Mounting Multiple Carkit Antennas
Interference to a GCK-1410 carkit will occur if more than one carkit antenna is hard-mounted (not using the mag mount) to a metal surface or if a carkit antenna and GSP-1620 antennas are all hard-mounted to the same metal surface. The problem appears to be caused by common grounding of carkit antennas and /or GSP-1620 antennas. Common grounding does not affect the GSP-1620s; it only affects the GCK-1410 carkits.
To prevent interference to the carkits, all antennas must be isolated from a conductive mounting surface, and the coaxial connectors must be isolated from each other. Since the carkit antenna rests on the radome, and the metal base of the carkit antenna does not touch the surface, it is very easy to isolate the GCK-1410 carkit antenna from the mounting surface and the other antennas by simply using nylon screws to attach the antenna. To isolate the SDM antennas from the common ground, a non-conductive material must be placed between the antenna base and the mounting surface, and nylon screws must be used.
If two or more carkits are to be installed together, the coaxial cable connectors of one carkit must be isolated from the connectors of the other carkits.