Prior to World War 2, FM radio was an experimental service. Edwin Armstrong who was a pioneer in AM radio was developing the FM technology after RCA concluded it had no future. Detailed History of the life of Edwin Armstrong here
42-50 MHz was set aside for FM stations for Armstrong and others to see if it could be made into something useful. World War 2 saw military benefits to using FM as the Germans were not familiar with how it worked or had a way to block it. Armstrong had also done pioneering work in RADAR, which became critical during the war years.
With World War 2 winding down in 1945, the FCC was tasked with allocating bandwidth to the newly developed FM radio and Television Services. The decision was made to set aside 88-92 MHz for non-Commercial radio stations, just above UHF Channel 6 – and 92-106 MHz for Commercial FM Radio. 106-108 MHz was quickly added to the allocation to provide more channels – beginning first in the crowded NorthEastern US markets.
In 1946, GE and Zenith made one last attempt to push the FCC to retain the pre-war FM band of 42-50 MHz, an idea the FCC had rejected based on careful measurement of which frequencies are affected by atmospheric reflection.
In the old days when people still watched TV “over the air”, TV channels 2 and 3 (54-66 MHz) often have interference from stations hundreds or even 1000s of miles away because the signals bounce off the atmosphere – while that problem never affects channels 5-6 (76-88 MHz). Wisely, the FCC stood by its decision and so FM was launched in its current allocation.
Edwin Armstrong continued his legal battle with the FCC until his death in 1954, at which time experimental FM station KE2XCC was turned off, and the last pre-war FM station ended operations in the 42-50 MHz band.
[Interesting side note: Following the destruction of the World Trade Center on 9/11/2001, Armstrong’s old antenna tower in Alpine, New Jersey was a temporary home for several TV stations while they built more permanent transmitters back at the Empire State Building]
FM stations have a spectrum width of about 200 KHz, which permits 5 stations per MHz – so the non-commercial setaside consists of 20 channels. FM stations cannot be on adjacent channels in the same area because the station signals will interfere with each other – at least that was true before modern receivers.
The idea of setting aside some licenses for non-commerical stations traces back to a number of sources:
- John B Harney. a Catholic priest of the Paulist Fathers. Their organization had operated station WLWL in New York City, and fought bitter battles against commercial interests to stay on the air.
- WCFL, the station owned by the CFL labor union in Chicago, also fought to retain their non-commercial voice on the airwaves.
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The National Advisory Council on Radio in Education (NACRE) – backed by Carnegie and Rockefeller Foundation money. NACRE fought for voluntary cooperation between commercial and educational interests, while the National Committee on Educational Radio (NCER) fought for a stronger public interest standard.
The battle came to a head in Congress with the Wagner-Hatfield amendment, which would have set aside 25% of spectrum for non-commercial licensees. Influenced by the political power of the commercial networks, the amendment was defeated 42-23 in the US Senate. In order to prevent further delay, section 301(c) was added to the act, that required the FCC to “study” the issue of a non-commercial set-aside.
The result of that study is the current 4 Mhz non-commercial setaside. In 2009, the stations in that area fit into 4 basic categories:
- Stations operated primarily as educational experiences for high schools and colleges, staffed by students. These stations are typically low power, don’t ask for money to operate, and have limited operations. They are required to operate 8 hours a day while school is in session in order to retain their operating license. Where the school no longer has much interest in the station, often automation is used to satisfy that requirement.
- Religious Broadcasters – either syndicated satellite delivered (Educational Media Foundation (K-Love,Air1), Moody Bible, Family Broadcasting, etc) or local stations operated by a church or an individual
- Community Radio – operated by volunteers and focused on the needs of the community where it is located – not affiliated with an educational institution. Many of them are owned and run by Native American tribes.
- NPR affiliates – while many NPR stations were affiliated with State-Owned University systems, the trend has been to move the NPR licenses to corporations that are separated legally from the State Governments (and their political control). NPR operates 2 main programming services – the News and Ideas network, and a Classical Music Network.