Single wire AM radio circuit

Shown is a single-wire AM radio circuit. The broadcast signal received by the antenna is sent to the @ pin of IC1. After efficient mixing,
the intermediate frequency signal is output from the ④ pin. After frequency selection by the intermediate frequency transformer , it is sent to the frequency review amplifier in IC1 through the ② pin, and then the @ pin is output through the ② pin. After the second intermediate frequency transformer , the @ pin is sent to the detection circuit
in ICl . After the audio signal is amplified, the @l pin output is sent to the speaker and earphones.