UHF

Enter center frequency to be calculated for a quad
mHz
Total Length Length
ONE SIDE
Spreader Arm Length
ONE SIDE  "C"
Reflector
Driven Element
Director 1
Director 2
Director3 optional
Director4 optional
Director5 optional
IN / CM / MM IN / CM / MM IN / CM / MM

spacing between the reflector and driven element should be
inches
centimeters
millimeters
Gain vs Spacing
The gain of an an antenna with parasitic elements varies with the spacing and tuning of the elements, and thus for any
given spacing there is a tuning condition that will give maximum gain this spacing. The maximum front to back ratio seldom,
if ever occurs at the same condition that gives maximum forward gain.
The impedance of the driven element also varies with the tuning and spacing, and thus the antenna system must be tuned
to its final condition before the match between the coax and the antenna can be completed. However, the tuning and matching
may interlock to some extent, and it is usually necessary to run through the adjustments several times to insure that the best possible tunning has been obtained.
spacing between the driven element and the first director and between the directors should be
inches
centimeters
millimeters


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