Thanks to efforts by Cobra, FM CB radio was approved in the U.S. by the FCC in 2021 – this is the biggest change to CB radio in decades, since the expansion from 27 to 40 channels in 1977. FM mode has been widely available to CB users in countries in Europe and other parts of the world for years, rising in popularity due to its much higher sound quality and clarity.
FM generally provides clearer sound with less background noise. FM's improved audio quality is due to the "capture effect," meaning that one strong signal is selected, and other signals are suppressed. See how AM vs. FM sound compares.
