| 摘要 |
PURPOSE:To attain sure dropout compensation, by controlling autoatically a dropout detecting level in response to an FM reproducing output level. CONSTITUTION:After a reproduced output obtained from video heads A, B is amplified respectively at amplifiers 1, 2, the output is led to an output terminal 7 via a switch circuit 3, a high pass filter 4, a limiter 5, and a switch circuit 6. After the output of the limiter 5 is detected at a peak detecting circuit 8, the output is applied to a Schmitt circuit 9. Further, the detected output of the peak detecting circuit 8 is inputted to a dropout detecting level control circuit 13, and the dropout detecting level at the Schmitt circuit 9 is controlled in response to the average level of the detected output. When a dropout is detected, an output delayed at a 1H delay line 10 is led to an output terminal 7. |
