Six-channel multiplex for submarine cable telegraphy

THE RICHLY CULTIVATED CARIBBEAN area has imposed ever-increasing demands upon communication facilities to North America. To serve this market place and crossroads of transportation, the Western Union Telegraph Company operates three submarine telegraph cables between Havana, Cuba, and Key West, Fla., an average distance of 101 nautical miles. Originally operated duplex in a differential polar relay arrangement, each cable was capable of sustaining a 3-channel time division multiplex at a signaling speed of 50 cycles per second.