[amsat-bb] Re: Has the ARISSat-1 CW-2 frequency shifted?
Alan P. Biddle
APBIDDLE at UNITED.NET
Wed Aug 31 14:30:43 PDT 2011
I have been catching a couple of passes a day for TLM since deployment.
After the initial tweaks, is has been consistently within +/ 20 Hz of the
predicted value. I haven't seen a large jump, though I did tweak it down 20
Hz yesterday to refine my initial values.
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
Behalf Of Ronald G. Parsons
Sent: Wednesday, August 31, 2011 4:15 PM
Subject: [amsat-bb] Has the ARISSat-1 CW-2 frequency shifted?
A couple days ago, I noticed that to get a 500 Hz signal for CW-2 (nominally
145.9190 MHz) to decode the BPSK-1000 signal, I had to change the
unDoppler-shifted frequency on my USB receiver from 145.918500 MHz to
145.918280 MHz, a change of 220 Hz.
This new value have been consistent over a couple days of careful watching.
I don't believe it to be an error in the keps or clock as it has been true
both at the beginning and end of the pass. My receiver has been on for over
a month, so unless a component changed value suddenly, ....
Has ARISSat-1 changed, has my radio changed, or does only my hairdresser
know for sure?
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