PURPOSE: To remarkably reduce a synchronizing jitter, by adding a feedback resistance in order to use a hold-off transistor as a shunt feedback amplifier, and providing a coupling circuit between said transistor and an input terminal.
CONSTITUTION: In order to use a hold-off transistor 6 as a shunt feedback amplifier instead of an emitter-ground amplifier, a feedback resistance RF is added, and a coupling circuit 10 consisting of a series circuit of a capacitor CB and a resistor RB is provided between an input terminal 1 and the base of the transistor 6. According to such constitution, in case of a synchronizing signal of high frequency which is sufficiently shorter than a sweep time and a hold-off period, a time from the end of the hold-off period to restarting of sweep can be made constant in accordance with a period of the synchronizing signal, the influence of a transient response noise by a variation time of a trigger pulse and a hold- off circuit 9 can be made invariable by a constant timing, and a synchronizing jitter can be reduced remarkably.
SUZUKI SATORU
BABA SUEO
HAYASHI SHIGERU
