Effect of environment on drop-outs in rotary head—tape drives

Abstract

The effect of environment on the drop-out performance of magnetic tapes in a rotary head-tape drive was studied. A capacitance probe, mounted on the rotating upper drum and positioned to measure tangential deflection of the head, was used to measure friction force. This technique, in conjunction with the measurement of head signal amplitude, was used to investigate the effect of environment on drop-outs. Streaming mode tests were conducted with two brands of S-VHS tapes at various combinations of temperature (6-38 °C) and relative humidity (10-80% RH). From the experiments, it was found that the propensity for intermittent drop-outs increases in a low relative humidity environment. A low relative humidity environment increases the propensity for debris to persist over the head gap and create a loss in the head signal. High temperature further increases the propensity for drop-outs in a low relative humidity environment. The propensity for intermittent drop-outs is reduced by increasing the relative humidity, changing magnetic tapes and to some extent by lowering the temperature of the environment. It was also determined that variability in the quality of magnetic tapes has a significant impact on the number of intermittent and permanent drop-outs encountered during playback.