A Frequency-Modulated Resistance-Capitance Oscillator

A method of producing frequency-modulated waves is described in which a resistance element in a resistance-capacitance-tuned oscillator is replaced by the output resistance of a variable-μ tube. As the grid potential of the latter tube is varied, its output resistance varies, and a wide-band frequency modulation of the oscillator is obtained. Mathematical relations between the frequency variation and the grid-potential change are derived. Experimental results are discussed.