Walkie-talkie works receive part
The receiving section mixes the amplified signal from the radio frequency with the first local oscillation signal from the PLL frequency synthesizer circuit at the first mixer and generates a first intermediate frequency signal. The first intermediate frequency signal further removes the clutter signal of the adjacent channel through the crystal filter. The filtered first intermediate frequency signal enters an intermediate frequency processing chip and is again mixed with the second local signal to generate a second intermediate frequency signal which is amplified and discriminated by a ceramic filter to filter out unwanted spurious signals. Generate audio signal. Audio signal through the amplifier, band-pass filter, to increase the circuit, into the volume control circuit and the power amplifier to amplify, drive the speaker, get the information people need.
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