| 摘要 |
PURPOSE:To avoid output fluctuation, even if a main modulator is failed and switched to a slave modulator, by changing the compression rate of an AFC loop of the slave modulator, in the modulator of slave synchronism system where the master and slave modulators are in parallel operation. CONSTITUTION:When a main modulator is normal and the output of a modulator is an output of the main modulator 1, a switch SW is selected to e.g. the resistor R1 position. In decreasing the value of the resistor R1, the gain of a DC amplifier 2'' is reduced, the compressing rate of an AFC6'' is decreased and a slave modulator 1' is synchronizingly operated with the main modulator 1 easily for stable operation. If the main modulator 1 is failed, the output of the main modulator 1 is interrupted and the switch SW is selected to the resistor R2 position. Since the resistor R2 is selected to a gain the same as that of a DC amplifier 2, the gain of the amplifier 2'' is increased and the compression rate of the AFC6'' is made equal to that of an AFC6. Thus, even if the modulator is switched into the slave modulator 1', no output is fluctuated and no frequency stabilization is deteriorated. |
