Have you ever watched static on the analog television after the broadcaster off the air? How about listening to 10 meters on the down side of teh sunspot cycle . . .you know just listening to white nose. I can recall doing that a while back (way back!) when I decided to check my SWR. Instead of going into tune mode, i simply did "aaahhhhhhh" sort of thing. Out the dead band, comes back " You can at least identify your self!"
Turned out to be a station in Colorado. I wonder how often a band is "dead" just because no one is trying. Sort of profound?
