[RFI] Frequency-Specific Interference

[Scott Yost]

Gentlemen:
 
One hope I had for my post has possibly been answered -  a source for an HF DF setup.  I did not know about the National HFDF
system.  A call is in to National
regarding ordering a unit, right now.  Thanks for the tip, KB4T.
 
Secondly, as KD7JYK pointed out so well, there are indeed
clues in the detail I shared in my first post that could help narrow down this
search.  Since time is a precious
commodity, it seems prudent to focus the search.  Very well put, Kurt.  
 
Along that line I still hope for someone to weigh in with
information from a similar experience with such a frequency specific HF arc
source.  What kind of device makes an
arc-like noise, yet is so defined in its spectrum?  And the fact that it avoids the amateur bands seems like a clue
in this age (hopefully waning) of BPL.  A full description of the frequency range is in my original post.  
 
Please continue sharing ideas and tips.  
 
73 and thanks,
 
ScottNM8R