§  22.657   Transmitter locations.

   The purpose of the rules in paragraphs (a) and (b) 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 (c) through
   (f) of this section is to reduce the likelihood that interference to
   television reception from public mobile operations on these channels
   will occur. The protected TV station locations specified in paragraphs
   (d), (e)(1) and (f) of this section are the locations of record as of
   September 1974, and these do not change even though the TV stations may
   have been subsequently relocated.

   (a) Base transmitter locations. Base transmitter locations must be
   within 80 kilometers (50 miles) of the designated locations in this
   paragraph. Mobile transmitters must not be operated at locations more
   than 129 kilometers (80 miles) from the designated locations in this
   paragraph. Note: All coordinates are referenced to North American Datum
   1983 (NAD83).
       Urban area     N. latitude W. longitude
   Houston, TX        29°45′26.8″  95°21′37.8″
   New York, NY-NE NJ 40°45′06.4″  73°59′37.5″

   (b) Mobile area of operation. Mobile transmitters must not be operated
   at locations more than 48 kilometers (30 miles) from all associated
   base stations.

   (c) Protection from intermodulation interference. Base transmitter
   locations must be at least 1.6 kilometers (1 mile) from the current
   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 base station will
   transmit. This requirement is intended to reduce the likelihood of
   intermodulation interference.

   (d) Adjacent channel protection from mobile transmitters. Base
   transmitter locations must be at least 145 kilometers (90 miles) from
   the applicable protected TV station locations specified in this
   paragraph. This requirement is intended to provide a 0 dB minimum
   desired to undesired signal strength ratio at the Grade B contour of an
   adjacent channel TV station. Note: All coordinates are referenced to
   North American Datum 1983 (NAD83).
   Control transmitter frequency range Protected TV station location TV
   channel
   470-476 MHz Lancaster, PA, 40°15′45.3″ N. Lat. 76°27′47.9″ W. Long.
   (15)
   476-482 MHz Scranton, PA, 41°10′58.3″ N. Lat. 75°52′19.7″ W. Long. (16)

   (e) Co-channel protection from mobile transmitters. Base transmitter
   locations must be at least the distance specified in paragraph (e)(2)
   of this section from the applicable protected TV station locations
   specified in paragraph (e)(1) of this section. This requirement is
   intended to provide a 40 dB minimum desired to undesired signal
   strength ratio at the Grade B contour of a co-channel TV station.

   (1) The protected TV station locations are as follows (all coordinates
   are referenced to North American Datum 1983 (NAD83)):
   Control transmitter frequency range Protected TV station location
   470-476 MHz Washington, DC, 38°57′17.4″ N. Lat. 77°00′15.9″ W. Long.
   476-482 MHz Lancaster, PA, 40°15′45.3″ N. Lat. 76°27′47.9″ W. Long.

   (2) The required minimum distance depends upon the effective radiated
   power (ERP) of the most powerful mobile transmitter(s) in the system:
   Mobile unit ERP (watts) Minimum distance
                           Kilometers Miles
   60                             193 (120)
   50                             185 (115)
   25                             177 (110)
   10                             169 (105)
   5                              161 (100)

   (f) Co-channel protection from base transmitters with high antennas.
   This paragraph applies only to base transmitter locations in the New
   York-Northeastern New Jersey urban area that utilize an antenna height
   of more than 152 meters (500 feet) above average terrain. The distance
   between the location of such a base transmitter and the applicable
   protected TV station location specified in this paragraph must equal or
   exceed the sum of the distance from the base 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 base transmitter). The distance to the radio horizon
   is calculated as follows:
   eCFR graphic er14de98.026.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

   Note: All coordinates are referenced to North American Datum 1983
   (NAD83)):
   Control transmitter frequency range Protected TV station location
   470-476 MHz Washington, DC, 38°57′17.4″ N. Lat. 77°00′15.9″ W. Long.
   476-482 MHz Lancaster, PA, 40°15′45.3″ N. Lat. 76°27′47.9″ W. Long.

   (g) The FCC may waive specific distance separation requirements of
   paragraphs (d) through (f) of this section if the applicant submits an
   engineering analysis which demonstrates that terrain effects and/or
   operation with less effective radiated power would satisfy the
   applicable minimum desired to undesired signal strength ratios at the
   Grade B contours of the protected TV stations. For this purpose, the
   Grade B contour of a TV station is deemed to be a circle with a 89
   kilometer (55 mile) radius, centered on the protected TV station
   location, and along which the median TV signal field strength is 64
   dBµV/m. In any showing intended to demonstrate compliance with the
   minimum desired to undesired signal ratio requirements of this section,
   all predicted field strengths must have been determined using the UHF
   TV propagation curves contained in part 73 of this chapter.

   [ 59 FR 59507 , Nov. 17, 1994, as amended at  63 FR 68947 , Dec. 14, 1998]

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