I have been getting interference and I need some help identifying it.
It is intermittent, a static-like sound, occurs both day and night on
HF from about 5mhz through 30mhz.  It pulses on and off, on about 1
second and off about 10 seconds.  Signal peaks in strength, S9+10db,
just below 20 meters, but also peaks at that level around 9.85mhz and
11.85. These periods last about 20 minutes, with the cycling rate going
to about 3 seconds on and 3 seconds off in the last minute before it
quits. The time lapse between the sessions of interference varies.  
  I have eliminated my environment as the source.  Weather here is cold
with snow.  Last winter I went through a similar situation. I have no
idea of what could cause this, except maybe a neighbor's electric
blanket or maybe an electric heat tape?  I really have no idea if these
items can do that. Any ideas? 
 I do have a Sprague Model 700 interference locator here but no
antenna(s) for it, I have never used it but I'm sure I can figure it
out. What kind of  antenna can I make to help sniff out this irritating
problem?
  Any help will be greatly appreciated.
  
  John  N0EE


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