You and me both. I'm still looking for an article I read somewhere where it was reported that when the tower near the prison was examined, all that was found was a bunch of fine silver wires. Not being able to find it again is driving me crazy. I have it in my head that a method of communication that could not be traced was being used and it's not a huge leap to imagine who by. It will be a eureka moment when I find that story again, let me assure you.
I haven't read the entire thread, and I hope the story on the silver wires is found. It could someting as simple as chaff, thin aluminum coated threads that the military drops to jam radars and to short out power grids. It could something more, which brings me to my point.
Berg was involved in low power FM. With low power I would assume you would want to maximize your reach and you can do that with propagation of the radio waves, bouncing off the troposhere, sunspot activity, etc, which he would know something about. As a kid I remember talking by a standard CB radio in Iowa to Key West because of sunspots.
It has been said that Berg traveled (and worked?) at night. Some frequencies propogate better at night, that's the reason some AM stations go to lower power at night. There are hobbyists that use various methods to get propagated radio signals from around the world, including lengths of bare wire on the ground to shooting a wire with a bow and arrow up a tree. On a metal tower you would want insulated wire so it would be interesting to find out more about the wire they found.
Now the tinfoil hat question some experts might be able to answer. Can military signals be intercepted from a safe distance using propagation? What about low power walkie talkies like might be used by prison guards?