Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Keith Dysart wrote:
You have done this before; postulating
explanations that only work in the complexity
of the "real" world, but fail when presented with
the simplicity of ideal test cases.

For Pete's sake, Keith, Ohm's law doesn't even
work when R=0.

Then, when the explanations fail on the simple
cases, claiming these cases are not of interest
because the real world is more complex.

I define the boundary conditions within which my
ideas work. Whether they work outside those defined
conditions is irrelevant. I believe they do work
for ideal conditions, but I don't have the need
to prove a "theory of everything".

Every model that we use has flaws. Asking me to
come up with a flawless "theory of everything"
model is an obvious, ridiculous diversion but
you already know that.

This isn't a diversion: it's the core of the whole dispute.

These days, mathematical models are the normal, everyday way that
engineers go about their business. A bedrock principle is that if a
model is going to be usable and trustworthy, it MUST join up correctly
with existing knowledge. Your model can be as elaborate as you like, but
it always has to prove itself against the simple cases that we already
know about.

Anyone with experience knows that these "simple" reality tests are the
most often the hardest for an elaborate model to pass... but that
doesn't excuse them from the test. If a model cannot handle the simple
situations that we do understand, we can never trust it in more complex
situations.

Ohm's law is a perfect example of a model that works. The whole point is
that Ohms' law IS a good model of reality for a very wide range of
situations, including the simple but extreme case where R equals
exactly zero. It's absurd to suggest that there's a glitch - it simply
means that V would be exactly zero too.

Likewise there are no glitches in the standard circuit models for
inductance and capacitance. They work just fine, for all cases where the
dimensions of the circuit are very small with respect to the wavelength,
so that distributed effects and radiation are negligible. Where those
assumptions are no longer accurate, we can extend the simple model to
include some corrections. But the most important point is, we always
know that we're building up from a solid foundation.

That is also the sensible way to think about loaded antennas. Calculate
it the simple way first, assuming lumped inductive loading, and then
apply corrections as necessary. As I've said before, this simple, solid
method is the one that works. It can take you straight to a workable
prototype, which can be quickly adjusted to frequency. Countless authors
have demonstrated how to do this, and anyone can download G4FGQ's
MIDLOAD program to do the same.

While other people choose to build on those solid foundations, Cecil
insists that simple routine reality tests are a "diversion". He prefers
to keep his floating castles well clear of such hard rocks.


--

73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Loading Coils; was : Vincent antenna
 

On Dec 8, 12:52 am, Cecil Moore wrote:
Keith Dysart wrote:
The best example was when you refused to discuss
the reflections at the output of an amplifier with a
well defined output impedance because a typical
amateur transmitter does not have a well defined
output impedance.

I tend to avoid discussions about amplifiers because
I know very little about amplifiers, real or imagined.

Serious revisionism here.

You should count your posts on (re)reflections at the
output terminals of amplifiers.

....Keith

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
Cecil, on the other hand, wants to argue,
so his posts aren't as much fun, but he does write some entertaining
things on occasion, and his theories are tolerable enough as long as you
realize they're all quite wrong.

Tom, please download this EZNEC file, hit the "Load Dat"
button, and tell us what is "wrong" with the current phase
as reported by EZNEC.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Ian White GM3SEK wrote:
That is also the sensible way to think about loaded antennas. Calculate
it the simple way first, assuming lumped inductive loading, and then
apply corrections as necessary. As I've said before, this simple, solid
method is the one that works. It can take you straight to a workable
prototype, which can be quickly adjusted to frequency. Countless authors
have demonstrated how to do this, and anyone can download G4FGQ's
MIDLOAD program to do the same.

The point is that IT OBVIOUSLY DOESN'T WORK, Ian, for
the delay through a loading coil. If it worked, W8JI
would not have gotten a 3 ns delay through a 2" dia,
100 TPI, 10" long loading coil. If his test setup
looked like mine, he would have measured a valid
delay around 25 ns.

http://www.w5dxp.com/coiltest.gif

Ian, are you afraid to run that test for yourself?

Cecil
insists that simple routine reality tests are a "diversion".

Please don't twist my words. I insist that simple routine
*UNreality* tests are a diversion. But, my personal opinion
doesn't change anything. The model that I am using works. The
model that W8JI is using doesn't work.

Please take a look at: http://www.w5dxp.com/coil512.ez
and tell me why EZNEC disagrees with W8JI's model.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Keith Dysart wrote:
You should count your posts on (re)reflections at the
output terminals of amplifiers.

Conceptually, I know what has to happen based on the
principle of conservation of energy, i.e. all energy
is conserved. If the reflected wave energy is not
entering the source, it is being reflected at the
source. That is all I was saying during those posts.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:


---43.4 deg 600 ohm line---+---10 deg 100 ohm line---open

The Smith Chart does make it clear what is happening.
Here is the math to go with it. The impedance at the
junction of the two lines is:

-j100*tan(90-10) = -j100*tan(80) = -j567 ohms
-j600*tan(43.4) = -j600*tan(43.4) = -j567 ohms

The phase shift at the junction of the two lines is:
80-43.4 = 36.6 degrees

Time permitting, I will work up the phasor diagrams of
the component voltages (or currents) at the junction
where rho = (600-100)/(600+100) = 0.7143

So how many nanoseconds does that 36.6 degree phase shift represent?

8-)

73,
Gene
W4SZ

Loading Coils; was : Vincent antenna
 

On 7 Dec, 22:25, Richard Clark wrote:
On Fri, 7 Dec 2007 18:14:36 -0800 (PST), art
wrote:

I did not know that equation. Einstein said a lot of things and
was often proved in error. Did he mention equilibrium or the
other laws like:
Every action has an equal and opposite reaction?

Hi Arthur,

Every equation describes equilibrium, by definition.

For that matter
how many laws of Newton did he put down?

All of them.

Any idea where I can read up on that and how he arrived at that
conclusion? Seems odd that we have so many gravity centers in this
universe and a neutral point never occurs.....anywhere.

Not so. A simple example is called the "Trojan points."

Some of those stationary things in the sky must be holding on to a
piece of string tied to the moon

Well, given the moon moves, the string must move whatever is tied to
it. In short, there is nothing stationary anywhere.

No. I do not have any books on Einstein but do have Planck and
I don't recall him mentioning that.Is it just called Einsteins Law
of ???????

General relativity.

73's
Richard Clark, KB7QHC

As with the convergence of energy vectors described
in the Columbian lectures so is general relativity.
Both are procedures that are being followed
in an effort to find a path to GAT. As I stated before
it often is not the destination that counts but what
one learns on the journey . Both of these procedures
have provided insights to the universe but neither
proved to be the answer for Einsteins main quest
which was GAT. Yes, a lot of theories have been produced
by using these procedures some of which relate to our universe
and some of these theories may prove to be correct
but for the wrong reasons. Such was the making of the word
"theory" which deviates from a standard when considering a "law".
If you review Einsteins work in the search of GAT you will
find that most of his theories by his peers which he often
confided in so he is not immune to error.
With respect to the moon and the sun you are quite correct tho
I was being a bit vacitious, but it does show you are capable
of serious debate when you have a mind to together with sufficient
knoweledge to venture into unknown trails of thought, musings
and deduction.
Art Unwin KB9MZ.....xg (uk)

Loading Coils; was : Vincent antenna
 

Gene Fuller wrote:
Cecil Moore wrote:
Time permitting, I will work up the phasor diagrams of
the component voltages (or currents) at the junction
where rho = (600-100)/(600+100) = 0.7143

So how many nanoseconds does that 36.6 degree phase shift represent?

As far as impedance discontinuity *points* go, a nonsense
question.

How many nanoseconds does it take for a signal to travel
through a dimensionless point???? Well, let's see. What
is the speed of light multiplied by zero? Hmmmm, that's
a really tough one.

At any instant of time the forward voltage on
one side of the discontinuity *point* has a relative phase
difference from the forward voltage on the other side of
the *point*. This relative phase difference is constant as
long as the conditions remain unchanged.

The reason that it takes nanoseconds for a signal to travel
through a 75m Bugcatcher loading coil is that the coil is
NOT a dimensionless point. Mine occupies almost 200 cubic
inches. Loading coils with zero dimensions exist *only* in
the human mind and are impossible in reality.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:

...
http://www.w5dxp.com/coiltest.gif
...


Gesus Cecil!

Beautiful artwork! What'd you use to construct that?

Warm regards,
JS

Loading Coils; was : Vincent antenna
 

John Smith wrote:
Dave Heil wrote:

...
Dave K8MN

Dave:

While your statements are quite well constructed to inflame and insult a
child--that has to do with your mind, not my age ... ROFLOL!

Which comments, "John"? You snipped everything I wrote.

Dave K8MN