On Tue, 18 Dec 2007 17:42:00 -0800, Richard Clark
wrote:

On Tue, 18 Dec 2007 12:53:06 -0800, Richard Clark
wrote:

We can then proceed into where confusion might reside (it not being
found in these antennas): GROUND. Yes, the death embrace of the
original models with GROUND profoundly skews the data.

Hi All,

Well, I find there is more technical content to dissect in at least
one dead horse.

Let's look at the "traveling wave" model and see what it has to offer
in the cold harsh light of reality.

Well first, mea culpa's to the readership in using Cecil's models
(never a good idea as they did not attend the question he introduced
whereas mine did). However, moving on to the nut of my copping a
plea. I had not noticed that Cecil drove his wires into MiniNEC
ground - something I have never done in all my modeling. So, my
"changes," as reported, were faithful, but very much unbalanced the
implicit return path through that MiniNEC ground.

Being the good analyst, I then considered my previous work in an even
colder, harsher light of brutal reality. What I did was to replace
that ground path with a wire symmetrical to the 60 footer and then
raised the assembly an inch.

Right off the bat with its performance: -23.74dB
-42.04dB
What could possibly account for all this loss? The "load?"?
And through a follow-up last time, the same conclusion. The
transmission line apparent load for a 100W constant power consumes
99.25 watts

Instead of tossing the load, let's toss ground and put this corpse in
free space. It's performance: -0.30dB
-42.20dB

I don't know how any math error like this could be used to validate a
model, but the efficiency as an antenna that hugs ground so vigorously
hardly measures up to either a dipole or a rhombic. On the plus side,
confusion certainly offers many vendors an income, and suckers are
born every minute who would love a low noise antenna.
Now it enjoys nearly 20dB less noise than before my mistake.

However, what happened to the currents when we discarded ground? Well,
the pristine constant current of the former model plunges right down
the toilet of expectations (while performance shot through the ceiling
at the same time - one has to wonder what was confusing about this?).
Phase change? That cute 90 degrees formerly nudged and cosseted onto
center stage has now been nailed to the floor with no more total
variation than 2.15 degrees. Hard to imagine how a transmission line
could so thoroughly rape its inventor.
The current is still not constant (the original model must rely on a
poor return path to accomplish this). The phase does vary by 90
degrees.

As modified, the current slope reveals this is no longer a traveling
wave antenna (but it never was anyway). This can be remedied by
shifting the last load (the apparent transmission line load) to 750
Ohms.

This, of course, improves nothing in performance.

Turning to the "standing wave" model, would it be instructive how a
ground free performance might similarly fare?

Right off the bat with its performance: -1.69dB
-21.43dB
it would seem a stretch to find any more efficiency (and shows how
that traveling wave model really sucks). However, without ground for
completeness' sake: -0.28dB
-21.12dB

However, what happened to the currents when we discarded ground? Well,
Not enough to discuss.
roughly the same 2 degree shift we found when the "traveling wave"
model split the sheets with ground, but beyond that, an almost
identical current taper and phase lock-down found with the "traveling
wave" model free of ground (or in comparison to itself close to
ground).


So, is there any substantial difference between the two models once
ground's death grip is released? I will leave that question for
tea-leaf analysis, because engineers would have buried this dead horse
long ago.

Well, after sifting my own tea-leaves (one has to wonder how this
escaped the intrepid author's scrutiny) - no not much difference after
all. Transmission lines are pretty robust when designed correctly.

However, neither bear any resemblance to the original post's mention
of rhombic or dipole antennas; and my models of those clearly discard
Cecil's confusion over his named currents by using conventional
designs of conventional antennas. After all, who ever heard of a
traveling wave transmission line? [This is probably the only point
Cecil could ever hope to argue as he would immediately seize on the
opportunity to force that term into the canon.]

***** Irony meter pegged *****

I would like to point out that the only things changed with these
original models was a switch from 2D to 3D analysis to reveal total
loss; and a switch from the ground offered to free space. I look
forward to Cecil, once again, impeaching his own evidence (and
typically without once mentioning the data).

I am sure I have sunken to new lows

Having beaten Cecil in the game of analysis, even to my own, I must be
pond scum by now.

and once I am exposed for what I
am (an English major), vindication will taste sweeter than wine. (may
as well steal that thunder too)

Imagine, I got to the wine decanter first too! :-)

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Tue, 18 Dec 2007 17:42:00 -0800, Richard Clark
wrote:

On Tue, 18 Dec 2007 12:53:06 -0800, Richard Clark
wrote:

We can then proceed into where confusion might reside (it not being
found in these antennas): GROUND. Yes, the death embrace of the
original models with GROUND profoundly skews the data.
Hi All,

Well, I find there is more technical content to dissect in at least
one dead horse.

Let's look at the "traveling wave" model and see what it has to offer
in the cold harsh light of reality.

Well first, mea culpa's to the readership in using Cecil's models
(never a good idea as they did not attend the question he introduced
whereas mine did). However, moving on to the nut of my copping a
plea. I had not noticed that Cecil drove his wires into MiniNEC
ground - something I have never done in all my modeling. So, my
"changes," as reported, were faithful, but very much unbalanced the
implicit return path through that MiniNEC ground.

Being the good analyst, I then considered my previous work in an even
colder, harsher light of brutal reality. What I did was to replace
that ground path with a wire symmetrical to the 60 footer and then
raised the assembly an inch.

Right off the bat with its performance: -23.74dB
-42.04dB
What could possibly account for all this loss? The "load?"?
And through a follow-up last time, the same conclusion. The
transmission line apparent load for a 100W constant power consumes
99.25 watts

Instead of tossing the load, let's toss ground and put this corpse in
free space. It's performance: -0.30dB
-42.20dB
I don't know how any math error like this could be used to validate a
model, but the efficiency as an antenna that hugs ground so vigorously
hardly measures up to either a dipole or a rhombic. On the plus side,
confusion certainly offers many vendors an income, and suckers are
born every minute who would love a low noise antenna.
Now it enjoys nearly 20dB less noise than before my mistake.

However, what happened to the currents when we discarded ground? Well,
the pristine constant current of the former model plunges right down
the toilet of expectations (while performance shot through the ceiling
at the same time - one has to wonder what was confusing about this?).
Phase change? That cute 90 degrees formerly nudged and cosseted onto
center stage has now been nailed to the floor with no more total
variation than 2.15 degrees. Hard to imagine how a transmission line
could so thoroughly rape its inventor.
The current is still not constant (the original model must rely on a
poor return path to accomplish this). The phase does vary by 90
degrees.

As modified, the current slope reveals this is no longer a traveling
wave antenna (but it never was anyway). This can be remedied by
shifting the last load (the apparent transmission line load) to 750
Ohms.

This, of course, improves nothing in performance.

Turning to the "standing wave" model, would it be instructive how a
ground free performance might similarly fare?

Right off the bat with its performance: -1.69dB
-21.43dB
it would seem a stretch to find any more efficiency (and shows how
that traveling wave model really sucks). However, without ground for
completeness' sake: -0.28dB
-21.12dB

However, what happened to the currents when we discarded ground? Well,
Not enough to discuss.
roughly the same 2 degree shift we found when the "traveling wave"
model split the sheets with ground, but beyond that, an almost
identical current taper and phase lock-down found with the "traveling
wave" model free of ground (or in comparison to itself close to
ground).

So, is there any substantial difference between the two models once
ground's death grip is released? I will leave that question for
tea-leaf analysis, because engineers would have buried this dead horse
long ago.

Well, after sifting my own tea-leaves (one has to wonder how this
escaped the intrepid author's scrutiny) - no not much difference after
all. Transmission lines are pretty robust when designed correctly.

However, neither bear any resemblance to the original post's mention
of rhombic or dipole antennas; and my models of those clearly discard
Cecil's confusion over his named currents by using conventional
designs of conventional antennas. After all, who ever heard of a
traveling wave transmission line? [This is probably the only point
Cecil could ever hope to argue as he would immediately seize on the
opportunity to force that term into the canon.]

***** Irony meter pegged *****

I would like to point out that the only things changed with these
original models was a switch from 2D to 3D analysis to reveal total
loss; and a switch from the ground offered to free space. I look
forward to Cecil, once again, impeaching his own evidence (and
typically without once mentioning the data).

I am sure I have sunken to new lows

Having beaten Cecil in the game of analysis, even to my own, I must be
pond scum by now.

and once I am exposed for what I
am (an English major), vindication will taste sweeter than wine. (may
as well steal that thunder too)

Imagine, I got to the wine decanter first too! :-)

73's
Richard Clark, KB7QHC

Cecil's decanter has too much lead in the glass.
73,
Tom Donaly, KA6RUH

Tom Donaly wrote:
Cecil's decanter has too much lead in the glass.

Tom, why haven't you calculated the phase shift from
Vfor1 to Vfor2 in the following example?

--43.4 deg 600 ohm line--+--10 deg 100 ohm line--open
Vfor1--|--Vfor2

Assume that 100v at 0 deg is incident upon the open
at the end of the stub.

I get
Vfor2 = 100v at -10 deg and Vfor1 = 143.33v at -46.6 deg.
Looks like the phase shift is 36.6 degrees after all.
Please feel free to prove me wrong.
--
73, Cecil http://www.w5dxp.com

Richard Clark wrote:
As modified, the current slope reveals this is no longer a traveling
wave antenna (but it never was anyway). This can be remedied by
shifting the last load (the apparent transmission line load) to 750
Ohms.

Duhhhhhhhh! When you changed the conditions, you changed
the characteristic impedance. The reason for your confusion
is obvious below.

This, of course, improves nothing in performance.

This is not a performance issue. This is a current phase
issue. The purpose for the existence of that EZNEC file
is to illustrate traveling-wave current - nothing else.

After all, who ever heard of a traveling wave transmission line?

Who indeed? Richard, FYI, a transmission line terminated
in its characteristic impedance *IS* a traveling wave
transmission line. Do you understanding the meaning of
a "flat" transmission line? A flat transmission line *is*
a traveling wave transmission line. Here is one modeled
in EZNEC. Download and click on "Load Dat".

http://www.w5dxp.com/stub514R.EZ

Why is the ignorance level about traveling waves so high
on this newsgroup? It's the result of those inadequate
lumped circuit models.
--
73, Cecil http://www.w5dxp.com

On Wed, 19 Dec 2007 22:11:23 GMT, Cecil Moore
wrote:

This is a current phase issue.

The Rhombic antenna shows phase variation for every configuration.

The Rhombic is, by the way, a traveling wave antenna, and your own
topic selection.

The Rhombic antenna does not support your thesis. Absolutely no
correspondence (other than my own for a non-antenna) has been offered
to assault my data.

So, the bottom line is that EZNEC faithfully models both traveling
wave antennas, and resonant lines; and no one here is surprised about
that. Still confused? You don't seem to be particularly motivated
with this issue at all - it must be a humbling experience for you to
have introduced this in terms of a real antenna that refuses to toe
any of your absurd propositions.

Clever crafting only makes your theories ever simpler to blow away.

I wait for your next joke, that one was too easy! :-)

Richard Clark wrote:
The Rhombic antenna does not support your thesis.

Of course it does, Richard. The rhombic is a traveling-
wave antenna. Unlike a 1/2WL dipole, its current phase
changes with distance from the feedpoint.

We certainly have an EZNEC 1/2WL dipole model but
I don't think EZNEC comes with a rhombic model. Do
you happen to have one? If not, I'll be glad to
whip one out. I guarantee the results will be no
different from the 1/4WL terminated wire that I
presented previously.
--
73, Cecil http://www.w5dxp.com

On Wed, 19 Dec 2007 23:06:58 GMT, Cecil Moore
wrote:

I don't think EZNEC comes with a rhombic model. Do
you happen to have one?

With that, I can tell you didn't read anything in this thread. That's
OK, the topic was a snooze from the first paragraph.

If not, I'll be glad to
whip one out. I guarantee the results will be no
different from the 1/4WL terminated wire that I
presented previously.

And this proves you didn't read anything in this thread.

But, your comment was a good laugh! You are already several postings
shy of results already here. As the Red Queen informed Alice, "You
have to run awful fast just to keep up in one place."

When that dawns on you (sorry, but you will have to read the posting),
it will probably expose me for what I am (scum of the earth? or is it
wine sipping Liberal Arts major this week?).

Looking forward to your damage control. :-)

Richard Clark wrote:
The Rhombic antenna does not support your thesis.

On the contrary, I just whipped out an EZNEC rhombic
without taking any special care. I copied it out of
The ARRL Antenna Book, 20th edition, page 13-13.
I only installed ten zero ohm loads, but clicking
on "Load Dat" clearly shows the phase shift in the
traveling wave current along the wire.

http://www.w5dxp.com/rhombic.EZ

Sorry, a rhombic won't run on the free demo version
of EZNEC.
--
73, Cecil http://www.w5dxp.com

On Wed, 19 Dec 2007 17:50:53 -0600, Cecil Moore
wrote:

The "traveling wave" antenna
clearly shows
standing waves.

This is just too, too easy! :-)

Richard Clark wrote:
Cecil Moore wrote:

The "traveling wave" antenna
clearly shows
standing waves.

This is just too, too easy! :-)

Too bad for you the threaded newsreader shows that
the only thing I wrong above was "clearly shows".
It also shows that you wrote the rest. Any idiot
can falsify a posting.
--
73, Cecil http://www.w5dxp.com