[amsat-bb] Flex 5000a FM tone issues

Alan wa4sca at gmail.com
Thu Apr 14 23:37:10 UTC 2016


While not normally recommended, as a test try working SO-50 in half duplex rather than full duplex and 
see what happens.   There is a very peculiar buffer issue which can cause bad audio in full duplex.  If 
that is it, there is a work around.

Question about your comment about building an FM repeater filter.  Are you referring to the Transmit 
tab, Transmit Filter?



<-----Original Message-----
<From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Jeff
<Sent: Thursday, April 14, 2016 5:52 PM
<To: Amsat <amsat-bb at amsat.org>
<Subject: [amsat-bb] Flex 5000a FM tone issues
<I?m working my way through setting up my Flex 5000 for satellites. I?m very happy with the
<performance on the linear bird?s , but having some issues with AO-85, and SO-50. After getting some
<bad audio reports on SO-50 yesterday I tried to work the problem out with someone on a local repeater
<who was familiar with my voice. After a few minutes it became very clear that it was a CTCSS tone
<issue as simplex performance was excellent. I thought about this a minute and came to the realization
<that there might be a TX filter in play, and discovered, yes it was set to a default of 150 to 2700.
<Obliviously not FM values. So just before the last pass of AO-85 I quickly built an FM RPTR filter of
<50 to 4k and saved it. It worked a bit better on the pass but I still had obvious issues.  Anyone have 
<ideas what the issue might be? I?m thinking a tone level issue, but after goggling I found  issues with
<CTCSS was too HIGH of a level. Any suggestions welcome...
<73 Jeff kb2m
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