[Antennaware] Help with Short Dipole

[Guy Olinger K2AV]

Very interesting. You should note from the resonance Z of 42 ohms and the
combined R in the big coils of 40 ohms that just about all the power is
dissipated in the coils. This is why people have gone to top loading on
verticals. Suppose that you went to a much larger gauge wire to reduce the
loss to the coil itself. You then find yourself in the position that there
is as much wire in the coil as there is in the dipole per se. That will be
the reason that people have gone to top loaded verticals, first to get the
highest current on the radiator as possible, and then to only have to deal
with the mass of one half of a dipole, instead of two halves. Of course
then you have to deal with ground and radials.

The ground will add to the coil losses.

The jaggedies in the trace indicate that the problem needs the double
precision engine (as in EZNEC Plus) to calculate smoothly. Jaggedies happen
when some portion of the math needs more bits in the floating point number
than allowed by a single precision engine. That and other such stuff is why
I use the NEC4 double precision engine and very small segments all the
time. If I want to export a finished model for others to view, I will
fiddle with reducing the number of segments and other stuff in the single
precision NEC2 until I get identical results and if it was "touchy" to get
it right, then I warn not to adjust the model because it's touchy in the
NEC2 single precision engine. I have some all conductor, entire location
models with over 25,000 segments in this NEC4 DP small segment mode, but
they don't get weird on me.

The next question, what are you trying to accomplish with this? You wanting
to put this in the air? Coming up with the coils will be interesting.  1265
ohms X is a lot of wire turns.

73, Guy

On Tue, Mar 5, 2019 at 2:16 PM Gedas <w8bya at mchsi.com> wrote:

> > Hello Guy. ok I have taken my 1st stab at creating my model based on
> > your suggestions. I have picked ground constants that represent very
> > very poor "city" soil, a value of 5 or and .001.
> >
> > Enclosed is a URL that will allow you to DL a screen capture showing
> > several EZNEC windows. Please let me know what I need to change in the
> > model. Thanks !
> >
> > https://drive.google.com/open?id=1XR1Jo23xIOPMVx6mQNUR1eKCundBf523
> > Gedas, W8BYA
> >
> > Gallery athttp://w8bya.com
> > Light travels faster than sound....
> > This is why some people appear bright until you hear them speak.
> >
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