A new wave-shape factor and meter

J. J. Smith: When considering the effect of harmonics, it is perhaps well to divide them into different classes: (1) those which may give rise to resonant conditions or large circulating currents on the power circuit, (2) those which may give rise to telephone interference, (3) those which may give rise to radio interference, (4) those which may give rise to any other type of trouble that may be discovered. Let us consider, for instance, the case of telephone interference, as somewhat similar remarks will apply to other types of interference. In the telephone-interferencefactor meter an attempt was made to weight the various harmonics in accordance with the experimental data available as to the interfering effed; of each harmonic. A special type of network was designed to do this, and the impedance characteristics of such a network, which is used in the telephone-interferencefactor meter, can be varied, within certain limits at least, to correspond with any new data which may show that it is desirable to weight the harmonics differently. In the method suggested by Messrs. Doggett, Heim, and White, no such adjustment is possible.