§ 73.807   Minimum distance separation between stations.

   Minimum  separation  requirements  for LPFM stations are listed in the
   following paragraphs. Except as noted below, an LPFM station will not be
   authorized unless the co-channel, and first- and second-adjacent channel
   separations are met. An LPFM station need not satisfy the third-adjacent
   channel separations listed in paragraphs (a) through (c) of this section in
   order to be authorized. The third-adjacent channel separations are included
   for use in determining for purposes of § 73.810 which third-adjacent channel
   interference  regime applies to an LPFM station. Minimum distances for
   co-channel and first-adjacent channel are separated into two columns. The
   left-hand column lists the required minimum separation to protect other
   stations and the right-hand column lists (for informational purposes only)
   the  minimum  distance  necessary  for  the LPFM station to receive no
   interference from other stations assumed to be operating at the maximum
   permitted facilities for the station class. For second-adjacent channel, the
   required minimum distance separation is sufficient to avoid interference
   received from other stations.

   (a)(1) An LPFM station will not be authorized initially unless the minimum
   distance  separations  in  the following table are met with respect to
   authorized FM stations, applications for new and existing FM stations filed
   prior to the release of the public notice announcing an LPFM window period,
   authorized LPFM stations, LPFM station applications that were timely-filed
   within  a previous window, and vacant FM allotments. LPFM modification
   applications must either meet the distance separations in the following
   table or, if short-spaced, not lessen the spacing to subsequently authorized
   stations.
   Station class protected by LPFM Co-channel minimum separation
   (km) First-adjacent channel
   minimum separation
   (km) Second and
   third adjacent
   channel
   minimum
   separation
   (km)
   Required For no
   interference received from max. class
   facility Required For no
   interference
   received
   from
   max. class
   facility Required
   LPFM 24 24 14 14 None
   D 24 24 13 13 6
   A 67 92 56 56 29
   B1 87 119 74 74 46
   B 112 143 97 97 67
   C3 78 119 67 67 40
   C2 91 143 80 84 53
   C1 111 178 100 111 73
   C0 122 193 111 130 84
   C 130 203 120 142 93

   (2) LPFM stations must satisfy the second-adjacent channel minimum distance
   separation requirements of paragraph (a)(1) of this section with respect to
   any  third-adjacent channel FM station that, as of September 20, 2000,
   broadcasts a radio reading service via a subcarrier frequency.

   (b) In addition to meeting or exceeding the minimum separations in paragraph
   (a) of this section, new LPFM stations will not be autorized in Puerto Rico
   or  the  Virgin Islands unless the minimum distance separations in the
   following tables are met with respect to authorized or proposed FM stations:
   Station class protected by LPFM Co-channel minimum separation (km)
   First-adjacent channel
   minimum separation
   (km) Second and
   third adjacent
   channel
   minimum
   separation
   (km)—required
   Required For no
   interference received from max. class
   facility Required For no
   interference
   received
   from
   max. class
   facility
   A 80 111 70 70 42
   B1 95 128 82 82 53
   B 138 179 123 123 92

   Note  to  paragraphs (a) and (b): Minimum distance separations towards
   “grandfathered” superpowered Reserved Band stations are as specified. Full
   service FM stations operating within the reserved band (Channels 201-220)
   with facilities in excess of those permitted in § 73.211(b)(1) or (b)(3)
   shall be protected by LPFM stations in accordance with the minimum distance
   separations for the nearest class as determined under § 73.211. For example,
   a Class B1 station operating with facilities that result in a 60 dBu contour
   that exceeds 39 kilometers but is less than 52 kilometers would be protected
   by the Class B minimum distance separations. Class D stations with 60 dBu
   contours that exceed 5 kilometers will be protected by the Class A minimum
   distance separations. Class B stations with 60 dBu contours that exceed 52
   kilometers will be protected as Class C1 or Class C stations depending upon
   the distance to the 60 dBu contour. No stations will be protected beyond
   Class C separations.

   (c) In addition to meeting the separations specified in paragraphs (a) and
   (b), LPFM applications must meet the minimum separation requirements in the
   following table with respect to authorized FM translator stations, cutoff FM
   translator applications, and FM translator applications filed prior to the
   release of the Public Notice announcing the LPFM window period.
   Distance to FM translator 60 dBu contour Co-channel minimum separation (km)
   First-adjacent channel
   minimum separation (km) Second and
   third adjacent
   channel
   minimum
   separation
   (km)—required
   Required For no
   interference
   received Required For no
   interference
   received
   13.3 km or greater 39 67 28 35 21
   Greater than 7.3 km, but less than 13.3 km 32 51 21 26 14
   7.3 km or less 26 30 15 16 8

   (d) Existing LPFM stations which do not meet the separations in paragraphs
   (a)  through  (c)  of  this section may be relocated provided that the
   separation to any short-spaced station is not reduced.

   (e)(1) Waiver of the second-adjacent channel separations. The Commission
   will entertain requests to waive the second-adjacent channel separations in
   paragraphs (a) through (c) of this section on a case-by-case basis. In each
   case,  the  LPFM  station  must establish, using methods of predicting
   interference  taking  into  account  all  relevant  factors, including
   terrain-sensitive propagation models, that its proposed operations will not
   result in interference to any authorized radio service. The LPFM station may
   do  so  by demonstrating that no actual interference will occur due to
   intervening terrain or lack of population. The LPFM station may use an
   undesired/desired signal strength ratio methodology to define areas of
   potential interference.

   (2) Interference. (i) Upon receipt of a complaint of interference from an
   LPFM station operating pursuant to a waiver granted under paragraph (e)(1)
   of this section, the Commission shall notify the identified LPFM station by
   telephone or other electronic communication within one business day.

   (ii) An LPFM station that receives a waiver under paragraph (e)(1) of this
   section  shall  suspend operation immediately upon notification by the
   Commission that it is causing interference to the reception of an existing
   or modified full-service FM station without regard to the location of the
   station receiving interference. The LPFM station shall not resume operation
   until such interference has been eliminated or it can demonstrate to the
   Commission that the interference was not due to emissions from the LPFM
   station. Short test transmissions may be made during the period of suspended
   operation to check the efficacy of remedial measures.

   (f) Commercial and noncommercial educational stations authorized under
   subparts B and C of this part, as well as new or modified commercial FM
   allotments, are not required to adhere to the separations specified in this
   rule section, even where new or increased interference would be created.

   (g) International considerations within the border zones. (1) Within 320 km
   of  the Canadian border, LPFM stations must meet the following minimum
   separations with respect to any Canadian stations:
   Canadian station class Co-channel
   (km) First-adjacent channel
   (km) Second-
   adjacent
   channel
   (km) Third-adjacent channel
   (km) Intermediate
   frequency (IF)
   channel
   (km)
   A1 & Low Power 45 30 21 20 4
   A 66 50 41 40 7
   B1 78 62 53 52 9
   B 92 76 68 66 12
   C1 113 98 89 88 19
   C 124 108 99 98 28

   (2)  Within  320 km of the Mexican border, LPFM stations must meet the
   following separations with respect to any Mexican stations:
   Mexican station class Co-channel
   (km) First-adjacent channel
   (km) Second- and third-adjacent channel
   (km) Intermediate
   frequency (IF)
   channel
   (km)
   Low Power 27 17 9 3
   A 43 32 25 5
   AA 47 36 29 6
   B1 67 54 45 8
   B 91 76 66 11
   C1 91 80 73 19
   C 110 100 92 27

   (3) The Commission will notify the International Telecommunications Union
   (ITU) of any LPFM authorizations in the US Virgin Islands. Any authorization
   issued for a US Virgin Islands LPFM station will include a condition that
   permits the Commission to modify, suspend or terminate without right to a
   hearing  if  found by the Commission to be necessary to conform to any
   international regulations or agreements.

   (4)  The Commission will initiate international coordination of a LPFM
   proposal even where the above Canadian and Mexican spacing tables are met,
   if it appears that such coordination is necessary to maintain compliance
   with international agreements.

   [ 78 FR 2102 , Jan. 9, 2013]

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