[amsat-bb] SO-50, IC-910H, and Sat PC32 Issues

Les Rayburn les at highnoonfilm.com
Thu Sep 19 10:23:33 PDT 2013

Before I ask again for assistance, I'd like to say that I've read the 
"manual" for both the software and the rig, experimented, and tested on 
my own trying to resolve these issues. This includes staying up well 
past midnight so that I can run tests on the bird without bothering 
other users too much.

Here, briefly is a description of my station, and the issues I'm 
experiencing. Any assistance or advice in resolving the problem would be 
gratefully accepted:

Running an Icom IC-910H into antennas in the attic. The 432 antenna is 
an Arrow 7 element Yagi, mounted at a fixed elevation of 25 degrees. The 
2 Meter antenna is a 6 element K1FO Yagi, mounted horizontal. Both can 
be rotated on the stack in azimuth only. Feedline is 75' foot runs of 
1/2" hardline with antennas mounted in the attic.

The 432 antenna has an ARR mast mount pre-amp, while the 2 Meter antenna 
has an SSB Electronics mast mount pre-amp. Performance on FO-29, VO-52 
is fair to good. High elevation passes on all satellites seem to give me 
reception problems, but down nearer the horizon things are good. Hoping 
to upgrade to AZ/EL in the near future.

I've learned how to deal with Doppler on the other birds, and generally 
can used the stored corrections in SATPC32, or adjust it on the fly 
using the software to hear my own downlink well, and work other stations.

However, on FM I continue to struggle.

A.) Reception is poor. Especially high elevation passes.
B.) Successful reception of other stations requires adjusting the RIT 
control on the rig. Often to "plus" 5 KHz and sometimes to somewhere in 
between 0 and +5 Khz.
C.) Switching the rig to FM Narrow mode helped, but did not resolve the 
D.) Attempting to adjust for Doppler using the software control doesn't 
seem to help much.
E.) I can only rarely hear my own downlink on this satellite, even in 
the middle of the night when the bird is empty.
F.) Numerous reports of others calling me without success, even though 
I'm getting into the bird fine.

I realize that polarity is an issue with all satellites. Signals arrive 
out of phase, and I have no way to compensate. Also having a fixed 
elevation is a problem, and explains the poor performance at high 
elevation. But I fail to understand why the system seems to work well on 
other birds, but not SO-50. What am I missing?


Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114

6M VUCC #1712
AMSAT #38965
Grid Bandits #222
Southeastern VHF Society
Central States VHF Society Life Member
Six Club #2484

Active on 6 Meters thru 1296, 10GHz & Light

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