| 摘要 |
PURPOSE:To prevent assuredly the misjudgement between a carrier dropout and a horizontal synchronizing signal, by detecting the carrier dropout when a PCM signal is reproduced and then setting forcibly the level of the synchronizing signal at a prescribed value. CONSTITUTION:A detector 15 detects the amplitude of the carrier signal of the output of an equalizer 4, and delivers an output ''1'' when a carrier dropout is produced and then ''0'' in the normal mode, respectively. A gate 16 is controlled by the output ''1'' or ''0''. When the output is ''1'', the synchronizing signal given from a comparator 12 is cut off and ''1'' is forcibly fed to a terminal X. While the synchronous signal is fed to the terminal X as it is when the output is ''0''. |
