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Magnetic Recording Master Tape

IP.com Disclosure Number: IPCOM000091304D
Original Publication Date: 1968-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Bradford, RC: AUTHOR [+2]

Abstract

A prerecorded master tape that provides output signal levels equivalent to those obtainable from a conventional magnetic record tape, but which is resistant to erasure by residual fields present in a conventional tape drive, is prepared as follows. A high-output magnetic tape having a signal output-to-residual magnetism characteristic, shown by the dashed curve A, is prerecorded with the information required. Subsequent to recording, this tape is partially erased with conventional erasing apparatus to reduce the level of signals recovered from it to the acceptable level S. The resulting tape has the characteristic shown by solid curve B.

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Magnetic Recording Master Tape

A prerecorded master tape that provides output signal levels equivalent to those obtainable from a conventional magnetic record tape, but which is resistant to erasure by residual fields present in a conventional tape drive, is prepared as follows. A high-output magnetic tape having a signal output-to-residual magnetism characteristic, shown by the dashed curve A, is prerecorded with the information required. Subsequent to recording, this tape is partially erased with conventional erasing apparatus to reduce the level of signals recovered from it to the acceptable level S. The resulting tape has the characteristic shown by solid curve B. Comparison of this characteristic with that of a conventional tape, curve C shows that while output signals of equal intensity are obtained from both tapes, the partially erased high-output tape B is completely insensitive to residual fields less than intensity h, while the conventional tape is partially erased and rendered unfit for continued test use.

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