A 2-Channel Carrier Telegraph System for Short Submarine Cables

A new 2-channel carrier telegraph system for short submarine telegraph cables is described. Developed specifically for the Western Union Key West¿Havana cables, about 100 nautical miles in length and with attenuations up to 80 decibels at 1,000 cycles per second, it utilizes standard land-line frequency-modulation channel terminal equipment and provides excellent 50-cycle telegraph transmission on both channels without appreciably degrading the physical circuits. Depending upon the facilities available the carrier may be operated either as a metallic or a ground-return circuit.