"Ed Price" wrote
I can easily imagine an antenna that looks good in
"test range" conditions, but is badly influenced by
real-life items like proximity to ground, chimneys and trees.
Does the FCC (or anyone else) define any standard site
for measurement of antennas? Could the closest thing be
NIST's antenna calibration ranges?
_________________

Most test ranges are designed to measure (as accurately as practical) the
radiation pattern of the antenna hardware alone, and normally in relative
field only -- not in absolute gain.

The affect of the installation environment on the free-space patterns of an
antenna vary widely. The azimuth patterns of FM broadcast transmit antennas
are sometimes measured at the OEM's test range while mounted on a section of
tower, and in the mounting configuration to be used for the final
installation. That will show how the signal will be "launched," but gives
no final data about how well the antenna will perform after installation.
That will depend on its height above ground and propagation conditions along
the path from the transmit site to the receiver.

RF

Visit http://rfry.org for FM broadcast RF system papers.