[amsat-bb] SatPC32 Doppler problem

Mark Johns mjohns166 at yahoo.com
Sun Oct 23 17:32:53 UTC 2016

Thank you to all for your responses.

I've been out of town, so I haven't had the chance to check other satellites besides FO-29 (and AO-73, but that one is always shifting around due to issues with the satellite). I'm going to try more experimenting with Pedro's Doppler.SQF line and Erich's correction procedure. Yes, I've checked location and time, and they are all as they should be.

I do have a theory that something has become corrupt in the program files themselves, and I'm going to try a new download and clean installation of SatPC32 to see if that fixes things.

Mark D. Johns, KØMDJ 
Decorah, Iowa USA  EN43
"Heaven goes by favor; if it went by merit, 
   you would stay out and your dog would go in." 
     ---Mark Twain

----- Original Message -----
From: Erich Eichmann <erich.eichmann at t-online.de>
To: Mark Johns <mjohns at luther.edu>; Mark Johns <mjohns166 at yahoo.com>; AMSAT-BB at amsat.org
Sent: Sunday, October 23, 2016 5:00 AM
Subject: Re: [amsat-bb] SatPC32 Doppler problem

Hello Mark,
try the following:
Track a FO-29 pass and find your signal using the "Upl. Corr." up/down 
controls in menu "CAT". Fine tune the uplink for best audio (best around 
the middle of the pass).  Then click the "Change/Store Data File" in  
menu "CAT" and in the little window that opens click on "Upl. 
Correction". That will save the correct uplink frequency. That is easier 
and more reliable than to enter observed frequencies manually in 
Doppler. SQF.

At the next program start you should immediately hear your signal. 
Little  deviations (100 ... 300 Hz) may remain due to temperature 
differences at the sat or the radio. You can easily correct them using 
the +/- keys of the numerical pad with a few hits in steps of 100 Hz. 
(The keys work only if SatPC32 must be the active program  - blue header 

73s, Erich, DK1TB..

Am 22.10.2016 um 22:32 schrieb Mark Johns via AMSAT-BB:
> For some reason, my SatPC32 has stopped correctly compensating for Doppler shift on FO-29. I'm continually having to "find myself" all over the passband, making adjustments throughout the pass, just like the old days when everything was manual.
> I've updated the Keps. I marked the uplink and downlink freqs at time of closest approach on a high-elevation pass, and re-edited my Doppler.SQF with those numbers.
> SatPC32 is talking to the rig, and it does make regular changes to both uplink and downlink frequencies -- they just happen not to be correct.
> I'm stumped! Any thoughts?--
> Mark D. Johns, KØMDJ
> Decorah, Iowa USA  EN43
> -----------------------------------------------
> "Heaven goes by favor; if it went by merit,
>     you would stay out and your dog would go in."
>       ---Mark Twain
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