Is anyone familiar with what might cause an intermittent loss of AF signal in a Sennheiser wireless mic set (ew100)? The guide recommends lowering the squelch and checking the pilot signal. I've tried both. The squelch on the receiver is on low (the lowest setting) and I've experienced the same problem both with and without a pilot signal. Turning the mic (transmitter) off then on again restores the signal back to full strength but then the signal will degrade along with the volume to nothing, necessitating another restart of the mic. I've tried changing the channel and frequency too but the problem would still occur. Then mysteriously the problem will dissapear and the signal will be fine for an hour or two. Note the rehersal space is tiny and I'm very close to the speakers and the receiver. Any ideas?