  Tx INHIBIT ON BUSY CHANNEL


  This option, when enabled, prevents the radio from transmitting on a PL
  channel if the radio is receiving a carrier with no PL, or a carrier with
  the wrong PL.  Receive PL must be enabled when enabling Transmit Inhibit
  on Busy Channel for the feature to operate properly.
  
  NOTE: Tx Inhibit on busy channel can only be enabled if CHANNEL SCAN 
        and EMERGENCY (Digital Signalling feature) are set to NONE. 
