Improved tracking method for VTR - measuring min. and max. amplitudes of received signal, and generating control voltage to alter variable gain amp. which controls capstan revs.

摘要

The tracking method automatically measures the min. and max. amplitudes of the received frequency modulated signal during an initial test run, and generates a control voltage (Ur) for controlling the pick-up (1,16) positions. A variable gain amplifier (6) has a control input (c) connected to a capacitor (9) that stores the control voltage, with the output connected back to the capacitor via a matching circuit (8). A clamping circuit (10,11) fixes the signal level at its max. level for optimal tracking adjustments. The position of the pick-ups is adjusted (13) w.r.t. the control voltage by varying the capstan (14) revs. via an A/D converter (12) linked to a controller (13). ADVANTAGE - Accurate tracking that is independent of tape type, condition or mfr. tolerances.