Faulty/Oscillating Preamp?


We had some thunderstorm activity here a few days ago and I think the preamp for my UHF station has suffered some damage.

Intermittently, perhaps tied to being cold (under about 15C), it seem to get some sort of weird oscillation/frequency shift artifacts such as shown in this waterfall; http://network.satnogs.org/observations/3415495/

by contrast previous good observation on same station https://network.satnogs.org/observations/3381838/

with some imagination I can sorta see a good signal at the start of the 3415495 pass and again at about the 650s mark - but might be optimistic :slight_smile:

Anyways - before I delve too far into it, just curious if anyones seen similar waterfall displays. Have already confirmed similar behaviour on two different SDRs


Other “bad” passes include