| 摘要 |
PURPOSE:To correct drop-out like the one that puts horizontal synchronization into disorder by inverting the high pass component of a video signal and adding an original video signal and the output of a grounded emitter amplifier. CONSTITUTION:The high pass component of the video signal of negative polarity is taken out at a high pass filter that consists of a capacitor C1 and resistors R1 and R2. With adjusting a variable resistor VR2 so that pedestal level is adjusted to the cut-off level of a grounded emitter amplifier Q1, the grounded emitter amplifier Q1 inverts and amplifies the drop-out lowered under the pedestal level. With adjusting a variable resistor VR1 for adding level adjustment, the dropout can be raised over the pedestal level.
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