Tuning circuit for FM radio circuit

Tuning circuit for FM radio circuit

(2) Application of FET in FM radio circuit
    The figure shows the tuning circuit
of FM radio circuit, which is composed of high-frequency amplifier VT1, mixer VT3 and local oscillator VT2 . The FM radio signal induced by the antenna is added to the gate of the rri transistor through the input transformer Li. VT1 is the main component of the high-frequency
amplifier . It amplifies the FM high-frequency signal and adds it to the gate of the mixing circuit VT3 through the transformer L2. pole, yrl2 and the LC resonant circuit constitute
a local oscillator, and the oscillation signal is sent to the source of the mixing circuit VT3 from the secondary of the oscillation transformer. The mixing circuit VT3 is output from the drain and
outputs a 10.7 MHz intermediate frequency signal through the intermediate frequency transformer IFT (L4).