| 摘要 |
<p>PURPOSE:To correctly set a recording level even if the width of a rotary head is different from that of a recording track, by running a magnetic tape at a fixed speed in both recording and reproducing times and automatically setting the optimum recording level by reproducing test signals after the test signals are recorded by making the level variable. CONSTITUTION:A recording level is set by means of a switch which is not shown in the figure and the signal of a test signal generating circuit 1 is amplified at a gain control amplifier circuit 2. ATF signals are added to RF signals from the circuit 2 while the output increasing by gain control signals from a controller 8 and the RF signals, to which the ATF signals are added, are supplied to heads A and B through switches 4 and 5. Outputs of the heads A and B are alternately recorded on a magnetic tape. When the switch 4 is switched to the reproduction side thereafter, the RF signals, on which tracking is performed by the AFT signals, are subject to peak level detection at a level detecting circuit 7 through a band-pass filter 9. Then the controller 8 detects the optimum level from the number of reproduced RF signals detected by a counter 10 and the output of the level detecting circuit 7. Therefore, the optimum recording levels can be set automatically to the heads A and B.</p> |
