SCA-124 Communal Aerial System is designed for listening radio and watching TV satisfactory in any direction at sea and the omni-directional antenna and whip antenna are made of solid material in consideration of hard marine environment at sea. The multi-amplifier built in main unit enables to cover AM, SW, FM, VHF and UHF band and adopted AGC (Automatic Gain Control) circuit to prevent the rage of a weak electro-magnetic wave.