§ 97.303   Frequency sharing requirements.

   The following paragraphs summarize the frequency sharing requirements that
   apply to amateur stations transmitting in the frequency bands specified in
   § 97.301 of this part. Each frequency band allocated to the amateur service
   is designated as either a secondary service or a primary service. A station
   in a secondary service must not cause harmful interference to, and must
   accept interference from, stations in a primary service.

   (a) Where, in adjacent ITU Regions or sub-Regions, a band of frequencies is
   allocated to different services of the same category (i.e., primary or
   secondary  services),  the basic principle is the equality of right to
   operate. Accordingly, stations of each service in one Region or sub-Region
   must operate so as not to cause harmful interference to any service of the
   same or higher category in the other Regions or sub-Regions.

   (b) Amateur stations transmitting in the 70 cm band, the 33 cm band, the 23
   cm band, the 9 cm band, the 5 cm band, the 3 cm band, or the 24.05-24.25 GHz
   segment must not cause harmful interference to, and must accept interference
   from,  stations  authorized  by  the  United  States Government in the
   radiolocation service.

   (c) Amateur stations transmitting in the 76-77.5 GHz segment, the 78-81 GHz
   segment, the 136-141 GHz segment, or the 241-248 GHz segment must not cause
   harmful  interference  to, and must accept interference from, stations
   authorized by the United States Government, the FCC, or other nations in the
   radiolocation service.

   (d) Amateur stations transmitting in the 430-450 MHz segment, the 23 cm
   band, the 3.3-3.4 GHz segment, the 5.65-5.85 GHz segment, the 13 cm band, or
   the 24.05-24.25 GHz segment, must not cause harmful interference to, and
   must accept interference from, stations authorized by other nations in the
   radiolocation service.

   (e) Amateur stations receiving in the 33 cm band, the 2400-2450 MHz segment,
   the  5.725-5.875 GHz segment, the 1.2 cm band, the 2.5 mm band, or the
   244-246 GHz segment must accept interference from industrial, scientific,
   and medical (ISM) equipment.

   (f) Amateur stations transmitting in the following segments must not cause
   harmful  interference  to  radio  astronomy stations: 3.332-3.339 GHz,
   3.3458-3.3525 GHz, 76-77.5 GHz, 78-81 GHz, 136-141 GHz, 241-248 GHz, 275-323
   GHz,  327-371 GHz, 388-424 GHz, 426-442 GHz, 453-510 GHz, 623-711 GHz,
   795-909 GHz, or 926-945 GHz. In addition, amateur stations transmitting in
   the following segments must not cause harmful interference to stations in
   the Earth exploration-satellite service (passive) or the space research
   service (passive): 275-277 GHz, 294-306 GHz, 316-334 GHz, 342-349 GHz,
   363-365 GHz, 371-389 GHz, 416-434 GHz, 442-444 GHz, 496-506 GHz, 546-568
   GHz,  624-629 GHz, 634-654 GHz, 659-661 GHz, 684-692 GHz, 730-732 GHz,
   851-853 GHz, or 951-956 GHz.

   (g) [Reserved]

   (h)  60 m band: (1) In the 5330.5-5406.4 kHz band (60 m band), amateur
   stations may transmit only on the five center frequencies specified in the
   table  below.  In order to meet this requirement, control operators of
   stations transmitting phone, data, and RTTY emissions (emission designators
   2K80J3E, 2K80J2D, and 60H0J2B, respectively) may set the carrier frequency
   1.5 kHz below the center frequency as specified in the table below. For CW
   emissions (emission designator 150HA1A), the carrier frequency is set to the
   center frequency. Amateur operators shall ensure that their emissions do not
   occupy more than 2.8 kHz centered on each of these center frequencies.

   60 M Band Frequencies (kHz)
   Carrier Center
   5330.5  5332.0
   5346.5  5348.0
   5357.0  5358.5
   5371.5  5373.0
   5403.5  5405.0

   (2) Amateur stations transmitting on the 60 m band must not cause harmful
   interference to, and must accept interference from, stations authorized by:

   (i) The United States (NTIA and FCC) and other nations in the fixed service;
   and

   (ii) Other nations in the mobile except aeronautical mobile service.

   (i) Amateur stations transmitting in the 7.2-7.3 MHz segment must not cause
   harmful interference to, and must accept interference from, international
   broadcast stations whose programming is intended for use within Region 1 or
   Region 3.

   (j) Amateur stations transmitting in the 30 m band must not cause harmful
   interference  to, and must accept interference from, stations by other
   nations in the fixed service. The licensee of the amateur station must make
   all  necessary adjustments, including termination of transmissions, if
   harmful interference is caused.

   (k) For amateur stations located in ITU Regions 1 and 3: Amateur stations
   transmitting in the 146-148 MHz segment or the 10.00-10.45 GHz segment must
   not  cause harmful interference to, and must accept interference from,
   stations of other nations in the fixed and mobile services.

   (l) In the 219-220 MHz segment:

   (1)  Use is restricted to amateur stations participating as forwarding
   stations  in  fixed point-to-point digital message forwarding systems,
   including intercity packet backbone networks. It is not available for other
   purposes.

   (2) Amateur stations must not cause harmful interference to, and must accept
   interference from, stations authorized by:

   (i) The FCC in the Automated Maritime Telecommunications System (AMTS), the
   218-219  MHz Service, and the 220 MHz Service, and television stations
   broadcasting on channels 11 and 13; and

   (ii) Other nations in the fixed and maritime mobile services.

   (3) No amateur station may transmit unless the licensee has given written
   notification  of  the  station's specific geographic location for such
   transmissions in order to be incorporated into a database that has been made
   available to the public. The notification must be given at least 30 days
   prior to making such transmissions. The notification must be given to: The
   American  Radio  Relay  League,  Inc.,  225 Main Street, Newington, CT
   06111-1494.

   (4) No amateur station may transmit from a location that is within 640 km of
   an AMTS coast station that operates in the 217-218 MHz and 219-220 MHz bands
   unless the amateur station licensee has given written notification of the
   station's specific geographic location for such transmissions to the AMTS
   licensee. The notification must be given at least 30 days prior to making
   such  transmissions.  The  location  of  AMTS coast stations using the
   217-218/219-220 MHz channels may be obtained as noted in paragraph (l)(3) of
   this section.

   (5) No amateur station may transmit from a location that is within 80 km of
   an AMTS coast station that uses frequencies in the 217-218 MHz and 219-220
   MHz bands unless that amateur station licensee holds written approval from
   that  AMTS  licensee.  The  location  of AMTS coast stations using the
   217-218/219-220 MHz channels may be obtained as noted in paragraph (l)(3) of
   this section.

   (m) In the 70 cm band:

   (1) No amateur station shall transmit from north of Line A in the 420-430
   MHz segment. See § 97.3(a) for the definition of Line A.

   (2) Amateur stations transmitting in the 420-430 MHz segment must not cause
   harmful  interference  to, and must accept interference from, stations
   authorized by the FCC in the land mobile service within 80.5 km of Buffalo,
   Cleveland, and Detroit. See § 2.106, footnote US230 for specific frequencies
   and coordinates.

   (3) Amateur stations transmitting in the 420-430 MHz segment or the 440-450
   MHz  segment  must  not cause harmful interference to, and must accept
   interference from, stations authorized by other nations in the fixed and
   mobile except aeronautical mobile services.

   (n) In the 33 cm band:

   (1) Amateur stations must not cause harmful interference to, and must accept
   interference from, stations authorized by:

   (i) The United States Government;

   (ii) The FCC in the Location and Monitoring Service; and

   (iii) Other nations in the fixed service.

   (2) No amateur station shall transmit from those portions of Texas and New
   Mexico that are bounded by latitudes 31°41′ and 34°30′ North and longitudes
   104°11′ and 107°30′ West; or from outside of the United States and its
   Region 2 insular areas.

   (3) No amateur station shall transmit from those portions of Colorado and
   Wyoming that are bounded by latitudes 39° and 42° North and longitudes 103°
   and 108° West in the following segments: 902.4-902.6 MHz, 904.3-904.7 MHz,
   925.3-925.7 MHz, and 927.3-927.7 MHz.

   (o) Amateur stations transmitting in the 23 cm band must not cause harmful
   interference to, and must accept interference from, stations authorized by:

   (1) The United States Government in the aeronautical radionavigation, Earth
   exploration-satellite (active), or space research (active) services;

   (2) The FCC in the aeronautical radionavigation service; and

   (3)   Other  nations  in  the  Earth  exploration-satellite  (active),
   radionavigation-satellite  (space-to-Earth) (space-to-space), or space
   research (active) services.

   (p) In the 13 cm band:

   (1) Amateur stations must not cause harmful interference to, and must accept
   interference from, stations authorized by other nations in fixed and mobile
   services.

   (2) Amateur stations transmitting in the 2305-2310 MHz segment must not
   cause harmful interference to, and must accept interference from, stations
   authorized by the FCC in the fixed, mobile except aeronautical mobile, and
   radiolocation services.

   (q) Amateur stations transmitting in the 3.4-3.5 GHz segment must not cause
   harmful  interference  to, and must accept interference from, stations
   authorized   by   other  nations  in  the  fixed  and  fixed-satellite
   (space-to-Earth) services.

   (r) In the 5 cm band:

   (1) Amateur stations transmitting in the 5.650-5.725 GHz segment must not
   cause harmful interference to, and must accept interference from, stations
   authorized  by  other nations in the mobile except aeronautical mobile
   service.

   (2) Amateur stations transmitting in the 5.850-5.925 GHz segment must not
   cause harmful interference to, and must accept interference from, stations
   authorized  by  the  FCC  and  other  nations  in  the fixed-satellite
   (Earth-to-space) and mobile services and also stations authorized by other
   nations  in the fixed service. In the United States, the use of mobile
   service is restricted to Dedicated Short Range Communications operating in
   the Intelligent Transportation System.

   (s) Authorization of the 76-77 GHz segment for amateur station transmissions
   is suspended until such time that the Commission may determine that amateur
   station transmissions in this segment will not pose a safety threat to
   vehicle radar systems operating in this segment.

   (t) Amateur stations transmitting in the 2.5 mm band must not cause harmful
   interference to, and must accept interference from, stations authorized by
   the  United States Government, the FCC, or other nations in the fixed,
   inter-satellite, or mobile services.

   Note to § 97.303: The Table of Frequency Allocations contains the complete,
   unabridged, and legally binding frequency sharing requirements that pertain
   to the Amateur Radio Service. See 47 CFR 2.104, 2.105, and 2.106. The United
   States, Puerto Rico, and the U.S. Virgin Islands are in Region 2 and other
   U.S. insular areas are in either Region 2 or 3; see appendix 1 to part 97.

   [ 75 FR 27203 , May 14, 2010, as amended at  77 FR 5412 , Feb. 3, 2012;  80 FR 38912 , July 7, 2015]

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