Determination of electrical characteristics of loaded telegraph cables

The use of permalloy for continuous loading has introduced a number of new factors of importance in the study of transmission of signals over long submarine telegraph cables. Data to check the theoretical assumptions that are used in the design of permalloy loaded cables can be obtained by measuring on such cables the attenuation and time of propagation of sinusoidal currents of various frequencies in the telegraph range. By combining the results of these measurements with data obtained on the cable during process of manufacture, the resistance, inductance, capacity and leakance of the cables can be determined. This paper describes the experiments that were performed on three laid cables and discusses in a general way the methods of computing the cable parameters.