Establishment of radio standards of frequency by the use of a harmonic amplifier

Scientific Paper No. 530 of the Bureau of Standards, by C. B. Jolliffe and Grace Hazen, bears the above title, and describes a method for measuring the ratio of a radio to an audio-frequency by the use of a harmonic amplifier. The harmonic amplifier makes it possible to use harmonics of a very high order from a known low-frequency source, such as a standard tuning fork. The method consists essentially of the production of harmonics of the fundamental frequency of an alternating current by means of the nonlinear characteristics of electron tubes, the selection of any desired harmonic by means of tuned circuits, and its amplification to sufficient power to operate a standard frequency meter (wave meter). Any harmonic of the source may be selected, and thus from a known audio-frequency source a frequency meter may be standardized throughout its entire range.