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?
Ron W5RKN
Ron,
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.
73s,
Alan WA4SCA
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ronald G. Parsons Sent: Wednesday, August 31, 2011 4:15 PM To: AMSAT-BB 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?
Ron W5RKN _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Alan, For the last week or so we have been observing it come out of eclipse. I have noted at worst, a very slow 40Hz shift as ARISSAT1 warms up. I update the TLE's every day for ARISSAT1 (possibly an overkill) but it is always within +/-20 Hz at AOS that you quoted. 73 Colin VK5HI.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Alan P. Biddle Sent: Thursday, 1 September 2011 07:01 To: 'Ronald G. Parsons'; 'AMSAT-BB' Subject: [amsat-bb] Re: Has the ARISSat-1 CW-2 frequency shifted?
Ron,
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.
73s,
Alan WA4SCA
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ronald G. Parsons Sent: Wednesday, August 31, 2011 4:15 PM To: AMSAT-BB 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?
Ron W5RKN _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
participants (3)
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Alan P. Biddle -
Colin Hurst -
Ronald G. Parsons