| 摘要 |
PURPOSE:To enable the automatic adjustment of optimum gain without giving effect on dropout. by lowering the gain of amplifier having the maximum gain according to the readout output based on the amplitude. CONSTITUTION:The constant amplitude signal from the amplitude reference area 3 of the magnetic tape 1 is read out and fed to the comparator 13 via the amplifier 12 having the highest gain. Further, according to the down signal output from the Self Auto-Gain Control 15 based on the output of the comparator 13, the gain of the amplifier 12 is lowered and controlled for the maximum value. Accordingly, as the upward control of gain, the control obtaining high gain as required with the dropout is not made and the automatic adjustment is made to the optimum gain without the effect by dropout. |
