Richard Clark wrote:

On Fri, 04 Nov 2005 11:42:43 -0800, Jim Kelley
wrote:

This would be a
given seeing that the parasitic elements would be virtually invisible,
rendering the "driven" element un-differentiable from the simple
dipole.

i.e. what Roy said.


On Wed, 02 Nov 2005 00:11:09 -0800, Roy Lewallen among many things wrote:


I have to admit, I was looking at this a[s] more of a problem of equal
signals arriving from all directions


Hi Jim,

I also approached the problem the same way, this is in glaring
contrast to what I've written in the past two posts which are vastly
divergent from this sense of "equal signals."

As I originally presented data from the model of "equal signals
arriving from all directions" it presented that a dipole's response
was separable from that of a yagi, and showed more response which
contradicts some correspondents, and aligns with others.

Such an outcome stands to reason, the yagi cannot see all sources, the
dipole can. If I illuminated the yagi from each source in turn (all
others off) and correlated the response to the source's angle, the
composite would simply reveal the characteristic yagi response lobe
and the sum of those powers MUST fall below the total power available
to the dipole.

The one over-riding difference between all these scenarios and the
expectations of the yagi is that the yagi is not illuminated with a
plane field, but with a radial field. The composite front of many
sources presents a complex antenna (the yagi) with the appearance of a
wave of extremely high curvature impinging upon it. The mechanics of
gain/directivity are not going to function in the same manner to that
yagi for both fashions of applying the power. Hence the yagi fails to
exhibit a higher response than the simple dipole.

73's
Richard Clark, KB7QHC

Let me thank you again for the work you've put in on this. The thing
is, the idea of squeezing a dipole field pattern into the shape of a
Yagi pattern for example, pretty much dictates that with the proper
field geometry, we should be able to realize equal amounts of energy in
both antennas. I think that's the correct answer. I'm just trying to
see a way to get to it. Another approach might be to integrate the
results from a large number of point sources.

73, AC6XG

On Fri, 04 Nov 2005 15:39:18 -0800, Jim Kelley
wrote:

Another approach might be to integrate the
results from a large number of point sources.

Hi Jim,

I just did that - literally.

73's
Richard Clark, KB7QHC