Resistance and Capacity of Coils at Radio Frequencies

The various practical methods of determining the resistance of coils at radio frequencies are described, and their conditions of maximum usefulness given. The resistances of various forms of coils on different mountings are determined at various frequencies, and the laws of variation of resistance with frequency are considered. Measurements are also made of the internal capacity of coils at radio frequencies, and the physics of this capacity is investigated. The effects on its resistance and capacity of various methods of terminating the coil, mounting it, and varnishing it are experimentally investigated. Finally, solid wire and stranded cable are compared at various frequencies; and numerical data are given on the possible resistances obtainable in actual receiving sets.