"Jim Kelley" wrote in message
...
snip
The other point of disconnect between the parties hereabouts relates to
the occasional lack of distinction between the 'flow' of electrons, and
the propagational 'flow' of an EM wave.

73, Jim AC6XG
snip

You got that right, bubba.
73
H.
NQ5H

H. Adam Stevens, NQ5H wrote:
"Jim Kelley" wrote:
The other point of disconnect between the parties hereabouts relates to
the occasional lack of distinction between the 'flow' of electrons, and
the propagational 'flow' of an EM wave.

You got that right, bubba.

So does a current wave flow or not? This is not a trivial question
and tends to distinguish between the problems one can solve with
a DC circuit model Vs the more complicated distributed network model
where current waves and voltage waves share a lot of common characteristics.
--
73, Cecil, w5dxp

Richard Clark wrote:

On Sun, 07 Nov 2004 00:56:00 -0800, Roy Lewallen
wrote:


The difference between gain relative to isotropic (which you're
unnecessarily calling "true gain") and directivity is only the
efficiency.


Hi Roy,

Let's call it relative gain then. The point of the matter is not in
terminology but in magnitude and correlation.

Let's not call it "relative gain". There's no need to invent new
nomenclature to describe known quantities which we don't understand.
There are plenty of terms which are universally agreed upon and hence
communicate concepts adequately -- inventing new ones just obscures what
we have to say.

The Thread, throughout, is constituted of four principles:
Rr;
Current;
Radiator size;
Loading;

To reveal their inter-relatedness required an impartial witness of an
external load (the remote antenna which is the raison d'etre of
communication).

An "external load" (by which I believe you mean a receive antenna) is
necessary for measurements, but not for calculation as by a program. But
there's no harm in using one for computer analysis, as long as you don't
misinterpret what the results mean.


The gain evidenced in this remote antenna is not some arbitrary change
of terms that is alien to the craft of communication (nor even the
majority of engineering).

I believe you mean the *signal strength detected by* rather than *gain
evidenced in*. If you make that replacement, I agree. Otherwise, it
makes no sense -- the remote antenna does not "evidence gain".

It encompasses differences that exceed 1dB,
eclipsing that even to the point of being 7dB in the first iteration.
When in the second iteration the shortened antenna is brought to
resonance, the change still exceeds 1dB (2.9dB by my reckoning). ALL
such changes, when viewed through the veil of dBi simply reveal
miniscule changes of what you call ground reflection. As such, dBi is
a poor mechanism to reveal Rr's characteristic through structural
variations.

I'm sorry, I can't make any sense out of that, so I can't respond.

I won't go on with the remainder of iterations because no new
observations would be drawn. Indeed, the data supports the generality
that suits the purpose of achieving the expected results. As I
offered:


This comes as no surprise to many.


Now, the issue of Isotropism is one that is power centric, and this is
certainly the common experience of any Ham trying to load an antenna
from a real transmitter. They have a finite amount of power they wish
to maximize, and this then becomes an issue of efficiency. However,
there is NOTHING in my work that states this is a goal - or I would
have expressed that in no uncertain terms. If any seek that
divergence of issue, then my data supports it without further
qualification.

I'm having some trouble understanding this, too, but think maybe you're
trying to say that hams want to maximize the signal received by a
distant station. If so, I agree. But your analysis doesn't show how this
is done by increasing Rr. As I said earlier, the advantage to raising Rr
is to improve efficiency -- your models were nearly 100% efficient, so
weren't able to demonstrate this. If you had added resistance to
simulate ground resistance as I had suggested, this would lower the
efficiency so the effect of changing Rr could be clearly shown. And
raising the efficiency does indeed improve the strength of the received
signal.


So, gain is entirely consistent within the context of the simple
agenda that was explicitly described. Gain was shown to follow
structural changes with positive correlation. Gain was shown to
follow those changes in direct proportion. Gain was shown to be
consistent with expectation. If such Gain is shown to be a wash in
efficiency at best, worst for wear, or a boon to mankind, that is
simply an issue of implementation and outside of my discussion of
examining:
Rr;
Current;
Radiator size;
Loading.

Again, I'm baffled. I'm sure that more highly educated readers than I
understand what you're saying, but I also hope that even those with less
education in the fine arts of language can understand what I've said.
The principles involved are really simple, and I hate to seem them made
unnecessarily complex by misinterpretation.

Roy Lewallen, W7EL

On Tue, 09 Nov 2004 04:50:37 -0800, Roy Lewallen
wrote:

Again, I'm baffled

Hi Roy,

So you insist.

73's
Richard Clark, KB7QHC

Roy, W7EL wrote:
"The principles involved are really simple and I hate to see them made
unecessarily complex by misinterpretation."

Amen.

Directive gain according to Terman is distribution in space of radiated
power versus the power that would be radiated by an isotropic. Losses
are not considered.

Power gain takes loss into account and is the ratio of the power
necessary to an isotropic versus the power to a gain antenna required
for the same signal strength in the same direction.

Kraus says the directive gain is the ratio of maximum power density to
its average value over a sphere as observed in the far field.

Terman and Kraus agree in their calculated examples. The directive gain
of an elementary dipole (Kraus says maybe i/10-wavelength) is 1.5. It
can be found on page 34 of Kraus` 3rd edition. It`s the same on page 871
of Terman`s 1955 edition.

The directive gain of a 1/2-wavelength dipole is 1.64 for Terman. For
Kraus, it`s 1.63 on page 35. These are power ratios, not dB.

Best regards, Richard Harrison, KB5WZI