Sec. 73.1690  Modification of transmission systems.

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    (b) The following changes may be made only upon specific authority 
of the FCC. Applications requesting authorization must be filed on FCC 
Form 301 for commercial stations and on FCC Form 340 for noncommercial 
educational stations.
    (1) Any change in the location, or directional radiation 
characteristics of a directional antenna system. (See Sec. 73.45 and 
Sec. 73.150, AM; Sec. 73.316, FM; or Sec. 73.685, TV.)
    (2) Change in the operating power from that specified on the station 
authorization, except as provided in paragraph (c)(4) of this section.
    (3) Change in location of the main studio to a location outside the 
station's principal community contour, except as provided for in 
Sec. 73.1125.
    (c) The following FM and TV station modifications may be made and 
operation commenced without prior authorization from the FCC, provided 
that the modifications would not possibly affect the operation of any 
co-located or nearby AM station. An application for license modification 
must be filed on FCC Form 302 within 10 days following completion of the 
changes. Equipment performance measurements are not required for 
applications covering changes described in paragraphs (c) (1) and (2) of 
this section.
    (1) Replacement of a non-directional antenna with one of the same or 
different type or number of bays, provided that the height above ground 
of the center of radiation is within 2 meters of that specified in the 
station authorization, the parameters are within that permitted by its 
class designation, and there is no change in the maximum effective 
radiated power.
    (2) Installation of a transmission line with one of a different type 
or length which requires change in the transmitter output power to 
maintain the licensed effective radiated power.
    (3) Installation of harmonic filters, sideband filters or diplexers 
of a different type which requires a change in the transmitter output 
power to maintain the licensed effective radiated power.
    (4) On or after December 1, 1989, increase in the effective radiated 
power of eligible Class A FM stations pursuant to MM Docket 88-375, when 
such increase is effected by:
    (i) Replacement of a non-directional antenna with another non-
directional antenna having higher gain, provided that the height above 
ground of the center of radiation is within &177;2 meters of that 
specified in the station authorization; and/or
    (ii) Increase in the power input to the antenna, as a result of 
adjustment of the transmitter output power, change in the type or

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length of the transmission line, and/or installation of filters or 
diplexers.

    Note: Class A stations eligible for a power increase pursuant to 
paragraph (c)(4) are those which appear on a list issued by the 
Commission in November 1989.

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