NOAA 9 was one of the early NOAA polar-orbiting weather satellites which was launched in 1984. The last contact was in February 1998.
However, it has recently been broadcasting during daylight with a narrow constant frequency. This is most likely due to the solar panels still functioning but the batteries have failed and become somewhat conductive, meaning that it is still able to broadcast one (or more) carrier wave(s) of the frequencies it could transmit at.
However, don’t get too excited. Because the satellite has lost it’s orientation system, even if the AVHRR (Advanced very high resolution radiometer) powers up and sends data, none of it would be useful due to the lack of stabilisation because of how the instrument functions.
It has previously been transmitting, with a video on YouTube showing it emitting signals at two frequencies.
One of the moderators, https://www.reddit.com/user/derekcz/, is looking for data captures from this satellite with the discussion being available to be read at https://www.reddit.com/r/amateursatellites/comments/h91qp8/looking_for_noaa9_recordings/.
The writer is requesting for people who can capture the data to provide him with the data to try to better understand what the satellite is doing and if there could be any useful information obtained.
We’ve set up WxCapture, our satellite data capture solution, to download passes that NOAA 9 makes over New Zealand, despite them probably not containing any usable data. This means we will only be saving the audio file and will not be processing it automatically, as we usually do with satellite passes.