Sec.  2.1053   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. 2.1049, 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.

   [ 39 FR 5919 , Feb. 15, 1974. Redesignated and amended at  63 FR 36599 , July 7,
   1998]