try taking a look at the ubiquitous 555 timer chip - one could rig the thing
so that it would key up a radio upon recieving a carrier that was above a
certain level - something like taking the signal from the s-meter and using
it for a trigger signal works real well, and ensures that only the local
area gets qrmed. naturally, the interval it keys up for is up to the
builder, with the 555. Another interesting thing is , that if this is placed
real close to the guy's house, very little power will be needed to operate
it. a motorcycle battery would last a long time at a 100 milliwatt
level.......... and if close enough, would give him 20-over s-9. Think i
remember someone doing this once, but cant remember just who it was... G