FM broadcasting

FM broadcasting is a radio broadcasting method that uses frequency modulation (FM) transmissions. In November 1919, Hans Idzerda began broadcasts, using narrow-band FM, over station PCGG, located at The Hague in the Netherlands. However, most early broadcasting stations instead employed Amplitude Modulation (AM) transmissions.

In 1933, American engineer Edwin Armstrong began development of wide-band FM. This offered higher fidelity—more accurate reproduction of the original program sound—than other analog broadcasting techniques, such as AM broadcasting. It is also less susceptible to common forms of interference, having less static and popping sounds than are often heard on AM broadcasts.

FM radio stations are usually assigned to transmit on very high frequency (VHF) radio frequencies. The use of these frequencies generally limits a station's coverage to local line-of-sight distances.