[RFI] Sources of wideband hiss

[nlsa at nlsa.com]

Dear friends,

What are some sources of wideband hiss?  I'm talking about an unstructured,
apparently unmodulated many-dB increase in the noise floor across the 2m
band*  No associated birdies or other noticeable signals, just a nasty hiss.
I see it in the direction of high-voltage power lines 2km away and also
toward a couple of houses I just a few hundred meters distant.  The
mechanisms of those sources are not necessarily the same of course.  Ideas
welcome.

Best regards,

Michael

 

*I don't know whether it affects other HF or VHF bands.