§  74.751   Modification of transmission systems.

   (a) No change, either mechanical or electrical, may be made in
   apparatus which has been certificated by the Commission without prior
   authority of the Commission. If such prior authority has been given to
   the manufacturer of certificated equipment, the manufacturer may issue
   instructions for such changes citing its authority. In such cases,
   individual licensees are not required to secure prior Commission
   approval but shall notify the Commission when such changes are
   completed.

   (b) Formal application (FCC Form 346) is required for any of the
   following changes:

   (1) Replacement of the transmitter as a whole, except replacement with
   a transmitter of identical power rating which has been certificated by
   the FCC for use by low power TV, TV translator, and TV booster
   stations, or any change which could result in a change in the
   electrical characteristics or performance of the station.

   (2) Any change in the transmitting antenna system, including the
   direction of radiation, directive antenna pattern, antenna gain,
   transmission line loss characteristics, or height of antenna center of
   radiation.

   (3) Any change in the overall height of the antenna structure, except
   where notice to the Federal Aviation Administration is specifically not
   required under § 17.14(b) of this chapter.

   (4) Any horizontal change of the location of the antenna structure
   which would (i) be in excess of 152.4 meters (500 feet), or (ii)
   require notice to the Federal Aviation Administration pursuant to
   § 17.7 of the FCC's Rules.

   (5) A change in frequency assignment.

   (6) Any changes in the location of the transmitter except within the
   same building or upon the same pole or tower.

   (7) A change of authorized operating power.

   (c) Other equipment changes not specifically referred to in paragraphs
   (a) and (b) of this section may be made at the discretion of the
   licensee, provided that the FCC in Washington, DC, Attention: Video
   Division, Media Bureau, is notified in writing upon the completion of
   such changes.

   (d) Upon installation of new or replacement transmitting equipment for
   which prior FCC authority is not required under the provisions of this
   section, the licensee must place in the station records a certification
   that the new installation complies in all respects with the technical
   requirements of this part and the station authorization.

   [ 28 FR 13722 , Dec. 14, 1963, as amended at  38 FR 6827 , Mar. 13, 1973;
    39 FR 38652 , Nov. 1, 1974;  45 FR 26067 , Apr. 17, 1980;  47 FR 21501 , May
   18, 1982;  48 FR 41423 , Sept. 15, 1983;  50 FR 23710 , June 5, 1985;  52 FR 31405 , Aug. 20, 1987;  63 FR 33879 , June 22, 1998;  63 FR 36605 , July 7,
   1998;  67 FR 13233 , Mar. 21, 2002]