FCC 73.45 Revised as of October 1, 2014
Goto Year:2013 |
§ 73.45 AM antenna systems.
(a) All applicants for new, additional, or different AM station
facilities and all licensees requesting authority to change the
transmitting system site of an existing station must specify an antenna
system, the efficiency of which complies with the requirements for the
class and power of station. (See § § 73.186 and 73.189.)
(1) An application for authority to install an AM broadcast antenna
must specify a definite site and include full details of the antenna
system design and expected performance.
(2) All data necessary to show compliance with the terms and conditions
of the construction permit must be filed with the application for the
station license to cover the construction. If the station has
constructed a directional antenna, a directional proof of performance
must be filed. See § § 73.150 through 73.157.
(b) The simultaneous use of a common antenna or antenna structure by
more than one AM station or by a station of any other type or service
may be authorized provided:
(1) Engineering data are submitted showing that satisfactory operation
of each station will be obtained without adversely affecting the
operation of the other station(s).
(2) The minimum field strength for each AM station complies with
(c) Should any changes be made or otherwise occur which would possibly
alter the resistance of the antenna system, the licensee must commence
the determination of the operating power by a method described in
§ 73.51(a)(1) or (d). (If the changes are due to the addition of
antennas to the AM tower, see § 1.30003.) Upon completion of any
necessary repairs or adjustments, or upon completion of authorized
construction or modifications, the licensee must make a new
determination of the antenna resistance using the procedures described
in § 73.54. Operating power should then be determined by a direct
method as described in § 73.51. Notification of the value of resistance
of the antenna system must be filed with the FCC in Washington, DC as
(1) Whenever the measurements show that the antenna or common point
resistance differs from that shown on the station authorization by more
than 2%, FCC Form 302 must be filed with the information and
measurement data specified in § 73.54(d).
(2) Whenever AM stations use direct reading power meters pursuant to
§ 73.51, a letter notification to the FCC in Washington, DC, Attention:
Audio Division, Media Bureau, must be filed in accordance with
[ 43 FR 53735 , Nov. 17, 1978, as amended at 45 FR 28141 , Apr. 28, 1980;
47 FR 8589 , Mar. 1, 1982; 50 FR 32416 , Aug. 12, 1985; 51 FR 2707 ; Jan.
21, 1986; 51 FR 26250 , July 22, 1986; 63 FR 33875 , June 22, 1998; 67 FR 13231 , Mar. 21, 2002; 78 FR 66298 , Nov. 5, 2013]
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