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

Kevin M n4ufo at yahoo.com
Thu Sep 19 20:31:11 PDT 2013

Adding to Drew's comments...

A.) Reception is poor. Especially high elevation passes.

 Yep I hear SO-50 better with an IO antenna mounted on my HT sitting
 in the shack than with my fixed elevation yagis mounted outside
 when the bird is overhead. I can twist and turn the HT to match the bird

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.

If it is just yourself you cannot hear then your 2m transmit is likely wiping out your 436 receive. (The third harmonic of the transmit is 437.55) You might try adding some filtering. Look at using a  2m/440 diplexer on one or the other side. (or both) Better yet, try backing power down to 5 watts and see if you don't hear yourself better. But it more sounds like you just have a general receive problem...  the cable between the antenna and the preamp can matter. Like I said, I hear better with an HT mounted antenna. If I were to add even a couple feet of coax between the HT and antenna, that would change.

As for fading... SO-50 is in a slow tumble.  I will lose the bird for a minute and then it comes strong for a minute... then it fades again for a minute. If there is a station I want to work, I have to hope I can get a chance to call when the bird is strong to me. But if I call when the bird is weak, I will still be heard by others... SO-50 'hears' quite well, even if you don't hear it.

Best go back to basics... build yourself a 'CJU' antenna (contact me off list and I can send you a link to plans a pic of mine; some 12 gauge solid copper, a piece of pex pipe and a short piece of coax with a BNC) and try listening with a handheld. As I say, on overhead passes, I have to turn on the HT and listen that way until it gets to the 'other side'. So what you are finding is fairly normal... Simply put, SO-50 is not easy to work with fixed elevation antennas.

73  Kevin N4UFO

"Control is the need of the fearful mind. Trust is the need of the courageous heart."

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