The above article is a must read. Here is the story of testing what would become Paul Brown and the NFL's first radio system:

The inventors carefully mounted the receiver in a Cleveland helmet and tested it in a secluded area behind Campbell's home. Sarles would wander into the woods wearing the helmet, and Campbell would try to keep contact with him. They found the signal got weak very quickly and, once, Campbell searched all over for Sarles before spotting him talking to a police officer who had located the signal. The officer was a Brown fan, according to a Pro Football Hall of Fame account of the story, and promised not to reveal the radio secret to anyone.
This article features Bum Phillips, Marv Levy and Ditka being a dope, yet succeeding. It has everything.