Greetings. I wanted to ask if it’d be possible to switch the NOAA-9 136.77 MHz observations from FM to USB since on FM demod nothing can really be heard.
Me and a few other people are currently collecting as many samples of the stray beacon carrier as we can and analyzing it to hopefully better understand the state of the satellite, and USB samples from SatNOGS would be of a huge help to us!
As it turns out, there isn’t actually a USB demodulator flowgraph. The closest would be the BPSK flow-graph, which will put the signal at a 12 kHz IF in the output OGG file.
Do we know what modulation the beacon is meant to be?
I’ve just switched the beacon modulation to BPSK in the DB, which is possibly closer to the truth anyway.
The beacon should if the transmitter was working (which really is far from the case) be split-phase PSK with a carrier, just like DSB on current NOAA POES satellites.
Since we’re mostly looking at how it behaves to understand how it may be affected, the best would be,if possible, I/Q wavs. (something like 10k sample rate would do it).
Short of enabling IQ recordings on your station, the 12 kHz IF recordings you get using BPSK are probably suitable. That should contain the entirety of the beacon signal.
Thanks a lot, the BPSK recordings are way more useful than FM, since they actually show the signal itself unlike only its intensity that could be read from FM!