| 摘要 |
PURPOSE:To eliminate the beat disturbance of the received signal which is due to the higher harmonic wave of an oscillation output through a simple constitution, by switching the oscillation frequency with ON/OFF of a switching transistor connected in parallel or series to a capacitor. CONSTITUTION:A transistor (TR) 8 is turned on when a switch 1 is turned on, and a capacitor 7 is connected to a capacitor 6. Therefore the oscillation frequency is decided by a coil 4 and capacitors 6 and 7. As a result, a slight adjustment is possible for the oscillation frequency by turning on and off the switch 1. This can prevents the generation of beats even when the signal received by a radio receiving circuit is sound recorded. The TR8 is connected to the capacitor 7 and turned on and off by the switch 1. Thus the TR8 can be set close to the coil 4 and capacitors 6 and 7, and the leakage of the oscillation output owing to a lead wire between them can be extremely reduced. |
