| 摘要 |
PURPOSE:To stabilize the color synchronization, by replacing a reproducing burst signal which has been reproduced as a fundamental signal for color reproduction, with a standard burst signal, in the course of its transmission. CONSTITUTION:A reproduced low band converting signal is converted to an NTSC system signal of 3.58MHz band by a frequency converter 12. A voltage control oscillator 15 for frequency conversion is broght to an APC loop control by an output which has compared a phase difference between a signal of 3.58MHz from a fixed oscillator 26 and 3.58MHz of the converting signal, by a comparator 16. 3.58MHz is replaced with a standard burst signal whose burst has phase-adjusted the output of the fixed oscillator 26 by a voltage control variable phase shifter 25, by a burst replacing switch 17. The voltage variable phase shifter 25 is corrected in phase by controlling circuit consisting of a 90 deg. phase shifter 19, a multiplier 20 and a comparator 24. In this way, the color synchronization of a signal outputted from a terminal 18 is stabilized. |
