| 摘要 |
PURPOSE:To operate the modulate stably against the disturbance of a modulation signal or the like or a large external disturbance at application of power and at frequency changeover. CONSTITUTION:The modulator is provided with a time constant circuit comprising resistors 31, 32, diodes 39-42 and capacitors 43, 44 against a phase error pulse of phase comparison outputs 51, 52. The diodes 39-42 are responsive to a large disturbance at application of power and at frequency changeover to decrease a response time of a phase locked loop and the diodes 39-42 are reverse-biased against the disturbance of a modulation signal or the like to extend the response time. |
