| 摘要 |
PURPOSE:To measure wow and flutter accurately and quickly and to reduce the measuring time, by using a pre-formed reference tape and eliminating the need for recording the reference signal at each measurement with a VTR to be measured. CONSTITUTION:A VTR reproduces a reference tape and supplies a reproduction signal from an audio control head to an input terminal 21. The signal is applied to a frequency discriminator 23 via a limiter 22, the output is at a level corresponding to the frequency variance, and applied via an amplifier 24 to one input terminal 26a of a switch 25 and a filter 27. The output of the filter 27 is applied to the terminal 26b and a low pass filter 28 via an output terminal 26c. A voltage proportional to the amount of wow.flutter is caused at this output and applied to a meter 30 via a meter circuit 29 and also to a display part 31. |
