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Washington, D.C. 20554
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TTY: 202/418-2555
This is an unofficial announcement of Commission action. Release of the full text of a Commission order constitutes official action. See MCI v. FCC. 515 F 2d 385 (D.C. Circ 1974).
March 24, 2000
DALE
HATFIELD,
CHIEF, OFFICE OF ENGINEERING AND TECHNOLOGY, AND
ROY
STEWART,
CHIEF, MASS MEDIA BUREAU
CONCERNING LOW POWER FM
ENGINEERING ISSUES
We are concerned that Members of Congress have received misleading engineering information about alleged interference from low power FM radio stations.
One particularly misleading disinformation effort involves a compact disc being distributed by NAB that purports to demonstrate the type of interference to existing radio stations that NAB claims will occur from new low power FM radio stations. This CD demonstration is misleading and is simply wrong.
- The NAB CD does not portray actual interference that might be experienced. The NAB CD was produced by artificially mixing two previously recorded radio signals and is not a demonstration of actual interference between two FM radio stations.
- The type of "crosstalk" interference suggested by NAB, that is, where you can intelligibly hear portions of both transmissions, does not occur from LPFM stations operating on 3rd adjacent channels. Any such interference that might occur would only appear as noise or hissing. The NAB "crosstalk" demonstration simply does not represent actual FM radio performance and therefore is meaningless.
- The NAB also incorrectly states that the FCC considers a 3% level of total harmonic distortion plus noise from interference to be acceptable. This too is wrong. The FCC Report and Order refuted a similar previous NAB assertion and clearly indicated that the Commission based its evaluations on a 1% level. To continue to make the argument in this CD about the 3% level can only be viewed as a deliberate misrepresentation of the FCC's findings and analysis.
There also have been concerns raised by NPR about the impact of low power FM radio on radio reading services. Radio reading services, which carry newspapers and other information aurally to the visually impaired population, operate as subcarriers on FM frequencies. Just as our testing has determined that existing stations will not experience harmful interference, the Commission stated in the Report & Order that subcarriers on these frequencies should not experience harmful interference. Nevertheless, we will continue to work with NPR to test radio reading service receivers, and will, if necessary, recommend to the Commission steps specifically tailored to deal with the radio reading service issue.
We believe the Commission took a thorough and indeed conservative approach in designing a low power FM radio service that protects the integrity of the broadcast radio spectrum.