Amplitude modulation circuit composed of MC1496

The amplitude modulation circuit composed of integrated analog multiplier MC1496
is shown in Figure 21-39.     The DC potential of pins ⑧ and ⑩ of the two input terminals of the channel is both 6V, which can be used as a carrier input channel} There is an external
zero-adjustment circuit between the two input terminals ① and ④ of the Y channel. The 50kn potentiometer can be adjusted to make the potential of pin ① higher than that of pin ④. High Uy, the modulated signal u(￡) is superimposed on the DC voltage UY and then input into
the Y channel. Adjusting the potentiometer can change the modulation index Ma. The output terminal ⑥ and @ pin are connected to a band-pass filter tuned to the carrier frequency. An external
Y channel negative feedback resistor is connected between the ② and ③ pins .
    The circuit shown in Figure 21-39 can form a double-sideband amplitude modulation circuit . The purpose of adjusting the potentiometer is to make the DC
potential difference between the Y channel ① and ④ pins zero, that is, the Y channel input signal is only an AC modulation signal. In order to reduce the current flowing through the potentiometer and facilitate accurate zero adjustment,
the resistance values ​​of the two 75051 resistors can be increased, for example, by 10kn each.