Kevin,
I have modeled Ts and Ls and quarter wave verticals. When you model them
against the same ground they are all pretty close to each other (like within
a db or two). I like the T because the pattern is round and the takeoff
angle is overall lower than the L. The L gets not symmetrical as a function
of where the horizontal part goes and how high it is, and the takeoff angle
is different in different directions as a result of the same factors.
What I have noticed is that getting the feedpoint off the ground had the
biggest effect (on the models). I could have a 130 foot vertical if I fed
it at ground level, but I chose to elevate the feedpoint 40 feet and have a
90 foot T instead because it modeled better with fewer, easier to install
radials (the four radials slope down to about face height). (My ground is
sand and rock with lots of wildlife). I guess that makes my antenna more of
a "groundplane" than a "vertical." On the air it works real good.
See you in the Stew.
Mark, N5OT
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