Art Unwin wrote:


snip

In direct terms I have stated that current flows down the
center
of a radiator if it is of a fractional wave length.

OK, you must be talking about an AC current as there is a wavelength
involved. But if you are implying there is current in the center matching
the amplitude of the current on the surface you are wrong.

See this link
http://en.wikipedia.org/wiki/Skin_depth

Note the phrase regarding current;"the magnitude of which is greatest at the
conductor's surface". This is where the current is.

There is also this statement "the current can be flowing in the opposite
direction to that at the surface." Note that there are qualifications on
that statement (on the page referenced).

So, while there can be some current flowing inside the conductor, it does
not say it is a matching current in the other direction. By saying most of
the current is at the surface, it conflicts with your statement.



A very simple
statement which nobody wishes to address.

You are trying to apply "For a force there is always an equal and opposite
reaction: or the forces of two bodies on each other are always equal and
are directed in opposite directions."
(from "http://en.wikipedia.org/wiki/Newton%27s_laws_of_motion" )

You make a simple statement, brought about but applying a concept
incorrectly. I don't think Newton said anything about electricity and flow
in conductors. Newton's law doesn't say what the opposing force is, so I
don't think you can say it is anything specific.

snip

I would
prefer however the discussion to at least start with equilibrium which
leads to why or why not it is correct that current can flow thru the
center of a conductor the answer of which is not in the books.

The right books would tell you that AC current does not flow in the center
of a conductor.

As others have stated, you need to clearly define what _you_ mean by
equilibrium.

Some
people prefer to read the last page of the book first.
I prefere to examine foundations before determining the merits of a
house.

Those foundations need to take into account all the considerations, not just
the ones you know or want to talk about. You may have read some of the
book, but you skipped quite a few chapters.

Regards
Art

Consider your statement to have been addressed.

You will note that both links include some math. This is something you don't
provide with your explanations. If you went through the rigor to work out
the math and present it to the group with sufficient clarity you might get
someone to believe you. If you want someone to believe you, it is up to you
to effectively communicate your ideas.

It is hard to tell if you have a useful concept regarding antennas, are
completely lost, or just a troll.

But, just in case you have something, then...

Many antennas are built using tubing for light weight. So, if there is a
current flowing in the middle, it is good that the ends of the tubes are
crimped, or plugged. I wouldn't want the flowing electrons spilling out
onto my lawn.

On Sep 17, 6:11*pm, joe wrote:
Art Unwin wrote:

snip

In direct terms I have stated that current flows down the
center
of a radiator if it is of a fractional wave length.

OK, you must be talking about an AC current as there is a wavelength
involved. But if you are implying there is current in the center matching
the amplitude of the current on the surface you are wrong.

See this linkhttp://en.wikipedia.org/wiki/Skin_depth

Note the phrase regarding current;"the magnitude of which is greatest at the
conductor's surface". This is where the current is.

There is also this statement "the current can be flowing in the opposite
direction to that at the surface." Note that there are qualifications on
that statement (on the page referenced).

So, while there can be some current flowing inside the conductor, it does
not say it is a matching current in the other direction. By saying most of
the current is at the surface, it conflicts with your statement.

A very simple
statement which nobody wishes to address.

You are trying to apply "For a force there is always an equal and opposite
reaction: or the forces of two bodies on each other are always equal and
are directed in opposite directions."
(from "http://en.wikipedia.org/wiki/Newton%27s_laws_of_motion" )

You make a simple statement, brought about but applying a concept
incorrectly. I don't think Newton said anything about electricity and flow
in conductors. Newton's law doesn't say what the opposing force is, so I
don't think you can say it is anything specific.

snip

I would
prefer however the discussion to at least start with equilibrium which
leads to why or why not it is correct that current can flow thru the
center of a conductor the answer of which is not in the books.

The right books would tell you that AC current does not flow in the center
of a conductor.

As others have stated, you need to clearly define what _you_ mean by
equilibrium.

Some
people prefer to read the last page of the book first.
I prefere to examine foundations before determining the merits of a
house.

Those foundations need to take into account all the considerations, not just
the ones you know or want to talk about. You may have read some of the
book, but you skipped quite a few chapters.

Regards
Art

Consider your statement to have been addressed.

You will note that both links include some math. This is something you don't
provide with your explanations. If you went through the rigor to work out
the math and present it to the group with sufficient clarity you might get
someone to believe you. If you want someone to believe you, it is up to you
to effectively communicate your ideas.

It is hard to tell if you have a useful concept regarding antennas, are
completely lost, or just a troll.

But, just in case you have something, then...

Many antennas are built using tubing for light weight. So, if there is a
current flowing in the middle, it is good that the ends of the tubes are
crimped, or plugged. I wouldn't want the flowing electrons spilling out
onto my lawn.

Ok Joe I will go along with everything you said Thank you for your
comments
Arft

On Sep 17, 6:11*pm, joe wrote:
Art Unwin wrote:

snip

In direct terms I have stated that current flows down the
center
of a radiator if it is of a fractional wave length.

OK, you must be talking about an AC current as there is a wavelength
involved. But if you are implying there is current in the center matching
the amplitude of the current on the surface you are wrong.

See this linkhttp://en.wikipedia.org/wiki/Skin_depth

Note the phrase regarding current;"the magnitude of which is greatest at the
conductor's surface". This is where the current is.

There is also this statement "the current can be flowing in the opposite
direction to that at the surface." Note that there are qualifications on
that statement (on the page referenced).

So, while there can be some current flowing inside the conductor, it does
not say it is a matching current in the other direction. By saying most of
the current is at the surface, it conflicts with your statement.

A very simple
statement which nobody wishes to address.

You are trying to apply "For a force there is always an equal and opposite
reaction: or the forces of two bodies on each other are always equal and
are directed in opposite directions."
(from "http://en.wikipedia.org/wiki/Newton%27s_laws_of_motion" )

You make a simple statement, brought about but applying a concept
incorrectly. I don't think Newton said anything about electricity and flow
in conductors. Newton's law doesn't say what the opposing force is, so I
don't think you can say it is anything specific.

snip

I would
prefer however the discussion to at least start with equilibrium which
leads to why or why not it is correct that current can flow thru the
center of a conductor the answer of which is not in the books.

The right books would tell you that AC current does not flow in the center
of a conductor.

As others have stated, you need to clearly define what _you_ mean by
equilibrium.

Some
people prefer to read the last page of the book first.
I prefere to examine foundations before determining the merits of a
house.

Those foundations need to take into account all the considerations, not just
the ones you know or want to talk about. You may have read some of the
book, but you skipped quite a few chapters.

Regards
Art

Consider your statement to have been addressed.

You will note that both links include some math. This is something you don't
provide with your explanations. If you went through the rigor to work out
the math and present it to the group with sufficient clarity you might get
someone to believe you. If you want someone to believe you, it is up to you
to effectively communicate your ideas.

It is hard to tell if you have a useful concept regarding antennas, are
completely lost, or just a troll.

But, just in case you have something, then...

Many antennas are built using tubing for light weight. So, if there is a
current flowing in the middle, it is good that the ends of the tubes are
crimped, or plugged. I wouldn't want the flowing electrons spilling out
onto my lawn.

I know books say a lot of things but do they explain WHY current
cannot flow thru the center?
Somebody said the current flow backwards now that is hard to
understand unles he is refering to a tank circuit
where the antenna has capacitance at one end and inductance at the
other and the current goes nowhere.
I think I will sit back and see what the experts say and if the IEEE
has accepted al these explanations.
One thing I particularly have difficulty with is that the secondary
current can overcome the primary current
where the power flows back to a wall plug or something like that.
Another infers that current travel in a aluminum tube is different to
the flow of a solid conductor presumably with double the surface area
you have double the amount of radiation. The next publication from the
ARRL is going to rock the science world with these findings on
radiation. Funny thing is that based on my findings I designed an
antenna which computer program AO Pro
determined was quite good, an arrangement that is if the program
doesn;'t follow the teachings of the books should I then throw the
program away?
NEC4 models the antenna that is in equilibrium also isn't that a
bummer? If only somebody would come up with a vector diagram of a
radiator that was NOT in equilibrium I could locate my fault very
quickly. Still if all of what has been described will be published in
the ARRL and IEEE papers I can afford to wait.
Thank you all
Art

Art Unwin wrote:
I know books say a lot of things but do they explain WHY current
cannot flow thru the center?
snip
Art

If you do the differential equations, it doesn't say why the center
can't so much as why the skin does. Similar to gravitation and water
flowing downhill vs uphill. I'll go into detail if you can't figure it
out. Or not.

tom
K0TAR

On Sep 17, 8:52*pm, Tom Ring wrote:
Art Unwin wrote:
I know books say a lot of things but do they explain WHY current
cannot flow thru the center?
snip
Art

If you do the differential equations, it doesn't say why the center
can't so much as why the skin does. *Similar to gravitation and water
flowing downhill vs uphill. *I'll go into detail if you can't figure it
out. *Or not.

tom
K0TAR

Please do. I would love to see your take on it. I am gratified that
somebody is tackling the problem
hopefully in laymans language so all can benefit. Possibly you could
start another thread as this one is greatly contaminated
I can then respond on my take of the matter and hopefully the flaw
will be exposed.
Regards
Art

Art Unwin wrote:
On Sep 17, 8:52 pm, Tom Ring wrote:
Art Unwin wrote:
I know books say a lot of things but do they explain WHY current
cannot flow thru the center?
snip
Art
If you do the differential equations, it doesn't say why the center
can't so much as why the skin does. Similar to gravitation and water
flowing downhill vs uphill. I'll go into detail if you can't figure it
out. Or not.

tom
K0TAR

Please do. I would love to see your take on it. I am gratified that
somebody is tackling the problem
hopefully in laymans language so all can benefit. Possibly you could
start another thread as this one is greatly contaminated
I can then respond on my take of the matter and hopefully the flaw
will be exposed.
Regards
Art

I did not mean to imply I would explain the diff eqs. That would
currently be a lost cause on you, because I am sure that I couldn't put
it in "layman's terms" - you need the math to understand it. I meant
that I would explain why the 2 situations were similar, or not explain,
depending upon my mood.

To understand the situation, I would suggest that you start down the
calculus road. The internet has to have tutorials on it. Differential
equations look terribly obtuse, but they are an obtainable destination
down that road if you choose to follow it.

tom
K0TAR

Tom Ring wrote:

...
To understand the situation, I would suggest that you start down the
calculus road. The internet has to have tutorials on it. Differential
equations look terribly obtuse, but they are an obtainable destination
down that road if you choose to follow it.

tom
K0TAR

My take on that is a bit different ... on "AMATEUR Radio" that is.

In building antennas, tank ciruits, etc., I very seldom whip out a
programmable scientific calculator and delve into the depths of the
maths which allow them to preform/function/"work."

A few times, I have just grabbed up some tubing/wire a variable
condenser or two, and "eyeballed" the construction--past experience
provided "ballpark" figures/placements/wiring, testing, trimming and
adjusting got me the final result ...

Mainly, I point this out so as not to "obsfucate" that layman, or
discourage him ... the men who first started/awakened my interest in
such things never gave any indication, to me, they had an understanding
of calculus, only basic-math/algebra, and of course, geometry!

Indeed, at least one passed away without ever expressing any real
interest in learning it!

However, in Arts pursuits, an understanding would be a real advantage ...

Regards,
JS

On Thu, 18 Sep 2008 06:59:35 -0700, John Smith
wrote:

In building antennas, tank ciruits, etc., I very seldom whip out a
programmable scientific calculator and delve into the depths of the
maths which allow them to preform/function/"work."

And what do you do when they don't work? Cut-n-try is a rather
expensive way to build something that works. Given infinite time and
materials, it will eventually result in a functional antenna. You
could probably do that at HF frequencies where construction errors are
about equal to calculation errors. However, don't try it at microwave
frequencies. While it's possible to cut-n-try various microwave
structures, it's messy, difficult, prone to error, and not very
effective. The techniques used to build a coat hanger ground plane at
VHF just are not going to work at X-band.

The only way to get it close to right the first time is to calculate
first, calculate again, have someone check the calculations, drink
some wine, and check your calcs again. Then build it.

A few times, I have just grabbed up some tubing/wire a variable
condenser or two, and "eyeballed" the construction--past experience
provided "ballpark" figures/placements/wiring, testing, trimming and
adjusting got me the final result ...

Yep. That will work at HF because the lower frequencies allow for
much larger construction errors. Your antenna lengths could be off
many cm and still work. Your xmitter can also tolerate a substantial
VSWR and still be considered functional and useful. You match box
could be grossly inefficient trying to match your constructed antenna,
and work well enough. Now, try that at microwave frequencies, where
every milliwatt is precious, where VSWR is too crude and reflection
coefficient comes close to describing the ultimate goal of a perfect
match, and where cm errors are disastrous. Some broadband antennas
(helix and horn) are very forgiving and can be build fairly crudely.
Others (stripline, phased arrays, cavity backed antennas, etc) have a
higher Q and require more accuracy than the eyeball can provide.

Mainly, I point this out so as not to "obsfucate" that layman, or
discourage him ... the men who first started/awakened my interest in
such things never gave any indication, to me, they had an understanding
of calculus, only basic-math/algebra, and of course, geometry!

Same here. My original mentors were operators first and technical
types last. However, I saw the light (and the distinction) between
amateur and professional when I went to college and saw that radio
things were easier and better if they were calculated (and understood)
first. I have several humorous examples of hams operating in a
professional environment (engineering lab at a radio manufactory) and
failing miserably using cut-n-try methods popularized by ham radio.

Indeed, at least one passed away without ever expressing any real
interest in learning it!

There are suspicions that math may hasten one's demise. Perhaps he
tried to do a calculation before he died?

However, in Arts pursuits, an understanding would be a real advantage ...

Agreed. Once he gets that understanding, he can work on the
communications problem. Perhaps publish his works. After solving all
that, he can possibly consider the applications and implementations.
The twisted road towards technical nirvana is littered with the
wreckage of failed great ideas.

Incidentally, I was also going to bash your suggestion of ignoring
patents. Might as well add that to my rant.

Patent are confusing. Many of them are totally bogus. It's difficult
to recognize the difference. However, at the bottom of every garbage
dumpster lies a diamond. You have to sift through a huge amount of
garbage in order to find the gem, but it's worth it. Just because a
typical patent search returns bogus patents, doesn't mean you should
ignore them. Most technical patents are legitimate and worth
inspecting. If you want to know exactly how something works, the
patents are the place to start. I haven't had time to look at the
quantum comb filter antenna thing, but plan to do so eventually.

During the dot.com heyday, I was doing sanity checks and technological
assessments for a venture capitalist. Many business plans had
technical problems. Some were based on bogus patents. Some held
conflicting patents. Identifying these was more than the VC's staff
could handle. I did fairly well, but still managed to miss a few.
Anyway, sifting through patents was part of the exercise and a great
learning experience. Often, a patent looks legitimate, but has a
fatal flaw or omission in the middle of the claims. It's not easy. If
you have the patience, it's possible to find these.

Also, I assembled a small list of tech patents that appear to be
bogus. I was going to post the list on the web but my attorney
advised against it. Even holders of bogus patents can sue for
damages. Oh well.

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

I know books say a lot of things but do they explain WHY current
cannot flow thru the center?
snip
Art
If you do the differential equations, it doesn't say why the center
can't so much as why the skin does. Similar to gravitation and water
flowing downhill vs uphill.

My understanding was about molecular alignment and that the flow of
electrons would be there first. Notice that stranded wire is often
preferred for it's current handling ability even though solid is easier to
terminate to and doesn't have the problem of discontinuities due to
corrosion on many surfaces that rub together.

This doesn't mean that eddy currents aren't there in hollow elements. Solid
or stranded or hollow tubing, the eddy currents contribute to loss but don't
contribute to radiation.

Ejection of particles should lead to deterioration of the metal but if you
were to coat the elements (with non-conductive and non-reactive coating)
there would be no deterioration. It would also prevent rain static.

I don't burden myself with paradigms to explain electromagnetic wave
propagation in free space. It and Gravity do very well without my
explanation. We know that the AC current in the antenna induces an
electromagnetic wave is sufficient for my purpose. Unless I can find
funding for renewed efforts... (wink nudge)

On Thu, 18 Sep 2008 16:26:18 GMT, "JB" wrote:

We know that the AC current in the antenna induces an
electromagnetic wave is sufficient for my purpose. Unless I can find
funding for renewed efforts... (wink nudge)

Funding is easy these days. All you need is an anti-terrorism or
disaster link. For example:
- Use of HF antennas for airport security.
- Antenna design optimized for disaster services.
- Survivable antenna design and construction.
While these topics are contrived, there has been considerable
rethinking of the basics in order to enhance survivability, tampering,
security, terrorist activities, general mayhem, and other post-911
buzzwords. I'm not sure this extends to basic concepts, but it's
possible. Something like:
- Re-evaluating E-M concepts in a post 911 world.
- Survey of antenna technology for optimum disaster communications.

You will need to use your imagination because all the obvious studies
have already been taken. Perhaps combining everything into:
- The effects of global warming, terrorism, economic collapse, and
natural disasters on antenna technology.
Try to emphasize the positive aspects such as the improved HF antenna
grounding provided by rising sea levels.

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