[amsat-bb] Re: AO7 calibration

Alan wa4sca at gmail.com
Mon Nov 18 11:43:54 PST 2013

Hi Bob,

There are many reasons why the transponder "constant" varies somewhat.  The temperature of the
satellite is somewhat dependent on sun angle, periods of eclipse, etc.  This usually results in a slow
seasonal variation, most frequently seen in SSB satellites, but also in some cases in the FM birds.
In the case of AO-7 there is no battery to stabilize the voltage, so at some (most?) times the 39 year
old arrays may not provide enough power for a completely stable output.  I recall an article on the
subject in the AMSAT Journal, though I don't have it handy.  



<-----Original Message-----
<From: amsat-bb-bounces at amsat.org 
<[mailto:amsat-bb-bounces at amsat.org] On Behalf Of Bob- W7LRD
<Sent: Monday, November 18, 2013 11:00 AM
<To: amsat-bb at amsat.org
<Subject: [amsat-bb] AO7 calibration
<Hello...More often than not I have to "adjust" the up link 
<calibration on satpc32 in order to accurately track the sat. 
<It is not always the same adjustment, it can vary from a few 
<cycles to as much as 2.5 khz. Given AO-7 is a grand old lady, 
<is she just being temperamental, or do I have an issue 
<(operator error). 
<73 Bob W7LRD 
<Sent via AMSAT-BB at amsat.org. Opinions expressed are those of 
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