Walter:

I thought you were just playing on a bit with my joke... I am sorry...
Let me explain, Reg made reference to the venerable "Jones Chart" in a
previous post in this thread--it was too temping a joke to leave alone
and I picked up upon it--I make no real claim my father had any hand in
the creation of the smith chart--again, I am sorry, but I thought you
just playing along--to tell you the truth, I am still not absolutely
sure you are not--you still might be... grin

(the only hand my father played in all this was to teach me, "Take it
like a man son!!! ... and blame it on a Brit!!! ... poor Reg... grin)
Warmest regards,
John

"Walter Maxwell" wrote in message
...

"Richard Clark" wrote in message
...
On Fri, 3 Jun 2005 10:49:58 -0400, "Walter Maxwell"
wrote:

John, are you telling us that Phillip H. Smith was your Father?

Hi Walt,

I'm sorry to have the distinction of telling you that you have now
twice tried to bite at air in two postings to the same thread.
[Outlook Express is a jinx for you to use!]

There is no "John Smith" corresponding to this group. Brett uses
this
"handle" for whatever reason, but certainly not because he thinks
that
his veil is impenetrable.

73's
Richard Clark, KB7QHC

Holy Cow, Richard, you've just diagnosed the pain in my jaw. Silly me.
I guess that means that the 'John Smith' we're corresponding with came
over on the Mayflower.

Walt, W2DU

Regarding the long-lasting, 67-years old, love affair with the Smith
Chart.

Where there's Love there's Beauty.

The beauty of a Smith Chart derives from the underlying Mathematics.
Mathematics is pure intellectual beauty.

In this case the underlying functions and their inverses are the
Complex Hyperbolic Functions like Sinh, Cosh and Tanh which Victorian
engineers were familiar with. The behaviour of the early telegraph,
telephone and power lines was exactly described by such functions. The
maths had been quietly waiting for many years for transmission lines
to
be invented.

In the absence of computers, engineers soon got fed up with designing
transmission lines, solving complex hyperbolic equations with the aid
of log tables and slide rules, and began to use graphical methods in
the form of charts.

Now, complex hyperbolic functions are 3 dimensional things. They have
two linear dimensions and angles. They cannot be represented on a flat
paper chart. They need a whole stack of charts. Such stacks of charts
were available round about the Boer War. So whilst the British Army
was setting up concentration camps in South Africa, phone engineers
were busy in their factory offices worrying about SWR on power and
long-distance telephone lines.

The Victorian multi-dimensional charts remained in use through the
days of VLF and LF radio and for 5 decades until the advent of
computers. Bear in mind the charts were just a more convenient
means of accessing data than from books of mathematica tables,
although they were of much lower precision.

See if you can find it - "A Chart Atlas of Complex Hyperbolic
Functions", A. E. Kennelly, Harvard University, 1914.

Worldwide HF radio rapidly expanded from the early 1930's. In 1938 a
certain Mr Smith noticed that at HF and higher frequencies, for rough
and ready calculations he had to use only one of the stack of charts.
This particular chart corresponded to the case of a lossless line and
when Zo was purely resistive. No real lines have zero loss or have a
purely resistive Zo. But practical lines have a sufficiently low
attenuation per wavelength and a Zo whose angle converges towards zero
with increasing frequency, for a single chart on a flat sheet of paper
to deal with sufficient accuracy calculations at frequencies down to
LF. So Mr Smith exercised his artistic talents to produce the chart we
are familiar with. Or at least which we have heard about.
----
Reg.














"Reg Edwards" wrote in message
...
Reg, you've aroused my curiosity on three points:

Why would you use 'Smith Chart' and 'anger' in the same sentence?

========================================
Just a figure of speech. "Anger" suggests setting about a job with
energy, determination and a sense of purpose. As distinct from
mere
amusement.
========================================
Why are there any frequencies where the Smith Chart is misleading
and useless?
Which frequencies are they?
========================================
Depending on the size of the errors one is prepared to tolerate and
on
the calculated parameter of interest -

Frequencies at which line attenuation per wavelength is not small.
Frequencies at which Zo is not purely real.
Frequencies at which CR is not equal to LG.
Frequencies at which the reflection coefficient is greater than 1.0

Comment : Zo is never purely real. CR is never equal to LG.
And the chart is good only to 2-digit accuracy anyway.

But Walt, you already know all this. Have you ever tried the Jones
Chart? ;o)
========================================

How can you say the Smith Chart is misleading and useless if
you've
never used
one, and never inspected one for more than a minute?

Walt, W2DU

========================================

No problem! Worked it out for myself many years ago. Some years
ago
I introduced to this newsgroup the excellent book "Transmission
Lines"
by Robert A. Chipman, 1968. It aroused some interest. Some of you
obtained a copy.

It has a whole chapter devoted to the Smith Chart and fully
describes
its limitations, imperfections, short-comings and approximations.

But the reason Chipman included the chapter was because of the great
savings in labour and time (in HIS day and age) when doing
approximate
calculations on short, low loss, HF transmission lines such as
antenna
feedlines for which it was designed. Which is all radio amateurs
ever
use it for. Hardly any amateurs ever use it in anger. It has other
applications.

I first programmed a computer for work on transmission lines around
1960. At frequencies between 0.1 Hz and 1 MHz, frequencies at which
nobody would dream of using a Smith Chart. So I never became
addicted
to it.
----
Reg.

On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards"
wrote:

See if you can find it - "A Chart Atlas of Complex Hyperbolic
Functions", A. E. Kennelly, Harvard University, 1914.

Hi Reg,

A rare citation indeed, following an equally rare citation (Kennelly
following Smith, that is, and rare meaning a citation offered by you
who usually claim such activity reveals plagiarism).

But as for your challenge (yes a heated term I suppose - but
still...):
Google "Complex Hyperbolic Functions" Kennelly
to find from:
http://www.geocities.com/neveyaakov/.../kennelly.html
"Arthur Edwin Kennelly was U.S. electrical engineer who made
innovations in analytic methods in electronics, particularly the
definitive application of complex-number theory to
alternating-current (ac) circuits."

Let me quickly add that Kennelly was US through immigration and
professional employment, but British schooled and trained.

Such an introduction would put your comment to the test:
The Victorian multi-dimensional charts remained in use through the
days of VLF and LF radio and for 5 decades until the advent of
computers.
Which on one hand would suggest rather Edwardian than Victorian, and
on the other hand, perhaps Wilsonian for where this tome was actually
published.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote in message
...
On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards"
wrote:

See if you can find it - "A Chart Atlas of Complex Hyperbolic
Functions", A. E. Kennelly, Harvard University, 1914.

Hi Reg,

A rare citation indeed, following an equally rare citation (Kennelly
following Smith, that is, and rare meaning a citation offered by you
who usually claim such activity reveals plagiarism).

But as for your challenge (yes a heated term I suppose - but
still...):
Google "Complex Hyperbolic Functions" Kennelly
to find from:
http://www.geocities.com/neveyaakov/.../kennelly.html
"Arthur Edwin Kennelly was U.S. electrical engineer who made
innovations in analytic methods in electronics, particularly the
definitive application of complex-number theory to
alternating-current (ac) circuits."

Let me quickly add that Kennelly was US through immigration and
professional employment, but British schooled and trained.

Such an introduction would put your comment to the test:
The Victorian multi-dimensional charts remained in use through the
days of VLF and LF radio and for 5 decades until the advent of
computers.
Which on one hand would suggest rather Edwardian than Victorian, and
on the other hand, perhaps Wilsonian for where this tome was actually
published.

73's
Richard Clark, KB7QHC

I have a copy of Kennelly's "A Chart Atlas of Complex Hyperbolic
Functions", in my library in Florida. I'd be pleased to scan it for anyone who'd
like a copy, but only if you have the patience to wait until I return south in
November.

Walt, W2DU

On Fri, 3 Jun 2005 14:14:35 -0400, "Walter Maxwell"
wrote:

I have a copy of Kennelly's "A Chart Atlas of Complex Hyperbolic
Functions", in my library in Florida. I'd be pleased to scan it for anyone who'd
like a copy, but only if you have the patience to wait until I return south in
November.

Hi Walt,

I cannot imagine that but being a very lengthy chore. However, it is
quickly becoming one that more than a few are willing to perform and I
offer to one and all my congratulations and thanks for such effort.

I will pass on this if I am your only motivation. I have a copy of
"Standard Handbook for Electrical Engineers," McGraw - Hill, that is
contemporaneous. It comes with many such charts, tables, figures, and
minutia in the classical Wilsonian style of illustration (and I cannot
imagine myself copying all 2000 pages for circulation).

73's
Richard Clark, KB7QHC

Cecil:

I must say, you are quite a talent, your threads draw more attention,
debate, argument and blood to boil--that I grow ill with jealousy!!!
grin

Warmest regards,
John

"Cecil Moore" wrote in message
...
I've added a Smith Chart graphic to my All-HF-Band-No-Tuner-Antenna
information on my web page.
--
73, Cecil http://www.qsl.net/w5dxp/smith.htm

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Regarding transmission lines, as somebody who has never thorougly
learned how to use a Smith Chart, it has never been worth the trouble,
I would like to say that the underlying, common sense, logical
mathematics are much easier to understand.
----
Reg

Reg:

As usual you are right on key...
If you know math, if you are not afraid of using complex formulas in
computations (and especially if you have a programmable calculator in
your back pocket) the math is much more appealing than charts--still,
the chart has uses... not all directly related to the math (my gf's
think they look kewl--frankly, I might get laid a tad more often just
for displaying a smith chart--women are hung up on intelligent men
yanno--I wonder if smith ever realized that? grin)...

Warmest regards,
John

"Reg Edwards" wrote in message
...
Regarding transmission lines, as somebody who has never thorougly
learned how to use a Smith Chart, it has never been worth the trouble,
I would like to say that the underlying, common sense, logical
mathematics are much easier to understand.
----
Reg

On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards"
wrote:

The beauty of a Smith Chart derives from the underlying Mathematics.
Mathematics is pure intellectual beauty.

On Fri, 3 Jun 2005 16:45:12 +0000 (UTC), "Reg Edwards"
wrote:

The beauty of a Smith Chart derives from the underlying Mathematics.
Mathematics is pure intellectual beauty.

In this case the underlying functions and their inverses are the
Complex Hyperbolic Functions like Sinh, Cosh and Tanh ...

Now, complex hyperbolic functions are 3 dimensional things. They have
two linear dimensions and angles. They cannot be represented on a flat
paper chart. They need a whole stack of charts.

On Sat, 4 Jun 2005 18:30:54 +0000 (UTC), "Reg Edwards"
wrote:

as somebody who has never thorougly
learned how to use a Smith Chart, it has never been worth the trouble,
I would like to say that the underlying, common sense, logical
mathematics are much easier to understand.

Hmm,

Same topic, same math, same correspondent, same language (apparently),
two different and diverging points of view (the last couched in double
negatives) -and- consistent(ly amusing).

I am at a loss to read these statements as Art criticism, Pedagogy,
Historical Romance, or what?

73's
Richard Clark, KB7QHC