Sec. 73.1590  Equipment performance measurements.

    (a) The licensee of each AM, FM and TV station, except licensees of 
Class D non-commercial educational FM stations authorized to operate 
with 10 watts or less output power, must make equipment performance 
measurements for each main transmitter as follows:
    (1) Upon initial installation of a new or replacement main 
transmitter.

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    (2) Upon modification of an existing transmitter made under the 
provisions of Sec. 73.1690, Modification of transmission systems, and 
specified therein.
    (3) Installation of AM stereophonic transmission equipment pursuant 
to Sec. 73.128.
    (4) Installation of FM subcarrier or stereophonic transmission 
equipment pursuant to Sec. 73.295, Sec. 73.297, Sec. 73.593 or 
Sec. 73.597.
    (5) Installation of TV stereophonic or subcarrier transmission 
equipment pursuant to Secs. 73.669 and 73.1690.
    (6) Annually, for AM stations, with not more than 14 months between 
measurements.
    (7) When required by other provisions of the rules or the station 
license.
    (b) Measurements for spurious and harmonic emissions must be made to 
show compliance with the transmission system requirements of Sec. 73.44 
for AM stations; Sec. 73.317 for FM stations and Sec. 73.687 for TV 
stations. Measurements must be made under all conditions of modulation 
expected to be encountered by the station whether transmitting 
monophonic or stereophonic programs and providing subsidiary 
communications services.
    (c) TV visual equipment performance measurements must be made with 
the equipment adjusted for normal program operation at the transmitter 
antenna sampling port to yield the following information:
    (1) Field strength or voltage of the lower side-band for a 
modulating frequency of 1.25 MHz or greater, (including 3.58 MHz for 
color), and of the upper side-band for a modulating frequency of 4.75 
MHz or greater.
    (2) Data showing that the waveform of the transmitted signal 
conforms to that specified by the standards for TV transmissions.
    (3) Photographs of a test pattern taken from a receiver or monitor 
connected to the transmitter output.
    (4) Data showing envelope delay characteristics of the radiated 
signal.
    (5) Data showing the attenuation of spurious and harmonic radiation, 
if, after type acceptance, any changes have been made in the transmitter 
or associated equipment (filters, multiplexer, etc.) which could cause 
changes in its radiation products.
    (d) The data required by paragraphs (b) and (c) of this section, 
together with a description of the equipment and procedure used in 
making the measurements, signed and dated by the qualified person(s) 
making the measurements, must be kept on file at the transmitter or 
remote control point for a period of 2 years, and on request must be 
made available during that time to duly authorized representatives of 
the FCC.

[ 47 FR 8589 , Mar. 1, 1982, as amended at  51 FR 18450 , May 20, 1986]