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

[Zach Leffke]

We also experienced a good bit of QRM on the the AO-92 downlink towards 
the end of the pass previous to the one mentioned in the subject line 
(~1450 UTC) during our demo yesterday.  We had the same problem (though 
less of an effect) the day prior during testing of our setup, but 
slightly offset in time (the QRM showed up just before the 7/11 ~1515 
UTC AO-92 pass).  Definitely had the doppler shift features indicating 
it was another satellite in the 2m band and close to the AO-92 
downlink.  On the 7/12 1450UTC pass, the interferer was strong enough 
that it 'edged out' the AO-92 downlink and was captured by our doppler 
correction loop (ending the demo, but that was OK because we already got 
a few images direct, and then I jumped to the website to show them more 
images recovered by the community).

We used GNU Radio married to FoxTelem for the passes.  I have the 
recorded IQ files for both passes where the , but haven't had a chance 
to go back and investigate what exactly was going on or hunt for which 
bird was the 'culprit' though now it seems CAS-4B is a good 
suspect......If I get a chance I'll play around with the flowgraph and 
see if I can manually tune in the AO-92 signal and filter out the 
interferer to see if I can recover any more telemetry/camera pieces.

Just offering another data point and similar experiences...



-Zach, KJ4QLP

Research Associate
Aerospace Systems Lab
Ted & Karyn Hume Center for National Security & Technology
Virginia Polytechnic Institute & State University
Work Phone: 540-231-4174
Cell Phone: 540-808-6305

On 7/13/2018 4:29 AM, John wrote:
> Hi Hal,
>
> I too have an FT-847, however instead of programming satellites into the memories, I let SatPC32 'get it right' for me, along with tuning for doppler and handling tones etc. It's a far easier solution.
>
> Otherwise, you could go through the AMSAT OSCAR Status page, and grab all the birds you're likely to want to work from that list.
>
> 73,
> John (XLX)
>
> -----Original Message-----
> From: AMSAT-BB <amsat-bb-bounces at amsat.org> On Behalf Of Hal Dale
> Sent: 12 July 2018 19:09
> Cc: amsat-bb at amsat.org
> Subject: Re: [amsat-bb] AO-92 1626UTC 7/12 PASS CAMERA TEST
>
>   I have a FT847. Anyone have a suggested list of Sats to input in the memory?? Hal/WB4AEG _______________________________________________
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