[Code of Federal Regulations]
[Title 47, Volume 2]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR73.37]

[Page 18-19]
 
                       TITLE 47--TELECOMMUNICATION
 
        CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)
 
PART 73_RADIO BROADCAST SERVICES--Table of Contents
 
                     Subpart A_AM Broadcast Stations
 
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:

------------------------------------------------------------------------
                                 Contour of
                                  proposed
                                   station       Contour of any other
   Frequency separation (kHz)     (classes          station (mV/m)
                                  B, C and
                                  D) (mV/m)
------------------------------------------------------------------------
0..............................       0.005  0.100 (Class A).
                                      0.025  0.500(Other classes).
                                      0.500  0.025 (All classes).
10.............................       0.250  0.500(All classes).
                                      0.500  0.250 (All classes).
20.............................           5  5 (All classes).
                                          5  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

[[Page 19]]

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]