§  22.625   Transmitter locations.

   This section governs where point-to-multipoint transmitters on the
   channels listed in §  22.621 may be located.

   (a) 928-960 MHz. In this frequency range, the required minimum distance
   separation between co-channel fixed transmitters is 113 kilometers (70
   miles).

   (b) 470-512 MHz. The purpose of the rule in paragraph (b)(1) of this
   section is to define the areas in which the 470-512 MHz channels are
   allocated for public mobile use. The purpose of the rules in paragraphs
   (b)(2) and (b)(3) of this section is to reduce the likelihood that
   interference to television reception from public mobile operations on
   these channels will occur.

   (1) Control transmitter locations. Control transmitter locations must
   be within 80 kilometers (50 miles) of the designated locations in this
   paragraph.
          Urban area         N. latitude W. longitude
   Boston, MA                42°21′24.4″  71°03′22.2″
   Chicago, IL               41°52′28.1″  87°38′22.2″
   Cleveland, OH             41°29′51.2″  81°41′49.5″
   Dallas, TX                32°47′09.5″  96°47′38.0″
   Detroit, MI               42°19′48.1″  83°02′56.7″
   Houston, TX               29°45′26.8″  95°21′37.8″
   Los Angeles, CA           34°03′15.0″  18°14′31.3″
   Miami, FL                 25°46′38.6″  80°11′31.2″
   New York, NY               40°45′6.4″  73°59′37.5″
   Philadelphia, PA          39°56′58.4″  75°09′19.6″
   Pittsburgh, PA            40°26′19.2″  79°59′59.2″
   San Francisco-Oakland, CA 37°46′38.7″ 122°24′43.9″
   Washington, DC            38°53′51.4″  77°00′31.9″

   Note: Coordinates are referenced to North American Datum 1983 (NAD 83).

   (2) Protection from intermodulation interference. Control transmitter
   locations must be at least 1.6 kilometers (1 mile) from the main
   transmitter locations of all TV stations transmitting on TV channels
   separated by 2, 3, 4, 5, 7, or 8 TV channels from the TV channel
   containing the frequencies on which the control station will transmit.
   This requirement is intended to reduce the likelihood of
   intermodulation interference.

   (3) Co-channel protection from control transmitters with high antennas.
   This paragraph applies only to control transmitters that utilize an
   antenna height of more than 152 meters (500 feet) above average
   terrain. The distance between the location of such a control
   transmitter and the applicable protected TV station location specified
   in this paragraph must equal or exceed the sum of the distance from the
   control transmitter location to the radio horizon in the direction of
   the specified location and 89 kilometers (55 miles—representing the
   distance from the main transmitter location of the TV station to its
   Grade B contour in the direction of the control transmitter). The
   protected TV station locations in this paragraph are the locations of
   record as of September 1974, and these do not change even though the TV
   stations may have been subsequently relocated.

   (i) The protected TV station locations are as follows:
   Control transmitter frequency range   Protected TV station location
   470-476 MHz                         Washington, DC 38°57′17″ 77°00′17″
   476-482 MHz                         Lancaster, PA 40°15′45″ 76°27′49″

   (ii) The distance to the radio horizon is calculated using the
   following formula:
   eCFR graphic er17no94.008.gif

   where

   d is the distance to the radio horizon in kilometers

   h is the height of the antenna center of radiation above ground level
   in meters

   [ 59 FR 59507 , Nov. 17, 1994, as amended at  63 FR 68946 , Dec. 14, 1998,
    70 FR 19309 , Apr. 13, 2005]

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