Loading Coils; was : Vincent antenna
 

On 29 Nov, 09:11, Jim Kelley wrote:
Cecil Moore wrote:
W8JI's mistake was using standing wave current to try
to measure that delay.

It's not at all apparent that that was his mistake.

Even though the delay changes with frequency,
it is highly unlikely to drop from 90 degrees to 4.5
degrees in a few MHz.

Any phase delay given in degrees would of course vary as function of
angular frequency independent of any systematic effect simply by
virtue of the fact that the amount of time per period varies with
frequency while the number of degrees per period obviously do not.

Over the range of a few octaves, propagation delay on the other hand
does not vary to any significant extent as a function of frequency.
Ostensibly, it should be equal to sqrt(LC) series L, shunt C.
e.g.

http://www.rhombus-ind.com/dlcat/app1_pas.pdf

In order to either validate or invalidate claims, one must do at least
two things. First make verifyable and repeatable measurements.
Second, show how those measurements are supported by the underlying
principles, and are predicted by the associated mathematics. Without
those things, you may as well go shout it at cars.

Actually, it is an exercise in the physics of reality.
A 3nS delay through a 100 uH coil is the real "exercise
in philosophical fantasy" and obviously impossible.

The display on Tom's web page appears to be set for 100ns per
division. The delay between cursor 1 and cursor 2 is 486.43 nS, and
the position of cursor 1 appears to be arbitrarily set. The 3nS
measurement would be at ~0.3% of full scale - not normally the scale
one would employ to make such a measurement. Lacking any sort of
description of the stimulus or of the instrument, it's not clear to me
what W8JI's test unit is actually measuring. But at least he measured
something and isn't shouting at cars about it.

73, ac6xg

Darn it! why haven't you spoken up before with respect to slow wave
properties and the parameters required to make them? You could have
helped a lot in my threads on Gaussian antennas by cutting off old
wive tales.
Art KB9MZ

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
Do you really believe that an antenna + loading coil has
to be a quarter wave long to resonate?

Note: I am NOT talking about *physical* lengths.
The phase shift from feedpoint to tip has to be
*electrically 90 degrees* so the answer is yes.
For a base-loaded mobile antenna, the sum of the
phase shifts a

PS1. The phase shift through the loading coil.
PS2. The phase shift at the coil to stinger junction.
PS3. The phase shift in the stinger.

PS1 + PS2 + PS3 = 90 degrees.

In a typical 75m base-loaded mobile antenna, PS1
may be about 40 degrees, PS2 about 40 degrees, and
PS3 about 10 degrees.

PS2 is a freebie lossless phase shift compliments of
Mother Nature caused by the impedance discontinuity
between the coil and the stinger. If that phase shift
can be maximized, it should add to antenna efficiency.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

On 29 Nov, 09:42, "Tom Donaly" wrote:
Gene Fuller wrote:
Cecil Moore wrote:
Tom Donaly wrote:
What is the characteristic impedance of Tom's coil?

A few thousand ohms. Use equation 50 at:

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

What's your formula for the velocity factor of Tom's coil? Is it from
the same Tesla coil crackpot you quoted in previous posts?

Do you reject all IEEE white papers? The formula
is equation 32.

Cecil,

Have you actually read and understood that article? Corum mentions
several times that everything he reduces to the simple formulas applies
only to quarter-wave resonance conditions.

Look at the author's highlight between equations 31 and 32. Look at the
discussion near equation 47. Look at the discussion following equation
60. Read the entire discussion in section 5.

Note that he does not say the characteristic impedance is a constant
that can be deduced from resonance conditions and then applied to
operating conditions. In fact, he says exactly the opposite.

"It is worth noting that, for a helical anisotropic wave guide, the
effective characteristic impedance is not merely a function of the
geometrical configuration of the conductors (as it would be for lossless
TEM coaxial cables and twin-lead transmission lines), but it is also a
function of the excitation frequency."

I have no comment on the validity of the Corum analysis. He makes a lot
of approximations and simplifications which may or may not be completely
correct. However, it is clear that you are mis-quoting him.

73,
Gene
W4SZ

The Corum duo model their Tesla coil as "an isotropically conducting
cylindrical boundary." Later, they call it a "helically disposed surface
waveguide." Later, they write, "Further, the Tesla coil passes to a
conventional lumped element inductor as the helix is electrically
shortened." Do the first two quotes resemble a description of a
typical ham antenna loading coil? Has anybody here used a Tesla coil
to load an antenna? The Corums also state in one part of their paper
that their method of analysis is "fraught with danger." Indeed.
Cecil's misuse of the formulas certainly proves that.
Many people over the years have done just fine loading their antennas
with lumped inductors. There's no need to put a "helically disposed
surface waveguide" on a mobile antenna, and if someone thinks that
modeling a coil as "an isotropically conducting cylindrical boundary"
actually turns that coil into an isotropically conducting cylindrical
boundary, that someone should seek help.
73,
Tom Donaly, KA6RUH- Hide quoted text -

- Show quoted text -

Tom,
May I point out that a Tesla coil is an "antenna" that does not
conform
to Maxwells laws with respect to the adherance to the LC ratio.
The LC ratio is out of balance such that the capacitor is not
of the correct size to store and then return the imposed energy from
the inductive heavy coil which is visually seen as resulting in a
spark.
Regards
Art

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:

It is exactly my point that
there is no phase shift associated with standing-
wave current in a coil or in a wire so it CANNOT
be used to "measure" phase shift.

On the other hand, the standing wave, which is nothing more than the
superposition of the forward and reflected waves, easily demonstrates
the effect the propagation delay has on the forward and reflected waves.

There is NO
phase information in the current used for the
W8JI and W7EL measurements.

That certainly can't be said about your measurements. Perhaps that's
why you're so reluctant to make any? :-)

They both apparently
thought they were measuring traveling-wave currents
when the currents were actually overwhelmingly
standing-wave currents.

Don't flatter yourself, Cecil. You're not that much smarter than
everybody else in the room.

73, ac6xg

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
Your problem is
that you've become so enamored of your little reflection theory that
you insist that only a set of transmission lines 90 degrees in total
length can resonate. Too bad your education isn't complete or you'd know
this isn't so.

Obviously, I am not talking about *physical* length.
The "90 degrees" is the total *electrical* length.
Please tell us how you get resonance out of a stub
that is *electrically* 45 degrees long? No resistive
or reactive components are allowed. Here's your
chance to nail me to the wall.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Jim Kelley wrote:
On the other hand, the standing wave, which is nothing more than the
superposition of the forward and reflected waves, easily demonstrates
the effect the propagation delay has on the forward and reflected waves.

But the phase information in the forward and reflected
waves does not appear as phase information in the standing
wave. The forward and reflected phase information appears
in the standing-wave amplitude. That is another error that
W8JI and W7EL made. The different amplitudes of standing-
wave current at each end of a coil is NOT caused by losses
and radiation. It is caused by superposition of the forward
and reflected waves. It would still happen if there was zero
losses and zero radiation.

Don't flatter yourself, Cecil. You're not that much smarter than
everybody else in the room.

Not smarter - just more observant. I saw something that
nobody else was looking for. It is only closed minds that
are the problem now.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

On Thu, 29 Nov 2007 14:18:22 -0600, Cecil Moore
wrote:

I should think that many hams have things that can measure 3 ns (1000mm
light time), particularly in a repetitive system. That's one cycle at
300 MHz, or 36 degrees at 30 MHz.

The referenced W8JI 3 nS "measurement" was the delay
in a 2' dia, 100 T, 10" long loading coil on 4 MHz,
i.e. 4.5 degrees.

Jim's point is that it can be done!

Your point is that you can't do it?

Asking for a handout, and escaping work is called mooching.

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Gene Fuller wrote:
Second, your analysis is utter rot! Are you suggesting that if the
coil can be made resonant at some frequency, and then you cut it in
half, that it still behaves the same?

No, it behaves approximately like half of the original
coil tending to have approximately the same Z0 and VF as
the original coil. The phase shift through the coil will
tend to be approximately 1/2 of the original phase shift -
not exact because of end effects.

Let's say we have a 1/4WL helical antenna with an obvious
phase shift of 90 degrees. If we cut that helical in half,
it is likely to have a phase shift of approximately 45
degrees, nowhere near the 4.5 degrees that W8JI has
"measured".

If we add a stinger to the above half-coil, we will have
a base-loaded antenna. The phase shift will be relatively
close to 45 degrees at the same frequency. The stinger
contributes another few degrees. The impedance discontinuity
between the coil and stinger contributes the rest of the
90 degrees of electrical length.

Cecil,

It appears you missed the primary message of the Corum article. He is
completely denying the simple concept you wrote above. He argues that
there is a very special effect near resonance. You cannot simply cut the
coil in half and expect the same behavior.

Frankly, I have little interest in Tesla coils, and I don't know or care
if Corum is right or wrong. I do believe, however, that it is a bit
careless for you to pick and choose equations from the article, ignore
the caveats, and then go ahead and misuse those equations.

73,
Gene
W4SZ

Loading Coils; was : Vincent antenna
 

I see Cecil is still using misdirection, that old but reliable trick of
illusionists, to try and divert attention away from the flaws in his
imaginative theories. Have patience. Even he will tire of it after a
while, and get back to his waves of average power that bounce off each
other when they collide.

Roy Lewallen, W7EL

Jim Kelley wrote:
Cecil Moore wrote:

It is exactly my point that
there is no phase shift associated with standing-
wave current in a coil or in a wire so it CANNOT
be used to "measure" phase shift.

On the other hand, the standing wave, which is nothing more than the
superposition of the forward and reflected waves, easily demonstrates
the effect the propagation delay has on the forward and reflected waves.

There is NO
phase information in the current used for the
W8JI and W7EL measurements.

That certainly can't be said about your measurements. Perhaps that's
why you're so reluctant to make any? :-)

They both apparently
thought they were measuring traveling-wave currents
when the currents were actually overwhelmingly
standing-wave currents.

Don't flatter yourself, Cecil. You're not that much smarter than
everybody else in the room.

73, ac6xg

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:

Don't flatter yourself, Cecil. You're not that much smarter than
everybody else in the room.


Not smarter - just more observant. I saw something that
nobody else was looking for.

Yes. Seek and ye shall find.

It is only closed minds that
are the problem now.

A perspective which apparently shifts depending on which side of the
room you happen to be standing.

73, ac6xg

Loading Coils; was : Vincent antenna
 

I hate to see Cecil and others criticizing Tom's (W8JI) measurements,
although I've certainly learned to expect this sort of response whenever
his theory is shown to be lacking. Tom does a careful job of making
measurements and he has good equipment. Most importantly, he's honest.
If someone finds an error with this measurement methodology or results,
he'll be the first one to correct it. But "finding an error" doesn't
mean just saying that his measurements fail to support a wild theory. It
means making careful measurements with good equipment and methodology
which give different results. I'm sure we'll never see this from Cecil.

Like I did some time ago, Tom has taken the time and trouble to make
measurements which simply confirm what established theory tell us. Then
Cecil and others respond by stating they're in error but haven't
presented any evidence to the contrary. (Sorry, hot air doesn't count as
evidence.) Any readers not astute enough to see the problem here
probably feel at home with astrology, homeopathy, and other alternative
disciplines that elicit belief without evidence.

Roy Lewallen, W7EL

Jim Lux wrote:
John Smith wrote:
Cecil Moore wrote:

AI4QJ wrote:

That is his "obvious" explanation. He should remove that from his
webpage as it is rather embarassing.


W8JI made a gross error in his measurement and
then tried to rationalize the impossible result.


Cecil:

How would you have like to be working at NASA, with this group; And,
you were the one responsible for not coverting kilometers to miles and
SMACKING that spacecraft we lost into Mars? ;-)


It wasn't km and miles, it was pounds and newtons AND
the error was that Lockheed Martin supplied the thrust data in pounds,
unlike the contractual requirement to supply it in Newtons (which is
what we at JPL have used for decades). The error wasn't caught because
the absolute magnitude of the force is very small, so the differences
from predict to observation were on the order of the measurement
uncertainty. (We're talking measuring the velocity to mm/sec and range
to mm, when its at Mars.)
I'd venture that anyone would find measuring distances to 1 part in 1E12
challenging...





Crud, I've volunteered on serving on those soup-lines, would hate to
have seen ya' there. chuckle

Regards,
JS

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Tom Donaly wrote:
Do you really believe that an antenna + loading coil has
to be a quarter wave long to resonate?

Note: I am NOT talking about *physical* lengths.
The phase shift from feedpoint to tip has to be
*electrically 90 degrees* so the answer is yes.
For a base-loaded mobile antenna, the sum of the
phase shifts a

PS1. The phase shift through the loading coil.
PS2. The phase shift at the coil to stinger junction.
PS3. The phase shift in the stinger.

PS1 + PS2 + PS3 = 90 degrees.

In a typical 75m base-loaded mobile antenna, PS1
may be about 40 degrees, PS2 about 40 degrees, and
PS3 about 10 degrees.

PS2 is a freebie lossless phase shift compliments of
Mother Nature caused by the impedance discontinuity
between the coil and the stinger. If that phase shift
can be maximized, it should add to antenna efficiency.

So, since the phase shift has to be 90 degrees, the antenna
should always resonate at the same frequencies a quarter wave
stub of the same electrical length would resonate at, right?
73,
Tom Donaly, KA6RUH

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Tom Donaly wrote:
Your problem is
that you've become so enamored of your little reflection theory that
you insist that only a set of transmission lines 90 degrees in total
length can resonate. Too bad your education isn't complete or you'd know
this isn't so.

Obviously, I am not talking about *physical* length.
The "90 degrees" is the total *electrical* length.
Please tell us how you get resonance out of a stub
that is *electrically* 45 degrees long? No resistive
or reactive components are allowed. Here's your
chance to nail me to the wall.

And, if the total electrical length isn't 90 degrees, you
add a few degrees to the loading coil to make it come out right.
Very ingenious.
73,
Tom Donaly, KA6RUH

Loading Coils; was : Vincent antenna
 

On 29 Nov, 14:52, "Tom Donaly" wrote:
Cecil Moore wrote:
Tom Donaly wrote:
Your problem is
that you've become so enamored of your little reflection theory that
you insist that only a set of transmission lines 90 degrees in total
length can resonate. Too bad your education isn't complete or you'd know
this isn't so.

Obviously, I am not talking about *physical* length.
The "90 degrees" is the total *electrical* length.
Please tell us how you get resonance out of a stub
that is *electrically* 45 degrees long? No resistive
or reactive components are allowed. Here's your
chance to nail me to the wall.

And, if the total electrical length isn't 90 degrees, you
add a few degrees to the loading coil to make it come out right.
Very ingenious.
73,
Tom Donaly, KA6RUH

I feel that many are disregarding the basics with respect to antennas!
It is one thing to say that an antenna is resonant which amateurs
are interested in for matching purposes. This is totally different
from being resonant AND in equilibrium which is demanded by Maxwell,
Newton and others when in the pursuit of the sciences
Art Unwin KB9MZ....xg

Loading Coils; was : Vincent antenna
 

Jim Lux wrote:
While the model is certainly valid within
their stated limitations, the real question that arises is "why".

Because some people are claiming a 3 nS delay through
a 75m mobile loading coil. Corum's VF estimate says
it is more like 40 degrees rather than 4.5 degrees.

Furthermore, people HAVE made current measurements at the top and bottom
of a large tesla coil and found very small phase differences, indicating
that there is little or no deviation from a lumped model.

There is virtually no phase difference in standing-wave
current which is what was being measured. Standing-wave
current cannot be used to measure the delay through a
loading coil.

If the loading coil is located in a traveling-wave
environment, the delay through the coil is obvious
by the phase shift through the coil.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Richard Clark wrote:
Cecil Moore wrote:
The referenced W8JI 3 nS "measurement" was the delay
in a 2' dia, 100 T, 10" long loading coil on 4 MHz,
i.e. 4.5 degrees.

Jim's point is that it can be done!

In that particular coil at 4 MHz - no, it cannot be done.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

"Cecil Moore" wrote
All of the boundary test conditions given in Corum's
IEEE white paper are satisfied by a 75m bugcatcher
loading coil. There is no reason to believe that
the underlying principles of physics do not apply.
In fact, the diagram of the 1/4WL resonant system
looks exactly like a base loading coil, stinger,
and top hat as is used for 75m mobile operation.
_____________

Cecil,

Do you believe that a 75m mobile antenna system using an artificially
resonant (as in bugcatcher-loaded), electrically short whip produces the
same elevation pattern and groundwave field strength at 1 km as an unloaded
1/4-wave vertical monopole for 75m with the same applied power using a good,
buried radial r-f ground (say, 2 ohms or less)?

RF

Loading Coils; was : Vincent antenna
 

Gene Fuller wrote:
It appears you missed the primary message of the Corum article.

I'm afraid you missed the point. As long as the frequency
is kept constant, the VF and Z0 of coil stock will be
relatively constant - why wouldn't it be? W8JI missed
the 4 MHz delay through that coil by at least a magnitude.
It is impossible for that delay to be 3 nS. The measured
delay through my 75m bugcatcher coil is 25 nS.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:
I see Cecil is still using misdirection, that old but reliable trick of
illusionists, to try and divert attention away from the flaws in his
imaginative theories.

This ad hominem attack brought to you by the person who
has asserted that he used a current with unchanging phase
to measure the phase shift through a loading coil and
that he stands by that measurement.

Even he will tire of it after a
while, and get back to his waves of average power that bounce off each
other when they collide.

Posting a statement that you know is false is not
ethical. EM waves do have energy which averaged over
a number of cycles is called irradiance in optics.
That energy passing a fixed measurement point is the
average power. And the waves don't bounce off each
other - they superpose, sometimes interfere, and
sometimes cancel.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Jim Kelley wrote:

Cecil Moore wrote:
It is only closed minds that
are the problem now.

A perspective which apparently shifts depending on which side of the
room you happen to be standing.

My mind is open, Jim, but since you refuse to enter into
a technical discussion, I am not likely to change mine.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:
I hate to see Cecil and others criticizing Tom's (W8JI) measurements,

I know you hate to see your and Tom's errors exposed.
But you have already confessed that even EZNEC says
that standing-wave current phase is almost unchanging
all up and down a 1/2WL dipole.

Which means that your "measurement" using standing-
wave current to measure phase shift through a loading
coil is something that you are well aware is invalid -
yet you have asserted that you are standing by that same
(invalid) "measurement". What is your agenda?

It
means making careful measurements with good equipment and methodology
which give different results. I'm sure we'll never see this from Cecil.

On the contrary, I reported a ~25 nS delay through my
75m bugcatcher loading coil when it was loaded with
a 3600 ohm load. Although this is an estimate from
observing current waveforms, it is close enough to
prove that is could never be the 3 nS reported by W8JI.
W8JI's delay "measurement" is off by a magnitude. Your
phase "measurements" are completely meaningless.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
So, since the phase shift has to be 90 degrees, the antenna
should always resonate at the same frequencies a quarter wave
stub of the same electrical length would resonate at, right?

Not sure what you mean by this statement. 90 degrees
is 90 degrees. A mobile antenna physically shorter
than 1/4WL is still close to 90 degrees long at
resonance. (It is not exactly 90 degrees because of
the well-known end effects.)

In order for the reflected wave to be in phase with
the forward wave at the feedpoint (purely resistive
feedpoint impedance), the reflected wave must traverse
180 *electrical degrees* during its round trip. That
fact inticates that the antenna is electrically 90
degrees long.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
And, if the total electrical length isn't 90 degrees, you
add a few degrees to the loading coil to make it come out right.
Very ingenious.

Adding or subtracting loading-coil degrees is what
happens while one is tuning a screwdriver antenna.
At resonance, the screwdriver is electrically very
close to 90 degrees in length.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Richard Fry wrote:
Do you believe that a 75m mobile antenna system using an artificially
resonant (as in bugcatcher-loaded), electrically short whip produces the
same elevation pattern and groundwave field strength at 1 km as an unloaded
1/4-wave vertical monopole for 75m with the same applied power using a good,
buried radial r-f ground (say, 2 ohms or less)?

No, the radiation pattern depends upon the *physical*
length. The feedpoint impedance depends upon the
*electrical* length. (I haven't said anything about
the radiation pattern in my postings.) Unless the
antenna is "full-sized", the physical length and
electrical length are different.

There is a free lossless phase shift between the top
of a loading coil and the stinger. There's obviously
zero radiation from that dimensionless point. That 40
electrical degrees of antenna is not physically there
so it cannot radiate.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Tom Donaly wrote:
And, if the total electrical length isn't 90 degrees, you
add a few degrees to the loading coil to make it come out right.
Very ingenious.

Adding or subtracting loading-coil degrees is what
happens while one is tuning a screwdriver antenna.
At resonance, the screwdriver is electrically very
close to 90 degrees in length.

Suuurrrre it is. You've got 90 degrees on the brain, Cecil.
Next, you'll be talking about 90 degree equilibrium.
73,
Tom Donaly, KA6RUH

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
Cecil Moore wrote:
Adding or subtracting loading-coil degrees is what
happens while one is tuning a screwdriver antenna.
At resonance, the screwdriver is electrically very
close to 90 degrees in length.

Suuurrrre it is. You've got 90 degrees on the brain, Cecil.
Next, you'll be talking about 90 degree equilibrium.

The technical content of your posting is noted, Tom.
I gave you the opening to nail my hide to the wall.
Is this the best technical argument that you have?

Please describe how 45 electrical degrees of transmission
line can be brought to 1/4WL resonance without help
from discrete components.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:

...
The same could have been said of Galileo. Do you
suggest that technical absurdities go unchallenged?

Cecil:

I have remained silent, I cannot continue to do so, I am attempting to
prove/disprove the areas you investigate--your posts are appreciated
here--if you are wrong? So what, it gives an old man something to do
.... ;-)

Anyway, the time is better spent; And, better than listening to someone
who went through a mental disorder focused on Shakespeare--those leaning
towards the gay lifestyle bore me ... ROFLOL

Regards,
JS

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:

Cecil:

All that is to be known, is known; there is nothing worth looking to. I
am nothing if I question the status quo--1984 I love you!!!

My gawd man, do you think me stupid??? ROFLOL

Regards,
JS

Loading Coils; was : Vincent antenna
 

On Nov 29, 9:11 am, Jim Kelley wrote:
....
Over the range of a few octaves, propagation delay on the other hand
does not vary to any significant extent as a function of frequency.
Ostensibly, it should be equal to sqrt(LC) series L, shunt C.


Actually, Jim, I do expect it to have considerable frequency
dependence. I think you can find info about this in books that
address the design of travelling-wave tubes.

But...one must be very careful about describing exactly the experiment
or the conditions around a particular scenario. That's why I don't
have much interest in getting involved in this "discussion": it could
well be that much of the difference among all the claims and counter-
claims could be trivially resolved through better communication.

Cheers,
Tom

Loading Coils; was : Vincent antenna
 

Jim Lux wrote:

...
It wasn't km and miles, it was pounds and newtons AND
the error was that Lockheed Martin supplied the thrust data in pounds,
unlike the contractual requirement to supply it in Newtons (which is
what we at JPL have used for decades). The error wasn't caught because
the absolute magnitude of the force is very small, so the differences
from predict to observation were on the order of the measurement
uncertainty. (We're talking measuring the velocity to mm/sec and range
to mm, when its at Mars.)
I'd venture that anyone would find measuring distances to 1 part in 1E12
challenging...
...

Damn, well someone told me, at work, told me it was a kilo/miles problem
.... however, the difference you state resulted in the same, apparent,
outcome--so sue me roflol

I must say, predictable!

Regards,
JS

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:

Oh Gesus! You self masturbating idiot!!! (and, did anyone ever tell
you that looks disgusting in public???)

You are not God, this is NOT a catholic, I don't feel guilty and we are
not in a confessional!

NUFF SAID!

JS

Loading Coils; was : Vincent antenna
 

art wrote:

But a dead horse will never get upregardless of the amount of
whipping.
Regards
Art

"upregardless"???

Hmmm, I remember my wife mentioning that ... evil smirk

Regards,
JS

Loading Coils; was : Vincent antenna
 

On Thu, 29 Nov 2007 20:50:29 -0500, "AI4QJ" wrote:

So, in other words you agree

Hi Dan,

I use my own words, not other words, and certainly not laden with
artificial constraints and presumptions. If you want to ask a
question without all these drapes, go ahead; it is far simpler, and
consumes less bandwidth.

73's
Richard Clark, KB7QHC

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Gene Fuller wrote:
It appears you missed the primary message of the Corum article.

I'm afraid you missed the point. As long as the frequency
is kept constant, the VF and Z0 of coil stock will be
relatively constant - why wouldn't it be? W8JI missed
the 4 MHz delay through that coil by at least a magnitude.
It is impossible for that delay to be 3 nS. The measured
delay through my 75m bugcatcher coil is 25 nS.

Yup, I guess I don't understand the "point". You continue to use the
equations and charts derived in the Corum article, but you don't agree
with his conditions and caveats. There would have been no purpose for
his article if your paragraph above was correct. Have you expanded the
applicability range for his results? Where can we find your IEEE white
paper?

So, the "point" is ??????

73,
Gene

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:

...
But since W8JI's measurements are NOT "supported by the
underlying principles", by your own assertions, he indeed
seems to be "shouting it at cars" on his web page. I am
merely objecting to a technical absurdity, e.g. a 3 nS
delay through a foot long loading coil. The standing-
wave current phase shift through a coil bears no
relationship to the delay through a coil.

Cecil:

Let's get real, principals above personalties ...

I don't know W8JI; from his pages, he seems alright. We all make
mistakes--that does not lessen us--I know you agree at some level ...

I have always looked at the lag of an inductance in degrees, the lead of
capacitance the same (when it comes to lump sums like antennas) ... I am
learning (a mindset on a certain model can limit one.) When someone
introduces the spinning of earth and its' rotation around the sun into
antenna formulas--I am always perplexed--such has NOTHING to do with
what is real in RF. Frankly, the importance of where your mind is at is
just beginning to hit home here.

If the earth/sun/solar-system did not exist--all would still be the same
.... this I KNOW.

There is SOMETHING we are ALL missing ... but, I do listen to your
arguments, I admit--I have a hard time following you--but then, you help
keeping me outta the bars and from fallen womens arms ;-) Your
argument(s) are based, somewhere, near the bone of the beast--well, I
think. Others are missing the core of this ...

Warm regards,
JS

Loading Coils; was : Vincent antenna
 

Gene Fuller wrote:
So, the "point" is ??????

Given a 100 foot long helical transmission line at
4 MHz terminated in its characteristic impedance.
The VF is easily measured. This is a slow-wave
configuration.

Change the length to 50 feet terminated in its
characteristic impedance. Why would the characteristic
impedance change? Why would the VF change?

The coil diameter is 0.5 feet. The coil diameter ratio
to wavelength is 0.002. The turns per foot is 48.
The turns per wavelength is about 11800. Reading from
Fig.1 in the Corum article gives a VF of about 0.02.
Why would that change appreciably with frequency?
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

AI4QJ wrote:
The close spacing of the coils reduces the time delays because the current
is "pushed along" faster.

This is true to a certain extent but not to the extent
that coil#1 couples heavily to coil#100 which is ten
inches away in W8JI's configuration. The 3 nS "measured"
delay at 4 MHz is off by approximately a magnitude. It
is much closer to 30 nS than it is to 3 nS.

I measured a ~25 nS delay in a 75m bugcatcher coil.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

John Smith wrote:
There is SOMETHING we are ALL missing ... but, I do listen to your
arguments, I admit--I have a hard time following you ...

Well, let's take a simple example. Given a lossless
90 degree stub. What is the phase shift in the total
current from one end of the stub to the other?
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
John Smith wrote:
There is SOMETHING we are ALL missing ... but, I do listen to your
arguments, I admit--I have a hard time following you ...

Well, let's take a simple example. Given a lossless
90 degree stub. What is the phase shift in the total
current from one end of the stub to the other?

Hmmm, 360? No, 180? Hmmm, 90? Well, 89.999999999999999999?

Ok, I give up, tell me ... :-)

Regards,
JS

Loading Coils; was : Vincent antenna
 

John Smith wrote:
Cecil Moore wrote:
John Smith wrote:
There is SOMETHING we are ALL missing ... but, I do listen to your
arguments, I admit--I have a hard time following you ...

Well, let's take a simple example. Given a lossless
90 degree stub. What is the phase shift in the total
current from one end of the stub to the other?

Hmmm, 360? No, 180? Hmmm, 90? Well, 89.999999999999999999?

Ok, I give up, tell me ... :-)

Regards,
JS

Anyway, why current, wouldn't voltage make the same shift, although
inversely proportional?

Regards,
JS