Playing head adjustment in magnetic tape recorder - feeds track sync. pulses to phase comparator which operates piezo-ceramic transducer to compensate recorded track deviations

摘要

In a magnetic tape recorder, a colour television signal is recorded using a double head onto two tracks simultaneously. The tracks run parallel side by side with no spacing. Synchronisation pulses derived from e.g. line sync pulses are recorded on both tracks. During playback, after amplification and demodulation stages, the pulses are isolated and enter a phase comparator. Any difference signal is used to operate a piezoceramic transducer. This adjusts the playback heads to compensate for deviations in the recorded tracks, thus providing a continuous, automatic correction.