| 摘要 |
PURPOSE:To always obtain stable oscillations for a radio transmitter using the FM broadcast band, by using a VCO of a PLL for a local oscillator. CONSTITUTION:A proper delaying circuit such as a monostable multivibrator, a CR circuit, etc. is used to give a delay to the start timing of transmission until the oscillating frequency of a local oscillator 4 is made stable. When a transmission/reception changeover switch 21 is set at the reception side, a prescribed communication frequency is received via a radio tuner part. When the switch 21 is set at the transmission side, the oscillating frequency of the oscillator 4 which is switched to the same level as the communication frequency is transmitted after receiving the FM modulation with the input audio signal given through a microphone 15 and superposed on the control voltage of the oscillator 4. |
