for vertical polarization tests, the standard feedpoint fixture is set to a height of 8 feet.
the upper element wire, a #14awg stranded tinned copper wire 16feet 9inches in length is supported vertically upward from the standard feedpoint fixture by an insulator hollow fiber tapered pole.
the lower element wire, also #14awg stranded tinned copper wire 16 feet 9 inches in length, is supported from the standard feedpoint fixture, and this wire slopes down towards the receiver site, ending at a height of 2 feet and supported by nylon cord. the combination of these two wires forms a dipole-like radiating element with a substantially vertically polarized wavefront in the direction of the test receiver antenna site.
the lower element wire of the reference vertical dipole is maintained throughout all vertical whip testing as the sole "counterpoise" or "ground radial" element for the whip antennas to "work against". all antennas under test utilize the lower element wire as a reference plane or "counterpoise" unless otherwise noted.
the reference vertical element used for the purpose of this event can be considered practically to have substantially no positive gain over a theoretical dipole in free space, and all antennas under test in the shootout measured in the vertical polarization are simply referenced in decibels with respect to the reference vertical element, with no calibration made to a theoretical dipole or isotropic radiator in free space. therefore, the decibel measurements reported in this chart are advisably utilized for comparison only among the antennas within each chart itself either for vertical or horizontal polarization. due to the unique nature of a particular antenna range, attempts to draw conclusions of comparison, relative measurements, or decibel gain/loss claims of other antennas not measured as part of this shootout with the measurements presented in these charts may result in significant error due to uncorrelated variables. 这是eham论坛上的文章
