[Moon-net] ARRL MW EME Contest

Al Ward w5lua at sbcglobal.net
Wed Sep 24 14:44:09 CEST 2008

Considering that the moon rose about the time I would normally go to bed, I
had a great time operating the microwave portion of the ARRL EME contest.
Fortunately I spent some time troubleshooting the system during the week so
the weekend was event free. Here are my results by band.


2304 MHz.

5 meter dish about 200 watts at the feed. Since I started out on 3400 MHz I
was only operational on 13 cm on the second day. I worked HB9Q, OM/OK1DFC,


3400 MHz

5 meter dish and about 100 watts at the feed. I only operated the first day
on 3400 MHz but was able to work PA0BAT, VE6TA, RW1AW, OK1CA, LX1DB, DL4MEA,
G3LTF and VK3NX. 


5760 MHz

5 meter dish and 70 watts at the feed

Due to the over run from 802.11a interferers in the neighborhood it has
become a challenge on this band for me to track the moon. With the help of
my SDR-1000, I determined that the band was a little cleaner down around
5755 MHz so I devised a secondary downconverter that supplies 5755 MHz to my
GR-1236 IF meter. This makes it a little easier to track the moon in a
quieter part of the band. As a result on 5760 MHz I was able to work IK2RTI,


10368 MHz

5 meter dish and 50 watts at the feed

3 cm was the challenge of the week as I had not been QRV on 3 cm for about a
year due to a waveguide relay that decided to quit after being in use for 15
years! I replaced the relay with a new WR-90 waveguide relay connected to my
horizontally polarized linear feed and proceeded to look for echoes with 100
watts in the shack earlier in the week. The results were zero echoes. So I
decided to take my WR-90 directional coupler and move it to the feed. Well I
was only getting less than a watt at the feed. After taking the waveguide
apart in sections, I found water had leaked in. I decided to use the air
hose to see what else was in the waveguide and much to my surprise I found a
couple handfuls of grass had been forced out. Well it turns out that when my
system is not operational, any bug or critter that enters the feedhorn has a
free ride back to the TWT where there is a pressure window! With the new
system, the normal non energized mode is now in the receive path so about as
far as some critter can go now is the LNA. But I also put in a cellophane
cover over the feedhorn. Despite all the hassles during the week, I was able
to work IQ4DF, G4NNS, HB9BHU, F5JWF, K1JT for state #15, OK1CA, ES5PC,


24048 MHz

2.4 meter offset fed dish with 100 watts at the feed

This was really the only band that did not require any work before the
contest. It worked flawlessly. As a result, I was able to work DF1OI and


Well it was a good weekend as I was able to work LX1DB on all 5 bands from
2304 MHz through 24048 MHz! Thank you Willi!

The contest wore me out but it was a lot of fun. I was wondering how the
folks would feel about expanding the microwave part of the ARRL EME contest
back in to August making it a August and September event?? I am going to
suggest this to KX9X and the ARRL's VUAC committee. If you have some
thoughts on this I would suggest including your comments in your soap box
when you submit your score or write KX9X direct at kx9x at arrl.org and he can
forward on your comments to the VUAC for recommendation to the ARRL's
Membership Services Committee who ultimately approves changes to contests.

Looking forward to the next microwave EME event!

Best 73 de W5LUA EM13qc


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