Hi, and thanks for reading.
I'm working on modeling a shortend vertical for 160 I want to build. The
model can be downloaded from:
http://www.reydata.com/160kb8jvh.ez if you wish to take a look. I'm using
the newest version of EZNEC. A couple of questions. I've noticed if I have
the loading coil at the base the current goes to zero at the top like a full
size vertical model. If I move the loading coil to near the top of the
vertical the current shows it stays at maximum for the full length. It also
seems to take more inductance to resonate the vertical if I place it at the
top. Is this normal or an effect of EZNEC ? The Radiation resistance is
around 15 ohms and the 2 to 1 bandwidth is about 20khz. Anyone have a
suggestion for broadening it out abit short of making it taller. The tophat
is already 10 feet in diameter, so I don't think I can deal structurally
with much more than that. The model currently has 12 radials, but I've
modeled it with as many as 30 without much effect on the bandwidth. Any
ideas or comments welcome.
Tony Reynolds
KB8JVH
EN80ua
160, 6, 2, 432, 3456, Laser
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