[RFI] AM Broadcast Intermod?

[N4ZR]

I'm embarrassed to admit that I had overlooked a noise-maker in my 
shack, my 1 TB USB disk drive.  I cleaned that up with a few turns of 
the DC power cable around a type 31 toroid, and now I've uncovered 
something under it.  It's a wideband signal (tuning makes no 
difference), but sounds very much like a badly distorted broadcast station.

Just on a hunch, I tried tuning across the AM broadcast band, and found 
a loud AM sports radio station on 1570 KHz that appears to be 
broadcasting the same content - pauses, pitch of voices, etc. all seem 
to match..  Unfortunately, just before I could get set up to record, the 
voices on 160 suddenly went away.  I'm assuming they'll be back, and 
while I wait to get a recording I'm wondering:

*  Does this sound like intermod, or some other phenomenon?

* Is it the result of something wrong at the station?

* If so, how best to approach them about it?

-- 
73, Pete N4ZR
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