As a magnetic head wears in normal operation, certain conditions and minor problems develop which indicate a gradual deterioration in performance. These indications include:
- Slight loss of high frequency response
- Signal amplitude instability
- Overall loss of level
- Unstable tracking and tape path
- Distorted signal
- Excessive oxide build-up
Generally these symptoms can be attributed to an uneven change in contour due to wear, or in the case of ferrite, gap deterioration caused by material erosion. The change in performance is usually very slight; it can be normally compensated for by adjusting record or playback equalization and mechanical head alignment. As the wearing continues, however, a point is reached in which the acceptable performance can not be achieved by compensation or adjustment. Our studies show that in most cases, less that 50% of the depth of the gap has worn at this stage. As a result, proper relapping will restore an unserviceable magnetic head to its original performance specifications.
在一定范围内,正确的研磨可以恢复磁头的功能.
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