[RFI] Recent 40 Meter AC noises?

Paul K. hglent at frii.com
Thu Aug 30 12:35:23 EDT 2012

The past few weeks, not only me, but several folks I talk to around 
7.260 in the mornings have complained about a "AC hum."  I have watched 
this hum on the panadapter.  It appears to be spread evenly across the 
band, no peaks or dips.  On the panadapter the spikes appear at about 
120Hz interval, about 3 to 6 dB above the noise.  I have rotated the 
beam and found the peak level to be approximately 135 degrees.  It has 
been confirmed by a station in western Missouri, central Indiana
and Annapolis Maryland.  This noise has been present nearly every 
morning for the past 2 weeks, but I did not hear or see it today.

When this is on it does not sweep or pulse.  It is just simply present. 
I believe due to the wide spread reception of the exact same noise by 
stations in vastly different areas the possibility of something locally 
to any of us is highly remote.

So the curiosity is up.  What do you folks think we are hearing, and are 
any of you hear other reports about it.


Paul K.

Paul K. WA0BAG

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