SECOM II communications system
W Olson · 1978
The SECOM II (SEcurity COMmunications) system is a High Frequency (HF) system which provides two-way digital communications between a central controller and vehicles carrying nuclear weapons and special nuclear material anywhere in the contiguous 48 states. The system operates on four HF frequencies in the 3 to 12 Mhz range. While the primary mode of operation is digital, a voice capability is also provided for unusual situations where additional information must be communicated. Initial system operation began in April, 1976 and the system became fully operational in March, 1977. The system consists of mobile terminals installed in vehicles which communicate with five relay stations. The relay stations are connected with the control center by leased telephone lines. The report describes the operation of the system and the equipment installed in the vehicles, relay stations, and the control center.