The Application of Western Union Multiplex to Navy Radio

At the beginning of and during the war with Japan, the wide expansion of operations in the Pacific Theater over-taxed the Navy´s radio communications to a point where the need of additional communication channels became acute. The adaptation of a 4-channel Western Union type multiplex to a single-channel frequency-shift radio system appeared to be the most logical way to solve this problem quickly. Improvements in the radio and the use of the multiplex enabled the Navy to set up communication channels between the United States and all the principal naval bases in the Pacific. A 4-channel circuit was established between Washington, D. C., and Honolulu, T. H., and San Francisco, Calif., and Honolulu within approximately nine months after the beginning of initial tests. Other systems followed in close succession.