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

The common intermediate frequencies (IFs) for AM and FM broadcast receivers are significant because they represent the frequencies to which the incoming radio signals are converted for processing. For AM broadcasts, the standard IF is typically 455 kHz. This frequency is chosen because it effectively passes the AM signal while minimizing interference and distortion. For FM broadcasts, the common IF is 10.7 MHz. This higher frequency serves to accommodate the wider bandwidth of FM signals, allowing for better fidelity and sound quality.

These IFs are standardized in the industry, making it easier for equipment manufacturers to design receivers that can effectively demodulate both AM and FM signals. The specific frequencies of 455 kHz and 10.7 MHz have been established based on technical performance criteria, including the ability to handle signal processing and achieve optimal sound quality.

Understanding these frequencies is crucial for a technician, as they are foundational to the design and repair of broadcasting equipment. Thus, selecting the correct IF values, which in this case are 455 kHz for AM and 10.7 MHz for FM, ensures that receivers function correctly and reliably in their intended applications.