§ 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]

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