AUTOMATIC ADJUSTMENT UNIT FOR RECORDING SENSITIVITY OF MAGNETIC RECORDING AND REPRODUCING UNIT

摘要

PURPOSE:To perform automatic adjustment for recording sensitivity in excellent manner even for different types of tapes, by controlling the gain of the recording circuit so that the integration value of the reference signal to be recorded and the reproducing signal of the reference signal recorded is in agreement. CONSTITUTION:The switches SW1,SW2 are selected with microprocessing or the like, and the reference signal from the reference oscillator OSC and the reference signal reproduced after recording are integrated at the integration circuit IA in a given timer period of the control unit LA to reject noise. The integration values are compared at the comparison circuit CM providing memories, and the variable attenuator VA is controlled so that the both integration values are in agreement via the circuit LA or the difference can be a given value. Accordingly, independently of types of tapes, the gain of the recording circuit is automatically controlled to give the recording sensitivity to a given value.