Low Power Radio
- Overview & Table of Contents
- What is LPFM?
- Congress Second Guesses its Expert Agency on Spectrum Allocation
- Low Power Radio: An Antidote to the Modern Radio Industry
- Demographics of Radio Station Ownership
- Participation in Employment by Minorities and Women
- Radio Consolidation and Homogenization
- Conclusion
Examples of Low Power Stations
Appendices
Appendix B: Third Adjacent, Second Adjacent — What does it all mean?
The FCC spaces out radio stations to keep them from interfering with one another. These spaces are known as “adjacent channels.” The existing FCC rules mandate that full-power radio stations — from 6,000 to 50,000 watts — be licensed at intervals four channels apart, so there are three adjacent channels between full power radio stations. As the diagram below illustrates, if there is a full power radio station at 100.1, the next full power radio station would be placed at 99.3
Existing FM Frequency and Interference Protection Standards
Existing FCC Interference standards would allow another station — full-power or low-power — to be licensed at 100.1.
Smaller, low power stations, operating at 100 watts are a different story. After conducting its technical analysis, the FCC concluded that small low power radio stations could be placed one channel closer than full power stations, opening up the third adjacent channel for use. In the illustration, a low power radio station at 100.1 could occur next to a full power radio station at 99.5 instead of 99.3.
Proposed FM Frequency and Interference Protection Standards
The Local Community Radio Act of 2009 would allow FCC to modernize its interference standards and issue low-power licenses on the third-adjacent channel.
This is a similar standard to the one the FCC uses for existing “translator” stations used by full power radio stations to extend their signals. Translators, which operate at the same power levels as low power radio stations, are permitted to broadcast only three channels apart. In other words, broadcasters who oppose LPFM for technical reasons use transmitters that follow the same rules as the FCC would like to adopt for LPFM. In addition, the FCC conducted a detailed study of modern radio receivers and found that most radios in use today would be able to obtain full power radio signals despite new low power radio stations. Moreover, the FCC looked at older full power stations that are currently three channels apart and have been grandfathered under existing FCC rules.
When Congress stopped the FCC, it prevented low power radio stations from occurring on third adjacent channels, which cut back by 75 percent the number of new low power radio stations that could be authorized and limited the new stations to less populated areas.
