Lightning Detector Remember this tip during thunderstorm season: A radio tuned to a clear chann- el at the low end of the AM band makes an excellent lightning detector. You can usually hear the characteristic lightning crackle on the radio long before you hear the thunder or see the approaching darkness. When you hear the static, it's a good time to save your program, shut down and unplug. It's not very likely that lightning will damage anything, but you're better safe than sorry. Don't forget the modem-its a good idea to unplug it from the telephone line.