I have a wireless mic (Shure SLX4 receiver) set up where the receiver is in one room with the 2 antennas extended with a 75' BNC cable into the main room and sitting about 15 feet apart suspended from the ceiling. We're finding that as the speaker moves around the main room, the receiever switches from antenna A to B. During this switch, the signal gets dropped, and sometimes the switch takes 2 or 3 seconds. The distance from the presenter to the antenna is approx 60 feet and they move around in a 10 foot circle. The line of sight is clear and there are no other wireless systems in the main room. Fresh batteries are always used and the presenters don't have cellphones on them. Any thoughts on why the antennas are switching and what I can do to combat the dropped signals?
By placing the antennae 15 feet, you are defeating the purpose of a diversity antenna system. If, in fact, the Shure is diversity. The antennae should be closer together. This will result in fewer RF reflections of the sort that can confuse the antenna system.
Secondly, I would move either the receiver or the antennae closer to the presenter and cable back from there. This will improve your odds of a solid signal.
Thirdly, you could also try directional shark fin receiving antennae to improve reception.
If the transmitting antennae are very flexible and flop over, try belt-mounting the transmitter so the antennae droop down, but straight. Make sure the receiver antennae are also vertical.
Thanks for those suggestions Ty! I'll try those and see what happens. For now, I just unplugged antenna "A" and it seems to be helping. Perhaps that distance between the antennae was causing an RF reflection issue like you said. I'll look into those shark fins. I know some other people that really like those results.
The antennae are hanging vertical from the ceiling, and the wireless mic is a hand held, so no drooping transmitting antenna. Our next step is to try and move them out further into the room, but it's a solid concrete ceiling so that gets a little difficult! I have noticed that it doesn't seem to be a distance issue as I can go 30+ feet farther away and not have a problem. There seem to be two or three 2' diameter spots that have issues.