1. (a) Except for assignments made pursuant to § 73.213 or 73.215, FM allotments and assignments must be separated from other allotments and assignments on the same channel (co-channel) and five pairs of adjacent channels by not less than the minimum distances specified in paragraphs (b) and (c) of this section. The Commission will not accept petitions to amend the Table of Allotments unless the reference points meet all of the minimum distance separation requirements of this section. The Commission will not accept applications for new stations, or applications to change the channel or location of existing assignments unless transmitter sites meet the minimum distance separation requirements of this section, or such applications conform to the requirements of § 73.213 or 73.215. However, applications to modify the facilities of stations with short-spaced antenna locations authorized pursuant to prior waivers of the distance separation requirements may be accepted, provided that such applications propose to maintain or improve that particular spacing deficiency. Class D (secondary) assignments are subject only to the distance separation requirements contained in paragraph (b)(3) of this section. (See § 73.512 for rules governing the channel and location of Class D (secondary) assignments.)

2. (b) The distances listed in Tables 1, 2, and 3 of this paragraph (b) apply to allotments and assignments on the same channel and each of five pairs of adjacent channels. The five pairs of adjacent channels are the first (200 kHz above and 200 kHz below the channel under consideration), the second (400 kHz above and below), the third (600 kHz above and below), the fifty-third (10.6 MHz above and below), and the fifty-fourth (10.8 MHz above and below). The distances in the Tables apply regardless of whether the proposed station class appears first or second in the “Relation” column of the table.

   1. (1) Domestic distance separation. Domestic allotments and assignments must be separated from each other by not less than the distances in Table 1 to this paragraph (b):

      Table 1 to Paragraph (b)—Minimum Distance Separation Requirements in Kilometers[Miles]

      Relation	Co-channel	200 kHz	400/600 kHz	10.6/10.8 MHz
      A to A	115 (71)	72 (45)	31 (19)	10 (6)
      A to B1	143 (89)	96 (60)	48 (30)	12 (7)
      A to B	178 (111)	113 (70)	69 (43)	15 (9)
      A to C3	142 (88)	89 (55)	42 (26)	12 (7)
      A to C2	166 (103)	106 (66)	55 (34)	15 (9)
      A to C1	200 (124)	133 (83)	75 (47)	22 (14)
      A to C0	215 (134)	152 (94)	86 (53)	25 (16)
      A to C	226 (140)	165 (103)	95 (59)	29 (18)
      B1 to B1	175 (109)	114 (71)	50 (31)	14 (9)
      B1 to B	211 (131)	145 (90)	71 (44)	17 (11)
      B1 to C3	175 (109)	114 (71)	50 (31)	14 (9)
      B1 to C2	200 (124)	134 (83)	56 (35)	17 (11)
      B1 to C1	233 (145)	161 (100)	77 (48)	24 (15)
      B1 to C0	248 (154)	180 (112)	87 (54)	27 (17)
      B1 to C	259 (161)	193 (120)	105 (65)	31 (19)
      B to B	241 (150)	169 (105)	74 (46)	20 (12)
      B to C3	211 (131)	145 (90)	71 (44)	17 (11)
      B to C2	241 (150)	169 (105)	74 (46)	20 (12)
      B to C1	270 (168)	195 (121)	79 (49)	27 (17)
      B to C0	272 (169)	214 (133)	89 (55)	31 (19)
      B to C	274 (170)	217 (135)	105 (65)	35 (22)
      C3 to C3	153 (95)	99 (62)	43 (27)	14 (9)
      C3 to C2	177 (110)	117 (73)	56 (35)	17 (11)
      C3 to C1	211 (131)	144 (90)	76 (47)	24 (15)
      C3 to C0	226 (140)	163 (101)	87 (54)	27 (17)
      C3 to C	237 (147)	176 (109)	96 (60)	31 (19)
      C2 to C2	190 (118)	130 (81)	58 (36)	20 (12)
      C2 to C1	224 (139)	158 (98)	79 (49)	27 (17)
      C2 to C0	239 (148)	176 (109)	89 (55)	31 (19)
      C2 to C	249 (155)	188 (117)	105 (65)	35 (22)
      C1 to C1	245 (152)	177 (110)	82 (51)	34 (21)
      C1 to C0	259 (161)	196 (122)	94 (58)	37 (23)
      C1 to C	270 (168)	209 (130)	105 (65)	41 (25)
      C0 to C0	270 (168)	207 (129)	96 (60)	41 (25)
      C0 to C	281 (175)	220 (137)	105 (65)	45 (28)
      C to C	290 (180)	241 (150)	105 (65)	48 (30)

   2. (2) Canadian border distance separation. Under the 1991 United States-Canada FM Broadcasting Agreement, as amended, any domestic U.S. allotment or assignment within 320 kilometers (199 miles) of the common border must either satisfy the contour overlap provisions set out in the Agreement or be separated from Canadian allotments and assignments by not less than the distance given in Table 2 to this paragraph (b), using the distance calculation methodology set out in the Agreement. When applying Table 2, U.S. Class C0 allotments and assignments are considered to be Class C; U.S. Class C2 allotments and assignments are considered to be Class B; and U.S. Class C3 allotments and assignments are considered to be Class B1.

      Table 2 to Paragraph (b)—Minimum Distance Separation Requirements in Kilometers[Canada]

      Relation	Co-channel	200 kHz	400 kHz	600 kHz	10.6/10.8 MHz(I.F.)
      A1 to A1	78	45	24	20	4
      A1 to A	131	78	44	40	7
      A1 to B1	164	98	57	53	9
      A1 to B	190	117	71	67	12
      A1 to C1	223	148	92	88	19
      A1 to C	227	162	103	99	26
      A to A	151	98	51	42	10
      A to B1	184	119	64	55	12
      A to B	210	137	78	69	15
      A to C1	243	168	99	90	22
      A to C	247	182	110	101	29
      B1 to B1	197	131	70	57	24
      B1 to B	223	149	84	71	24
      B1 to C1	256	181	108	92	40
      B1 to C	259	195	116	103	40
      B to B	237	164	94	74	24
      B to C1	271	195	115	95	40
      B to C	274	209	125	106	40
      C1 to C1	292	217	134	101	48
      C1 to C	302	230	144	111	48
      C to C	306	241	153	113	48

   3. (3) Mexican border distance separation. Under the 1992 United States-Mexico FM Broadcasting Agreement, any domestic U.S. assignment or allotment within 320 kilometers (199 miles) of the common border must either satisfy the contour overlap provisions set out in section 7.3 of the Agreement or be separated from Mexican assignments or allotments by not less than the distances given in Table 3 to this paragraph (b), using the distance calculation methodology set out in the Agreement. The minimum required distance separation between I.F. allotments and assignments cannot be reduced. When applying Table 3—

      1. (i) U.S. or Mexican assignments or allotments which have been notified internationally as Class A are limited to a maximum of 3.0 kW ERP at 100 meters HAAT, or the equivalent;
      2. (ii) U.S. or Mexican assignments or allotments which have been notified internationally as Class AA are limited to a maximum of 6.0 kW ERP at 100 meters HAAT, or the equivalent;
      3. (iii) U.S. Class C3 assignments or allotments are considered Class B1;
      4. (iv) U.S. Class C2 assignments or allotments are considered Class B;
      5. (v) Class C1 assignments or allotments assume maximum facilities of 100 kW ERP at 300 meters HAAT. However, U.S. Class C1 stations may not, in any event, exceed the domestic U.S. limit of 100 kW ERP at 299 meters HAAT, or the equivalent; and

      6. (vi) U.S. Class C0 assignments or allotments are considered Class C.

         Table 3 to Paragraph (b)—Minimum Distance Separation Requirements in Kilometers[Mexico]

         Relation	Co-Channel	200 kHz	400 kHz or 600 kHz	10.6 or 10.8 MHz (I.F.)
         A to A	100	61	25	8
         A to AA	111	68	31	9
         A to B1	138	88	48	11
         A to B	163	105	65	14
         A to C1	196	129	74	21
         A to C	210	161	94	28
         AA to AA	115	72	31	10
         AA to B1	143	96	48	12
         AA to B	178	125	69	15
         AA to C1	200	133	75	22
         AA to C	226	165	95	29
         B1 to B1	175	114	50	14
         B1 to B	211	145	71	17
         B1 to C1	233	161	77	24
         B1 to C	259	193	96	31
         B to B	237	164	65	20
         B to C1	270	195	79	27
         B to C	270	215	98	35
         C1 to C1	245	177	82	34
         C1 to C	270	209	102	41
         C to C	290	228	105	48

3. (c) The distances listed below apply only to allotments and assignments on Channel 253 (98.5 MHz). The Commission will not accept petitions to amend the Table of Allotments, applications for new stations, or applications to change the channel or location of existing assignments where the following minimum distances (between transmitter sites, in kilometers) from any TV Channel 6 allotment or assignment are not met:

   Minimum Distance Separation From TV Channel 6 (82-88 MHz)

   FM Class	TV Zone I	TV Zones II & III
   A	17	22
   B1	19	23
   B	22	26
   C3	19	23
   C2	22	26
   C1	29	33
   C	36	41

[48 FR 29504, June 27, 1983, as amended at 49 FR 10264, Mar. 20, 1984; 49 FR 19670, May 9, 1984; 49 FR 50047, Dec. 26, 1984; 51 FR 26250, July 22, 1986; 54 FR 14963, Apr. 14, 1989; 54 FR 16366, Apr. 24, 1989; 54 FR 19374, May 5, 1989; 54 FR 35338, Aug. 25, 1989; 56 FR 27426, June 14, 1991; 56 FR 57293, Nov. 8, 1991; 62 FR 50256, Sept. 25, 1997; 65 FR 79776, Dec. 20, 2000; 87 FR 15342, Mar. 18, 2022]