[RFI] Noise on 40

[Roger (K8RI)]

A few nights ago I fired up on 40 which of course was loaded with QRN. 
The band appeared to be open world wide, but the QRN was too much for an 
SSB contact.  Tremendous static crashes, but between 7.150 through about 
7.180 appeared to be a broad band signal.  It sounded like plain old 
receiver "hiss", and the scope on the 756 Pro did show peaks and valleys 
with a rather sharp roll off just above 7.150 and just below 7.180.  It 
would come and go with a typical duration of 3 to 5 minutes IIRC.  Start 
and stop were as if some one had thrown a switch.  I heard it late one 
night since then.  It takes a very strong signal to be heard over it.

Any idea as to what it is/was?

73

Roger (K8RI)