Antenna Cable Kit - 20M: Iridium's mast antenna cable - 20-Meter - Antenna cables for the Iridium passive Mast Antenna. The cable is made of high quality LMR 240 and each end of the cable has a male TNC connector. The Iridium Mast Antenna is sold separately. These cables cannot be used with active antennas. Installation and Weather Proofing: During installation, be very careful to avoid sharp bends in the coaxial antenna cable which increase signal loss. It is important to weatherproof the exposed connectors between the Mast Antenna and the antenna cable. This prevent moisture and salt water intrusion into the connection which can cause corrosion. For most applications, we recommend Coax-Seal Tape (hand moldable plastic) as a reliable weatherproofing product.