Sec. 2.993  Measurements required: Field strength of spurious radiation.

    (a) Measurements shall be made to detect spurious emissions that may 
be radiated directly from the cabinet, control circuits, power leads, or 
intermediate circuit elements under normal conditions of installation 
and operation. Curves or equivalent data shall be supplied showing the 
magnitude of each harmonic and other spurious emission. For this test, 
single sideband, independent sideband, and controlled carrier 
transmitters shall be modulated under the conditions specified in 
paragraph (c) of Sec. 2.989, as appropriate. For equipment operating on 
frequencies below 890 MHz, an open field test is normally required, with 
the measuring instrument antenna located in the far-field at all test 
frequencies. In the event it is either impractical or impossible to make 
open field measurements (e.g. a broadcast transmitter installed in a 
building) measurements will be accepted of the equipment as installed. 
Such measurements must be accompanied by a description of the site where 
the measurements were made showing the location of any possible source 
of reflections which might distort the field strength measurements. 
Information submitted shall include the relative radiated power of each 
spurious emission with reference to the rated power output of the 
transmitter, assuming all emissions are radiated from halfwave dipole 
antennas.
    (b) The measurements specified in paragraph (a) of this section 
shall be made for the following equipment:
    (1) Those in which the spurious emissions are required to be 60 dB 
or more below the mean power of the transmitter.
    (2) All equipment operating on frequencies higher than 25 MHz.
    (3) All equipment where the antenna is an integral part of, and 
attached directly to the transmitter.
    (4) Other types of equipment as required, when deemed necessary by 
the Commission.