TRANSISTOR FM OSCILLATOR

Compares the transistor FM oscillator and the reactance tube modulator. Reviews the characteristics of a simple PN junction, before explaining the operation of the circuit, explaining how the depletion region is established and how it can be used as a variable capacitance under a changing reverse bias. Shows how the voltage variable capacitor can be used in conjunction with an oscillator to make up a transistor FM oscillator. Explains the operation of the FM oscillator, emphasizing the fact that a positive input decreases the output frequency and a negative input increases the output frequency. (Kinescope)