August 2011
IN THIS ISSUE
Meeting and Activity Program
Club News
Future Meetings and Events
Members News
Technical Snippetts
Computer Corner
Miscellaneous News and Events
Noticeboard "Wanted" and "For Sale"
Adjacent Clubs
Meeting and Event Diary:
05 Aug
M
Summer BBQ
07 Oct
M
'Military Radio Equipment for the Amateur' by Dennis Noe M0NDJ
02 Sep
M
Junk Box Aerials by Martin Butler M1MRB
04 Nov
M
An Evening of Short Talks
02 Dec
M
Christmas Social
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
1st July 2011 - Construction Evening
Each team had a team leader and was provided with a circuit diagram, a bag of around 6 - 12 components, a piece of scrap printed circuit board and some basic tools. The object was just to build each of the circuits in whatever form the team chose and make them work. `Dead bug' construction was demonstrated and an example provided.
Test equipment in the form of power supplies, oscilloscope, test meter etc were provided. The majority of the projects were completed in the time available and made to work. The only exception was the direct conversion receiver which made some rather odd noises but did not behave quite in the expected manner. It was never going to be easy to test any receiver in the RF fog that is permanently present around Crystal Palace but some low level signals were heard.
A full writeup appears later in this newsletter.
Future Club Meetings and Events
5th August 2011 - Summer Barbecue
Our next meeting will be our Summer Barbecue for which the club will provide the main course plus refreshments. If members would like to contribute a desert please do not bring along too much as we do not want to be left with food over at the end of the event.
Members with special diets should advise your scribe as soon as possible.
2nd September 2011 - Junk Box Aerials by Martin Butler M1MRB
Martin has previously given a talk to the club and this time he is going to talk about the construction of aerials from whatever items happen to be to hand.
Foundation Training Course 2011
Our next Foundation training course will take place on five 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 Bob on 01737 552170 or g3oou@aol.com or Victor on 020 8653 2946 or victor@jmail.co.uk.
There will be some minor changes to the Foundation syllabus from 1st July 2011 and the new pass mark will be 19 out of 26.
Members News
Trevor M0DIA is now out of hospital and living at a new address in Norbury. He is now back on the Internet with a new laptop and looking forward to being back on the club net as soon as some aerials can be arranged. He would appreciate a visit - details from your scribe or Victor G1PKS.
Club Net
Your scribe has now upgraded his Yaesu FT-450 to an Icom IC-7400 which gives 100W multimode on 2m as well as 100W multimode on HF and 6m as was provided by the FT-450. The receive filtering in the IC-7400 is a vast improvement and this rig can be connected to a PC running Ham Radio Deluxe or a similar rig control package free from Icom.
Tests between myself and Victor G1PKS give good results on both 2m and 6m but poor results on the HF bands which may have been due to the time of day - local communications on the HF bands are usually better earlier in the day. Victor is currently reviewing his aerials as some unpredictable results were obtained during the tests.
Technical Snippetts
Communications on the HF bands have been showing signs of improvement and a recent listening session in the evening on 20m SSB resulting in many Stateside QSOs being clearly heard with S7 to S9 signal strengths and minimal interference.
Construction Evening Projects
The individual projects were as follows:
Twin Tee Audio Oscillator
This is a simple but highly stable audio oscillator if 1% specification components are used in the Twin Tee section - the leftmost seven components in the following circuit diagram.
The output is a slightly clipped sine wave which can be cleaned up with a simple low pass filter.
VISIO 4 Drawing
With the appropriate value components it was used in a 1750Hz tone burst oscillator and a 2125 / 2975Hz RTTY tone generator in the G3OOU station many years ago. The dead bug construction is shown below:
9V Regulated Power Supply
VISIO 4 Drawing
A very simple regulated power supply that uses a zener diode voltage source and an emitter follower current amplifier. The 10 ohm resistor provides a degree of current limiting protection.
The output voltage is about 700mV less than the zener voltage. The maximum output current is typically 100mA and a heat sink may be required on the BFY51 transistor.
RF Preamplifier
This broadband amplifier will provide about 14dB of gain with a low noise figure over a very wide frequency range. As shown it has a low input impedance and a high output impedance so output matching would be required to drive a 50 ohm load.
Some form of signal filtering would normally be used for on-air applications to reduce the possibility of overload.
Direct Conversion Receiver
This is an extremely simple direct conversion receiver for CW and SSB with a conversion gain of about 16dB. With WWII type high impedance headphones it will resolve a signal of around 50-100 microvolts so some form of audio amplification is required to improve the sensitivity. Signal filtering is required for best results but this was omitted for the construction evening to avoid unnecessary complexity.
During the test process some unusual noises were heard which were thought to be due to the high level RF fields from Crystal Palace and there was insufficient time to trace the problem.
AF Preamplifier
This circuit is a single stage audio amplifier which will provide a gain of 6 - 30dB depending on the setting of the emitter potentiometer.
7MHz Crystal Oscillator
This is a fundamental mode Colpitts crystal oscillator that will work from around 500KHz to 30MHz. Some adjustment to the 220p and 100p feedback capacitor values may be required at lower frequencies - as shown they are suitable for approximately 5 - 20MHz.
Project Test Results:
The following morning all of the projects were powered up and tested. The problem with the receiver was found to be an error by yours truly on the circuit where two capacitor values had been swapped over by mistake causing the VFO to squegg. This was corrected and the receiver performed as expected.
With the RF Amplifier and AF Preamplifier connected to the Receiver it was just possible to hear an 0.6 microvolt signal in the high impedance headphones.
Well done to all of the teams who managed to assemble the circuits correctly in the relatively short time that was available.
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.
Mode Components has a website at http://www.modecomponents.co.uk/ and can be contacted on 0121 554 5157 or 07984 071369.
Email at sales@modecomponents.co.uk or
modecomponents@yahoo.com
Outlook Stockholders Ltd in Coulsdon supply a wide range of ferrous and non-ferrous metals. Contact them on 020 8668 9656, sales_osl@live.co.uk or http://www.outlookmetalstock.com/
Paul Hill (Sales) Ltd in Bradford supply a wide range of stansdard size or cut lengths of non-ferrous metals. Telephone: 07585 772183, web: http://www.plhillsales.com/,
email: sales@plhillsales.com
73
G3OOU
Diary of External Events
30-31 JUL - AMSAT-UK Space Colloquium
Holiday Inn, Guildford, GU2 7XZ. Lecture programme, GB4FUN, AMSAT Shop. Details at www.uk.amsat.org
31 Jul - Colchester Rally
Cancelled.
14 Aug - Flight Refuelling ARS Hamfest
Cobham Sports and Social Club Ground, Merley, Nr. Wimborne, Dorset. BH21 3DA. Talk in S22, Opens 10.00. Details Mike, M0MJS, 01202 883 479. Website: www.frars.org.uk
21 Aug - Rugby (Princethorpe) Annual Radio Rally
Princethorpe College, Princethorpe, Rugby CV23 9PX (SP395710). Open 10am - 4pm, £2, Talk in. Contact Tony, 07759 684 411, rallyraugbyats.co.uk Website: www.rugbyats.co.uk
28th Aug - MILTON KEYNES ARS RALLY
Bletchley Park, Sherwood Drive, Bletchley, Milton Keynes MK3 6EB. TS, SIG, GB2BP. Why not make this a family day and visit the Betchley Park museum too? www.mkars.org.uk.
30th Sep - 1st Oct - NATIONAL HAMFEST
 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.
06 Nov - Kempton Park Radio & Electronics Rally
20 Nov - CATS Bazaar 10am - 1pm
A full list of rallies and events may be found at http://www.rsgb.org/events/index.php
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
2nd Aug
Constructors Competition
6th Sep
"Programming your modern VHF/UHF rig".
4th Oct
Annual General Meeting
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@catsradio.org
Web site: http://www.catsradio.org/
12 Sep
CATS Equipment Sale
10 Oct
Radio In The Scouting Movement by G6CJR and M0NDJ
14 Nov
CATS quiz:  Quizmasters Steve (G7SYO) and Wendy
Dorking & District Radio Society
Meetings at the Friends' Meeting House, Butterhill, South Street, Dorking RH4 2LE starting at 7.45pm.
Contact: Garth Swanson G3NPC on 01737 359472 or G3NPC@swansons.org.uk
Web site: http://www.ddrs.org.uk
23rd Aug
Social evening
27th Sep
The STEPPIR antenna, Rob Barter M0ZAF.
25th Oct
Software Defined Radio, Olof Lundberg G0CKV
22nd Nov
The 4 Square Antenna - results, Garth Swanson
Echelford Amateur Radio Society
Secretary Tony Collier 2E1IDK on 01932 564099 or e-mail tony@woodroad12.fsnet.co.uk
Web site: http://beam.to/ears
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:
tim.trew@btinternet.com
Meeting on 3rd Thursday of each month, 7:30pm at RNIB Redhill College, Philanthrophic Road, Redhill.
South East Essex Amateur Radio Society (SEARS)
Contact: Norman, M0FZW (Hon Sec)
Tel: 01268 692776,
Email: secretary@southessex-ars.co.uk
Web: http://www.southessex-ars.co.uk/
Meetings: 8pm 2nd Weds each month at: South Benfleet Primary School, High Rd, SS7 5HA.
10 Aug
Talk by Brian G7IIO on his Marine exploits working on the Tankers
14 Sep
Home Brew Antennas by Dave G4UVJ
12 Oct
Talk by Philip G8LHW on Power Supplies
09 Nov
AGM
14 Dec
Christmas Social
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 secretary@g3src.org.uk for more details.
15 Aug
SDR Update with Martin G3OQD
5 Sep
Radio Fox Hunting Terry G4CDY
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@scrs.org.uk  Web: http://scrs.org.uk/
18 Aug
'3D TV' by Mike Cox
15 Sep
'Repairing Vintage Radios' by Dave Smith MØSXD
20 Oct
'Noise Eliminating Products' by Graham Somerville M3ZGS of BHI Limited
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/wiki/index.php/Main_Page
29 Jul -
 07 Aug
The Summer Camp site will again be Crossways Farm (Crossways Lane, Upper Gatton, RH2 0TX),
near where the Brighton Road (A217) meets the
M25. Turn of the A217 at Babylon Lane
09 Sep
Summer Camp Retrospective
28 Oct
AGM
25 Non
Surplus Equipment Sale
9 Dec
Christmas Social
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
Price
Description
Price
Telequipment Model 43 dual beam oscilloscope - working but needs a good clean as very dusty inside.
£5
1 bag of pre-packed ICs, 1 bag of RS Components prepacked, 1 bag of identified ICs and transistors
£5
2 two-way data transfer switch box - useful painted project box
£2
A Future Electronics transistor tester FTC 401
£5 the lot
3 way data transfer switch box - useful painted project box
£2
Original HRO receiver printed manual with an S Meter conversion article.
£5
15W soldering iron, mains powered
£1
25W soldering iron, mains powered
£1
Pye fist microphone with 5pin connector
£2
Sangamo Weston E772 1000 ohms per voltanalyser with leads.
£5
1mA FSD meter with 3 inch dial
£1
b) The following items are from the shack of Ron G8OTG:
Description
Price
Description
Price
Advance Signal Generator SG62B
£30
Kenwood SP120 loudspeaker enclosure
£25
FT290 + manual 144-146MHz, 2.5W multimode transceiver
£50
Microwave Modules digital frequency counter with short aerial
£25
Trio 9130 1440146MHz 5 / 25W multimode transceiver
£75
Soldering iron base and spring - less soldering iron and sponge
£5
Crystal calibrator on a PCB with 1MHz crystal
£5
Bosch mobile radio with fist mic - amateur band frequencies not yet established
£20
Active ATU - requires external DC supply
£10
Complete 230V Soldering Iron station
£25
Icom IC-240 144-146MHz, 10W, 22channel FM transceiver
£80
Yaesu FT-225 RD 144-148MHz multimode transceiver
£80
Yaesu speaker/microphone YM-49
£10
Thandar battery oscilloscope SC110 with brief manual
£25
Nova mobile radio
£10
Diamond DSV3000 12V 25A PSU
£25
Mains Bench PSU with 12V output
£10
Kenwood PS-30 DC PSU
£30
ARRL Handbooks - 1976 and 1988 editions
£5 each
Colinear vertical aerial with white weatherproof outer cover for 6m and 2m, other bands not yet known
£15
AM Radio Techniques book by G3VA
£5
RSGB VHF Manual
£5
9 Q-Max chassis punches
£5 each
2 gang 500pF standard varable capacitor
£4
Heathkit RF Probe
£5
c) The following items are from Trevor's shack:
Description
Price
Description
Price
Yaesu FT-707 HF multimode solid state transceiver with matching FP-707 13.5V power supply. Covers 3.5-30MHz ham bands incl WARC with CW, SSB and AM but no Top Band.
£150
Q-Max chassis punches in various sizes including 1inch
£5 each with an Allen key, £4 without
Marconi TF2437 100MHz counter timer
£50
Project box, unused, in good condition approx 7" x 7" x 11" wide
£5
Marconi TF2103 AF oscillator
£30
Project box, unused, in good condition approx 4" x 5" x 6"
£2
Datong D70 battery powered Morse tutor
£25
PX3 small unused project box
£1
Ex Army Morse key
£5
Diamond Antennas 50 ohm 15W Dummy load with PL259 connector
£10
Home constructed kit frequency counter with LED display
£10
Box of assorted variable capacitors
£3 each
Small hand held hand cranked drill
£2
Avo Universal Multimeter - looks like a model 7
Box of assorted valves including two EF183 and one 6SA7
Unboxed £1 each, boxed £2 each
Commercial Loudspeaker in black case with lead and 3.5mm plug
£5
Box of assorted tools - will be sold separately unless a suitable offer for the lot is received.
All items are bought as seen.