FM broadcasting in the United States
Open-knowledge reference entry
FM broadcasting in the United States began in the 1930s at engineer and inventor Edwin Howard Armstrong's experimental station, W2XMN. The use of FM radio has been associated with higher sound quality in music radio.
History of FM radio in the U.S.
In the United States, the FM broadcast band is currently assigned to a 20.2 MHz-wide frequency band, spanning 87.8–108.0 MHz. This is divided into a total of 101 transmitting channels, each 200 kHz wide, with center frequencies of 87.9 to 107.9 MHz, that are designated as channels 200 to 300. In addition, there are a small number of TV stations, described as FM6 operations, which also include an FM station at 87.7 MHz, just below the standard FM band.
In the 1930s investigations were begun into establishing radio stations transmitting on "Very High Frequency" (VHF) assignments above 30 MHz. In October 1937, the Federal Communications Commission (FCC) announced new frequency allocations, which included a band of experimental and educational "Apex" stations, that consisted of 75 channels spanning from 41.02 to 43.98 MHz. Like the existing AM band these stations employed amplitude modulation, however the 40 kHz spacing between adjacent frequencies was four times as much as the 10 kHz spacing on the standard AM broadcast band, which reduced adjacent-frequency interference, and provided more bandwidth for high-fidelity programming.
Also during the 1930s a competing transmission technology, "wide-band frequency modulation", was developed in the United States by Edwin Howard Armstrong, which was promoted as being superior to AM transmissions, in particular due to its high-fidelity and near immunity to static interference. On June 17, 1936 Armstrong formally demonstrated his FM system to the FCC. That year he also set up the first FM radio station, W2XMN in Alpine, New Jersey, to function as a demonstration station. In 1937 the Yankee Network, looking to eventually establish commercial FM operations, was granted a construction permit for an experimental station, W1XOJ, in Paxton, Massachusetts.
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This entry incorporates text from “FM broadcasting in the United States” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.