[RFI] USB qrm - what to do?

[KD7JYK DM09]

I had RFI from a computer installation in a basement to an antenna 135' away
rendering HF useless.  I determined it was coming from the wiring.  I
wrapped chokes (loops of wire, as done since the 1800's, no ferrite) into 
each cable
while listening to the noise and watching it using spectrum analysis
software until the noise could not be heard and was not detectable more than
3" from the rat nest of wires behind the computer.  If a cable was too
short, I added an extension cable, then wound the chokes.  I secured the
wires with twist ties and have been noise free for almost a decade now.

Photos of before, after and choke upon request.

Kurt