摘要 |
In a magnetic recording system utilizing a non-return-to-zero format the reproduced recording is fed to positive and negative threshold detectors having no need for electrical hysteresis as well as, via differentiator means, to a zero-crossing detector. The signal from the positive threshold detector and one polarity of the signal from the zero-crossing detector are used to trigger a latch means to a first state to emit a signal having a first level, and the signal from the negative threshold detector and the other polarity of the signal from the zero-crossing detector are used to trigger the latch means to a second state whereby the signal emitted by the latch means is switched to a second level. |