VIDEORECORDER.

摘要

A pulse generator (1) is triggered by the rotation of the recording drum of a video recorder to provide synchronising signals. The phase error in the generated signal is determined by comparison (5) with a signal (A) produced by playing a reference tape during a servicing operation in which a switch (S1) is closed to enter the error signal into a memory (7). The switch is opened and a phase unit (11) generates a square wave signal that is converted into trapezoidal form (13) to be received by a sample and hold circuit (14) producing an error voltage (D). A control head (2) provides pulses that are converted into tracking vertical pulses that are used to control the sample and hold circuit. The pulses are compared (6) with the phase correcting head switchover signals and the result stored in a memory (8) that provides tracking error compensation.