| 摘要 |
PURPOSE:To attain simple adjustment of a gain offset without giving effects on the entire circuit by providing a variable resistor between a BPF and a smoothing circuit. CONSTITUTION:A signal processing circuit 1 converts four kinds of pilot signals recorded with frequency multiplex on a video signal on a video track of a video tape recorder into two kinds of pilot signals in 16.46kHz at reproduction. The 16kHz pilot signal is amplified by an amplifier circuit 4 via a 16kHz BPF 2, smoothed (7) and inputted to a differential amplifier circuit 9, whose amplification factor is adjusted by a variable resistor 5. On the other hand, a 46Hz pilot signal is inputted to the circuit 9 via a BPF 3, an amplifier circuit 6 and a smoothing circuit 8. When a reference video signal including the 4 kinds of pilot signals is fed to the circuit 1, the entire gain offset of the circuit is corrected by using the resistor 5 while supervising the output signal of the circuit 9.
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