purchased a new PC Monitor this week. after choosing carefully for a known manufacturer to hopefully eliminate any QRM.
I purchased a Philips make. after setting it up at the shack it was time to check for any QRM.
the only place I cold find any was on 28MHZ. a sharp rasping buzz. out with the AM receiver, yes it is the PSU inline with the power cable. I added some clamp on ferrites, still no good.
I then added a ft240-43 toroid on the output lead and added some clamp on ferrites to the input lead.
hey, noise eliminated.