Phase Shift through a 75m Texas Bugcatcher Coil

[Cecil Moore]

If a Texas Bugcatcher Coil could be turned into a
traveling wave device instead of a standing wave
device, the inherent phase shift through the coil
would become obvious. I used the Helix option in
EZNEC to generate a reasonably close model of a
75m Texas Bugcatcher coil and loaded it with a
resistance equal to the coil's characteristic impedance
which essentially eliminated the reflected current,
leaving the forward current intact and visible. All
of the data points on the following web page came from
EZNEC. All of the files are available for downloading.
Please take a look at:

http://www.w5dxp.com/current2.htm

[Yuri Blanarovich]

Post by Cecil Moore
If a Texas Bugcatcher Coil could be turned into a
traveling wave device instead of a standing wave
device, the inherent phase shift through the coil
would become obvious. I used the Helix option in
EZNEC to generate a reasonably close model of a
75m Texas Bugcatcher coil and loaded it with a
resistance equal to the coil's characteristic impedance
which essentially eliminated the reflected current,
leaving the forward current intact and visible. All
of the data points on the following web page came from
EZNEC. All of the files are available for downloading.
http://www.w5dxp.com/current2.htm
--
73, Cecil http://www.w5dxp.com

Soooo, W8JI and his worshippers were right! Current is just about constant
through the loading coil (for traveling wave) but they did not know the
case, in which this happens in the antenna circuit, while they were sticking
with DC circuit analysis.
I hope Roy approves your use of EZNEC for this demonstration and perhaps
will admit that they were wrong, and indeed the RF current through standing
wave antenna circuit, such a quarter wave resonant vertical monopole, the
loading coil has the current drop along the coil (standing wave circuit).

This exercise, and Walt's, and whole commotion of reflections and
interference has open my antenna eyes a bit wider and allow me to understand
better wasaaaap in antenna circuits, which should lead to mo' betta' antenna
designs.
The only problem I have swallowing Gaussian soup, to understand how on earth
and 100 years of antenna tinkering could not see the magic of this
(another) miraculous way of getting much more and better signals out of
antenna with given power.

Thanks guys, this is the best antenna NG, allowing good and questionable
posts and free discussion, unlike the TowerTalk antenna reflector where any
"heresy" against W8JI crapola "teachings" gets suspended.

Yuri, K3BU.us

[Cecil Moore]

Post by Yuri Blanarovich
Soooo, W8JI and his worshippers were right! Current is just about constant
through the loading coil (for traveling wave) ...

Especially since I modeled the coil with lossless wire. :-)

*Traveling wave current* amplitude is just about constant
at both ends of a loading coil but there's a phase shift
as can be seen at: http://www.w5dxp.com/current2.htm
In the middle of the coil, the current increases because
of the adjacent coil coupling. There is a little drop off
(unit percents)in amplitude end-to-end because of I^2*R
losses and radiation. But one can consider the coil to be
lossless and non-radiating and still get within a few percent
of reality.

The problem is that W8JI used *standing wave current* for
his measurements. What is flowing through the coil is the
forward current and reflected current, not the standing
wave current. The standing wave current is just standing
there as indicated by the cos(kz) term. The amplitude of the
standing wave current at any point in the coil or on the
antenna has more to do with the phase difference between
the forward and reflected currents than anything else. At
the tip of the antenna, the forward current and reflected
current are equal in magnitude, 180 degrees out of phase,
and thus sum to zero.

Post by Yuri Blanarovich
I hope Roy approves your use of EZNEC for this demonstration and perhaps
will admit that they were wrong, and indeed the RF current through standing
wave antenna circuit, such a quarter wave resonant vertical monopole, the
loading coil has the current drop along the coil (standing wave circuit).

The current "drop" is an illusion. The current decreases primarily
because of out-of-phase addition of the forward and reflected
current. If one makes the antenna longer and places the loading
coil somewhere else, one can measure a current "rise" through the
coil which is still an illusion created by the in-phase addition
of the forward and reflected currents.

I verified these findings on the bench a couple of months ago
using my 75m Texas Bugcatcher coil loaded with a 3K ohm resistor.
But I wanted to see if EZNEC agrees. It does.

[Jim Kelley]

Post by Cecil Moore
In the middle of the coil, the current increases because
of the adjacent coil coupling.

I'd like to see your Norton analysis of that one.

73, ac6xg

[Cecil Moore]

Post by Jim Kelley
I'd like to see your Norton analysis of that one.

RF is not DC. Edison questioned how one could measure
100 volts between any two of three terminals. :-)

[Jim Kelley]

Post by Cecil Moore

Post by Jim Kelley
I'd like to see your Norton analysis of that one.

RF is not DC. Edison questioned how one could measure
100 volts between any two of three terminals. :-)

Are you implying yours is a 3-phase antenna? :-)

ac6xg

[Cecil Moore]

Post by Jim Kelley
Are you implying yours is a 3-phase antenna? :-)

No, just that phasing of RF signals is what is confusing
the DC gurus, just like AC phasing confused Edison.

[Jim Kelley]

Post by Cecil Moore

Post by Jim Kelley
Are you implying yours is a 3-phase antenna? :-)

No, just that phasing of RF signals is what is confusing
the DC gurus, just like AC phasing confused Edison.

What is a DC guru, and why do you address comments to them?

As a suggestion, you might consider increasing the current for the
EZNEC simulation on your webpage. At 20 amps per division it's plus
or minus a pixel at 1024x768.

73, ac6xg

[Cecil Moore]

As a suggestion, you might consider increasing the current for the EZNEC
simulation on your webpage. At 20 amps per division it's plus or minus
a pixel at 1024x768.

Excellent suggestion, Jim. I'm sure there is a way to do that
within the EXCEL charting function but, so far, I haven't figured
out how to split the scales. I was going to mow the yard but it's
92 degrees out there and I would rather play with EZNEC anyway.

[Cecil Moore]

As a suggestion, you might consider increasing the current for the EZNEC
simulation on your webpage.

Done as you suggested by changing the current amplitude scale.
What do you think about the simulation? Stand by for more
additions to that web page.

[Jim Kelley]

Post by Cecil Moore

Post by Jim Kelley
As a suggestion, you might consider increasing the current for the
EZNEC simulation on your webpage.

Done as you suggested by changing the current amplitude scale.
What do you think about the simulation? Stand by for more
additions to that web page.

From what I gathered, the objective of loading the coil with its
characteristic impedance was that there would be no reflection. I was
therefore surprised when you reported something other than a straight
line for the current amplitude along the radiator (let alone an
increase at some point). It is now apparent that what you are
actually plotting is the superposed forward and reflected currents,
and that you have somewhat more than a negligible amount of reflected
current.

The primary utility in looking at the standing wave profile lies in
the fact that it gives an idea of what the superposed field intensity
plot might look like in the near field of the antenna. But it is
obviously the currents associated with waves traveling on the antenna,
both forward and reflected, that actually do the radiating.

I agree with you that it is useful to understand the exact effect the
loading coil has on the traveling wave, and hence the standing wave
profile of the antenna. But I still think it would be prudent to
explore and understand the precise nature of the delay through the
coil more thoroughly before making too many assumptions about this.

73, Jim AC6XG

[Cecil Moore]

Post by Jim Kelley
I was
therefore surprised when you reported something other than a straight
line for the current amplitude along the radiator (let alone an increase
at some point).

Just proves that you are not omniscient. Such is the nature
of a real world inductance especially close to self-resonance.
This is just evidence of another failure of lumped inductance
models. The current through a real-world inductance is NOT
linear if the operating frequency is within 15% of the self-
resonant frequency. For the Nth time, please read and
understand the IEEE white paper at:

http://www.ttr.com/TELSIKS2001-MASTER-1.pdf

[Jim Kelley]

Post by Cecil Moore

I was therefore surprised when you reported something other than a
straight line for the current amplitude along the radiator (let alone
an increase at some point).

Just proves that you are not omniscient.

I doubt that proof of that is actually required. In fact, I think
you'll find that to be true in general for other people as well.

Post by Cecil Moore
For the Nth time, please read and
http://www.ttr.com/TELSIKS2001-MASTER-1.pdf

University of Yugoslavia. Yeah, sure thing. Whether it's valid or
not, I'm not convinced that's what you have in your EZNEC printout.
And unless Roy accounts for "current pileup", it's unlikely that it
would show up there.

73, AC6XG

[Cecil Moore]

Post by Jim Kelley

Post by Cecil Moore
Just proves that you are not omniscient.

I doubt that proof of that is actually required. In fact, I think
you'll find that to be true in general for other people as well.

Actually, of the three possibilities listed by W7EL for people
not understanding him, none of the possibilities was that he
was not omniscient. :-)

[Yuri Blanarovich]

University of Yugoslavia. Yeah, sure thing. .....

What's that supposed to mean?
If it is not overpriced American Liberal Alma Mater then is "Yeah"????

Nikola Tesla did more for the mankind than anyone produced by US colleges.
Quite an insult to thousands of Slavic engineers immigrants who built IBMs,
GMs, etc.

Can we discuss technical matters or rather play know-it-alls gurus?
Can you point out what is wrong with that paper?

73 Yuri, oK3BU

[Jim Kelley]

Post by Yuri Blanarovich
If it is not overpriced American Liberal Alma Mater then is "Yeah"????

You make a good point.

Post by Yuri Blanarovich
Nikola Tesla did more for the mankind than anyone produced by US colleges.

Let's not get carried away. And I don't think Tesla was from
Yugoslavia.

Post by Yuri Blanarovich
Quite an insult to thousands of Slavic engineers immigrants who built IBMs,
GMs, etc.

No insult to them was ever intended. They didn't write the paper by
any chance....??

Post by Yuri Blanarovich
Can we discuss technical matters or rather play know-it-alls gurus?
Can you point out what is wrong with that paper?

I wish I understood this obsession you and Cecil have with gurus. I
don't share it.

About the paper; do you believe everything you read in the papers?
As I said, whether it is correct or not, I don't think it is
illustrated in Cecil's EZNEC printout.

73, Jim AC6XG

[Yuri Blanarovich]

Post by Jim Kelley

Post by Yuri Blanarovich
If it is not overpriced American Liberal Alma Mater then is "Yeah"????

You make a good point.

Post by Yuri Blanarovich
Nikola Tesla did more for the mankind than anyone produced by US colleges.

Let's not get carried away. And I don't think Tesla was from
Yugoslavia.

He was born in Smiljan Lika, Serbia, Yugoslavia, studied at Carl University
in Prague. People know more about tinkerer Edison, than about greatest
engineering genius who gave us AC and so much.

Post by Jim Kelley

Post by Yuri Blanarovich
Quite an insult to thousands of Slavic engineers immigrants who built IBMs,
GMs, etc.

No insult to them was ever intended. They didn't write the paper by
any chance....??

Seemed to me implied: "Yeah" = mickey-mouse universities in Yugoslavia (or
Eastern Eu). For your information and based on my experience, Eu
Universities have much more rigorous programs and theoretical depth than
NA-U. When I was working for Big Blue, about half of the bright engineers
were graduates from Eastern Europe (post war imigration).

Post by Jim Kelley

Post by Yuri Blanarovich
Can we discuss technical matters or rather play know-it-alls gurus?
Can you point out what is wrong with that paper?

I wish I understood this obsession you and Cecil have with gurus. I
don't share it.

It is more like reaction to people who are sometimes wrong and chime in on a
subject with: "hey stupid, it can't be" - parading as omnipotent gurus,
instead of asking questions and discussing the matter inteligently and
either defending their position or admitting that maybe we were not so
stupid and they COULD be wrong, and learn and get better.

What we perceive as "gurus" here, is a type of person who is wrong about the
subject, tends to get riding on a high horse putting down the opposition,
sometimes ridiculing and close minded to any, even elaborate explanation or
reasoning. Typically "guru" wants to have their last "right" word, even if
realizing that maybe they were wrong, never admitting or giving credit where
is due.

Looks like too much Woodstock generation getting into engineering and
forcing their "truth" to be the only one standing (Global Warming). If often
enough repeated in politics, it catches on with halfbright worshippers, but
has no place in science. Reality trumps theory, regardless who is trumpeting
it.

I am sorry that sometimes I get provoked and fire back in a like manner, but
when someone is trying to convince me that RF is behaving like DC current,
when I got burned my fingers on the bottom of the loading coil, then I just
react in kind.

Post by Jim Kelley
About the paper; do you believe everything you read in the papers?
As I said, whether it is correct or not, I don't think it is
illustrated in Cecil's EZNEC printout.

If it is New York Times, definitely not. Technical papers? I would read them
carefully, take them with grain of salt, and if important to me, try to
understand it and I would verify it if possible.

Even if sometimes discussions get tangled here, because some just can't, or
don't want to get it, I am gratefull to those involved, because they bring
some points, that I would have not paid attention to and missed important
link in the chain of knowledge on the subject.

Another outcome is, that some subjects in current literature are not all
that properly described and warrant more detailed explanation and proof to
get corrected, and some discussions here shed some light at it and
highlinght need for more down to earth tutorial to set the record straight.

Post by Jim Kelley
73, Jim AC6XG

73 Yuri, oK3BU

[Cecil Moore]

Post by Yuri Blanarovich
What we perceive as "gurus" here, is a type of person who is wrong about the
subject, tends to get riding on a high horse putting down the opposition,
sometimes ridiculing and close minded to any, even elaborate explanation or
reasoning.

What really gets my dander up are the gurus who use their
respected guru status to mount ad hominem attacks against
someone who they know is technically correct. In my book,
that is unethical behavior.

[John Smith I]

Post by Cecil Moore
What really gets my dander up are the gurus who use their
respected guru status to mount ad hominem attacks against
someone who they know is technically correct. In my book,
that is unethical behavior.

Cecil:

Which definition of Guru comes closest to your implied meaning:
(BTW, I think your use of "guru" is well justified)

# (Literally the word guru means teacher) Second level of its meaning is
that the guru is a spiritual leader, a saint, a Enlightener. GU
(darkness) RU (light); One who brings light into darkness. A teacher..
However, the meaning of the word Guru in Sikh terminology is at a
further higher level, and it stands for the 'prophet'.
www.sikhlink.com/sikh/terms.htm

# ("he who is heavy, weighty"): a spiritual teacher; cf. acarya
www.yogajournal.com/newtoyoga/159.cfm

# a religious percept or teacher, often the person from whom one
receives initiation or consecration.
www.trimondi.de/SDLE/Glossary.htm

# Literally teacher refers to one of the ten Sikh prophets, the Sikh
scripture (Guru Granth Sahib), or God.
www.sikhstudy.com/A7terms.html

# In general terms, a computer expert. UNIX experts are typically
referred to as gurus in polite company.
teladesign.com/ma-thesis/glossary.html

# a teacher who has attained mastery in the Supracosmic Sphere.
www.mudrashram.com/glossarypage.html

# "Remover of darkness;" guide. A teacher. Though it can connote a
teacher of any subject, guru usually denotes a spiritual teacher or master.
www.himalayanacademy.com/resources/books/virtue/SVGlossary.html

# A teacher, par ticularly of the spiritual kind.
www.well.com/user/jct/sageglo.htm

# Somebody who knows a great deal about computers, or some specific
aspect thereof.
associate.com/camsoc/ctt/gloss-g.html

# a Sanskrit and pan-Indian word denoting a spiritual master or teacher.
It implies an initiatory relation between master and disciple. The guru
passes on oral tradition and ascetic regimen to the student.
oregonstate.edu/instruct/anth370/gloss.html

# (Sanskrit) Spiritual teacher and guide.
www.buddhanet.net/e-learning/history/glossary_fk.htm

# A religious, spiritual teacher or mentor. According to ancient Indian
Philosophy, one cannot attain success in the spiritual field without the
help of a real Guru or Sadguru.
www.siddhashram.org/glossary.shtml

# (Skt. / Tib. lama): Spiritual teacher who guides disciples on the path
to liberation or enlightenment. A guru or lama is particularly important
in the vajrayana tradition.
www.bodhipath-west.org/glossary.htm

# ("weighty one") In Indian religion, a spiritual guide. In Sikhism,
only God, one of the ten Gurus, or the sacred book (Guru Granth Sahib)
may be called Guru.
www.religionfacts.com/sikhism/glossary.htm

# a man blessed by God, who is born enlightened, without needing to
learn how to be holy. Gu translates as 'evil darkness' and Ru as 'divine
light'; a guru is a man perfectly poised above good and evil, who has
already transcended to another level. The name is commonly used for a
religious teacher.
www.ethnicityonline.net/sikh_glossary.htm

# teacher / who helps to gain knowledge
lululemon.com/culture/yoga_info/dictionary_a.php

# Literally a teacher or spiritual advisor. However, in India and Tibet
it means one at a very high level of consciousness. In fact, worship of
Guru is done to develop devotion or adoration, because the teacher is
the highest expression of God we know on Earth in our personal experience.
www.reiki.nu/treatment/healing/dictionary2/dictionary2.html

# Spiritual preceptor, one who illumines the darkness of spiritual doubt.
www.poweryoga.com/aboutyoga/article.php

# A spiritual master who has attained oneness with God and who is able
both to initiate seekers and to guide them on the spiritual path to
liberation. A true Guru is required to be learned in the scriptures and
must belong to a lineage of masters..
www.siddhayoga.org.in/glossary.html

# A spriritual preceptor, either a person or the mystical voice of Akal
Purkh. In sikhism the term 'Guru' referes to the ten Gurus and Guru
Granth Sahib, and no other.
www.info-sikh.com/PageGloss2.html

# Literally, 'Gu'= Darkness or ignorance. 'Ru'= Illumination. Guru is
therefore the spiritual Master who initiates and guides a seeker across
the sea of Separation to the shore of Union and therefore, liberation.
Guru is not simply the psycho/physical human form - the Model. Guru is
principally the function of Self Revelation through the power of grace.
Direct and continuous contact with the Guru function within ourselves is
both the practise and the goal of the Guru/Disciple relationship. ...
www.shantimandir.com/glossary/glossary.htm

# The "help person". Expert on which one may rely to help solve problems
with software and/or hardware.
www.uta.edu/infosys/e_comm/terms/term_g.htm

# (bla ma yi dam mkha’ ‘gro). The three roots of Vajrayana practice: the
guru is the root of blessings, the yidam is the root of accomplishments,
and the dakini is the root of activities.
www.rangjung.com/books/lotus-born_glossary.htm

# in Hinduism, a spiritual teacher or preceptor, treated with the
deepest respect and greatest reverence; one who lights up the Way
Godward; a torch-bearer on the way back to the mansion of the Lord.
www.ruhanisatsangusa.org/gloss.htm

# ( Sanskrit word meaning “weighty one”), gurudev(a): spiritual
preceptor in the Hindu and yogic tradition.
www.storytellingmonk.org/ref/glossaries/g.htm

# a Hindu or Buddhist religious leader and spiritual teacher
# each of the first ten leaders of the Sikh religion
# a recognized leader in some field or of some movement; "a guru of
genomics"
wordnet.princeton.edu/perl/webwn

# A guru (गुरू Sanskrit) is a teacher in Hinduism, Buddhism and Sikhism.
It is based on a long line of philosophical understandings of the
importance of knowledge and that the teacher, guru, is the sacred
conduit to self-realization. Till today in India and among people of
Hindu, Buddhist, or Sikh persuasion, the title retains its significant
hallowed space.
en.wikipedia.org/wiki/Guru

Regards,
JS

[Cecil Moore]

Post by John Smith I
(BTW, I think your use of "guru" is well justified)

Sorta using my own definition for "guru" here, John.
It is an individual who refuses to listen to anything
that mere mortals have to say and either already knows
everything or gets any new information from God Almighty
himself. Anything that I cannot tell from a religion is
being asserted by a "guru". A perfect example is the
assertion by W8JI that current travels the length of
a 75m Texas Bugcatcher coil instantaneously.

If that were true, Intel could speed up its computer
buses by adding a 75m Texas Bugcatcher coil to each
data/control line, i.e. it is a ridiculous assertion.

[John Smith I]

Post by Cecil Moore

...

If that were true, Intel could speed up its computer
buses by adding a 75m Texas Bugcatcher coil to each
data/control line, i.e. it is a ridiculous assertion.

Cecil:

This whole discussion has been interesting. I have loved the debate and analysis ... krist, you guys keep this up and I just may end up finding ham radio fun again!

Let's just remember to all shake hands when this is done :-)

Warmest regards,
JS

[Cecil Moore]

Post by John Smith I
Let's just remember to all shake hands when this is done :-)

Gurus don't shake hands because they might get contaminated
by the outside world. :-)

[Jim Kelley]

Post by Yuri Blanarovich
He was born in Smiljan Lika, Serbia, Yugoslavia, studied at Carl University
in Prague. People know more about tinkerer Edison, than about greatest
engineering genius who gave us AC and so much.

You may be just a little biased when it comes to Tesla, but
understandably so. I am more of an enthusiast than a fanatic.

Post by Yuri Blanarovich
Seemed to me implied: "Yeah" = mickey-mouse universities in Yugoslavia (or
Eastern Eu).

It was a regretable choice. Cecil has that effect on me
occasionally. I did manage to control myself well enough to avoid
calling him a "guru" though. :-)

Post by Yuri Blanarovich

Post by Jim Kelley
I wish I understood this obsession you and Cecil have with gurus. I
don't share it.

It is more like reaction to people who are sometimes wrong and chime in on a
subject with: "hey stupid, it can't be" - parading as omnipotent gurus,
instead of asking questions and discussing the matter inteligently and
either defending their position or admitting that maybe we were not so
stupid and they COULD be wrong, and learn and get better.

If only that were a two-way street.

Post by Yuri Blanarovich
What we perceive as "gurus" here, is a type of person who is wrong about the
subject, tends to get riding on a high horse putting down the opposition,
sometimes ridiculing and close minded to any, even elaborate explanation or
reasoning. Typically "guru" wants to have their last "right" word, even if
realizing that maybe they were wrong, never admitting or giving credit where
is due.

Evidently a matter of perception and partiality. Cecil has more 'last
words' on this newsgroup than any other contributer by an order of
magnitude, and fits the rest of your description to a tee.

Post by Yuri Blanarovich
Looks like too much Woodstock generation getting into engineering and
forcing their "truth" to be the only one standing (Global Warming). If often
enough repeated in politics, it catches on with halfbright worshippers, but
has no place in science.

'Current pileup' could be just such a phenomenon.

Post by Yuri Blanarovich
I am sorry that sometimes I get provoked and fire back in a like manner, but
when someone is trying to convince me that RF is behaving like DC current,
when I got burned my fingers on the bottom of the loading coil, then I just
react in kind.

Do I stand accused of trying to convince you that RF behaves like DC?
I'm not sure that's entirely fair. I so admit to discouraging belief
that RF behaves like magic.

Post by Yuri Blanarovich
Even if sometimes discussions get tangled here, because some just can't, or
don't want to get it, I am gratefull to those involved, because they bring
some points, that I would have not paid attention to and missed important
link in the chain of knowledge on the subject.
Another outcome is, that some subjects in current literature are not all
that properly described and warrant more detailed explanation and proof to
get corrected, and some discussions here shed some light at it and
highlinght need for more down to earth tutorial to set the record straight.

That's pretty much how I feel about it. I think it helps to keep an
open mind and consider all of the relevant facts.

73, Jim AC6XG

[Cecil Moore]

Post by Jim Kelley
Evidently a matter of perception and partiality. Cecil has more 'last
words' on this newsgroup than any other contributer by an order of
magnitude, and fits the rest of your description to a tee.

Gurus are individuals who already know everything there is
to know and are therefore incapable of learning anything
new. That's not me. That's the arrogant individual who lists
all the possibilities that might cause someone to disagree
with him and none of those possibilities is that he might
be wrong.

[Jim Kelley]

Post by Cecil Moore
Gurus are individuals who already know everything there is
to know and are therefore incapable of learning anything
new. That's not me.

So, that makes you the guy who says things like that about a person
just because he disagrees with him on a newsgroup.

ac6xg

[Yuri Blanarovich]

Post by Jim Kelley

Post by Cecil Moore
Gurus are individuals who already know everything there is
to know and are therefore incapable of learning anything
new. That's not me.

So, that makes you the guy who says things like that about a person
just because he disagrees with him on a newsgroup.
ac6xg

It is not matter of disagreeing with person, more like discussing the
subject, finding out the reality (truth) and learning, sometimes admitting
of being off, or wrong, rather than defending the opposite, just
because.....

Many times I see that people do not bother trying to understand the problem,
researching it , but fire off "naaah, it can't be" and reduce their comments
to personal attacks.

Again, thanks to Cecil, Walt, Richard H and others for their contribution to
discussions, their persistence, it opened my antenna horizons and gave me
better understanding of wasaaaap with antennas. It will help me in my
further exploits and trying to build better arrays and taking advantage of
propagation modes and environment.

As a contester, I would encourage "gurus" to proclaim their "wisdom", for it
will confuse the competition and allow me to beat them by wider margin :-)
But as engineer, I would rather know the reality and what's behind it.

Just as an example: W8JI proclaims gospel on his web site that Beverage
antennas longer than 700 ft (on 160) are useless and waste of effort. When I
operated from W8LRL QTH and used his 3000 ft staggered phased JA Beverage, I
worked some 25 JAs, when rest of the East Coast hardly worked one or two.
Reality trumps over "guru theory" still insisting on his "gospel".

73 Yuri, K3BU

[Jim Kelley]

Post by Yuri Blanarovich
Many times I see that people do not bother trying to understand the problem,
researching it , but fire off "naaah, it can't be" and reduce their comments
to personal attacks.

Apparently you don't see it as much of it as some of the rest of us do.

Post by Yuri Blanarovich
But as engineer, I would rather know the reality and what's behind it.

It's probably fair to say that's what motivates most of us, Yuri.
It's the one thing most of us here share in common, other than ham radio.

Post by Yuri Blanarovich
Just as an example: W8JI proclaims gospel on his web site that Beverage
antennas longer than 700 ft (on 160) are useless and waste of effort.

I am not Tom, and you are not Tom. Neither of us speaks for Tom. Tom
doesn't even have a dog in this fight as far as I know. So in the
interest of maximizing the signal to noise ratio around here, why
don't we each let the other just speak for himself. It's much too
gossipy otherwise (and not very 'engineer-like').

73, Jim AC6XG

[Cecil Moore]

Tom doesn't even have a dog in this fight as far as I know.

Tom's web page is in this dog fight. Tom has posted hundreds
of postings in the past in support of his instantaneous
current with no phase shift through a loading coil. He
even "measured" the phase shift through a large coil at
5 nS. Of course, his "measurement" was made with standing-
wave current which doesn't change phase.

[Jim Kelley]

Post by Cecil Moore

Tom doesn't even have a dog in this fight as far as I know.

Tom has posted hundreds
of postings in the past in support of his instantaneous
current with no phase shift through a loading coil.

Tom hasn't posted a single word to this thread that I am aware of.
The point is if you don't like what he says, you should take it up
with him. Know what I mean?

ac6xg

[Cecil Moore]

Tom hasn't posted a single word to this thread that I am aware of. The
point is if you don't like what he says, you should take it up with
him. Know what I mean?

What is your agenda in asserting that the contents of
Tom's web page concerning loading coils and his past
postings on the subject are off limits for this newsgroup?

[Jim Kelley]

Post by Cecil Moore

Tom doesn't even have a dog in this fight as far as I know.

Tom's web page is in this dog fight. Tom has posted hundreds
of postings in the past in support of his instantaneous
current with no phase shift through a loading coil. He
even "measured" the phase shift through a large coil at
5 nS. Of course, his "measurement" was made with standing-
wave current which doesn't change phase.

Then let me put it to you this way. I don't have a dog in your fight
with him. Why don't you go tell it to him?

73, Jim AC6XG

[Cecil Moore]

Post by Jim Kelley
Then let me put it to you this way. I don't have a dog in your fight
with him. Why don't you go tell it to him?

I already did.

But let's extend your logic to John Kraus. He doesn't
have a dog in this fight either. Why is it OK to quote
Kraus and not OK to quote w8ji?

[Richard Harrison]

Jim Kelley wrote:
"Let`s not get carried away. And I don`t think Tesla was from
Yugoslavia."

WebTV is owned by Microsoft and uses their search engine. Searching for
"radio amateur fact of the day from Tigertek" immediately turned up
their site. I scrolled down to find Tesla`s boat on their March 3
offering:
"On May 18, 1899, Nikola Tesla demonstrated a six-foot-long
radio-controlled boat to members of the Chicago Commercial Club. He had
designed and built the boat the previous year, but only few had seen it
prior to the Chicago Commercial Club demonstration. Club members saw
that could remotely start the boat`s motor, switch flashing boat lights
on and off, and navigate around a miniature lake that he created for the
demonstration. Individuals in the crowd shouted commands that he sent
wirelessly by radio, so that the astonished crowd could see that the
boat actually was being wirelessly-remotely-controlled. Copyright 2005
Tigertek, Inc.

It wasn`t until WW-2 and the U.S. invasion of Salerno when the Germans
tried to repel it using remotely controlled bombers, that radio control
was used so expertly.

I first read about Tesla in "Prodigal Genius", a book supplied by some
donor ro relieve the boredom aboard my navy ship in WW-2. I was a fiesel
engine nechanic interested in electricity and radio so I read it. Tesla
impressed me. He was more famous for his inventions of 3-phase electric
power, the induction motor, and harnessing the power of Niagra Falls for
electricity than he was for radio control. By all accounts he was born
in Yugoslavia, educated in Europe, and came to the U.S. to work for
Thomas Edison who was unimpressed with Tesla. So Tesla went to George
Westinghouse and made a deal.

Incidently. nothing exceeds the speed of light, not even photons which
are supposed to be massless at rest by Einstein`s special law of
relativity. You must have current before it creates a magnetic field.
Current is not instantaneous in any case in a conductor where the
electrons set in motion do have have mass.

Best regards, Richard Harrison, KB5WZI

[Jim Kelley]

Post by Richard Harrison
Incidently. nothing exceeds the speed of light, not even photons which
are supposed to be massless at rest by Einstein`s special law of
relativity. You must have current before it creates a magnetic field.
Current is not instantaneous in any case in a conductor where the
electrons set in motion do have have mass.

Hi Richard,

Perhaps it should be noted that electromagnetic waves and photons
travel neither faster nor slower than the speed of light in their
medium of travel.

73, Jim AC6XG

[Richard Harrison]

Uim, AC6XG wrote:
"Perhaps it should be noted that electromagnetic waves and photons
travel neither faster nor slower than the speed of light in their medium
of travel."

Yes. Corpuscles and waves have the same velocity given the same medium.

Best regards, Richard Harrison, KB5WZI

[Cecil Moore]

Perhaps it should be noted that electromagnetic waves and photons travel
neither faster nor slower than the speed of light in their medium of
travel.

Obviously true for traveling waves. But how about the
"electromagnetic waves and photons" involved in standing
waves? Some folk here would have us believe that they are
not moving at all.

[Jim Kelley]

Post by Cecil Moore

Post by Jim Kelley
Perhaps it should be noted that electromagnetic waves and photons
travel neither faster nor slower than the speed of light in their
medium of travel.

Obviously true for traveling waves. But how about the
"electromagnetic waves and photons" involved in standing
waves?

The only kind of electromagnetic waves I know about are the traveling
kind. Sorry I can't be more help.

73, ac6xg

[Cecil Moore]

Post by Jim Kelley
The only kind of electromagnetic waves I know about are the traveling
kind. Sorry I can't be more help.

Seems to beg the question - are standing-waves electromagnetic
waves? If so, why are they standing? If not, what are they?
(Rhetorical questions AFAIAC)

[Richard Harrison]

Cecil, W5DXP wrote:
"---are standing waves electromagnetic waves?"

According to Tigertek they are not. Photons are massless at rest. They
cease to exist. Waves made of photons thus don`t exist if they are not
in motion. A real electromagnetic wave must be moving to exist. Check
out Tigertek`s fact of the day.

Best regards, Richard Harrison, KB5WZI

[Cecil Moore]

Post by Richard Harrison
"---are standing waves electromagnetic waves?"
According to Tigertek they are not. Photons are massless at rest. They
cease to exist. Waves made of photons thus don`t exist if they are not
in motion. A real electromagnetic wave must be moving to exist. Check
out Tigertek`s fact of the day.

I agree that there is a logical contradiction between standing
waves and electromagnetic waves. Too bad the people using
standing wave current for measuring phase don't realize that.

[Jim Kelley]

Post by Cecil Moore
I agree that there is a logical contradiction between standing
waves and electromagnetic waves.

If there is, then there must also be contradiction between traveling
waves and destructive interference, and between two dissonant notes
and the beat they create. They are all simply the result of
superposition. Two things happening at the same time in the same place
with one result. But nothing more.

Take two sound waves of identical frequency and superpose them. The
result is a single waveform. Now decrease the frequency of one just a
bit. They still superpose to create a single waveform but now the net
amplitude varies with time according to the difference in frequency.
Decrease the frequency even more. We still have a single waveform,
and the beat frequency may now be too rapid to easily discern, but now
we can begin to discern two distinct pitches. Look at it on a
spectrum analyzer and we can see each of the two frequencies
individually. Yet all we see on the oscilloscope is one waveform.

Is that the contradiction?

73, Jim AC6XG

[Jimmie D]

Post by Jim Kelley

Post by Cecil Moore
I agree that there is a logical contradiction between standing
waves and electromagnetic waves.

If there is, then there must also be contradiction between traveling
waves and destructive interference, and between two dissonant notes
and the beat they create. They are all simply the result of
superposition. Two things happening at the same time in the same place
with one result. But nothing more.
Take two sound waves of identical frequency and superpose them. The
result is a single waveform. Now decrease the frequency of one just a
bit. They still superpose to create a single waveform but now the net
amplitude varies with time according to the difference in frequency.
Decrease the frequency even more. We still have a single waveform,
and the beat frequency may now be too rapid to easily discern, but now
we can begin to discern two distinct pitches. Look at it on a
spectrum analyzer and we can see each of the two frequencies
individually. Yet all we see on the oscilloscope is one waveform.
Is that the contradiction?
73, Jim AC6XG

No, Its an illusion. The same thing happens when you view an AM signal. On
an oscilloscope the pattern you see may give you the impression that the
carrier is changing in amplitude with the modulation. Perhaps standing waves
are this same type of illusion.

Jimmie

[Keith Dysart]

Post by Jimmie D
No, Its an illusion. The same thing happens when you view an AM signal. On
an oscilloscope the pattern you see may give you the impression that the
carrier is changing in amplitude with the modulation. Perhaps standing waves
are this same type of illusion.

I am unsure why you would call this an illusion.

The modulated waveform can be accurately described by
(f(t)+1)*cos(2*pi*fc*t) where f(t) is the modulating signal

from which it is easy to discern that the amplitude is changing
with the modulation.

There is often more than one way to describe an observation and
the existence of this description in no way detracts from the
alternative which has a carrier plus and minus the modulating
signal.

Many of the arguments here do seem to be of the form "You
say tomatoe and I say tomatoe", but the important point is
that the appropriate description be used for the problem at
hand. Filter design is probably better done with the latter,
while modulators and envelope detectors are likely better
analyzed with the former.

But I find no reason to declare one to be less of an illusion than
the other.

You are correct though; this is exactly like the arguments
about "standing waves" and "travelling waves". The mathematical
expressions for each accurately describe the voltage and
current distribution on the line, yet some wish to argue that one
description is more real than the other.

They are equally real and equally illusions. The important point
is to choose the one that best helps solve whatever problem is
at hand and not to get carried away with a belief that one is more
real than the other.

...Keith

[Chuck]

Post by Keith Dysart

Post by Jimmie D
No, Its an illusion. The same thing happens when you view an AM signal. On
an oscilloscope the pattern you see may give you the impression that the
carrier is changing in amplitude with the modulation. Perhaps standing waves
are this same type of illusion.

I am unsure why you would call this an illusion.
The modulated waveform can be accurately described by
(f(t)+1)*cos(2*pi*fc*t) where f(t) is the modulating signal
from which it is easy to discern that the amplitude is changing
with the modulation.
There is often more than one way to describe an observation and
the existence of this description in no way detracts from the
alternative which has a carrier plus and minus the modulating
signal.
Many of the arguments here do seem to be of the form "You
say tomatoe and I say tomatoe", but the important point is
that the appropriate description be used for the problem at
hand. Filter design is probably better done with the latter,
while modulators and envelope detectors are likely better
analyzed with the former.
But I find no reason to declare one to be less of an illusion than
the other.
You are correct though; this is exactly like the arguments
about "standing waves" and "travelling waves". The mathematical
expressions for each accurately describe the voltage and
current distribution on the line, yet some wish to argue that one
description is more real than the other.
They are equally real and equally illusions. The important point
is to choose the one that best helps solve whatever problem is
at hand and not to get carried away with a belief that one is more
real than the other.
...Keith

Thank you for nicely elucidating the
distinctions in emphasis between
"science" and engineering, Keith.

I believe a perfect (just to keep this
at an abstract level) SA reveals the
underlying reality of the modulated AM
carrier.

An oscilloscope displays a waveform that
can be mathematically derived from the
underlying reality. On the scope, it is
produced by electronically combining
three (assumed) sine waves. Without the
mathematical or electronic operations, I
suggest the waveform displayed by the
scope does not exist.

Mathematical equivalence between time
and frequency domains does not
demonstrate (in my humble opinion) a
duality in the underlying reality.

In reality, there are only the original
three frequencies which can be
demonstrated by selective filtering.
Whether the oscilloscope waveform is an
illusion is perhaps a semantic issue
since it is an artifact constructed
from, and convertible at will back into
the three continuously existing sine
waves which never surrender their
independent qualities.

Quite a bit of difference from
transmission line standing waves, no?

My $02.

Chuck


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[Keith Dysart]

Post by Chuck
Thank you for nicely elucidating the
distinctions in emphasis between
"science" and engineering, Keith.
I believe a perfect (just to keep this
at an abstract level) SA reveals the
underlying reality of the modulated AM
carrier.

Let me offer two examples.

I turn on my RF signal generator. I turn up the RF Level,
then I turn it down, then up, then down, ....
I can see this varying RF level on my oscilloscope (slow
sweep), and even on my RF voltmeter.
I know I am varying the level of the RF.
But I also know that I could produce exactly the same
output by adding 3 signals of slightly different frequency
together. I am not at all comfortable with saying the latter
is 'real' while the former isn't. I know I was varying the RF
Level.

Or,
I turn on my RF signal generator with some level for 1
minute. I turn it off for a week. I turn it on for one minute.
I turn it off. I compute the Fourier transform. I can create
exactly the same signal by adding all the Fourier terms,
extending forward and backwards in time, forever.
But is this more real than: I turn it on, then off, then
on, then off?

Using these examples, I can find no reason why the
multiple signal explanation is more real than the
varying amplitude explanation. And I suggest, that for
these two cases, the varying amplitude explanation
is probably more useful.

...Keith

[Chuck]

Post by Keith Dysart

Post by Chuck
Thank you for nicely elucidating the
distinctions in emphasis between
"science" and engineering, Keith.
I believe a perfect (just to keep this
at an abstract level) SA reveals the
underlying reality of the modulated AM
carrier.

Let me offer two examples.
I turn on my RF signal generator. I turn up the RF Level,
then I turn it down, then up, then down, ....
I can see this varying RF level on my oscilloscope (slow
sweep), and even on my RF voltmeter.
I know I am varying the level of the RF.
But I also know that I could produce exactly the same
output by adding 3 signals of slightly different frequency
together. I am not at all comfortable with saying the latter
is 'real' while the former isn't. I know I was varying the RF
Level.
Or,
I turn on my RF signal generator with some level for 1
minute. I turn it off for a week. I turn it on for one minute.
I turn it off. I compute the Fourier transform. I can create
exactly the same signal by adding all the Fourier terms,
extending forward and backwards in time, forever.
But is this more real than: I turn it on, then off, then
on, then off?
Using these examples, I can find no reason why the
multiple signal explanation is more real than the
varying amplitude explanation. And I suggest, that for
these two cases, the varying amplitude explanation
is probably more useful.
...Keith

Well, if I understand, and I often
don't, you are saying that the spectrum
produced by method 1 is
indistinguishable from the spectrum
produced by method 2 and THEREFORE,
neither spectrum alone can be considered
true reality.

I grant immediately that it doesn't
matter how you produce the spectrum.

What is at issue, if I am not mistaken,
is whether the reality is that which is
observed on the scope, vs. that which is
observed on the SA (in the case of an
amplitude modulated carrier, of course).

Abstracting, there are three (by
assumption) coherent sinusoids in the AM
modulation case. Each can be directly
measured and characterized.

A composite of these sinusoids can be
displayed on a scope. Any number of
mathematical or electronic operations
can be performed on the sinusoids, and
the results displayed on a scope.

Usefulness, like convenience, may share
a bed with veracity, but its intentions
should be suspect.

I guess I can continue to assert that
mathematical equivalence between
frequency and time domains is not
evidence to me of an underlying duality
in reality, and you can continue to
assert that to you, it is. And I guess
we could still be friends. ;-)

73,

Chuck





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[Jim Kelley]

Post by Keith Dysart
Using these examples, I can find no reason why the
multiple signal explanation is more real than the
varying amplitude explanation. And I suggest, that for
these two cases, the varying amplitude explanation
is probably more useful.
...Keith

Well, if I understand, and I often don't, you are saying that the
spectrum produced by method 1 is indistinguishable from the spectrum
produced by method 2 and THEREFORE, neither spectrum alone can be
considered true reality.

What he said is neither case is less real than the other. It's simply
two different ways of describing the same thing. Have a look at a
table of trigonometric identities. It is a list of different ways of
saying the same thing, mathematically. Each is real in one way or
another, but not necessarily in the same way.

I guess I can continue to assert that mathematical equivalence between
frequency and time domains is not evidence to me of an underlying
duality in reality, and you can continue to assert that to you, it is.

I guess that would depend on what underlying duality you are inferring
from the mathematical equivalence. Not that it necessarily applies
here, but one of the problems we frequently face here on the newsgroup
is a direct result of incorrect inference.

And I guess we could still be friends. ;-)

One of the great contributors to the ham radio newsgroups used to
remind us that "a gentleman is a man who can disagree without being
disagreeable". The challenge then is to remain agreeable amidst a
barrage of disagreeable comments.

73, Jim AC6XG

[Cecil Moore]

Post by Jim Kelley

Post by Cecil Moore
I agree that there is a logical contradiction between standing
waves and electromagnetic waves.

Is that the contradiction?

You obviously misunderstood what I was trying to say
so let me expand my statement:

Since contradictions do not exist in reality, any
apparent contradiction between standing EM waves and
traveling EM waves has to exist only in the human mind.
There is no contradiction in the real world. The photons
in a standing wave are moving at the speed of light,
c*VF, not standing still in the standing wave. Believing
that the component traveling waves cease to exist is
the contradiction and cannot occur in reality.

[Gene Fuller]

Post by Cecil Moore

Post by Jim Kelley

Post by Cecil Moore
I agree that there is a logical contradiction between standing
waves and electromagnetic waves.

Is that the contradiction?

You obviously misunderstood what I was trying to say
Since contradictions do not exist in reality, any
apparent contradiction between standing EM waves and
traveling EM waves has to exist only in the human mind.
There is no contradiction in the real world. The photons
in a standing wave are moving at the speed of light,
c*VF, not standing still in the standing wave. Believing
that the component traveling waves cease to exist is
the contradiction and cannot occur in reality.

Cecil,

Why do you seem to believe that bringing photons into the discussion
adds any light? (pun intended)

Does the word "photon" sound more hifalutin than "wave"?

It is instructive to follow the lead of Kraus. In the second edition of
"Antennas", on page 19, Kraus notes, "In simplest terms an antenna
converts photons to currents or vice versa."

He then goes on to write nearly 900 pages, and it is not apparent that
he ever again mentions "photon". I did not find any cases in a quick review.

Have you ever seen any technical treatment of HF radiation that actually
used photons in the equations?

73,
Gene
W4SZ

[Cecil Moore]

Post by Gene Fuller
Why do you seem to believe that bringing photons into the discussion
adds any light? (pun intended)
Does the word "photon" sound more hifalutin than "wave"?

Using "photons" instead of "EM waves" makes things a little
more obvious. While "standing EM waves" may imply EM waves
that are standing still, "standing photons" are obviously
impossible. Photons cannot stand still. EM waves cannot
stand still for the same reason. A "standing EM wave" is
a human abstraction that doesn't really exist in reality.

The only people with something to gain by objecting to
the use of "EM waves" and "photons" interchangeably are the
people trying to hoodwink the uninitiated into believing
that photons can stand still. :-)
--
73, Cecil, w5dxp.com

[Gene Fuller]

Post by Cecil Moore

Post by Gene Fuller
Why do you seem to believe that bringing photons into the discussion
adds any light? (pun intended)
Does the word "photon" sound more hifalutin than "wave"?

Using "photons" instead of "EM waves" makes things a little
more obvious. While "standing EM waves" may imply EM waves
that are standing still, "standing photons" are obviously
impossible. Photons cannot stand still. EM waves cannot
stand still for the same reason. A "standing EM wave" is
a human abstraction that doesn't really exist in reality.
The only people with something to gain by objecting to
the use of "EM waves" and "photons" interchangeably are the
people trying to hoodwink the uninitiated into believing
that photons can stand still. :-)
--
73, Cecil, w5dxp.com

Cecil,

There seems to be a pretty fundamental disconnect here. Waves don't
create radiation; photons don't create radiation; accelerating charges
do create radiation.

You seem to be placing some sort of restriction on the motion of those
charges. They can move or stand still as they please. Some folks around
here appear to think that standing waves are totally inert, and
therefore totally useless or even fictitious. There are most definitely
accelerating charges in a standing wave, and that accelerated charge
generates the desired radiation. Call it "sloshing" if you wish, but it
still works.

What difference does it make if the wave on the antenna and the radiated
wave in space can be defined as photons?

Answer: None whatsoever, and there is not even any insight gained into
the radiation mechanism at HF.

In case there is any doubt, let me say it again;

Adding photons into the discussion of HF radiation adds absolutely
nothing but confusion.

73,
Gene
W4SZ

[Richard Clark]

Post by Gene Fuller
Adding photons into the discussion of HF radiation adds absolutely
nothing but confusion.

Hi Gene,

I seriously doubt that, the confusion is already super-saturated.
Perhaps you meant it might add more precipitate.

73's
Richard Clark, KB7QHC

[Cecil Moore]

Post by Gene Fuller
There seems to be a pretty fundamental disconnect here. Waves don't
create radiation; photons don't create radiation; accelerating charges
do create radiation.

Who cares? Photons can form standing waves in free space.
Where are your accelerating charges in a vacuum? Everything
that happens to EM waves in a wire, or a waveguide, also
happen to EM waves in free space.

You want to talk about the ocean and ignore the Tsunami.

Post by Gene Fuller
What difference does it make if the wave on the antenna and the radiated
wave in space can be defined as photons?
Answer: None whatsoever, ...

That's your agenda and you're sticking to it. Like
I said, some people apparently enjoy hoodwinking the
uninitiated. What else do you have to gain by ignoring
the photonic nature of EM waves?

Accelerating charges do not morph into EM waves.
Accelerating charges release photons that are the
wave. Ignoring the photonic nature of EM waves is
the cause of the present mass confusion about
standing waves. Why on earth would you want that
mass confusion to continue?
--
73, Cecil, w5dxp.com

[Gene Fuller]

Post by Cecil Moore

Post by Gene Fuller
There seems to be a pretty fundamental disconnect here. Waves don't
create radiation; photons don't create radiation; accelerating charges
do create radiation.

Who cares? Photons can form standing waves in free space.
Where are your accelerating charges in a vacuum? Everything
that happens to EM waves in a wire, or a waveguide, also
happen to EM waves in free space.
You want to talk about the ocean and ignore the Tsunami.

Post by Gene Fuller
What difference does it make if the wave on the antenna and the
radiated wave in space can be defined as photons?
Answer: None whatsoever, ...

That's your agenda and you're sticking to it. Like
I said, some people apparently enjoy hoodwinking the
uninitiated. What else do you have to gain by ignoring
the photonic nature of EM waves?
Accelerating charges do not morph into EM waves.
Accelerating charges release photons that are the
wave. Ignoring the photonic nature of EM waves is
the cause of the present mass confusion about
standing waves. Why on earth would you want that
mass confusion to continue?
--
73, Cecil, w5dxp.com

Cecil,

So sorry. I thought that your 75m Bugcatcher Coil was a real, metallic
object. If it is really nothing but free space, then I will agree with
your assertions. The waves on your free space coil therefore have no
connection to charges on a wire.

I also forgot that all standing waves are identical, whether in free
space or on a wire.

I particularly love the wording you used, "Accelerating charges do not
morph into EM waves. Accelerating charges release photons that are the
wave."

Did you ever hear of wave-particle duality? Did you ever read a serious
treatment of radiation from antennas. Did you find lots of references to
photon release, say, in Kraus or Balanis?

Reversing the question you posed above, what do you gain by including
the photonic nature of EM waves?

I will try harder to follow the change of topic in the future.

8-)

73,
Gene
W4SZ

[Richard Harrison]

Gene Fuller wrote:
"Waves don`t cause radiation."

Waves induce current into an antenna. Any mismatched antenna reradiates
most of the energy induced into it. A perfectly matched antnna only
reradiates 50% of the energy it receives.

Best regards, Richard Harrison, KB5WZI

[art]

Post by Richard Harrison
"Waves don`t cause radiation."
Waves induce current into an antenna. Any mismatched antenna reradiates
most of the energy induced into it. A perfectly matched antnna only
reradiates 50% of the energy it receives.
Best regards, Richard Harrison, KB5WZI

Richard,
Some time ago I stated that a yagi antenna operated under a
mathematical binomial function. This was termed as junk science in
this group which raises the question again as where does the energy
that is not reradiated go ?

" A perfectly matched antenna only reradiates 50 % of the energy that
it receives"

This also suggests that an array without parasitics required for
reradiation is a lot more efficient than an antenna with parasitics.
Seems like this group is going around in circles unless this 50% finds
a way to radiate in some alternative way !
Is the 'perfectly matched' statement of any importance that demands
it's inclusion with respect to re-radiation efficiency of an antenna?
Regards
Art

[Gene Fuller]

Post by Richard Harrison
"Waves don`t cause radiation."
Waves induce current into an antenna. Any mismatched antenna reradiates
most of the energy induced into it. A perfectly matched antnna only
reradiates 50% of the energy it receives.
Best regards, Richard Harrison, KB5WZI

Richard,

That is a well-known factoid. Do you think it differs from something I
said? You note that current is involved in the reradiation.

73,
Gene
W4SZ

[Cecil Moore]

Post by Gene Fuller

Post by Richard Harrison
"Waves don`t cause radiation."
Waves induce current into an antenna. Any mismatched antenna reradiates
most of the energy induced into it. A perfectly matched antnna only
reradiates 50% of the energy it receives.

That is a well-known factoid. Do you think it differs from something I
said? You note that current is involved in the reradiation.

Hint: If waves cause currents that in turn, cause
re-radiation, then Richard has proved your, "waves
don't cause radiation", assertion to be false.

[Cecil Moore]

Post by Gene Fuller
I also forgot that all standing waves are identical, whether in free
space or on a wire.

The same laws of physics apply to both. There are not, as you are
trying to imply, a separate set of laws for EM waves on a wire
and EM waves in free space.

Post by Gene Fuller
Reversing the question you posed above, what do you gain by including
the photonic nature of EM waves?

It keeps some people from sweeping the photonic nature of EM waves
under the old standing wave rug. I won't mention any names.
--
73, Cecil, w5dxp.com

[Gene Fuller]

Post by Cecil Moore

Post by Gene Fuller
I also forgot that all standing waves are identical, whether in free
space or on a wire.

The same laws of physics apply to both. There are not, as you are
trying to imply, a separate set of laws for EM waves on a wire
and EM waves in free space.

Post by Gene Fuller
Reversing the question you posed above, what do you gain by including
the photonic nature of EM waves?

It keeps some people from sweeping the photonic nature of EM waves
under the old standing wave rug. I won't mention any names.
--
73, Cecil, w5dxp.com

What rug? What are you talking about? How does the (unnecessary) use of
photons change anything?

73,
Gene
W4SZ

[Richard Harrison]

Gene, W4SZ wrote:
"It is instructive to follow the lead of Kraus. In the second edition of
"Antennas", on page 19, Kraus notes, "In simplest terms an antenna
converts photons to currents or vice versa."

In the paperback 3rd edition, which I think Cecil has, I was pleased to
find a similar quotation at the top of page 12.

Best regards, Richard Harrison, KB5WZI

[Jim Kelley]

Post by Cecil Moore

Post by Jim Kelley

Post by Cecil Moore
I agree that there is a logical contradiction between standing
waves and electromagnetic waves.

Is that the contradiction?

There is no contradiction in the real world.

My point exactly.

ac6xg

[Cecil Moore]

Post by Jim Kelley

Post by Cecil Moore
There is no contradiction in the real world.

My point exactly.

My point exactly first! Contradictions exist *only*
in human minds.
--
73, Cecil, w5dxp.com

[Gene Fuller]

Post by Cecil Moore

Post by Jim Kelley
Perhaps it should be noted that electromagnetic waves and photons
travel neither faster nor slower than the speed of light in their
medium of travel.

Obviously true for traveling waves. But how about the
"electromagnetic waves and photons" involved in standing
waves? Some folk here would have us believe that they are
not moving at all.

Cecil,

So do you actually believe that standing waves are completely static and
inert?

73,
Gene
W4SZ

[Cecil Moore]

Post by Gene Fuller
So do you actually believe that standing waves are completely static and
inert?

Of course not, Gene, but some on this newsgroup apparently
believe that. (Hint: I said it was a rhetorical question).

Why do some posters on this newsgroup go out of their way
to deny the photonic nature of the two traveling wave
components that are the cause of the standing wave?

[Richard Harrison]

Cecil, W5DXP wrote:
"But how about the electromagnetic waves and photons involved with
standing waves?"

Terman has an answer. The standing wave is only a manifestation of
interference between two waves traveling in opposite directions, so on
page 870 of his 1955 opus Terman writes:

"The directional characteristic of a resonant (standing wave) system is
the vector sum of the directional patterns pointed in opposite
directions, as illustrated in Fig. 23-8."

In other words, the wave traveling in one direction produces its pattern
and the wave traveling in the other direction produces its pattern. The
sum of the patterns in both directions is the directional pattern for
the rod or wire. Standing waves have nothing to do with it but to stand
there and do nothing.

Best regards, Richard Harrison, KB5WZI

[Richard Harrison]

Cecil, W5DXP wrote:
"No, just that phasing of RF signals is what is confusing the DC gurus,
just like AC phasing confused Edison."

In W8JI`s pages I found this on the subject of "Mobile antennas, short
verticals, loading" :
It`s long and Tom warns about taking anything from context, so it should
be searched out and read in its entirety. I have no quarrel with most of
Tom`s pages but find this statement curious:
"When current flows in the transmitter-end of the coil, a magnetic field
is created. The time-varying magnetic field causes charges in the other
turns to instantly move."

Instant movement of charges is instant current, and everyone knows that
current in a coil lags the voltage.

Best regards, Richard Harrison, KB5WZI

[Cecil Moore]

Post by Richard Harrison
"When current flows in the transmitter-end of the coil, a magnetic field
is created. The time-varying magnetic field causes charges in the other
turns to instantly move."
Instant movement of charges is instant current, and everyone knows that
current in a coil lags the voltage.

Instant movement of charges is impossible except in the mind
of someone using the lumped-element model. Apparently, anything
is possible in that kind of mind. As Dr. Corum said: "Lumped
circuit theory fails because it's a *theory* whose presuppositions
are inadequate. Every EE in the world was warned of this in their
first sophomore circuits course. ... Lumped circuit theory isn't
absolute truth, it's only an analytical *theory* - and in those
resonators we have the case where this sophomore *theory* fails
*experimentally. The engineer must either use Maxwell's equations
or distributed elements to model reality."

[Gene Fuller]

Post by Richard Harrison
"No, just that phasing of RF signals is what is confusing the DC gurus,
just like AC phasing confused Edison."
In W8JI`s pages I found this on the subject of "Mobile antennas, short
It`s long and Tom warns about taking anything from context, so it should
be searched out and read in its entirety. I have no quarrel with most of
"When current flows in the transmitter-end of the coil, a magnetic field
is created. The time-varying magnetic field causes charges in the other
turns to instantly move."
Instant movement of charges is instant current, and everyone knows that
current in a coil lags the voltage.
Best regards, Richard Harrison, KB5WZI

Richard,

This is one of those situations where the exact definitions are
critical. In the case of "current lags voltage" the current is measured
through the coil and the voltage is measured between the ends of the coil.

The voltage at the input of the coil (to some reference point) is not
important; only the voltage across the coil matters. Since there is
nothing in the problem statement about the coil output voltage it is not
possible to determine if there is any violation of "current lags
voltage" or not.

I am not saying anything about the assertion from W8JI. The "current
lags voltage" principle simply does not settle anything in this case.

73,
Gene
W4SZ

[Richard Harrison]

Gene, W4SZ wrote:
"The current lags voltage principle does not settle anything in this
case."

W8JI claims that current flows into a turn at a coil end/s and is
induced without delay into all turns of the coil, overcoming delay that
the coil might otherwise impose.

If that were true, Terman would have told us so. In fact, Terman tells
us the opposite is true in explaning the traveling wave tube begining on
page 678 of his 1955 opus:

"The signal to be amplified is applied to the end of the helix adjacent
to the electron gun. Under appropriate operating conditions an amplified
signal then appears at the other end of the helix.-------inapplicable
info deleted-----. The applied signal propagates around the turns of the
helix and produces an electric field that is directed along the helix
axis. Since the velocity with which the signal propagates along the
helix wire approximates the velocity of light if the frequency is not
too low (caveat is unimportant, see footnote in book), the axial field
due to the signal advances with a velocity that is very closely the
velocity of light multiplied by the ratio of helix pitch to helix
circumference."

In other words, the axial advance is much like that of a threaded bolt
as the pitch angle is always fractional. Kraus details this in his
section on helical antennas.

Best regards, Richard Harrison, KB5WZI

[Jim Kelley]

"Since the velocity with which the signal propagates along the
helix wire approximates the velocity of light if the frequency is not
too low (caveat is unimportant, see footnote in book), the axial field
due to the signal advances with a velocity that is very closely the
velocity of light multiplied by the ratio of helix pitch to helix
circumference."

Well done, sir.

Kraus details this in his
section on helical antennas.

Fig. 7-19 is certainly interesting.

Cecil owes you a fruit basket I think. ;-)

73, Jim AC6XG

[Cecil Moore]

Post by Jim Kelley

"Since the velocity with which the signal propagates along the
helix wire approximates the velocity of light if the frequency is not
too low (caveat is unimportant, see footnote in book), the axial field
due to the signal advances with a velocity that is very closely the
velocity of light multiplied by the ratio of helix pitch to helix
circumference."

Fig. 7-19 is certainly interesting.
Cecil owes you a fruit basket I think. ;-)

Unfortunately, I must disagree (very slightly) with Kraus.
Using Kraus' concepts *verbatim*, the delay through a coil
would be the same whether the wire is coiled up or straightened
out (if I understand correctly what he is saying).

On my web page at w5dxp.com/current2.htm I have a 30 turn
coil with a diameter of 6" causing a 38 degree phase shift
at 3.8 MHz. If the coil were straightened out, it would be
about pi*6"*30 = 565 inches or 47 feet. Since a wavelength
is about 259 feet at that frequency, 47 feet would be about
65 degrees. So Kraus' rule-of-thumb is off by about 70%.
His VF would be about 0.009 where the actual VF is more
like 0.106. 65 degrees of wire doesn't replace 65 degrees
of antenna. In this case, 65 degrees of wire replaces
38 degrees of antenna. The "missing degrees" are in the
impedance discontinuity between the coil and stinger.

There is an interaction between turns that increases the
VF of the coil so there is a very tiny grain of truth in
what Tom says. The interaction between turns increases the
coil VF from Kraus' 0.009 to the actual value of 0.016
but certainly not all the way to 1.0 as W8JI asserts.

Kraus may have been off by 70% but W8JI is off by 6000%
so it seems that Kraus was still a lot closer to the
technical truth that W8JI ever was.

[Gene Fuller]

Post by Cecil Moore

Post by Jim Kelley

"Since the velocity with which the signal propagates along the
helix wire approximates the velocity of light if the frequency is not
too low (caveat is unimportant, see footnote in book), the axial field
due to the signal advances with a velocity that is very closely the
velocity of light multiplied by the ratio of helix pitch to helix
circumference."

Fig. 7-19 is certainly interesting.
Cecil owes you a fruit basket I think. ;-)

Unfortunately, I must disagree (very slightly) with Kraus.
Using Kraus' concepts *verbatim*, the delay through a coil
would be the same whether the wire is coiled up or straightened
out (if I understand correctly what he is saying).
On my web page at w5dxp.com/current2.htm I have a 30 turn
coil with a diameter of 6" causing a 38 degree phase shift
at 3.8 MHz. If the coil were straightened out, it would be
about pi*6"*30 = 565 inches or 47 feet. Since a wavelength
is about 259 feet at that frequency, 47 feet would be about
65 degrees. So Kraus' rule-of-thumb is off by about 70%.
His VF would be about 0.009 where the actual VF is more
like 0.106. 65 degrees of wire doesn't replace 65 degrees
of antenna. In this case, 65 degrees of wire replaces
38 degrees of antenna. The "missing degrees" are in the
impedance discontinuity between the coil and stinger.
There is an interaction between turns that increases the
VF of the coil so there is a very tiny grain of truth in
what Tom says. The interaction between turns increases the
coil VF from Kraus' 0.009 to the actual value of 0.016
but certainly not all the way to 1.0 as W8JI asserts.
Kraus may have been off by 70% but W8JI is off by 6000%
so it seems that Kraus was still a lot closer to the
technical truth that W8JI ever was.

Cecil,

I don't have the third edition of Kraus' antennas book, but I do have
the second edition. He does not make that simplified statement in the
second edition. He has equations and charts showing how the Vf changes
with the dimensions of the coil and the wavelength. He also references a
paper by Chu and Jackson that is now about 60 years old. In that paper,
the authors show that the Vf increases dramatically as the relative
wavelength becomes longer with respect to the coil dimensions.

73,
Gene
W4SZ

[Cecil Moore]

Post by Gene Fuller
I don't have the third edition of Kraus' antennas book, but I do have
the second edition. He does not make that simplified statement in the
second edition.

I have the 3rd edition, but I have not been able to find
the previous quotations. I certainly hope that I am not
disagreeing with Kraus. "Coils" or "Loading Coils" are
not even in the index.

[Richard Harrison]

Cecil. W5DXP wrote:
"Unfortunately, I must disagree (very slightly) with Kraus."

I had invited readers to the helical antenna pages of Kraus to support
my wave advance comparison to the progress of a threaded bolt. I had
looked at page 229 in the 3rd edition with its Figs. 8-8 and 8-9 or at
similar figures in an earlier edition.

Upon looking agin, I still believe the figs. support my bolt comparison.
In any case, I`d study long and hard before sarguing with Kraus.

Best regards, Richard Harrison, KB5WZI

[Cecil Moore]

Post by Richard Harrison
"Unfortunately, I must disagree (very slightly) with Kraus."
I had invited readers to the helical antenna pages of Kraus to support
my wave advance comparison to the progress of a threaded bolt. I had
looked at page 229 in the 3rd edition with its Figs. 8-8 and 8-9 or at
similar figures in an earlier edition.
Upon looking agin, I still believe the figs. support my bolt comparison.
In any case, I`d study long and hard before arguing with Kraus.

No doubt, your bolt comparison is valid when each turn on
the "coil" is one wavelength long. But what happens when
each turn is 0.006 wavelength? Do you reckon something
might change?

Hopefully, I am not disagreeing with Kraus. It appears that
the question is: Does Kraus' one wavelength per turn helical
antenna have the same VF as a 75m Texas Bugcatcher loading coil?

Kraus' own graph shows that if one varies the turn circumference,
the phase velocity is not a linear correspondence. I would suggest
that lack of linear correspondence occurs in the 75m Texas Bugcatcher
coil. We cannot tell what the exact phase difference would be at
0.006 wavelength per turn, but the trend seems obvious to me.

[Jim Kelley]

Post by Richard Harrison
"Unfortunately, I must disagree (very slightly) with Kraus."
I had invited readers to the helical antenna pages of Kraus to support
my wave advance comparison to the progress of a threaded bolt. I had
looked at page 229 in the 3rd edition with its Figs. 8-8 and 8-9 or at
similar figures in an earlier edition.
Upon looking agin, I still believe the figs. support my bolt comparison.
In any case, I`d study long and hard before sarguing with Kraus.
Best regards, Richard Harrison, KB5WZI

I didn't quite grasp the purpose of your bolt comparison, Richard.
The only limits Kraus puts on helices is that they are helical -
anything between a flat single turn loop at one limit and a straight
line at the other.

73, ac6xg

[Cecil Moore]

I didn't quite grasp the purpose of your bolt comparison, Richard. The
only limits Kraus puts on helices is that they are helical - anything
between a flat single turn loop at one limit and a straight line at the
other.

My 3rd edition only shows coil circumferences between 0.6
and 1.5 wavelengths. But the relative phase velocity is
1.0 when the circumference is 1.1 wavelength and the pitch
angle is 5 degrees. If the relative phase velocity is 1.0
when the circumference is 1.1 WL, doesn't that imply a
change in VF away from a straight piece of wire?

[Jim Kelley]

Post by Cecil Moore

I didn't quite grasp the purpose of your bolt comparison, Richard. The
only limits Kraus puts on helices is that they are helical - anything
between a flat single turn loop at one limit and a straight line at
the other.

My 3rd edition only shows coil circumferences between 0.6
and 1.5 wavelengths. But the relative phase velocity is
1.0 when the circumference is 1.1 wavelength and the pitch
angle is 5 degrees. If the relative phase velocity is 1.0
when the circumference is 1.1 WL, doesn't that imply a
change in VF away from a straight piece of wire?

Hi Cecil,

The entire point of Richard's citation is that VF is a function of
pitch to circumference ratio. It explains the very thing that you
need to support your argument about phase delay across a coil. It's
what I meant when I said "I still think it would be prudent to explore
and understand the precise nature of the delay through the coil more
thoroughly before making too many assumptions about this."

Beyond that, I don't understand the question. Kraus is pretty
explicit. I didn't see much need to read between the lines. But all
I have to look at is the scanned version on the web that someone
posted a link to a week or so ago.

You should send Richard H. a fruit basket. Who woulda thought to look
under Helical Antennas. :-)

73, Jim AC6XG

[Cecil Moore]

The entire point of Richard's citation is that VF is a function of pitch
to circumference ratio. It explains the very thing that you need to
support your argument about phase delay across a coil.

Does "circumference" mean the circumference of the coil or
is it the actual wire length once around the helix?

[Jim Kelley]

Post by Cecil Moore

The entire point of Richard's citation is that VF is a function of pitch
to circumference ratio. It explains the very thing that you need to
support your argument about phase delay across a coil.

Does "circumference" mean the circumference of the coil or
is it the actual wire length once around the helix?
--
73, Cecil http://www.w5dxp.com

2*Pi*radius

ac6xg

[Cecil Moore]

Post by Jim Kelley
2*Pi*radius

Sorry, I'm a little handicapped since I have never seen
"Figure 7-19" and it has been removed from the web site.

[Jim Kelley]

Post by Cecil Moore

Post by Jim Kelley
2*Pi*radius

Sorry, I'm a little handicapped since I have never seen
"Figure 7-19" and it has been removed from the web site.

I have the file. It's 7.5 megabytes. Do you have a broadband connection?

73 jk

[Cecil Moore]

Post by Jim Kelley

Post by Cecil Moore
Sorry, I'm a little handicapped since I have never seen
"Figure 7-19" and it has been removed from the web site.

I have the file. It's 7.5 megabytes. Do you have a broadband connection?

Yes, I have DSL but I also have the 3rd edition of "Antennas".
I think "Figure 8-32: Relative phase velocity p for different
pitch angles as a function of the helix circumference, C(lamda),
for the condition of in-phase fields in the axial direction",
is probably the same graph as Figure 7-19 in the 1st edition.
I'm assuming that the "relative phase velocity" is the same
thing as the VF of the coil.
--
73, Cecil, w5dxp.com

[Richard Harrison]

Cecil, W5DXP wrote:
"I`m assuming that the "relative phase velocity" is the same thing as
the VF of the coil."

Back a couple of pages on 251, Kraus defines v/c as equal to "relative
phase velocity of the wave propagating along the helical conductor, v
being the phase velocity along the helical conductor and c being the
velocity of light in free space."

Repetition of "along the helical conductor" implies to me, thal like
Terman, Kraus says the signal follows the actual wire, not sprinting
across the coil as if it were a straight rod.

Best regards, Richard Harrison, KB5WZI

[Cecil Moore]

Post by Richard Harrison
Repetition of "along the helical conductor" implies to me, thal like
Terman, Kraus says the signal follows the actual wire, not sprinting
across the coil as if it were a straight rod.

Yes, I believe you are right about that.
--
73, Cecil, w5dxp.com

[Jim Kelley]

Post by Richard Harrison
Repetition of "along the helical conductor" implies to me, thal like
Terman, Kraus says the signal follows the actual wire, not sprinting
across the coil as if it were a straight rod.

It seems to me there is more than just one way to use a wire to convey
a signal. In fact it can be difficult to prevent a wire from using
more than just one, especially when there are other wires nearby.

73, Jim AC6XG

[Cecil Moore]

It seems to me there is more than just one way to use a wire to convey a
signal. In fact it can be difficult to prevent a wire from using more
than just one, especially when there are other wires nearby.

Yep, I'm afraid that Kraus was wrong to a certain degree.
Of course, he didn't have NEC in 1950. If we double Kraus'
calculated relative phase velocity for loading coils, we
will be closer to the results predicted by EZNEC.

[Cecil Moore]

But all I
have to look at is the scanned version on the web that someone posted a
link to a week or so ago.

Unfortunately, it has been removed. Did you save it?

[Richard Harrison]

Jim Kelley wrote:
"I don`t quite grasp the purpose of your bolt comparison, Richard."

My point was that the signal is guided by the wire on the coil and isn`t
instantly transported by induction from one end of the coil to the
other. How long it takes the signal to travel the length of the coil
depends on the length of wire in the coil as well as the velocity factor
of the wave on the wire in the coil. If it were not so, Terman`s
explanation of the traveling wave tube (TWT) would not be valid. But,
GTE Lenkurt gives a similar explanation in its "Demodulator" of the TWT.
They manufactured TWT amplifiers and surely knew how they worked.

A coil is a coil whether it is used in a traveling wave tube or used to
load an antenna. The velocity factors are surely a function of coil
dimensions as illustrated by the research results given by Kraus in
Fig.7-19 in the 1950 edition of "Antennas". The variation surprises me.
There is probably more research which explains such variations.

Best regards, Richard Harrison, KB5WZI

[Richard Clark]

Post by Richard Harrison
A coil is a coil whether it is used in a traveling wave tube or used to
load an antenna.

Hi Richard,

That seems to be hardly so at the frequency under consideration, and
the application being described. TWTs and antenna loads vary
considerably with regard to this conjunction you are rhetorically
drawing.

A coil, in the classic circuit sense, is dimensionless in the face of
wavelength employed. (Yes, there are dimensions of length, radius,
and pitch etc.; yet and all, these are infinitesimal in comparison to
the wavelength of the signal analysis. If you move to the arena of
dimension becoming a significant portion of wavelength, then calling
it a coil is simply descriptive, not prescriptive. That is, it looks
like a coil, but it could in fact act like anything (such as
transmission line or antenna) or as a coil (but this would be a rare
occurrence). Hence, a coil is not always like a coil when there is
enough baggage such as the legacy of coil meaning inductance alone.

Many writers solve this by calling the structure a helix - which is
exactly the term used by Terman. So, a coil is a coil, except when it
is an helix.

Post by Richard Harrison
The velocity factors are surely a function of coil
dimensions as illustrated by the research results given by Kraus in
Fig.7-19 in the 1950 edition of "Antennas". The variation surprises me.
There is probably more research which explains such variations.

I rely on his work in the same volume of 1955 that you have. The
velocity factors seem to be the same irrespective of sources or
terminology.

Post by Richard Harrison
My point was that the signal is guided by the wire on the coil and isn`t
instantly transported by induction from one end of the coil to the
other.

The notion of instantaneous current and inductance is anathema.
However, phase lag via coupling should be a trivial computation and
the debate becomes one of degree (figuratively and literally). To
this point (and through the many years) few seemed interested in
quantification that would endanger the appearance of lofty discussion.

73's
Richard Clark, KB7QHC

[Jim Kelley]

Post by Richard Harrison
"I don`t quite grasp the purpose of your bolt comparison, Richard."
My point was that the signal is guided by the wire on the coil and isn`t
instantly transported by induction from one end of the coil to the
other. How long it takes the signal to travel the length of the coil
depends on the length of wire in the coil as well as the velocity factor
of the wave on the wire in the coil. If it were not so, Terman`s
explanation of the traveling wave tube (TWT) would not be valid. But,
GTE Lenkurt gives a similar explanation in its "Demodulator" of the TWT.
They manufactured TWT amplifiers and surely knew how they worked.
A coil is a coil whether it is used in a traveling wave tube or used to
load an antenna. The velocity factors are surely a function of coil
dimensions as illustrated by the research results given by Kraus in
Fig.7-19 in the 1950 edition of "Antennas". The variation surprises me.
There is probably more research which explains such variations.
Best regards, Richard Harrison, KB5WZI

Ok. But what I was asking is what does any of that have to do with a
bolt?

73, Jim AC6XG

[Richard Clark]

Post by Jim Kelley

Post by Richard Harrison
"I don`t quite grasp the purpose of your bolt comparison, Richard."
My point was that the signal is guided by the wire on the coil and isn`t
instantly transported by induction from one end of the coil to the
other. How long it takes the signal to travel the length of the coil
depends on the length of wire in the coil as well as the velocity factor
of the wave on the wire in the coil. If it were not so, Terman`s
explanation of the traveling wave tube (TWT) would not be valid. But,
GTE Lenkurt gives a similar explanation in its "Demodulator" of the TWT.
They manufactured TWT amplifiers and surely knew how they worked.
A coil is a coil whether it is used in a traveling wave tube or used to
load an antenna. The velocity factors are surely a function of coil
dimensions as illustrated by the research results given by Kraus in
Fig.7-19 in the 1950 edition of "Antennas". The variation surprises me.
There is probably more research which explains such variations.
Best regards, Richard Harrison, KB5WZI

Ok. But what I was asking is what does any of that have to do with a
bolt?

The travel of one turn of a point at the radius (helical distance) in
relation to the travel of the same point in the depth (the linear
displacement after 360 degrees of the turn) is related to pitch. A
simple mechanical relationship. This is the bolt.

The signal flowing in the helix modulates a beam traveling within the
axis of the helix to impose its frequency upon it
(amplification/oscillation) through the pitch. This is the TWT.

The helical distance is supposed to express the linear completion of
the truncated 90 degrees of a quarterwave radiator. This is for the
loading coil.

There is no obvious correlation between the mechanical description,
the harmonic relation of the TWT and the degree relation of the
loading coil beyond the simple, visual metaphor which doesn't really
add any quid-pro-quo.

What is missing for the TWT is the necessary correlation of the beam
drift velocity which is wholly lacking from the bolt metaphor.

To say that the coil replaces the missing degrees of the truncated
quarterwave has likewise been so sloppily handled in the past, that
60-70% error brushed aside to prove equality provokes "so what?"

73's
Richard Clark, KB7QHC

[Jim Kelley]

Post by Richard Clark

Post by Jim Kelley
Ok. But what I was asking is what does any of that have to do with a
bolt?

The travel of one turn of a point at the radius (helical distance) in
relation to the travel of the same point in the depth (the linear
displacement after 360 degrees of the turn) is related to pitch. A
simple mechanical relationship. This is the bolt.

Thanks so much, Richard. I'm going to keep this on file somewhere in
case I ever forget what a bolt is. :-)

73, ac6xg

[Richard Harrison]

Jim Kelley wrote:
"Fig. 7-19 is certainly interesting."

Jim`s cryptic statement sent me on a search.

Eureka! My 1950 version of Kraus has that Fig. 7-19 on page 193. It
shows propagarion velocities found by several researchers as a function
of helix circumference.

Phase velocity is the velocity at which a point of constant phase is
propagated in a progressive (traveling) sinusoidal wave.

Best regards, Richard Harrison, KB5WZI

[Cecil Moore]

Post by Richard Harrison
Eureka! My 1950 version of Kraus has that Fig. 7-19 on page 193. It
shows propagation velocities found by several researchers as a function
of helix circumference.
Phase velocity is the velocity at which a point of constant phase is
propagated in a progressive (traveling) sinusoidal wave.

My 3rd edition, shows the lack of a 1:1 correspondence between
the circumference of a turn and the phase velocity of that
turn. If one projects Kraus' graph back to 0.006 wavelength
for the circumference of the coil, the lack of correspondence
should become pretty large, maybe even matching my reported
EZNEC results?

[Gene Fuller]

Post by Richard Harrison
"The current lags voltage principle does not settle anything in this
case."
W8JI claims that current flows into a turn at a coil end/s and is
induced without delay into all turns of the coil, overcoming delay that
the coil might otherwise impose.
If that were true, Terman would have told us so. In fact, Terman tells
us the opposite is true in explaning the traveling wave tube begining on
"The signal to be amplified is applied to the end of the helix adjacent
to the electron gun. Under appropriate operating conditions an amplified
signal then appears at the other end of the helix.-------inapplicable
info deleted-----. The applied signal propagates around the turns of the
helix and produces an electric field that is directed along the helix
axis. Since the velocity with which the signal propagates along the
helix wire approximates the velocity of light if the frequency is not
too low (caveat is unimportant, see footnote in book), the axial field
due to the signal advances with a velocity that is very closely the
velocity of light multiplied by the ratio of helix pitch to helix
circumference."
In other words, the axial advance is much like that of a threaded bolt
as the pitch angle is always fractional. Kraus details this in his
section on helical antennas.
Best regards, Richard Harrison, KB5WZI

Richard,

I would never argue with Terman.

You completely changed the subject, so I have nothing further to say.
The line you quoted above is still correct. Feel free to continue on in
whatever new direction you want.

73,
Gene
W4SZ

[Cecil Moore]

Post by Jim Kelley
I'd like to see your Norton analysis of that one.

Take a look at: http://www.k6mhe.com/n7ws/Loaded%20antennas.htm

"Figure 2 and Figure 3 clearly show the peaking of the current
that Hansen and Cebik write about."

[art]

Post by Jim Kelley
I'd like to see your Norton analysis of that one.

Take a look at:http://www.k6mhe.com/n7ws/Loaded%20antennas.htm
"Figure 2 and Figure 3 clearly show the peaking of the current
that Hansen and Cebik write about."
--
73, Cecil http://www.w5dxp.com

Thanks for pointing that out Cecil. He did a really good job of
explaining things
Art

[h***@gmail.com]

do you now how to explain this so normal people can understand?

Post by Cecil Moore
If a Texas Bugcatcher Coil could be turned into a
traveling wave device instead of a standing wave
device, the inherent phase shift through the coil
would become obvious. I used the Helix option in
EZNEC to generate a reasonably close model of a
75m Texas Bugcatcher coil and loaded it with a
resistance equal to the coil's characteristic impedance
which essentially eliminated the reflected current,
leaving the forward current intact and visible. All
of the data points on the following web page came from
EZNEC. All of the files are available for downloading.
http://www.w5dxp.com/current2.htm
--
73, Cecil http://www.w5dxp.com