Hi, I've just borrowed a VHF microphone, and the receiver takes two microphones (channels A and B), both antennas are slightly damaged, channel A more so. The channel B microphone works perfectly, when the channel A mic is switched on the light on the receivers comes on to indicate the mic is active, but there is no sound output. Is this likely to be an issue with the antenna or mic? Any ideas on how to fix it? Thanks!