What are the Common Intermediate Frequencies (IF's) for AM and FM commercial broadcast receivers?

The common intermediate frequencies (IFs) for AM and FM commercial broadcast receivers are 455 kHz for AM and 10.7 MHz for FM.

In AM broadcasting, the signal is first mixed with a local oscillator frequency to produce an intermediate frequency of 455 kHz. This frequency is a standard value that allows for efficient signal processing in all AM receivers. Similarly, for FM broadcasting, the intermediate frequency of 10.7 MHz is widely adopted because it provides good performance in terms of selectivity and fidelity, allowing the receiver to accurately process the frequency modulated signal.

These frequencies were established based on a balance of technical performance factors such as image frequencies, component availability, and the characteristics of the typical broadcast signals. The selection of these specific values has become industry standards that help ensure compatibility among various devices and manufacturers in the broadcasting environment.