The info below is full of estimated guesses... I'm no expert!
I was monitoring a failing ham satellite (I suspect) TO-108). It seems to transmit only when receiving sunlight. As it seems to be tumbling or rotating, the ystem seems to restart each time. It does transmit BJ1SV in morse code, so that confirms its origin...
Now, while doing that, I heard short bursts of another signal. Only after widening the waterfall range (a lot) did I notice that the signal is actually drifting - quite rapidly - in a downward direction, over a range of over 1MHz. Here are some characteristics:
- The scan range and speed varies randomly
- I can't find any modulation, though there seem to be frequency jumps
- I've been looking at the sig for more than an hours, which would exclude the possibility of a LEO satellite (which would mostly limit the visibility to about 14-15 minutes, though the repetitivity could also indicate 'tumbling' and sun dependency.
- It start at the upper frequency then floats to the lower
- then disappears for tens of seconds
- and restarts.
- the scan range is large - 100's of kHz (not comparable to the TO-108.
- The signal level change quite drastically.
This is an example of such a signal. (Note that the waterfall 'falls': The top is the most recent:
I was monitoring a failing ham satellite (I suspect) TO-108). It seems to transmit only when receiving sunlight. As it seems to be tumbling or rotating, the ystem seems to restart each time. It does transmit BJ1SV in morse code, so that confirms its origin...
Now, while doing that, I heard short bursts of another signal. Only after widening the waterfall range (a lot) did I notice that the signal is actually drifting - quite rapidly - in a downward direction, over a range of over 1MHz. Here are some characteristics:
- The scan range and speed varies randomly
- I can't find any modulation, though there seem to be frequency jumps
- I've been looking at the sig for more than an hours, which would exclude the possibility of a LEO satellite (which would mostly limit the visibility to about 14-15 minutes, though the repetitivity could also indicate 'tumbling' and sun dependency.
- It start at the upper frequency then floats to the lower
- then disappears for tens of seconds
- and restarts.
- the scan range is large - 100's of kHz (not comparable to the TO-108.
- The signal level change quite drastically.
This is an example of such a signal. (Note that the waterfall 'falls': The top is the most recent:
