| 摘要 |
PURPOSE:To obtain a waveform comprising two peaks having equal amplitude by applying differential amplification between a reproduced waveform subjected to attenuation and delay with a prescribed time to apply waveform processing to an isolated reproducing waveform comprising two peaks having largely different amplitude. CONSTITUTION:One of a reproduced waveform 2 read by a magnetic head is delayed by a time equal to the peak interval of the waveform 2 and becomes a waveform 11. Furthermore, the waveform 2 is multiplied by a coefficient K at an attenuator 13 and becomes a waveform 10. They are amplified by a differential amplifier 9 and an output waveform 12 is obtained. A peak 14 of the waveform 11 is produced at a position coincident with a peak 15 of the waveform 10 and a peak 18 of the output 12 is larger than a peak 20 of the waveform 2. On the other hand, the peak 15 is overlapped with the rear side slope of the peak 17 of the waveform 10 and the polarity is the same, then the peak 19 of the output 21 is smaller than the peak 21 of the waveform 2. Thus, the peaks 18, 19 of the output 12 are made equal by selecting properly the attenuation factor of an attenuator 13.
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