As a general rule... if the RF section is generating an output signal you should remove the transmitter module or extend the antenna.
You can look at the Home screen of the 9Z to tell if it is the RF section is generating output or not. You will see a flashing message that reads ON AIR when it is transmitting. When you connect the DSC/Buddy/Interlink lead the 9Z will come on automatically. It will not be transmitting in this case, so you do not need to remove the module.
Travis