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== Spurious Emissions == | == Spurious Emissions == | ||
A properly designed and certified LPFM transmitter in good working order, will keep the signal on the LPFM station's assigned channel/frequency. Sometimes, due to either an issue with the transmitter or improper installation, the transmitter may also broadcast additional signals on undesired frequencies. This is known as spurious emissions (or "spurs"). Transmissions from spurs are not just limited to the FM broadcast band and over the years, there has been numerous reports that a defective transmitter will place a signal on a frequency in the spectrum adjacent to the FM band on frequencies that are used for aeronautical navigation or communications. | A properly designed and certified LPFM transmitter in good working order, will keep the signal on the LPFM station's assigned channel/frequency. Sometimes, due to either an issue with the transmitter or improper installation, the transmitter may also broadcast additional signals on undesired frequencies. This is known as [[Wikipedia:Spurious emission|spurious emissions]] (or "spurs"). Transmissions from spurs are not just limited to the FM broadcast band and over the years, there has been numerous reports that a defective transmitter will place a signal on a frequency in the spectrum adjacent to the FM band on frequencies that are used for aeronautical navigation or communications. | ||
If the FCC notifies the LPFM station that their station is causing spurious emissions, it is very urgent that the LPFM transmitter be shut off immediately. There is no 24 hour waiting period as the transmissions may cause danger to the safety of life. During the time the station is suspended, it may make short test transmissions to test the repairs to the transmitter. | If the FCC notifies the LPFM station that their station is causing spurious emissions, it is very urgent that the LPFM transmitter be shut off immediately. There is no 24 hour waiting period as the transmissions may cause danger to the safety of life. During the time the station is suspended, it may make short test transmissions to test the repairs to the transmitter. | ||
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== Regulatory history == | == Regulatory history == | ||
The original version of this rule was enacted in the ''LPFM Report and Order'' when the service was created in 2000. The rule at the time only considered interference to the full-service FM station's city grade contour and covered co-channel, first and second adjacent channels as well as intermediate frequencies (+/- 10.6 or 10.8 MHz). In the ''Order on Reconsideration'' from September, 2000, the FCC added the additional interference criteria to include the "Interference in the community of license" (for commercial stations) and the "contour overlap in the community of license" (for noncommercial stations) criteria. In the ''Third Report and Order,'' enacted in 2007, the distinctions between commercial and noncommercial were removed from the rule language. Criteria for displacement on second-adjacent channels were also eliminated. 2013, in the ''Sixth Report and Order'', the FCC removed the criteria that intermediate frequency overlap would be considered as actionable interference. | The original version of this rule was enacted in the ''[[LPFM Report and Order]]'' when the service was created in 2000. The rule at the time only considered interference to the full-service FM station's city grade contour and covered co-channel, first and second adjacent channels as well as [[intermediate frequencies]] (+/- 10.6 or 10.8 MHz). In the ''[[Order on Reconsideration]]'' from September, 2000, the FCC added the additional interference criteria to include the "Interference in the community of license" (for commercial stations) and the "contour overlap in the community of license" (for noncommercial stations) criteria. In the ''[[Third Report and Order]],'' enacted in 2007, the distinctions between commercial and noncommercial were removed from the rule language. Criteria for displacement on second-adjacent channels were also eliminated. 2013, in the ''[[Sixth Report and Order]]'', the FCC removed the criteria that intermediate frequency overlap would be considered as actionable interference. | ||
== Federal Register citation == | == Federal Register citation == | ||