On a Design for a Bifilar Type of Non-Reactive Resistance Coil

A bifilar non-reactive coil usually gives a condensive reactance at high frequency. The present paper analyses this frequency error observed over the audio-frequency range. An impedance characteristic curve is recognized, resembling that of an electric cable. From this experimental fact, a cable theory of a bifilar non-reactive coil is deduced. Employing an experimental constant, which the writers call the apparenrt dielectric constant K, a method is given for designing a 100,000-ohm coil, which gives a phase angle less than 5 deg., at a frequency of 5000 cycles per second, assuming the apparent dielectric constant to be K = 3.