OPEN UNIVERSITY AMATEUR RADIO CLUB
NEWS LETTER no:31
G0OUR Affiliated to the OU Club and the Radio Society of Great Britain
A happy new year to everyone. This years AGM took place on the 6th January, and despite some regulars not being able to make it we had quite a good turn out of ten members, plus six apologies. Copies of the minutes can be obtained from the Secretary, adrian@euroneta.com . Also a reminder that subscriptions were due on 1st January, and remain at 5 per annum. If a red cross appears on this newsletter it means your subs are due. A cheque made payable to OUARC can be sent to the Treasurer, Fraser Robertson, S1021 Venables Building, Open University, Walton Hall, Milton Keynes, MK7 6AA. Your continued support of the club is appreciated.
Welcome to new member Joe Mills, who works in IFEC, Technology Faculty. Joe has helped us put up various aerials in recent years. This year he made the mistake of attending the AGM, and not only ended up joining the club but also took on the role of Safety Officer. Also, Robert Seaton has (been) volunteered to smarten up the clubs web site. Other club officers remain unchanged.
Not much has changed aerial wise, except that we recently put up a sloping doublet for 30m and the other WARC bands, fed with 450W line, and suspended from the new P60 mast. This works quite well but is very noisy on receive. We did try suspending a delta loop from the P60 but found it interacted with the beam significantly so was taken down.
Speaking of noise, interference from the OUs UTP LAN suddenly increased in level early in January by around 15dB, rendering some bands virtually unusable. We had assumed this was due to the new library building, but did some tests with the network people and switching off the hubs in that building made no difference. At that stage only a quarter of the library system had gone live, and there are 1800 UTP cables in that building alone. (The library is due to open on the 7th February). Also the new Science block will be completed and occupied in the next few months, so it seems that matters can only get worse. Meanwhile we plan to do some direction finding, to see if we can locate any specific bad sources of noise. Its likely though that the high level is due to cumulative noise from the many thousands of long UTP runs on campus. The hubs used are Hewlett Packard type Procure switch 2626 which apparently meet the EMC requirements for emissions from IT equipment. Unfortunately this only applies to radiated emissions above 30MHz, and conducted below 30MHz, and does not take account of the cumulative effect.
Our noise problem has been positively traced to the UTP LAN. The worst case being on topband (1.81-2MHz). Until recently the noise was 10dB above s9 (in 2.4kHz bandwidth) right across the band it has now increased to 25dB over s9. Considering our topband dipole is several hundred of feet from the nearest LAN cabling, and given the very wide bandwidth of radiated noise spread right across the HF spectrum, it follows that considerable power is being unintentionally radiated. This was never a problem when the OU used coax Ethernet. Current policy is for fibre backhaul links between buildings, but copper within buildings, and boy theres a lot of copper involved.
The last newsletter outlined our involvement with GB5HQ. ARRL published the results recently, but somehow there had been a mix-up whereby two scores were greatly inflated above those claimed. Subsequently the correct results were published, putting us in second place with 15705914 points, behind the German team who won with 16507800 points, with France in third place with 15394425 points. Not bad for a first serious attempt from the UK. Given the increased noise level here its very unlikely that we can participate this year, on 80m anyway. Currently 40, 20 and 15m are the only bands with reasonably low noise levels.
We recently received a glossy booklet from the Five Star DX Assn. This group is associated with CDXC the Chiltern DX Club, and successfully mounted the 9M0C and D68C expeditions in 1998 and 2001. This March/April they are embarking on a major expedition to Rodrigues Islands, with the callsign 3B9C. Each member of the group is paying their own way, and the trip is heavily sponsored, for example by Yaesu who are providing ten FT1000MP MK V transceivers and Quadra 1kW solid state amplifiers. However the group are seeking help to cover the cost of antennas, feeders and other such hardware. Not only is this a high profile UK expedition, it also aims to promote amateur radio on many levels. It was agreed at the AGM that OUARC should make a contribution towards this project.
As mentioned before, the new library building is finished and is being fitted out. Finally the access road, which was formally exclusive to the field site, has been tarmaced and white lined. The adjacent areas are being cleared up, although access still means negotiating through a mud bath. The situation should improve over the coming months.
The P200 in the shack has been replaced with a P233, which is proving more reliable. On the packet front Im sorry to report the theft of our FT8500 9k6 dual band rig (s/n 6C130194) from the OU node. This was used to link to Bedford. As a result of reduced packet activity, we are considering shutting down the node this year, or at least shutting down some of the ports. We hope to raise a bit of cash for other projects by selling off the redundant packet equipment and aerials. The good news locally on the packet front is that, for the first time, we have a solid packet cluster link, thanks to David G0TWN who runs GB7IMK in Bletchley. His Linux TCP/IP system now runs DXSpider, and we have a solid link to it from the OU shack on 2m. We also now have a 9k6 link on 70cm from the OU node to Davids system. See http://www.taurus2.plus.com/gb7imk/ for more info.
The last club video was Getting started in DXing back in October. The next video will be shown on Thursday 11th March, starting at 12.30pm in N2028 Venables Building. This is titled DXpedition to Howland Island (1993) and lasts 45 minutes. Everyone welcome.
73 for now
Contact: Adrian Rawlings adrianrawlings@googlemail.com