transmission lines and SWR and fractional wave antennas
 

J. B. Wood wrote:

Hello, Roy, and while the above is certainly correct, you're probably
wasting your time. Many folks like to fashion their own "reasonable"
explanations even when they're completely off track (should I mention the
CFA again?). Of course they're always right and it's the rest of the
world who's wrong. Certain folks on this ng appear to be in constant need
of validation. Persons without some knowledge of the underlying physics
and applied math are destined to reach the wrong conclusions IMO. Of
course that's not going to stop some from building a CFA because as we all
know it's the standard comms antenna used at the Groom Lake facility to
keep in touch with Klaatu. Sincerely, and 73s from N4GGO,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

If what you say is true, I am wasting my time. But I believe there's a
more diverse group of readers:

1. The people who already already know and understand what I'm explaining;
2. The people who think they know and understand what I'm explaining,
but don't, and won't change their minds no matter what I write; and
3. The people who are willing to read and understand what I write, and
learn from it or at least think about it.

Just like medical triage, only one of the three groups can be helped, in
this case #3. It's for those folks that I take the time to post. I hear
from them in various ways from time to time, so I know they're out
there. And I'm glad to pass along to them what I've learned, when I can.

Roy Lewallen, W7EL

transmission lines and SWR and fractional wave antennas
 

Art wrote:
"At the end of the radiator you state the energy is transfered to the
field so I would imagine there is zero skin effect at that point and the
chain of skin effect es still present on the outside of the radiator,
this is because the full period has not elapsed."

It will elapse as it does in every period so that the higher resistance
at RF will take its toll as predicted.

Because of skin effect, hollow conducting pipes exhibit almost as much
conducting ability as solid rods of the same material. This creates a
market for aluminum tubes as radiating elements and Copperweld wire in
antennas. High-powered transmitters use silver-plated coiled pipes to
carry distilled water to cool their final amplifiers. The space within
the coiled pipes carries no significant RF. RF energy does not flow out
on the surface of a conductor and return in the conducting material
within the conductor in ordinary circumstances, although phase lag
within a conductor increases as penetration depth increases.

Best regards, Richard Harrison, KB5WZI

transmission lines and SWR and fractional wave antennas
 

oh no! *now he doesn't believe in reflections! *how could we ever survive on
here without endless discussions of reflections and waves?

He believes that anything that trashes his delusions of how an antenna
works has to be wrong.

Jimmie

transmission lines and SWR and fractional wave antennas
 

On Dec 29, 1:36*pm, Roy Lewallen wrote:
J. B. Wood wrote:

Hello, Roy, and while the above is certainly correct, you're probably
wasting your time. *Many folks like to fashion their own "reasonable"
explanations even when they're completely off track (should I mention the
CFA again?). *Of course they're always right and it's the rest of the
world who's wrong. *Certain folks on this ng appear to be in constant need
of validation. *Persons without some knowledge of the underlying physics
and applied math are destined to reach the wrong conclusions IMO. *Of
course that's not going to stop some from building a CFA because as we all
know it's the standard comms antenna used at the Groom Lake facility to
keep in touch with Klaatu. *Sincerely, and 73s from N4GGO,

John Wood (Code 5550) * * * *e-mail: * * * * * * * * * *
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

If what you say is true, I am wasting my time. But I believe there's a
more diverse group of readers:

1. The people who already already know and understand what I'm explaining;
2. The people who think they know and understand what I'm explaining,
but don't, and won't change their minds no matter what I write; and
3. The people who are willing to read and understand what I write, and
learn from it or at least think about it.

Just like medical triage, only one of the three groups can be helped, in
this case #3. It's for those folks that I take the time to post. I hear
from them in various ways from time to time, so I know they're out
there. And I'm glad to pass along to them what I've learned, when I can.

Roy Lewallen, W7EL

Roy,
That is exactly how I felt when I declared that the addition of a
radiator
to a Gaussian statics field under the application of a time varying
field equates to the
mathematics of Maxwells laws. Nobody, including you, showed an error
in that thinking.
Another person provided the mathematics that proved my point again ,
nobody could disprove it.
Anybody can view the book by Ramo and co "Fields and waves in
communication Engineering"
where in Appendix 11 where the a sample method of tackling the proof
is available in it's entirety.
Some could even read the chapter on radiastrion which spells out
problems with the existing aproach.
Remember when the presence of particles on a radiator is determined by
any person well versed in mathematics
and science then the true vehicle of communication is thus determined.
All of the above is directly
applicable to the stance in words only that you have expressed above
but..........no action
It blows my mind when people desert from mathematics and science in
efforts to prevent change.
T,here is no evidence what so ever that Newton's laws applicable in
this case has now been discarded in science
and that evidence destroys the notion of communication and the
emmission of light can be attributed to a field wave form
instead of the particles outlined in Gaussian law.
Art

transmission lines and SWR and fractional wave antennas
 

On Dec 29, 1:14*pm, Cecil Moore wrote:
Art Unwin wrote:
So one acknowledges the presence of a capacitor at the end of a
radiator

Let's use IEEE definitions to avoid confusion. A "capacitor"
is a physical component that exhibits capacitance. Capacitance
can be exhibited without the existence of a physical lumped
component. At the end of a radiator, we would have a
distributed capacitance, not *a* lumped capacitor.

No Cecil. We are at the end of the radiator and there is no eddy
currents in front.
Ther apparently is a gap between the outside of the radiator end which
some see as a capacitor
( tho I see nothing that suggests that as yet) If one accepts a
capacitor as distributed then I will go along with that
but that alone cannot stop the flow of current.
Regards
Art





And
actually, it is not only at the end since it is "distributed".
In fact, an antenna element can be modeled as a distributed
RLC network where the R includes all "losses" including radiation.
--

I would love to see that circuit in its entirety since it will show
the points of collision


73, Cecil *http://www.w5dxp.com

transmission lines and SWR and fractional wave antennas
 

Cecil, W5DXP wrote:
"Richard , I`ll bet you know that the reflection coefficient is 1.0 for
an open circuit and -1.0 for a short circuit. :-)

Yes, Cecil caught me not paying attention. At an open circuit, the
impedance is infinite but the coefficient of reflection is the ratio of
the voltage of the reflected wave to the voltage of the incident wave.
As both have the same phase and magnitude, value of the reflection
coefficient for an open circuit is 1.0, not infinity.

Best regards, Richard Harrison, KB5WZI

transmission lines and SWR and fractional wave antennas
 

On Dec 29, 1:09*pm, (Richard Harrison)
wrote:
Art wrote:

"Yes, the common thinking is that current changes direction to oppose
the forward moving current as with a reflection where the eddy current
moving in the reverse direction cancels the eddy current moving in the
other direction."

Transformers are laminated to reduce eddy current core losses.

Reverse currents on a transmission line or on an antenna are usually
called the reflected current.

Reflections are caused by discontinuities in the path of the EM wave.

In the case of an open circuit, the reflection coefficient is infinite
and the incident and reflected waves have the same magnitude and phase.
The voltage at the discontinuity is thus doubled. See Terman`s 1955 opus
page 89. But, the current goes to zero as conduction ends at the open
circuit. No energy is lost in the open circuit. It is just concentrated
in the electric field as the magnetic field loses its energy.

Best regards, Richard Harrison, KB5WZI

Richard,
the above does not address my question other than a stream of words
It is difficult to cull anything with respect to my question that
allows for scientific debate or response
to which actual numbers can be applied. I know what the status quo is
with respect to present day thinking
so repetitive statements provide nothing to the thread.
Note how Cecil is responding in a scientific way without deviating
off point and learn from it. Otherwise there is no reason for me to
respond
Art

transmission lines and SWR and fractional wave antennas
 

On Dec 29, 2:27*pm, JIMMIE wrote:
oh no! *now he doesn't believe in reflections! *how could we ever survive on
here without endless discussions of reflections and waves?

He believes that anything that trashes his delusions of how an antenna
works has to be wrong.

Jimmie

Enough of the talking Jimmie and prove the Gaussian equation
transformation is wrong.
You missed your chance when it was shown on the net. My earlier
posting pointed you
to a place so you can handle the CGS units and trash it if you can.
All those posts you
have wasted would not have been necessary if you had educated yourself
in the mean time
instead of becoming just a talking head
Art

transmission lines and SWR and fractional wave antennas
 

Roy Lewallen wrote:
1. The people who already already know and understand what I'm explaining;

Assumes that you are omniscient and others should worship at
your feet.

2. The people who think they know and understand what I'm explaining,
but don't, and won't change their minds no matter what I write;

Assumes that you are omniscient and anyone who disagrees with
you is wrong.

3. The people who are willing to read and understand what I write, and
learn from it or at least think about it.

Assumes that you are omniscient and people can only learn
facts from you.

Roy, I don't think that any assumption of your omniscience
is warranted. Is it impossible that you are wrong about
anything in the world? Is the reason that you absolutely
refuse to engage in a rational discussion of the role of
interference in antenna systems because you might be proven
to be wrong and also learn something new in the process?
--
73, Cecil http://www.w5dxp.com

transmission lines and SWR and fractional wave antennas
 

On Mon, 29 Dec 2008 11:36:34 -0800, Roy Lewallen
wrote:

If what you say is true, I am wasting my time. But I believe there's a
more diverse group of readers:

1. The people who already already know and understand what I'm explaining;
2. The people who think they know and understand what I'm explaining,
but don't, and won't change their minds no matter what I write; and
3. The people who are willing to read and understand what I write, and
learn from it or at least think about it.

Just like medical triage, only one of the three groups can be helped, in
this case #3. It's for those folks that I take the time to post. I hear
from them in various ways from time to time, so I know they're out
there. And I'm glad to pass along to them what I've learned, when I can.

Roy Lewallen, W7EL

Well, this is probably a suitable time to offer my thanks for taking
the time to explain how things work (and to correct my screwups).
Thanks much. I suspect that the time and effort are not a major
problem. It's tolerating the nonsense that passes as a substitute for
intelligence that bothers me. It's difficult to argue with
unsubstantiated illogic and one-line simulated cleverness.

I do the same in alt.internet.wireless.
http://groups.google.com/groups/profile?hl=en&enc_user=bLQuYRAAAACBvdjA7WBXQw3w3fq wxHRj
Hmmm... there should be much more dating back to about 1987.

One of my tag lines is:
"I judge people by their willingness and ability to learn".
I have no problem with those that disagree with me. It's easy enough
to make the distinction between disagreement and learning failure. If
they understand both sides of a debate, they're doing just fine.
Otherwise, you're debating against dogma and bias, with little home of
having anyone change their opinion.

I'm mostly in #3. I read, learn, sometime ask, occasionally comment,
and save some postings for reference. I'm fairly well informed in my
areas of expertise, but am seriously lacking in others. Antennas is
one of those where I'm lacking. Sometimes you go over my head, which
is not a problem. I can dig out the details later. However, some
URL's, references, and additional reading pointers would be helpful.
Overall, your postings are all useful, interesting, and well worth
reading.

As for the diversity of the readers, it's probably all over the map.
You have the difficult problem of trying to write something that is
understandable by every knowledge level from complete beginner to
professional antenna designer. It's easy if you know something about
the person with whom your discussing some topic, but very different if
you're dealing with an anonymous visitor.

Thanks again.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558