Amplitude Characteristics of Coupled Circuits Having Distributed Constants

A general solution for the amplitude characteristics (resonance curves) for bridge-coupled circuits having distributed line constants is obtained and applied to typical circuit arrangements including those encountered in wavelength measurement using parallel wires. The physical conditions under which the theory may be applied are analyzed; theoretical curves are computed for a typical selection of constants, and are shown to be in excellent agreement with corresponding experimental ones. A new precision method for measuring ultra-short waves is described; the maximum deflection and the minimum deflection methods are shown to be exact. A method is devised for experimentally determining the characteristics of short-wave detectors, and for measuring their input impedance at ultra-high frequencies. The screen-grid resonance indicator is shown to have a linear resonance current-deflection characteristic, and its input impedance is measured at 434 centimeters wavelength.