| 摘要 |
PURPOSE:To achieve measurement at low cost with high accuracy, by transmitting a signal having a prescribed repetitive frequency being centered its frequency at a frequency apart from a transmission signal through FM modulation and making an oscillator output matched to the modulated wave in phase as a time interval forming signal for a frequency counter. CONSTITUTION:A subcarrier FM-modulating a signal of a reference frequency oscillator 4 of a frequency counter and a transmission signal inputted from an input terminal 8 of a radio section at a terminal station with an FM modulator 5 passes through a radio device 1 and reaches a radio device 2. The signal branched at the radio device 2 demodulates the reference frequency with an FM demodulated 6, and noise is compressed with a phase locked loop 7, the frequency is changed to a desired frequency and used as a time interval input of a frequency counter 3. The frequency of each local oscillator is measured by connecting a measuring terminal 11 or 12 of the radio device 2 to an input terminal 10 of the counter 3. |
