This paper will discuss trends in compatibility issues between radio systems and Tactical Vehicle on-board systems which have been identified as potential interference sources and discuss electromagnetic compatibility (EMC) between co-located radio systems. All Tactical vehicles have electronic systems which come as part of the base vehicle, such as lights, air-conditioners, wind shield wipers, etc. all of which have the potential to disrupt communications. To further complicate the radio frequency environment today’s tactical vehicles are being outfitted with new sophisticated technology such as programmable communications systems, sensor systems and remote weapon stations. The new systems are complex and are subject to emitting and absorbing electromagnetic radiation which can severely degrade radio system performance and cause inadvertent electromagnetic fratricide.