Keying a gm350
 

On a Motorola GM350 4 channel is there a way I can key the radio to
transmit through the microphone socket ? I know pin 6 is the PTT line
is it a case of shorting 6 to 0v ? The microphone has a circuit in
it ! I dont intend to use the fist mic and want a reome way of
putting
the radio into tx.