I just replaced the battery to be certain. It doesn't happen all the time--but the issue crops up annoyingly often. One moment it will work, and then the five minutes later-nothing. I'm absolutely baffled that in passive mode, of all things, it emits no signal whatever...even my tuner can't detect a signal, but it works fine in both of the active positions. If anyone can shed some light on what may be going on here I would be extremely grateful!