Radio circuit of monolithic integrated circuit radio

Radio circuit of monolithic integrated circuit radio

Shown is the radio circuit of a single-chip integrated circuit radio , powered by 3V (two batteries). If you use headphones to listen, it consumes very little power and
can be used for a long time.
    The coil and variable capacitor on the magnetic rod antenna resonate with the sky broadcast carrier, and after induction, the radio frequency signal (RF) is sent from the @ pin to
the mixing circuit in the integrated circuit. ① The pin is externally connected to the local oscillator coil and is tuned by a double capacitor. The mixed output is frequency-selected by the intermediate frequency transformer and sent to
the intermediate frequency amplifier in the integrated circuit through pin ③ . The audio signal is detected by the AM detector in the integrated circuit
and output from pin ⑦ . After being adjusted by the potentiometer VR50k, from ( The @ pin is sent to the power amplifier circuit. The amplified signal of the power amplifier circuit is output from the @ pin to the earphones or speakers.