This reminds me of an experience that a local radio station engineer witnessed years ago in the mid-late 1940s or early '50s.
An experimental one million watt radio broadcasting tower was setup in the eastern US and they discovered one wedge shaped area was only receiving some weak signals.
So they set out from the broadcasting antenna in the direction of the weak signal looking for the cause. Some miles out they discovered that some enterprising scout leader had setup a huge wire antenna grid and it was being used to capture the powerful signal to power their scout camp. Pretty clever.