| 摘要 |
PURPOSE:To make the reproducing level of a reproducing pilot signal always constant, by controlling the AGC circuit of pilot signals installed to a reproducing system with AGC signals produced from pilot signals or tracking signals. CONSTITUTION:The reproducing level of reproducing pilot signals S2 detected at a detecting circuit 2 is maintained at a constant value by sending a signal S5 indicating the frequency difference DELTAfA between pilot signals to an S/H circuit 22 from an AC/DC converter circuit 13 through a newly provided voltage controlling amplifier (VCA) 21 and sample-holding the detecting outputs S5 obtained in a prescribed period, and then, supplying the output SAGC of the circuit 22 to the VCA21 through an amplifier 23. On the other hand, tracking signals S8 outputted from a switching circuit 17 are sample-hold by another S/H circuit 25 and sent to a capstan servo system as tracking error signals SE and the tracking error of a reproducing head is corrected.
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