| 摘要 |
PURPOSE:To obtain a frequency modulation wave, by changing the power source voltage of the oscillating circuit according to the amplitude level of the modulation signal to vary the collector output capacity of the transistor constituting the oscillating circuit. CONSTITUTION:The frequency modulating circuit consists of collector tuning type RF self-oscillating circuit 10 and modulating circuit 26. The tuning circuit of this frequency modulating circuit consists of coil 13, capacitor 14, and the collector output capacity of oscillating transistor 11. When the voltage applied to the base of modulating transistor 20 is varied, collector potential Vc and emitter potential Ve of transistor 11 in oscillating circuit 10 are changed, and the collector output capacity of oscillating transistor 11 is changed. As a result, the tuning frequency is changed. |
