Sorry, I don't have the time or inclination to get into another
protracted "last man standing is the winner" diatribe. I'll leave it to
the readers to evaluate what I've written and decide whether or not it
makes sense, or whether they'll choose instead to be persuaded by your
objections. Either is fine with me.

Roy Lewallen, W7EL

Richard Clark wrote:
On Mon, 12 Jul 2004 23:02:30 -0700, Roy Lewallen
wrote:

Hello Roy,

There are any number of problems with your comments:


This analysis should be done in free space, not over ground.


The application demands ground as an inescapable reality of design.
Designing in free space, unless you expand upon your commentary, is
meaningless. In other words, the product of a free space analysis
offers no more insight that this blighted version. Your comments that
follow fairly shout this as a wholly undecipherable problem.


Propagation to the moon should avoid reflection from the ground,


This has already been offered as a cautionary. However, as a
cautionary it says nothing about the impact of application aside from
the introduction of noise (ground temperature) which lies outside of
EZNEC's constraints. There would undoubtedly be issues of ducting,
much less diffraction at the air/space boundary - and these too are
within the domain of propagation modelers which is not what I perceive
EZNEC to be. However, propagation modelers do work from antenna
characteristics and it would seem this work is adequate to that
(anticipated) task. The propagation modelers I am used to seem to
expect ground considerations rolled into the antenna characteristics.


and in any case EZNEC's flat, infinite-extent ground model isn't representative of what
the signal would encounter in real life.


No doubt, but this still says nothing on which to hang a hat. The
valuations offered range from 10 to 22dBi. Are these values off by
3dB, 10dB, 100dB? Rather than having a good low angle response, the
actual response is straight up? What is the context of your warning?
If they are not representative do we have an unimaginable response?
If the EZNEC is sufficient for Rhombics at HF, certainly at VHF the
wavelength horizon is much further off and earth appears that much
flatter. Earth curvature exists for all applications and your
warnings would suggest no model is useful.

73's
Richard Clark, KB7QHC