| 摘要 |
PURPOSE:To make it possible to set a recording level to the most suitable one for digital purpose, by detecting distortion elements of a transmission system through operation of an automatically set switch, and controlling the level of transmission signal. CONSTITUTION:When the operator depresses automatically set switch 12, time set circuit 10 is immediately driven and generates a pulse of time width corresponding to a prescribed set time, and the pulse is sent to maximum value holding part 9. Holding part 9 holds the maximum one out of the levels of waveform distortion elements detected by level detector 8 within the time set by circuit 10 and supplies the control signal corresponding to it to gain control circuit 3. Initial value set circuit 11 sets the gain of circuit 3 with a prescribed initial value for a prescribed time set by circuit 10 and with the maximum value held by holding part 9 after the prescribed time has passed, respectively. Therefore, circuit 3 can be set at the most suitable recording level for digital purpose. |
