An investigation of separation losses in high-speed, high-density recording tapes

The trend in digital tape recording is toward larger storage capacity and faster accessing, which necessitate packing information at greater densities on tapes moving at higher speeds. The losses that inevitably arise from the finite separation between the head and the moving tape become much more serious as the length of the magnetized regions in the tape is reduced and as the relative velocity of head and tape is increased. The purpose of this paper was to investigate experimentally the dependence of separation losses on bit density and head gap length, and to distinguish from the reading losses those losses introduced during the writing process. Briefly, results showed that, for the heads and tapes used in the experiment, virtually all the losses could be attributed to the reading process. Furthermore, writing with a wide gap head and reading back with the four heads established that the percentage reading losses as a function of separation were apparently the same whatever reading head was used.