Sec.  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  Sec. 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  Sec. 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]