Answer

Superheterodyne: Converts RF to fixed IF $f_{IF}=|f_{LO}-f_{RF}|$ via mixer+LO. IF amp 455kHz AM, 10.7MHz FM, sharp IF filter gives selectivity, sensitivity. RF amp→Mixer←LO→IF amp→Detector→AF. Image $f_{im}=f_{RF}+2f_{IF}$ needs preselection.