Lightning strikes are great broad-band radiators (remember the
old spark-gap transmitters....) You actually can use a TV set (not
connected to cable) as good lightning detector. Just tune it to a
channel that is not used in your locality. Lightning signals produce an
easily recogized video "noise" burst on the screen. Because of the
line-of-sight nature of the RF at TV frequencies, the set responds only
to relatively near strikes (as opposed to an AM radio where the static
crashes from lighting strikes can be from quite large distances.)
Cheers,
Dr. Mark H. Shapiro
Physics Department
California State University, Fullerton
Fullerton, California 92634