OPEN UNIVERSITY AMATEUR RADIO CLUB
NEWS LETTER no:38
G0OUR Affiliated to the OU Club and the Radio Society of Great Britain
make a note of our forthcoming 2011 AGM on Tuesday 18th January at
12.30pm. We are in the same room as last year, Central Meeting
Room 6, on the ground floor. This is accessed from outside via
the West Central Meeting Rooms entrance, near the shop.
Alternatively you can get there through the back of the Hub Lecture
Theatre. An email reminder will be sent nearer the time, and
local members are urged to attend if they can.
Back in the
summer we changed the club/shack meeting day from Thursday to Tuesday
of each week for a trial period. This has worked out well so we
are sticking with it for now, hence the AGM also being on a Tuesday.
reminder that subscriptions are due on 1st January, and remain at £5
per year. Subs can be paid at the AGM, or 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. Copies of the 2010 minutes can be obtained
from the Secretary, Adrian. Please note that Adrian has changed
his email address to: firstname.lastname@example.org
is still no further news regarding the proposed car park extension and
possible relocation of the Field Research Site (where our club station
is located). So we hope that no news is good news.
The area in front of the shack is still being used extensively by
building contractors, and has become a bit of a storage area.
This has occasionally caused access problems for us. Other news
is that there are plans to erect a 3m diameter radio telescope on the
Field Research Site, close to the existing optical telescope.
This will be remotely controlled by students as part of the new S288
Practical Science course. The telescope will be looking at the
21cm hydrogen line, using a specialised receiver system that measures
the Doppler shift of noise around 1420MHz. If there are local
noise issues the system will be relocated elsewhere, but it will be
mounted here for initial testing at least.
Back in May we had
our traditional stall at the DDRC sale at Stockwood Park, Luton, and
cleared £227.20 for club funds. Following that we attended the
MKDARS sale in August, which we have missed in recent years due to it
being on a Bank Holiday weekend and clashing with holidays
etc. This sale has returned to its old venue in Bletchley
Park. It is a smaller event than the DDRC one; even so we cleared
£175.70, so making a total of just over £400. As always, we still
have a large stock of junk in the shed next to the shack, and it keeps
on coming in dribs and drabs.
Purchases since the last
newsletter have included the general coverage module for the K3, along
with the matching fist mic. and a pair of 8 pole SSB filters for the
main and second receivers. We are very grateful to the OU Club
for their grant towards the cost of these.
We are hoping to
branch into the world of SDR (software Defined Radio) next year.
After looking at various options, mostly in the form of single band
receiver or transceiver kits, we decided that the commercial Flex-1500
SDR would be a much more useful option long term. This has
internal 48kHz sampling A/D and D/A convertors so unlike many other
SDRs it does not need a high quality sound card, and simply connects to
the PC via a USB port. It covers all bands, 160m to 6m with a 5W
output transmitter and has general coverage receive capability.
We are also hoping to add the internal ATU for the K3 next year.
We are currently waiting to hear if our bid for OU Club grant money
towards purchasing these items has been successful.
We have had
some minor problems with the K3, in the form of burnt out resistors
associated with the rear panel accessory port. These are tiny
surface mount devices, and have been replaced with more manageable 1206
size surface mount resistors. After talking to Elecraft we’re
still not sure of the cause of these failures. We use the ACC
port for band data to switch the antennas, but the current drawn on
these lines is very small. Also, the digital I/O resistors have
also burnt out, and we’re not using those lines at all. We
suspected RF getting back into the rig via the RX ant socket and/or
second RX ant socket. The power on these ports was measured worst
case at 100mW, which is way below the limit specified by
Elecraft. We’ve temporarily reduced this by 10dB. We also
measured up to 100mA common mode RF current on the screen of the band
data cable, and this has since been reduced to 15mA with a common mode
choke. So hopefully, one way or another, this problem has been
solved. The Omni6+ still has a problem that is proving a bit more
involved to fix than at first thought.
Unfortunately the PC that
was donated to the shack by Steve M0BPQ has given up the ghost.
Either the PSU or the motherboard are suspected, as the power light
comes on but it won’t start up at all. Fortunately we were able
to retrieve data from the hard drive. The older shack PC that was
on loan from the OU MCT Faculty has been upgraded. This is now is
now installed and working well after fixing some initial RFI
issues. We are still using Steve’s Wi-Fi USB dongle for internet
access. This gives a marginal connection, and we’re looking into
improving the antenna.
The OU packet node is still running in a reduced capacity, and awaits decommission.
were busy again during the summer months clearing vegetation from
around the shack, guys etc. This has become an annual chore, but
is good exercise and gets us out in the sunshine at least. We
haven’t had to do any major antenna maintenance this year.
Replacing the guys and general maintenance on the M100 mast remains on
the “to do” list.
As usual we were active during the November
RSGB Club Calls contest on Topband SSB, putting the G0OUR callsign on
the map alongside other UK club stations. G0OUR was also active
during the CQ WW Topband contest. Paul M0OOM remains quite active
in the shack on digital modes using the IC7400.
That’s about it for now; hope to see some of you at the AGM.
Contact: Adrian Rawlings email@example.com