§  73.315   FM transmitter location.

   (a) The transmitter location shall be chosen so that, on the basis of
   the effective radiated power and antenna height above average terrain
   employed, a minimum field strength of 70 dB above one uV/m (dBu), or
   3.16 mV/m, will be provided over the entire principal community to be
   served.

   (b) The transmitter location should be chosen to maximize coverage to
   the city of license while minimizing interference. This is normally
   accomplished by locating in the least populated area available while
   maintaining the provisions of paragraph (a) of this section. In
   general, the transmitting antenna of a station should be located in the
   most sparsely populated area available at the highest elevation
   available. The location of the antenna should be so chosen that
   line-of-sight can be obtained from the antenna over the principle city
   or cities to be served; in no event should there be a major obstruction
   in this path.

   (c) The transmitting location should be selected so that the 1 mV/m
   contour encompasses the urban population within the area to be served.
   It is recognized that topography, shape of the desired service area,
   and population distribution may make the choice of a transmitter
   location difficult. In such cases consideration may be given to the use
   of a directional antenna system, although it is generally preferable to
   choose a site where a nondirectional antenna may be employed.

   (d) In cases of questionable antenna locations it is desirable to
   conduct propagation tests to indicate the field strength expected in
   the principal city or cities to be served and in other areas,
   particularly where severe shadow problems may be expected. In
   considering applications proposing the use of such locations, the
   Commission may require site tests to be made. Such tests should include
   measurements made in accordance with the measurement procedures
   described in § 73.314, and full data thereon shall be supplied to the
   Commission. The test transmitter should employ an antenna having a
   height as close as possible to the proposed antenna height, using a
   balloon or other support if necessary and feasible. Information
   concerning the authorization of site tests may be obtained from the
   Commission upon request.

   (e) Cognizance must of course be taken regarding the possible hazard of
   the proposed antenna structure to aviation and the proximity of the
   proposed site to airports and airways. Procedures and standards with
   respect to the Commission's consideration of proposed antenna
   structures which will serve as a guide to persons intending to apply
   for radio station licenses are contained in Part 17 of this chapter
   (Construction, Marking, and Lighting of Antenna Structures).

   [ 28 FR 13623 , Dec. 14, 1963, as amended at  41 FR 22943 , June 8, 1976;
    49 FR 38131 , Sept. 27, 1984;  49 FR 45146 , Nov. 15, 1984;  51 FR 9965 ,
   Mar. 24, 1986;  52 FR 10570 , Apr. 2, 1987;  65 FR 79778 , Dec. 20, 2000]