[amsat-bb] AO-92 1626UTC 7/12 PASS CAMERA TEST

[Alan]

Christy,

Nice problem, usually, to have a crowded sky. ;) That is a tough geometry. I
had a similar problem with my earlier pass due to a thick stand of trees
which attenuated the AO-92 signal. 

You didn't mention your equipment. The typical Elk/Arrow has a wide
beamwidth, which is normally ideal, but makes it hard to reject a second
signal in the same general area. If you have an antenna with a narrower
beamwidth, you can sometimes reduce the interfering signal while still
getting a usable signal for the target by careful pointing. FoxTelem with a
FCD does a great job, but as you know it can be "spoofed" by a much stronger
but similar signal. You can manually "steer" it a bit. 

I have a system where the dongle feeds SDR#, and then audio to FoxTelem.
This does allow you to narrow the RX passband, and tune precisely to the
desired signal. You can ignore CAS-4B so long as it is near but not
overlapping AO-92, which sometimes happens due to Doppler. You do need to
keep AO-92 carefully centered, either manually or with computer control.
This general approach is discussed in the FoxTelem manual.

While not hard, this approach is a bit more complicated, and may not be
justified for very occasional work. Fortunately CAS-4B seldom causes a
problem with the normal transponder downlink.

73,

Alan
WA4SCA




<-----Original Message-----
<From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of christy
<hunter
<Sent: Thursday, July 12, 2018 12:36 PM
<To: amsat-bb at amsat.org
<Subject: [amsat-bb] AO-92 1626UTC 7/12 PASS CAMERA TEST
<
<I was hoping to get a partial decode on the camera test this am, but
<because it was a low pass (6deg) for me, the stronger signal from CAS-4B
<(also overhead at the time) high speed telemetry signal captured the
<telem decoder. Is there a way to prevent these stronger signals from
<over-powering the telem decoder AO-92 target frequency? (Don't read this
<as a complaint as having too many satellites)
<
<thanks, 73 Christy KB6LTY DM14
<
<
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