OPEN UNIVERSITY AMATEUR RADIO CLUB
NEWS LETTER no:31
G0OUR Affiliated to the OU Club and the Radio Society of
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, firstname.lastname@example.org .
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
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