Recent WSPR activity on 5MHz has seen power levels reduced to 0dB, 1mW and consistent decodes at distances in excess of 1000Km.
I was pleased to achieve 890Km with 1mW myself, but even more pleased to receive other stations who are running that power level. At this QTH I have high noise levels and a regular almost constant comb of 4 or 5 carriers spaced at 25Hz.
I don't think it is local, i.e. TV's or computers, it seems to come and go with propagation. It threw me the other night when just after 23.00 it went off abruptly. Maybe a TV then. However note the 10 minute break in the screen grab above, then change of format, not consistent with TV or computer use.
This is what the carriers look like on Spectran.
