Keith’s Shack

Shack facilities at this QTH are divided. “In house” so to speak , is equipped for 2m & 70cm with aerials for 4 & 6m. However 4m is redundant ever since the rig

blew up. General coverage of the short-wave bands is via a Marconi Nebula receiver. Those who have brought equipment to Club surplus sales will recognise some old friends in both parts of the shack but especially in the workshop and may be gratified to know that it is cared for and working even if at times it is a bit on the arthritic side!

Cont’d page 3

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ContentsPage Title Author Call Sign

1 Keith’s Shack Keith G8MKO3 Episode 2 On The Clubs ZPY Key Albert G3ZHE4 Club Spotlight Competition Ron G0WJX5 2m Ramblings Albert G3ZHE

6 G3NFB and XYL visit the National Space Centre Jim G3NFB8 Club Christmas Party Ron G0WJX9 OMNI VI Plus Receiver Audio Modifications George G3OGQ10 The Clubs Signal Generator Albert G3ZHE11 Marconi Centenary Contest Ron G0WJX

12 The G0IQE AwardRon &Chris

G0WJX &G7GZB

Any one wishing to contribute to the magazine should send or give their copy to theeditor Ron, G0WJX preferably in MS Word, .txt format or e-mail.

Club ProgrammeDate Title SpeakerJan-20 Oldham RallyJan-22 "Battle of the rigs" George G3OGQJan-29 1st Norbreck discussionFeb-12 Discussion about National Science WeekFeb-19 More about microwaves Jim G3NFBFeb-26 2nd Norbreck discussionMar-05 Final discussion on National Science WeekMar-08 National Science Week to Mar 17Mar-12 Final discussion on Norbreck and National Science WeekMar-17 Norbreck ExhibitionMar-19 Norbreck and NSW post mortemsMar-26 Spring season socialMay John Thorp of AOR talks about AOR 7030RX (date to be confirmed)Jun-11 Fox HuntJul-09 BarbecueSep-20/21 Leicester RallyOct-15 Autumn season social

Suggestions and offers of talks to the events organiser

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In the workshop are facilities for 2 & 6m whilst the scanner and the venerable AR 88 take care of the remaining bands. The AR88 is there because that was as far as I could carry it.

Keith G8MKO

Episode 2 On The Clubs ZPY Key

You may remember that the key went open circuit a few months ago. I contacted G4ZPY, but he wasn’t interested even though the key was just a year old. At the

time I soldered an external wire link to keep the key working. Maurice was in hospital but said he would dig out the slate filled epoxy in the base to clear the fault, when he felt better.

I received a report on the repair from Maurice and it showed up some faulty work in the key base. The marble had been drilled out for the connections and contacts with a pointed end drill which left behind a set of countersunk holes. The wire was put into the connection, a washer placed on top and the nut when pulled down got tight when the washer came up against the top of the countersunk hole. The wire was left loose behind the washer in the countersunk space. Slate filled epoxy was  poured into the base to seal it all and the fault was waiting for us.

Maurice dug out the components, filled the holes with epoxy to get a level surface, then redrilled, made new connection posts - did a proper job. He even repolished the marble to remove a mark I had made during the soldering job!

Many thanks Maurice for your skillful work and the way you serve the club.

      73 Albert G3ZHE ...-.-

From page 1

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Practical Wireless Club Spotlight Competition 2001

There were 14 entries this year and the competition was even more intense. Our entry tied with those from Oldham Radio Club and Silverthorne Radio Club with

the award of 35 points out of a maximum of 40. The winners, Cockenzie and Port Seton Amateur Radio Club, scored 38.5. Crawley Radio Club were second with 38 points and in third place with 36.5 points were Echelford ARS and Milton Keynes ARS. The seven other entrants received marks ranging from 34 to 26. The sight of copies of the judges comments, copied below, is useful and can lead to improvements but the main purpose of the magazine is to serve club members so you are the final judges and your views are paramount. Please make suggestions, complaints and above all contributions to your club magazine.

Judges commentsDave Wilkins G5HYVery nice photo / print quality.Good club contentGood to see the club’s programme included. Awarded 8 out of 10

Jim Bacon G3YLAAn example of how effectively a few quality colour photos can lift a publication. Hard to find contact details and meeting venue. Awarded 8 out of 10

David Barlow G3PLEThis is what a club magazine is really about – info – news – articles – colour.A good presentation fulfilling a purpose. Awarded 9 out of 10

Rob Mannion G3FXDAbsolutely superb! Excellent use of colour on front cover.I know this club well – it reflects them adequately.Superb quality printing – one gripe is typeface size but maybe that’s my problem.Awarded 10 out of 10

Total score 35 out of a possible 40Ron G0WJX

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2m Ramblings

I have mentioned before my first 2m transmitter. It was an ex RAF 128Mhz job that I modified to a single frequency AM crystal rig. It was before we had channels.

Each area of the country had different frequencies to call and work on. A 2m to 10m converter at the HF receiver allowed tuning of the receiver so that 28Mhz =144Mhz, 29Mhz=145Mhz and 30mhz=146Mhz. After a CQ call you had to say how you intended to tune your receiver to listen for a return call. For example “CQ G3ZHE tuning 144 to145 MHz listening for a call.” Eventually you would hear a reply several 100Khz from your own frequency. It was lots of fun.

I eventually bought an Icom IC240 from Gordon Adams. With it you had to choose which 22 FM channels you wanted and then solder diodes into a matrix board then when a channel was selected currents through the selected diodes gave a binary number to a synthesizer system, which in turn gave you the frequency you required. A multimode FT480 followed and gave good service. A trip to Matlock got me a Kenwood TS751E multimode rig. It was great, I kept it about 7 years and it never gave any problems. I know now that I was foolish to trade it in for a dual band FM rig. It was an FT8200 it was small, it used mini din sockets (useless) and a so called military spec. microphone plug. It also suffered from 153Mhz pager break through and needed a costly band pass filter. After about 3 years it started to go intermittent. I found the positive rail on the main printed circuit board had cracked around one corner. This was due to expansion. The printed circuit board was held firmly at its corners one end being attached to the heat sink. A wire link was installed around the crack and all went OK for a couple of weeks, then the receiver went very deaf. I could not trace the problem but a friend rang me to ask if a lightning pulse could damage a PC modem connected to telephone wires. The penny dropped when I realised we had a big storm the night before my rig went deaf. As Corporal Jones says “They don’t like it up ’em”. It was a pleasure to throw that rig into the bin.

A simple 2m replacement was needed. The FT2600 (the one that looks like a PMR rig with the speaker at the front) looked OK. It had been reduced in price for the previous 2 months in Radcom adverts. I got one but after a few days of operation I noticed the heat sink got very hot and the rig tripped out if the full 60 watts was asked for. The book tells us the currents required for the various powers e.g. with a 13.8volt supply 5w=3A, 10w=4A, 25w=6A and 60w=10A. I calibrated an ammeter and got 5w=6A, 10w=7A, 25w=12A and 60w=15A.

At 25 watts I had a volt drop of over 2v in the supply lead and it was getting quite warm and tacky. At PTT inrush current could drop the supply voltage to about 12v for a moment at the power supply unit which meant 10v at the rig. 10v was below the sustaining voltage for the regulators in the rig, which explained the rig trip outs.

A phone call and a letter had the rig on its way back to the dealer. A few days later it

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returned with a note saying they had tested it and found it fit for use. I asked Keith G8MKO to get me a 4 inch 12v fan from the Winsford rally. I laced it onto the heat sink with tie raps. The over heating problem is solved. Without the fan a 4 minute 10watt QSO would have the heat sink too hot to put my fingers on it. This rig does not suffer from pager break through but people with older 25Khz bandwidth rigs often complain about the volume of my voice, e.g. carrier 20 over 9, voice weak..

My microphone gain and deviation are set in software (no adjustment). I can choose 3Khz or 6Khz and that’s it.

As the older rigs vanish we will all finish up with these narrow bandwidth rigs. The sooner the packet nodes go narrow the better as their 12.5 kHz overlap at this QTH makes packet operation difficult.

73 from Albert G3ZHE

G3NFB and XYL visit the National Space Centre - September 2001

The National Space Centre (NSC) was opened in June of this year and is located just off the A6 about 2 miles North of the centre of Leicester. It is fairly well

signposted with brown tourist signs from the M1 J21A and J22. The best route from Warrington is via Uttoxeter, Burton, Ashby de la Zouche (aspidestra) and thence on to the Leicester outer ring road (clockwise).

As you approach the NSC it is easily recognised by the large , yellowish maggot-shaped tower which is at the entrance to the building. This tower houses a Blue Streak and a Thor Able rocket. It has several levels which contain various bits of space hardware and models of satellites, including a full-size Sputnik.

Entrance costs £7.50 (£5.50 concession for students, OAPs etc). This seems a bit steep, but includes entrance to a planetarium with multimedia show and is well worth the money. Car parking costs £2.00 but we were lucky as we went on a Sunday when parking is free.

Now all the commercials are out of the way we can start on the good stuff - firstly a little more about the rockets. The Blue Streak was eventually developed into the first stage of the Arianne rocket which carried the AMSAT A40 satellite into orbit. It is on

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long term loan from the Liverpool Museum. The U.S.A.F Thor Atlas is from the St Louis Science Centre in the USA.

As you enter the NSC there is a USSR Soyuz spacecraft. This was salvaged from a courtyard in Tiblisi, Georgia and was owned by Zvezda the Russian spacesuit maker. Only in Washington DC and Moscow are other Soyuzs on display. I was very fortunate to see and photograph the Apollo-Soyuz mock-up at Cape Kennedy when I worked there in the 1970s. Unfortunately the photos are not up to the standard for publication that we expect for WARC-QSX.

The museum exhibitions are grouped into topics including, spaceflight, applications, Solar System and astronomy.

Spaceflight looks at the involvement of Britain in the world-wide space effort. It demonstrates how many people and disciplines it takes to put a man into space and what benefits are derived from space research. The training of astronauts and the conditions they experience during space flight were well illustrated as were the effects of space flight on the human body. Did you know that you have a 50% chance of being sick for the first three days in orbit, or that you can end up with kidney stones due to your bones degrading? How would you like to feed on peas in milk, which is a favourite Russian astronaut food? More importantly, how would you like to be cooped up in a confined space with someone who is being sick and/or has been eating peas in milk?

For me one of the most interesting sections dealt with the applications of space flight, particularly remote sensing for earth resources, mapping, meteorology and oceanography. The topic of satellite communications was well covered and included the use of satcom networks, navigation satellites and GPS. Amateur radio was well represented with a display dedicated to explaining and demonstrating the A40 amateur satellite. A video monitor showed the realtime earth orbit of the satellite and another showed a map of the Earth and the satellite footprint. On an outside corner of the NSC building at the furthest extreme from the entrance an antenna system is mounted. The antennae appear to be for 2m and 70cms on a common boom and both vertically polarized. They are rotatable in azimuth and elevation and a rotator control unit was part of the indoor display. Several dishes are mounted near to the amateur antenna. These are for the control and data reception associated with the Leicester University Space Science Research Unit which has a satellite control centre in the NSC Building.

The Solar System was well explained and illustrated and included the history of planetary exploration, from early mythology and folklore to the present day and beyond. I was pleasantly surprised to see that the two Helios solar probes I worked on were mentioned in conjunction with solar research, as was the Ulysses probe. Helios satellites orbited the sun in the equatorial plane and Ulysses is a solar polar orbiter.

The emphasis of the NSC is on the current and future status of space research, with all the information being up-to-date. With these aims it could hardly be called a museum.

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The NSC claims to review, daily, developments at space agencies, research establishments and other organisations. You can also keep up-to-date via the NSC web site - Space Now Online at www.spacecentre.co.uk .

I note also, that in the September RadCom (p91) there is a NSC ARS with a web site at www.nsc-arc.fsnet.co.uk and that they are recruiting from local amateurs to increase the manning levels for its station. (Pity it's such a long way to Leicester). On leaving the NSC we discovered that next door there is an old pumphouse which has been converted to a science and industry museum. The good news is that entrance to this museum is free. You could easily spend many hours at the NSC, as we did, so if you want to visit the pumphouse as well you had better plan for a whole day. My XYL Carol has always had an interest in space and thoroughly enjoyed the experience. She recommends the NSC to other YLs and confirms it is an interesting place for the whole family to visit.

Jim G3NFB

Club Christmas Party

There was a good turnout for the club’s Christmas celebration although perhaps not as many attended as in previous years. The decorations put up by club members

added to the festive atmosphere and, surprisingly, stayed where they were put considering the fact that they were mainly fixed with blue tack.

Our thanks are due to Ian M0BXR and Mike M0AWD for their sterling work in organising the party and the buffet and to those members who assisted both before and after the event.

Pictured left at the club Christmas party Keith, G8MKO, shows his delight at gaining a further call sign from 1st January 2002. The photo by Ian, M0BXR, has been edited slightly to make it more exciting!

Pictured below, a table full of revellers!

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OMNI VI Plus Receiver Audio Modifications

The Omni VI+ has an exceptionally good receiver (yes, really), but the audio response can be significantly improved by making a few simple modifications,

marketed by International Radio Corporation of Umpqua Oregon USA. They market mods for most of the rigs in use today which improve things like AGC, noise reduction, sensitivity etc and also, and most important, they market filters which are better than the stock ones supplied with your set.

I found this firm when looking for 9 MHz crystal filters for the CDG2000 and while they are not cheap, (no filters seem to be as there is a great degree of ‘select on test’ regarding components) they have excellent responses.

Anyway, back to the Omni VI+. The stock radio audio pass band is limited on both the top and bottom ends by several circuit components which are easily changed.

The sweep frequency response picture labelled ‘BEFORE’ shows the overall frequency response of a stock Omni VI+

Several things are evident:

1. The response is tipped down from the low side towards the high side. There is approximately 8 or 9 dB of high frequency loss from 500 Hz to 2500 Hz.

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2. Pass band ripple is greater than 2 dB.

3. The low frequency cutoff is about 350 to 400 Hz at –3 dB.

Simple modifications can improve the Omni audio in each of these areas. The sweep response labelled ‘AFTER’ shows the results of these modifications.

Note the improvements:

1. From 500 to 2500 Hz the frequency is tipped only 2.5 or 3 dB. Note: the DSP circuitry in the Omni has 2.5 dB of roll off from 500 to 2500 Hz. This cannot be easily altered.2. There is now little or no pass band ripple.3. The low end response has been improved to about 250 to 300 Hz at –3 dB.The change in sound of the receiver audio in the SSB mode is dramatic (or so say International Radio, with some modesty!)

I have purchased one of their kits for the Omni mods and it arrived today. It cost $15 – that is $14.50 for the instructions and 50c for the bits. I will do the mods and stand back!!!

Happy New Year

George G3OGQ

The Clubs Signal Generator

A few weeks ago Mike M0ACK and myself got involved with the St Helens Air Cadets. They wanted help and advice on their radio systems. They have a crystal

controlled Pye Westminster.

Neville G3EXG on hearing this gave us his Westminster, so they would have two. I ordered a pair of crystals for 78.1 mHz transmit/receive and was faced with the alignment. Using a PC driven scanner I got the transmit aligned quite well but the receive was a different matter. After a word with George G3OGQ I borrowed the club’s signal generator & digital frequency meter. A read of the instruction book didn't take long and the receiver set up began. First I found out where I had set it up. It was 6 kHz high and very insensitive. Several adjustment passes of the oscillator, 10.7 mHz & 0.455 mHz IFs had the receiver on spec with a loud signal in the speaker for 0.5 micro volts @ 30% mod into the antenna. The signal generator covers from 1 MHz to 1000 MHz in 100 Hz steps and its output can be adjusted from 1 volt to 0.1 micro volts. Its a magic bit of gear.

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Marconi Centenary Contest

On 29th December a number of WARC members escaped the clearing up after Christmas to take part in the MCC which was sponsored by Marconi plc in

conjunction with the Radio Amateurs of Canada and the Radio Society of Great Britain. It’s not often that QSOs with Japan and Australia are regarded as interruptions to the operating but on this occasion it was Canadian stations we were seeking. This was a useful opportunity to operate under competition conditions and also to practice computer logging. A flavour of the atmosphere can be gained from the photographs. Our thanks go to Mike, G4VSS, who organised the event and loaned equipment and Mike, M0ACK, who let us use his beloved Icom IC-756 PRO.

Ron G0WJX

Above, Ian M0BXR at the microphone, Mike G4VSS logging as Dave G0RVW looks on.Left, Mike G4VSS on the microphone as John M0ANM logs

Above, Bill G0PZP & Jim G3NFB

The digital field meter batteries had gone flat due to standing for months. I charged them at 50 ma over night and soon had the 1.5 kHz error in the transmitter output sorted. The frequency meter demands just over 500 ma from the batteries which is quite a lot. Thank you to whoever bought this gear - it’s top class equipment. It got me out of trouble - thanks again!

73 Albert G3ZHE...-.-

The G0IQE Award

I was surprised and delighted to share, with Christopher G7GZB, the award for 2001. There is no better compliment than to receive recognition of your efforts from your

friends and colleagues. I am proud to have my name join those on the shield. Because, in part at least, it was my work on QSX that was recognised I feel I should pay tribute to all those members of the club who have unfailingly responded when contributions were needed. Outstanding amongst these is Albert, G3ZHE, who is a continuous source

of innovative, informative and amusing articles but a glance through back issues will show that many others have put pen to paper or, more usually, fingers to keyboard. And then when the journal is ready and sent off electronically, Brian G6XRE, converts it to the quality production it has become. His suggestions for improvements have invariably proved successful. What is more Brian holds down a full time job. There have been occasions in the past when the timing of the transmission of QSX to Brian has been discussed with him via e-mail to the other side of the world! My thanks then to you all and please keep your fingers to the keyboard.

Ron G0WJXI can only reinforce the comments made by Ron G0WJX about the IQE award coming to us for our work on the club magazine. It is very much a club effort and without those who contribute with content or expertise it would not exist. We enter the Club Spotlight Competition each year and it is a tribute to the club, that our standards are keeping pace with the other entries in what is fast becoming a very competitive contest. A big thanks to all for making that possible.

Chris G7GZB