Tom,
Exactly. In fact, the portion of the curve looked at was appropriate
for each height. It showed an increase in Z at 28 M relative to 24M.
The curve is on page 3-2 of the 19th Edition of the ARRL Antenna
Handbook.
73 de Brian/K3KO
n4kg@juno.com wrote:
>
> The feed impedance for a dipole varies similar to a damped
> sinusoidal waveform as height is varied so whether it
> increases or decreases depends on what part of the curve
> you are traversing.
>
> Tom N4KG
>
> On Wed, 15 Aug 2001 alsopb <alsopb@gloryroad.net> writes:
> >
> > Marc,
> >
> > Just for kicks I ran EZNEC for a full sized 2 element beam (24'
> > boom) at 24 and 28 M height.
> >
> > 24 M SWR =1.306 IMPEDANCE =38 -1.8j
> > 28 M SWR =1.519 IMPEDANCE =33 -0.5j
> >
> > Interesting that the impedance actually decreases rather than
> > increasing with height as the dipole impedance plot vs height
> > predicts.
> >
> > I don't have a model for the 402CD. It would be interesting to
> > actually run such a model at the two heights.
> >
> > Of course, these values are at the feedpoint. What the reading
> > would
> > be at the shack end of the coax is unknown.
> >
> > 73 de Brian/K3KO
> >
> >
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