[amsat-bb] Opinions on improving receive for portable ops

Ka9p at aol.com Ka9p at aol.com
Fri Mar 10 17:24:51 UTC 2017

I've just started getting on the linear transponders in the last month or  
so after a 30 year absence from sat work, necessarily with a portable setup, 
and  would be eager to hear experienced opinions on what to do next to  
improve receive.
I'm running Cheap Yagis on V(3 el) and U(6 el), diplexers, about 10 feet of 
 RG8X, and receiving on an FT817 or 897, usually on FO29 and the XW's,  and 
have up to 25 watts available for the uplink.
Q's are:
1) with those radios and only about 10 feet of feed line, will a preamp  
help much on 432?
2) If it will, is the 50$ preamp on the AMSAT site a good start? Or?  and
3) With relatively short yagis, will it make a noticeable difference going  
to circular polarization?  
WRT to 3, I've pretty much exhausted what I can find the internet, but just 
 don't have a pragmatic sense for what it will do in terms of evening out  
reception over, say, an FO 29 pass - I read that you nominally lose 3 dbs  
most all the time but may pick up a lot on the deep fades, but still not sure 
 how that translates to the real world.
Or is the answer that the set up is marginal enough I need to do it all of  
the above if I want reliable communications above about 5 degrees or so?
Thanks for the bandwidth and any input.
Scott ka9p

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