Because the IF is always a constant frequency (e.g., 455 kHz for AM, 10.7 MHz for FM), filters can be tightly tuned to eliminate adjacent channel interference. Highly specialized transistor stages amplify this cleaned-up signal.
Unlocking Electronics: A Guide to Transistor Circuit Design Whether you’re a hobbyist or an aspiring engineer, the book Principles of Transistor Circuits Because the IF is always a constant frequency (e