[RFI] New unidentified QRN source

[K4RO Kirk Pickering]

I've got some strange new QRM on the HF bands.  It is quite 
strong on 40meters, but it's also audible on other bands as
well.  It is coming in from the street powerlines I believe,
as it is extremely strong right at the house mains power usage
meter.  The noise is still fully present on a portable radio 
when the house main breaker is thrown, so I'm pretty sure it's 
not in my home.   The interference is very loud, and seems to
be present 24/7.  It does seem to move around a bit, favoring
the 40 meter RTTY frequencies (7.070-7.100) 

Any help identifying it would be greatly appreciated.  
A recording is available at the following URL:  

http://www.k4ro.net/k4ro/audio/K4RO_40m_QRN.mp3

Thanks for any advice.

-Kirk  K4RO