of assorted valves including two EF183 and one 6SA7
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Unboxed £1 each, boxed £2 each
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Commercial Loudspeaker in black case with lead and 3.5mm plug
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£5
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Home constructed kit frequency counter with LED display
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£10
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Diamond Antennas 50 ohm 15W Dummy load with PL259 connector
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All items are bought as seen.
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