A way to assess the performance of heads and tapes for digital video recording

The authors describe a method to express the magnetic recording channel performance with a single number: the performance indicator (PI). PI is derived from the signal-to-noise ratio at the detector of a digital system for partial response class IV detection using a simple analytical expression. PI can be used as a figure of merit for a head-tape combination. The relative performance of heads can now be assessed by using the same tape and comparing the PI values. Also the relative performance of different kinds of tapes using the same head can be evaluated. Date from MIG and Sandwich heads obtained at a head-to-tape velocity of a 5 m/s and using various tapes (VHS, SVHS, MP, ME) are shown