Sec.  73.37   Applications for broadcast facilities, showing required.

   (a)  No application will be accepted for a new station if the proposed
   operation would involve overlap of signal strength contours with any other
   station as set forth below in this paragraph; and no application will be
   accepted  for a change of the facilities of an existing station if the
   proposed change would involve such overlap where there is not already such
   overlap between the stations involved:
   Frequency separation (kHz) Contour of proposed station (classes B, C and D)
   (mV/m) Contour of any other station (mV/m)
   0 0.005
   0.025
   0.500 0.100 (Class A).
   0.500(Other classes).
   0.025 (All classes).
   10 0.250
   0.500 0.500(All classes).
   0.250 (All classes).
   20 5
   5 5 (All classes).
   5 (All classes).
   30 25 25 (All classes).

   (b)  In determining overlap received, an application for a new Class C
   station with daytime power of 250 watts, or greater, shall be considered on
   the assumption that both the proposed operation and all existing Class C
   stations operate with 250 watts and utilize non-directional antennas.

   (c)  If  otherwise consistent with the public interest, an application
   requesting an increase in the daytime power of an existing Class C station
   on a local channel from 250 watts to a maximum of 1kW, or from 100 watts to
   a maximum of 500 watts, may be granted notwithstanding overlap prohibited by
   paragraph (a) of this section. In the case of a 100 watt Class C station
   increasing daytime power, the provisions of this paragraph shall not be
   construed  to  permit  an increase in power to more than 500 watts, if
   prohibited overlap would be involved, even if successive applications should
   be tendered.

   (d) In addition to demonstrating compliance with paragraphs (a), and, as
   appropriate, (b), and (c) of this section, an application for a new AM
   broadcast  station,  or  for a major change (see  Sec. 73.3571(a)(1)) in an
   authorized AM broadcast station, as a condition for its acceptance, shall
   make a satisfactory showing, if new or modified nighttime operation by a
   Class B station is proposed, that objectionable interference will not result
   to an authorized station, as determined pursuant to  Sec. 73.182(1).

   (e) An application for an authorization in the 1605–1705 kHz band which has
   been selected through the petition process (See  Sec. 73.30) is not required to
   demonstrate compliance with paragraph (a), (b), (c), or (d) of this section.
   Instead, the applicant need only comply with the terms of the allotment
   authorization issued by the Commission in response to the earlier petition
   for  establishment  of a station in the 1605–1705 kHz band. Within the
   allotment authorization, the Commission will specify the assigned frequency
   and the applicable technical requirements.

   (f) Stations on 1580, 1590 and 1600 kHz. In addition to the rules governing
   the authorization of facilities in the 535–1605 kHz band, stations on these
   frequencies seeking facilities modifications must protect assignments in the
   1610–1700 kHz band. Such protection shall be afforded in a manner which
   considers the spacings that occur or exist between the subject station and a
   station within the range 1605–1700 kHz. The spacings are the same as those
   specified for stations in the frequency band 1610–1700 kHz or the current
   separation distance, whichever is greater. Modifications that would result
   in a spacing or spacings that fails to meet any of the separations must
   include a showing that appropriate adjustment has been made to the radiated
   signal  which  effectively results in a site-to-site radiation that is
   equivalent to the radiation of a station with standard Model I facilities
   (10 kW-D, 1 kW-N, non-DA, 90 degree antenna ht. & ground system) operating
   in compliance with all of the above separation distances. In those cases
   where that radiation equivalence value is already exceeded, a station may
   continue to maintain, but not increase beyond that level.

   Note 1: In the case of applications for changes in the facilities of AM
   broadcast stations covered by this section, an application will be accepted
   even though overlap of field strength contours as mentioned in this section
   would occur with another station in an area where such overlap does not
   already exist, if:

   (1) The total area of overlap with that station would not be increased;

   (2) There would be no net increase in the area of overlap with any other
   station; and

   (3) There would be created no area of overlap with any station with which
   overlap does not now exist.

   Note 2: The provisions of this section concerning prohibited overlap of
   field strength contours will not apply where:

   (1) The area of overlap lies entirely over sea water: or

   (2) The only overlap involved would be that caused to a foreign station, in
   which case the provisions of the applicable international agreement, as
   identified in  Sec. 73.1650, will apply. When overlap would be received from a
   foreign station, the provisions of this section will apply, except where
   there would be overlap with a foreign station with a frequency separation of
   20 kHz, in which case the provisions of the international agreement will
   apply in lieu of this section.

   Note  3:  In determining the number of “authorized” aural transmission
   facilities in a given community, applications for that community in hearing
   or otherwise having protected status under specified “cut-off” procedures
   shall be considered as existing stations. In the event that there are two or
   more mutually exclusive protected applications seeking authorization for the
   proposed community it will be assumed that only one is “authorized.”

   Note 4: A “transmission facility” for a community is a station licensed to
   the community. Such a station provides a “transmission service” for that
   community.

   [ 56 FR 64858 , Dec. 12, 1991;  57 FR 43290 , Sept. 18, 1992]