About the COM3 MIC button

   
         
   

40 channel UHF FM Transceiver

   
         
    Pressing the COM3 MIC button selects the Com 3 transmitter and receiver.    
   

Check that the DU button on the front of Com 3 is OUT

   
         
    When COM3 MIC is selected, pressing COM1 and COM2 simultaneously monitors Comms 1 & 2 but transmission is only on Com 3    
         
    The COM3 MIC indicator light blinks while the Com 3 transmitter is keyed on    
    Include these indicators in your panel scan to detect inadvertent transmitter activation