Hi,
I keep seeing some false positives recently - no visible signal on waterfall but some ghosts are decoded.
Examples:
I don’t remember this kind of things from the past. Did something change in the decoder or is it normal and should not worry?
Thank you in advance for the answer 
Feel free to re-vet the waterfall as bad… for some modulations that have a form of error checking we decided to vet them automatically as good observations but from time to time some noise frames are demodulated causing a bad observations to be graded as good.
To be honest I don’t remember seeing this in AFSK but I guess it can happen. No recent change on this demodulator. If you see more let us know in this thread… maybe the demodulator needs some more care.
Thank you for the answer @fredy
In last weeks I saw maybe 10 observations like that, so these are not extremely big numbers. If I come across more, I’ll write them here, sure.