| 摘要 |
PURPOSE:To obtain a milliwave band mobile radio equipment used suitably for repeating of TV by exercising automatic control so that the subcarrier frequency of an audio signal varies with a radio frequency on a transmission side and an IF is made constant on a reception side. CONSTITUTION:On a transmission side, a subcarrier provided in the side band of video signal is frequency-modulated to transmit an audio signal corresponding to a channel of a radio frequency. On a reception side, on the other hand, automatic frequency control over a local oscillator to make an IF constant and leading- in operation by it are performed by a sweep oscillator 21. Then, a detector 26 outputs a frequency discriminating function signal that discriminates coincidence between a demodulated subcarrier frequency and a frequency set for every channel. The oscillator 21 is controlled by this frequency discriminating function signal to obtain a prespcribed subcarrier frequency after demodulation. |
