Skip to content The Open University

OPEN UNIVERSITY AMATEUR RADIO CLUB
NEWS LETTER no:23

G0OUR Affiliated to the OU Club and the Radio Society of Great Britain


Please make a note of our forthcoming AGM. This will be held on Thursday the 20th January at 12.30pm, as usual in the Green Room above the old Lecture Theatre. Subscriptions are due in January and remain at £5. Please send to OUARC, c/o F. Robertson, S1021 Venables Building, O.U., Walton Hall, MK7 6AA.

We have some very good news regarding the purchase of a portable mast for the club. Last month we took delivery of a used M100 Strumech mast. This was bought privately, and we are very grateful to club member Paul G0WAT for putting us in touch with the vendor, who as it turned out was also an O.U. student. It is in good condition, and came complete with its original guys and stakes. The mast was bought with generous grants from the O.U. Club and the O.U. General Purposes Fund, and with money raised by club members at recent boot sales. The O.U. club have also once again paid our licence fee, RSGB affiliation, and QST subscription.

We haven’t tried out the new mast yet, but hope to position it and try it out in the coming weeks. Initially we will just be using it to support some simple wire aerials for the LF bands, but it does open up lots of other possibilities for the future.

Part of the delay in trying out the new mast is due to us having problems with the existing aerials. The feeder to the topband dipole sustained damage in the heavy winds back at the beginning of November. Adrian and Fraser spent a day sorting that out, with Adrian once again doing all the tricky work up the ladder. This involved taking off the fifteen foot stub mast from above the beam, which is no picnic when perched twenty five feet up a ladder, neither is putting it back again! The work was completed in one day, including putting back up all the wire aerials. Unfortunately a week or so afterwards the beam developed a fault, again this came about following some very windy weather. The swr on all three bands was intermittently high, flicking around indicating a mechanical fault as the aerial swayed in the wind. We telescoped the tower down again and Adrian spent a further session up the ladder, with Bert and Fraser offering support from below. As suspected the feeder tested out ok, as did the 4:1 balun, so it looks as if the beam will have to come down for maintenance.

Back in September the IC756 developed a fault, whereby it would receive but not transmit. Actually it would transmit, but only for a few milliseconds at a time. We had a quick look inside, but with no service manual and the rig being full of tiny surface mount components, the lid was quickly screwed back on and the radio despatched back to Icom UK. Unfortunately it was a few months outside the two-year manufacturers warranty. It turned out that the driver IC had failed, which apparently is a known fault. Icom fitted additional components to protect the chip from what they describe as ‘static damage’, so hopefully the fault will not re-occur.

G0OUR continues to be regularly active on HF most weeks, as well as spells in the following contests: Worked All Prefixes (as GX0OUR), Islands On The Air, and CQ World Wide. Some good DX was worked on 40m during CQWW, including Grenada, Barbados, Saudi Arabia, Galapagos Islands, Jordon, Morocco, United Arab Emirates and Cyprus British bases, so we look forward to receiving QSL cards for those contacts. The club station was only on briefly during the club calls contest this year, partly due to the antenna problems. We have also had some contacts on six metres SSB.

We have finally started receiving QST direct from ARRL, and so far have the November and December issues, which are available in the shack. It seems the long delay was due to the ARRL, not the RSGB who arranged the subscription. We look forward to receiving future copies on a regular basis.

Adrian M0ANS and Bert G3FVO went to the HF convention, and Adrian has written this report: "I went to the RSGB HF Convention last October to pick up the Arial Trophy that Fraser G4BJM had won on behalf of the club. For trophy cognoscenti, it is truly remarkable. It's an old BBC microphone of, I guess, mid 1950s vintage. As usual there were plenty of talks and numerous stands where special interest groups had displays. The VLF stand was particularly fascinating. A Racal communications receiver was tuned into 136 kHz, picking up a signal from a Czech operator. The signal was so faint you couldn't hear it buried in all the noise. So how could they read the signal? They plugged the output of the receiver into the line input of a laptop computer's SoundBlaster, and ran a freeware programme called Spectrogram. The Spectrogram display 'slides' from right to left at the rate of about 1" per second, and the vertical scale covers the audio frequency from, I estimate, 1 - 10 kHz. In the absence of a signal, the screen is black, but as signals get stronger the frequency traces are displayed in blue, white and read for increasing signal strength. If you connected a microphone to the computer and whistled a single note for two seconds, you would see a single horizontal white line appear, two inches in length. The height of the line would correspond to the frequency. Imagine what you would see with a slow Morse transmission buried in the noise. What I actually saw was a multicoloured blue screen 'sliding' to the left of the screen with a faint white trace that clearly showed the stations CQ call in CW. The trick is to use the smallest bandwidth possible so that the signal is only just covered and the noise level relatively low. To do this with classical filters would be difficult, but the spectrum analyser is capable of doing this in real time. If you would like to use the Spectrogram software, it can be downloaded free from: http://www.monumental.com/rshorne/gram.html "

The last lunchtime video was back in September, entitled North Texas Contest Club – 1983. We have just received an up to date list of videos available from the RSGB, so the next video is a bit more recent, being the Dxpedition to Campbell Island – ZL9CI, 1999 by 9V1YC. This lasts for 58 minutes and will be shown at 12.30pm in N2028 Venables Building on Thursday 13 January. Everyone welcome.

That's all for this time, seasons greetings, hope to see you at the AGM.

73 for now…


Contact: Adrian Rawlings adrianrawlings@googlemail.com