Rotary head type digital magnetic recording-reproducing apparatus

摘要

A rotary digital magnetic recording-reproducing apparatus includes an envelope detecting unit and a one-of-heads jamming detector. The envelope detector receives an RF signal, reproduced through two heads, having first envelopes indicative of a first head and a second envelope indicative of a second head. The envelope detecting unit produces from the RF signal a train of pulses indicative of the first and second envelopes. The one-of-heads jamming detector monitors the train of pulses to output a signal indicative of the trouble or jamming of one of the first and second heads when an envelope corresponding to one of the first and second heads is lost.