The voltage characteristics of polythene cables

High-voltage characteristics of concentric radio-frequency cables with polythene dielectric have been studied. These have included determinations of power-frequency breakdown voltage, and the effect of power-frequency stressing on power factor, life with pulse voltages, discharge characteristics measured mainly at power frequencies, and performance with 600-Mc/s radio-frequency pulse operation. The correlation between life on unidirectional pulses and discharge characteristics has been examined, and a comparison has been made between thermal ratings derived by calculation and experimental determinations at a frequency of 600 Mc/s. Finally, tentative voltage ratings based on the experimental work are proposed.