Push-Pull Frequency Modulated Circuit and its Application to Vibratory Systems
The purpose of this paper is to describe a new push-pull frequency modulated circuit in which the push-pull action is accomplished by varying the resonant frequencies of both the oscillator and the discriminator in opposite phase relation to each other. Modulation of the oscillator and discriminator is achieved through the use of 2 capacitors with a common plate and arranged in a push-pull circuit. Thus, if the common plate is the moving element of a vibratory system, this circuit can be used for measuring vibrations or for monitoring purposes. — One of the applications of the push-pull FM circuit is to calibrate recording heads while cutting phonograph records. Using this calibrator, it is possible to measure, without mechanical or inductive coupling, the actual frequency response of the cutting head under normal load, and to observe the input-output characteristics as well as the amount of distortion. It is also possible to use it for monitoring while recording.
- Print ISSN
- 0097-5834
- Published
- 1946-01
- Content type
- Original Research
- DOI
- 10.5594/J11865