Carrier-current communication on submarine cables: Los Angeles-Catalina Island telephone circuits

Seven telephone channels and one telegraph channel on one single-conductor deep-sea cable have been made possible by the employment of carrier current on one of the two submarine cables across Catalina channel. This is the only application of carrier telephony to deep-sea cables; the system is the shortest carrier system (26 mi.) in commercial operation; it provides more separate carrier channels (six) than has been previously attempted; and it differs in other important respects from other systems. This paper describes this carrier-current system.