PURPOSE: To execute an adjustment to a prescribed intermediate frequency by adjusting only one direction, by constituting the titled indicator so that a direction of a shift from the prescribed intermediate frequency of a frequency of an input signal can be known.
CONSTITUTION: An input signal S is led to the first turning circuit 11 having a tuning frequency fL lower than a prescribed intermediate frequency fO, and the second tuning circuit 12 having a tuning frequency fH higher than the intermediate frequency fO, outputs of each tuning circuit are detected by the first detecting circuit 21, and the second detecting circuit 22, respectively, and an output signal corresponding to an output of the first detecting circuit 21 and an output of the second detecting circuit 22 is generated by a subtracting circuit 6. The output of the subtracting circuit is smoothed by a low-pass filter, amplified by an amplifier 8 as necessary, and indicated by an indicator 9. An output of a frequency discriminating circuit becomes zero, when the frequency of the input signal S is equal to the intermediate frequency fO, and a negative voltage and a positive voltage are generated, when the frequency of the input signal S is lower than the prescribed intermediate frequency fO, and when said frequency is higher than the prescribed intermediate frequency fO, respectively.
SUDO YUKIO
SAKURAI SHINOBU
| JPS4939312B1 | 1974-10-24 | |||
| JP53049901B |