Consumer Electronics

ERASE HEADS

There are similarities between the erase head and the record head although they differ in their construction in two principal aspects. Firstly, appreciable power is required (about 2 to 4 W) for efficient erasure, for that it is necessary for the recording head to be about 1 mW. Hence the core of the erase head must be of a material having a higher point of magnetic saturation than the material in the recording head. Secondly, the longer the tape is under the influence of the erasing field, the more complete will be the cleaning. Thus the gap in the erase-head core should be considerably larger than in the core of the combined head. The erase gap is usually about fifteen thousandths of an inch wide. Normally there is no auxiliary ...