| 摘要 |
PURPOSE:To prevent the fluctuation in the DC level accompanied with the signal switching between a reproduced video signal and a test video signal and to simplify the circuit constitution, by setting the synchronizing tip level of both the signals in common. CONSTITUTION:A video and an audio signal reproduced at a magnetic head 4 are processed at a reproducing signal processing circuit 6, and the synchronizing tip level is set at a Synch-tip circuit 14. The output of the Synch-tip circuit is transmitted to a TV tuner from a high frequency terminal 22 via a white clip circuit 16 and a balanced modulator 18. A test video signal forming circuit 36 in common use of a part of the circuit 14 is provided and a test video signal in response to a control signal SC given externally is formed and the switching from a reproducing video signal input mode to the test video signal forming mode is done. |
