A couple of things from experience... First, cable internet service does use HF frequencies. I forget which direction is down there, but one is.
Second, your power company is a rare find these days. Ten years back it seems most truimmed the "fixit" guys to cut expenses. I've gone thru it with two power companies now. Time was when all power companies did just that, look for problems. If it is an insulator breaking down, for example, that's current being spent that isn't being billed to anyone. Add up enough of it and its real money to them. but wideband noise like that may not be power company related. Here at my place I've had that now for a few years, making HF pretty useless. But don't discount wall warts. Most of them now are switchers, and make lots of noise. Just not wideband constant level noise so much. And since the energy bill last year, more to come, the feds now mandate efficiency of those things. My two cents. GeorgeC W2DB
