[amsat-bb] Colloquium Report

[Richard@xxxxxxxxxxxxxxxxx (Richard W L Limebear)]

Amsat-Uk's 16th annual Colloquium was held at the University of Surrey
last weekend, 27-29 July 2001. 85 delegates attended from 14 countries
and three continents; numbers are starting to increase.

The nicest surprise came when our Secretary, Jim G3WGM, asked how many 
people were there for the first time: about 20 hands went up. An equally
"nice" thing to see was the number of people in the Beginners' sessions;
also an increase on last year.

What worked and what didn't ?
o  The show-and-tell idea was a flop. No-one told me they wanted to talk so
   these time slots were replaced with real presentations.
o  Moving the Beginners session to Friday was a success and will be kept in
   future programmes (this means than beginners don't miss out on the sexier 
   talks which are on saturday)
o  The antenna test range was new; very well supported (report below)

How was it ?
Magic. We had an excellent bunch of talks this year; even better than the
usual high standard (honest!). I'll put pictures onto our web site over the
weekend (I have about 300 to pick from!).

Delegates were asked to vote for the AO 40 Logo competition which was well
won by Gene, W3PM; a separate report has been published about this. The
runner-up was submitted by G0CUQ.

There were also two speakers' awards of one hundred UK pounds (~$150): The
award for Best Speaker was won by Jerry Brown, K5OE, for his presentation
entitled "YAHE: Yet Another Helix Experiment". The award for Best New
Speaker went to Howard Long, G6LVB, for "Entry-Level AO 40 Capable Stations".
Congratulations to both winners; selecting the best wasn't easy.

This year the G3AAJ Trophy was awarded to Clive Wallis, G3CWV, for his
consistent hard work in following UO-11 and keeping everyone informed of
its status. Nice one, well earned, Clive. It was presented by G3AAJ
himself, nice to see Ron there again.

The Colloquium wouldn't be the same without practical activities:

Command station and UoS clean-room visits were, as usual well supported. 
The barbecue took place in balmy weather out on the grass (no rain this 
year) to the sound of AO-40 telemetry from a hand-held rig (more below).

The "Pub Quiz" written by Paul, VP9MU, was well supported in the bar on
Friday evening; winners were Niko PA0DLO and Bertus PE1KEH. Paul will be
putting this year's questions onto amsat-bb soon.

ON6UG and G3RUH had two S-band demos.  One simply had a bare RHCP patch
feed plus DJ9BV pre-amp pointed at AO-40 and received the beacon strong
enough for telemetry at 43,000 km plus.  The other represented a typical
end-user system and had a 60cm dish, patch feed and Kuhne MKU-24 converter
mounted on a camera tripod, and produced booming signals from the passband.
Both systems had 0.6 db noise figure devices at the sharp end.  Next day the
dish system's gain was measured on the antenna range at 21 dbic. [tnx G3RUH]

Microwave testing provided four types of measurement this year:
 Noise figure
 Frequency calibration 
 Antenna matching (10MHz to 4GHz)
 Antenna gain (2.4GHz only)

The following were measured:
 15 Drake 2880 converters  
 2 SSB Electronics UEK2000 
 2 Transystem MMDS converters
 1 DB6NT P3D converter
 2 DJ9BV preamps
 1 Down East preamp

Several antenna matching sessions were run and a number of lessons were 
learnt by some of our antenna makers!

The big event of the measurement weekend was the 2.4GHz antenna gain range. 
This was the first time such a range had been attempted at the Colloquium 
run by Dave, G0MRF and Sam, G4DDK with advice from Kent Britain, WA5VJB 
and Paul Wade, WIGHZ, on how best to set up the range, what to watch out 
for and especially how to make measurements on circularly polarised antennas.

The results were probably better than we could have hoped for. A wide 
variety of antennas were measured and there were a few disappointed 
customers, but equally, there were some surprises.

The main lessons learnt were:
o Short helix feeds do not produce very good circularity (typically 4dB 
  axial error). Long helices are much better.
o Certain commercial long helix  antennas are poor performers when measured 
  against what you can build yourself. 
o Dishes generally provide best gain, but need to be optimally illuminated
o Our recording of results requires improvement!
o We have several converts who want to set up their own antenna test ranges.

Full results from the range and the test bench will be published in Oscar News.
[tnx G4DDK]

News
In "The Old Days" we used to get lots of real news at the Colloquium but
this has declined over the years. 
o The Athena launch (PC-Sat and a UoS picosat for the USAF) is slipping; at
  least a week, maybe a month.
o DB2OS Reports (AO-40): The momentum wheels were close to the propulsive
  "event", not sure if they will function. The Arcjet problem was due to
  the (externally provided) mass flow controller delivering false information.
  Current plans: Rudak first, then CEDEX, then go back to the other (failed)
  experiments and try them again; plus, of course, all the other experiments.
o Amsat-UK Annual meeting: G0FCL stood down due to ill-health; new member
  Stan, G3DSS, joined the rest of the committee who were re-elected en-bloc.
  Full minutes will be published soon in Oscar News.

Many thanks to all the SSTL staffers who also gave some excellent talks
this year and supported us in other ways too numerous to mention.

The Proceedings will be made available within a week or two; this year 
an electronic version will be available by e-mail or CD.

The (unconfirmed) date of next year's event is 26 to 28 July 2002; put it 
in your diary NOW.

73
Richard W L Limebear G3RWL
g3rwl@amsat.org
FOC # 1188

          So many beautiful girls ..... (sob) so little time
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