[RFI] 17 mhz - 25 mhz - Distorted audio every 250 khz

[Aaron Kreider]

I recorded this RFI. It is about every 250 khz. Sounds like a distorted 
tv station.  It is distorted in both AM and FM.  It might be coming from 
one of the TV cables near my antenna or someone's tv.  It is fairly 
irregular.  Typically on late at night (10pm - 2am local).

https://www.youtube.com/watch?v=8soxjbT4uUg

I originally thought this could be from undersampling of the QS1R (a 
strong signal getting past the low pass filter), but I also heard it on 
my portable shortwave radio.

What could this be?

Locally we have Comcast.  Have they moved to a purely digital cable 
service?  If so, I'm guessing the TV audio would be digital as well.


Aaron
Philadelphia, PA.
QS1R
Wellbrook 1530 S+ (two of them) and a Quantum Phaser