"Richard Clark" wrote
Does the FCC (or anyone else) define any standard site for measurement of
antennas?

Hi Ed,

It is called in situ. A field survey is required in the process of
licensing.
_______________

However the FCC does *not* require in situ measurements for the
proof/operation of ANY transmit antenna used for FM or television
broadcast -- whether required to be directional or not. If directional, the
required pattern is defined in the license application/grant, and is
demonstrated only via relative field measurements by the antenna OEM on his
test range.

The reason is that the measured value on VHF/UHF can depend at least as much
on the propagation paths to the measured points as the true radiation
pattern from the antenna hardware itself.

In situ measurements are required for certain qualified bearings on the
calculated radiation patterns of MW broadcast directional arrays, to ensure
that co-channel interference is controlled. There really isn't another
choice in this case -- the array is purpose-built on site. Erecting and
testing it off site would not be practical, and the terrain likely would be
different anyway. MW directional arrays also have means of adjusting the
phase and power in each radiator to adjust the pattern values as shown
needed by the monitoring point measurements.

RF

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