Goto Section: 74.1203 | 74.1205 | Table of Contents

FCC 74.1204
Revised as of July 18, 2019
Goto Year:2018 | 2020
  § 74.1204   Protection of FM broadcast, FM Translator and LP100 stations.

   Link to an amendment published at  84 FR 27741 , June 14, 2019.

   Link to a correction to the above amendment published at  84 FR 29806 ,
   June 25, 2019.

   (a) An application for an FM translator station will not be accepted
   for filing if the proposed operation would involve overlap of predicted
   field contours with any other authorized commercial or noncommercial
   educational FM broadcast stations, FM translators, and Class D
   (secondary) noncommercial educational FM stations; or if it would
   result in new or increased overlap with an LP100 station, as set forth:

   (1) Commercial Class B FM Stations (Protected Contour: 0.5 mV/m)
   Frequency separation Interference contour of proposed translator
   station Protected contour of commercial Class B station
   Co-channel 0.05 mV/m (34 dBu) 0.5 mV/m (54 dBu)
   200 kHz 0.25 mV/m (48 dBu) 0.5 mV/m (54 dBu)
   400 kHz/ 600 kHz 50.0 mV/m (94 dBu) 0.5 mV/m (54 dBu)

   (2) Commercial Class B1 FM Stations (Protected Contour: 0.7 mV/m)
   Frequency separation Interference contour of proposed translator
   station Protected contour of commercial Class B1 station
   Co-channel 0.07 mV/m (37 dBu) 0.7 mV/m (57 dBu)
   200 kHz 0.35 mV/m (51 dBu) 0.5 mV/m (57 dBu)
   400 kHz/ 600 kHz 70.0 mV/m (97 dBu) 0.7 mV/m (57 dBu)

   (3) All Other Classes of FM Stations (Protected Contour: 1 mV/m)
   Frequency separation Interference contour of proposed translator
   Protected contour of any other station
   Co-channel 0.1 mV/m (40 dBu) 1 mV/m (60 dBu)
   200 kHz 0.5 mV/m (54 dBu) 1 mV/m (60 dBu)
   400 kHz/ 600 kHz 100 mV/m (100 dBu) 1 mV/m (60 dBu)

   (4) LP100 stations (Protected Contour: 1 mV/m)
   Frequency separation Interference contour of proposed translator
   station Protected contour of LP100 LPFM station
   Co-channel 0.1 mV/m (40 dBu) 1 mV/m (60 dBu)
   200 kHz 0.5 mV/m (54 dBu) 1 mV/m (60 dBu)

   Note to paragraph (a)(4): LP100 stations, to the purposes of
   determining overlap pursuant to this paragraph, LPFM applications and
   permits that have not yet been licensed must be considered as operating
   with the maximum permitted facilities. All LPFM TIS stations must be
   protected on the basis of a nondirectional antenna.

   (b) The following standards must be used to compute the distances to
   the pertinent contours:

   (1) The distances to the protected contours are computed using Figure 1
   of § 73.333 [F(50,50) curves] of this chapter.

   (2) The distances to the interference contours are computed using
   Figure 1a of § 73.333 [F(50,10) curves] of this chapter. In the event
   that the distance to the contour is below 16 kilometers (approximately
   10 miles), and therefore not covered by Figure 1a, curves in Figure 1
   must be used.

   (3) The effective radiated power (ERP) to be used is the maximum ERP of
   the main radiated lobe in the pertinent azimuthal direction. If the
   transmitting antenna is not horizontally polarized only, either the
   vertical component or the horizontal component of the ERP should be
   used, whichever is greater in the pertinent azimuthal direction.

   (4) The antenna height to be used is the height of the radiation center
   above the average terrain along each pertinent radial, determined in
   accordance with § 73.313(d) of this chapter.

   (c) An application for a change (other than a change in channel) in the
   authorized facilities of an FM translator station will be accepted even
   though overlap of field strength contours would occur with another
   station in an area where such overlap does not already exist, if:

   (1) The total area of overlap with that station would not be increased:

   (2) The area of overlap with any other station would not increase;

   (3) The area of overlap does not move significantly closer to the
   station receiving the overlap; and,

   (4) No area of overlap would be created with any station with which the
   overlap does not now exist.

   (d) The provisions of this section concerning prohibited overlap will
   not apply where the area of such overlap lies entirely over water. In
   addition, an application otherwise precluded by this section will be
   accepted if it can be demonstrated that no actual interference will
   occur due to intervening terrain, lack of population or such other
   factors as may be applicable.

   (e) The provisions of this section will not apply to overlap between a
   proposed fill-in FM translator station and its primary station
   operating on a first, second or third adjacent channel, provided That
   such operation may not result in interference to the primary station
   within its principal community.

   (f) An application for an FM translator station will not be accepted
   for filing even though the proposed operation would not involve overlap
   of field strength contours with any other station, as set forth in
   paragraph (a) of this section, if the predicted 1 mV/m field strength
   contour of the FM translator station will overlap a populated area
   already receiving a regularly used, off-the-air signal of any
   authorized co-channel, first, second or third adjacent channel
   broadcast station, including Class D (secondary) noncommercial
   educational FM stations and grant of the authorization will result in
   interference to the reception of such signal.

   (g) An application for an FM translator or an FM booster station that
   is 53 or 54 channels removed from an FM radio broadcast station will
   not be accepted for filing if it fails to meet the required separation
   distances set out in § 73.207 of this chapter. For purposes of
   determining compliance with § 73.207 of this chapter, translator
   stations will be treated as Class A stations and booster stations will
   be treated the same as their FM radio broadcast station equivalents. FM
   radio broadcast station equivalents will be determined in accordance
   with § § 73.210 and 73.211 of this chapter, based on the booster
   station's ERP and HAAT. Provided, however, that FM translator stations
   and booster stations operating with less than 100 watts ERP will be
   treated as class D stations and will not be subject to intermediate
   frequency separation requirements.

   (h) An application for an FM translator station will not be accepted
   for filing if it specifies a location within 320 kilometers
   (approximately 199 miles) of either the Canadian or Mexican borders and
   it does not comply with § 74.1235(d) of this part.

   (i) FM booster stations shall be subject to the requirement that the
   signal of any first adjacent channel station must exceed the signal of
   the booster station by 6 dB at all points within the protected contour
   of any first adjacent channel station, except that in the case of FM
   stations on adjacent channels at spacings that do not meet the minimum
   distance separations specified in § 73.207 of this chapter, the signal
   of any first adjacent channel station must exceed the signal of the
   booster by 6 dB at any point within the predicted interference free
   contour of the adjacent channel station.

   (j) FM translator stations authorized prior to June 1, 1991 with
   facilities that do not comply with the predicted interference
   protection provisions of this section, may continue to operate,
   provided that operation is in conformance with § 74.1203 regarding
   actual interference. Applications for major changes in FM translator
   stations must specify facilities that comply with provisions of this
   section.

   [ 55 FR 50694 , Dec. 10, 1990, as amended at  56 FR 56170 , Nov. 1, 1991;
    58 FR 42025 , Aug. 6, 1993;  65 FR 7649 , Feb. 15, 2000;  65 FR 67304 , Nov.
   9, 2000;  65 FR 79780 , Dec. 20, 2000]

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Goto Section: 74.1203 | 74.1205

Goto Year: 2018 | 2020
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