§  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 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 76-81 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: 76-81 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): 275-286 GHz, 296-306 GHz, 313-356 GHz, 361-365 GHz, 369-392
   GHz, 397-399 GHz, 409-411 GHz, 416-434 GHz, 439-467 GHz, 477-502 GHz,
   523-527 GHz, 538-581 GHz, 611-630 GHz, 634-654 GHz, 657-692 GHz,
   713-718 GHz, 729-733 GHz, 750-754 GHz, 771-776 GHz, 823-846 GHz,
   850-854 GHz, 857-862 GHz, 866-882 GHz, 905-928 GHz, 951-956 GHz,
   968-973 GHz and 985-990 GHz.

   (g) In the 2200 m and 630 m bands:

   (1) Amateur stations in the 135.7-137.8 kHz (2200 m) and 472-479 kHz
   (630 m) bands shall only operate at fixed locations. Amateur stations
   shall not operate within a horizontal distance of one kilometer from a
   transmission line that conducts a power line carrier (PLC) signal in
   the 135.7-137.8 kHz or 472-479 kHz bands. Horizontal distance is
   measured from the station's antenna to the closest point on the
   transmission line.

   (2) Prior to commencement of operations in the 135.7-137.8 kHz (2200 m)
   and/or 472-479 kHz (630 m) bands, amateur operators shall notify the
   Utilities Telecom Council (UTC) of their intent to operate by
   submitting their call signs, intended band or bands of operation, and
   the coordinates of their antenna's fixed location. Amateur stations
   will be permitted to commence operations after the 30-day period unless
   UTC notifies the station that its fixed location is located within one
   kilometer of PLC systems operating in the same or overlapping
   frequencies.

   (3) Amateur stations in the 135.7-137.8 kHz (2200 m) band shall not
   cause harmful interference to, and shall accept interference from:

   (i) Stations authorized by the United States Government in the fixed
   and maritime mobile services;

   (ii) Stations authorized by other nations in the fixed, maritime
   mobile, and radionavigation service.

   (4) Amateur stations in the 472-479 kHz (630 m) band shall not cause
   harmful interference to, and shall accept interference from:

   (i) Stations authorized by the FCC in the maritime mobile service;

   (ii) Stations authorized by other nations in the maritime mobile and
   aeronautical radionavigation services.

   (5) Amateur stations causing harmful interference shall take all
   necessary measures to eliminate such interference—including temporary
   or permanent termination of transmissions.

   (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) [Reserved]

   (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) [Reserved]

   (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;  82 FR 27215 , June 14, 2017;  82 FR 43872 , Sept.
   20, 2017;  85 FR 64068 , Oct. 9, 2020]