Sec.  74.1204   Protection of FM broadcast, FM Translator and LP100 stations.

   (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
    Sec. 73.333 [F(50,50) curves] of this chapter.

   (2) The distances to the interference contours are computed using Figure 1a
   of  Sec. 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  Sec. 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  Sec. 73.207 of this chapter. For purposes of determining compliance
   with  Sec. 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  Sec.  Sec. 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
    Sec. 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  Sec. 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  Sec. 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]