Passenger microphone muting circuit

Over the last few years we have been able to get our bike-to-bike VHF communication to work well. The only issue is that at highway speeds there is a lot of wind noise. When the rider is talking the passenger microphone is also 'on'. A theory I have is this open microphone is a large source of the extra noise.

I decided to try the above circuit to see if it would lessen the wind noise at high speed. It's a simple circuit. The passenger microphone line is ran through the 'normally closed' contacts of a relay. When the driver pushes the PTT switch on the radio it applies a ground to the relay coil and makes the relay switch to the 'normally open' contact and disconnecting the passenger microphone.

This circuit has worked in the garage setting. The passenger microphone is completely silenced. As it is tested in the real world I will report my findings.

E-mail me