A Million-Cycle Telephone System

A Million-Cycle Telephone System * years ago new multi-channel ABOUT two transmissiona over wide-band system forNew York and telephone coaxial cables was described. An experimental system has now been installed between 1 By M. E. STRIEBY Philadelphia. The various tests and trials which are planned for this system have not been carried far enough to justify a formal technical paper. Meanwhile, the considerable interest that has been aroused in the system has led to this brief statement of its principal features and its general technical performance as so far measured. The coaxial cable itself has been installed between the long distance telephone buildings in New York and Philadelphia, a distance of 94.5 miles. It has been equipped with repeaters, at intervals of about 10 miles, capable of handling a frequency band of about 1,000,000 cycles. This million-cycle system is designed to handle 240 simultaneous two-way telephone conversations. Only a part of the terminal apparatus has been installed, sufficient in this case to enable adequate tests to be made of the performance of the entire system. A general view of the New York terminal is shown in Fig. 2. Some preliminary test conversations have been held over the system, both in its normal arrangement for providing New York-Philadelphia circuits, and with certain special arrangements whereby the circuit is looped back and forth many times to provide an approximate equivalent of a very long cable circuit. The performance has been up to expectations, and no important technical difficulties have arisen to cast doubt upon the future usefulness of such systems.