| 摘要 |
PURPOSE:To record magnetically only an audio signal by providing a pseudo synchronizing signal generating circuit, and putting a servo circuit in normal operation on the basis of a pseudo synchronizing signal even when no video signal is inputted. CONSTITUTION:The pseudo synchronizing signal generating circuit is shown by 11 and generates the pseudo synchronizing signal equivalent to a vertical synchronizing signal. When no video signal is inputted to a terminal 2 while the audio signal is inputted to a terminal 1, a synchronizing signal detecting circuit 12 detects no synchronizing signal, so a switch 13 is so operated as to lead the pseudo synchronizing signal from the pseudo synchronizing signal generating circuit 11 to the servo circuit 9. Consequently, the servo circuit 9 outputs a drum driving signal on the basis of the pseudo synchronizing signal, so the rotation of a drum 7 is controlled and the video signal is inputted to the terminal 2, so that tracking is performed during reproduction. At this time, no video signal is inputted, so only the audio signal is recorded on a magnetic tape as a recording signal. |
