Reg:

Dr. Jones was in heavy competition with my father (Mr. Smith), before my
dad developed the "Smith Chart." Darn "Jones Chart" never was any good!
grin

Warmest regards,
John

"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.

Reg Edwards wrote:
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.

There's an attenuation scale on the bottom. Doesn't it just
result in an SWR spiral instead of an SWR circle?
--
73, Cecil, http://www.qsl.net/w5dxp

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"John Smith" wrote in message
...

Dr. Jones was in heavy competition with my father (Mr. Smith), before my dad
developed the "Smith Chart." Darn "Jones Chart" never was any good! grin

Warmest regards,
John

John, are you telling us that Phillip H. Smith was your Father? I have a letter
from him dated in 1972, giving me permission to publish his Chart in one of my
articles in QST.

Walt, W2DU

"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.

And I thought I understood the English language. Obviously I miss some of the
ways you Brits use it. Thanks for the clarification--makes sense now.

========================================
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)

You're right, Reg, I do know this, but as Cecil has just now beat me to the
punch, the attenuation scale that goes with the Smith Chart allows the complex
impedance loci to spiral inward with line length for any given value of line
attenuation. The loci is a circle only for lossless lines, but you already know
this.
========================================
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.

I used the Chipman tome since around 1969, shortly after it was released.
Interesting that you introduced it to this NG in 1968, but I didn't learn of
this NG until the 1990s. I have two copies, one at each of my homes in Michigan
and Florida.

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.

Very interesting, Reg, but of course I knew of your many years of work with
undersea lines, so use of computers around 1960 doesn't surprise me. A little
bird told me one day that those lines aren't lossless. But, shucks, I coulda
found that out if I'd only dug deeper into Chipman, couldn't I?

Thanks for the informative response, Reg,

Walt

Walter:

Next you will be wanting the secret of my fathers long life--and how he
was able to do it all before the discovery of Viagra!!!
innocent-look-and-a-chuckle

Warmest regards,
John
"Walter Maxwell" wrote in message
...
"John Smith" wrote in message
...

Dr. Jones was in heavy competition with my father (Mr. Smith), before
my dad developed the "Smith Chart." Darn "Jones Chart" never was any
good! grin

Warmest regards,
John

John, are you telling us that Phillip H. Smith was your Father? I have
a letter from him dated in 1972, giving me permission to publish his
Chart in one of my articles in QST.

Walt, W2DU

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

"John Smith" wrote in message
...
Walter:

Next you will be wanting the secret of my fathers long life--and how he was
able to do it all before the discovery of Viagra!!!
innocent-look-and-a-chuckle

Warmest regards,
John
"Walter Maxwell" wrote in message
...
"John Smith" wrote in message
...

John, your father was a genious. His pioneering in the field of wave guides at
Bell Labs is legend. I also have his book, "Electronic Applications of the Smith
Chart," from which I drew many concepts for use in Reflections to disprove
prevalent myths concerning SWR and other mechanics of reflections. Consequently,
there are many references to his book in mine, including two entire chapters to
aid in learning how to use his Chart.

Walt, W2DU

"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

On Fri, 3 Jun 2005 11:14:51 -0400, "Walter Maxwell"
wrote:

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.

And I thought I understood the English language. Obviously I miss some of the
ways you Brits use it. Thanks for the clarification--makes sense now.

Hi Walt,

I won't accuse you biting air on this one, again, Reg is in his usual
yarn spinning and this time both of you evidence the myth of those who
"use" a language believing they "know" that language. Brits are
terrible exemplars of best English usage. So are Americans, but they
rarely behave like they own the language they dominate (that is
changing as we write - the rest of the world is going to soon claim
that crown).

Reg has in fact fallen off the Anglo-Saxon wagon (or should I say
cart?) by trying to fit a new definition to an Old French import to
our common language. In a way, he has succumbed to the worst traits
of Americanizing English through cavalier redefinition.

Anger has always (to English speakers at least) meant just what you
thought it to mean - relating directly to the sense of pain or
affliction. Somehow Reg wants to convert those rather daily
experienced negative associations into something bright and cheerful.
Perhaps he has been reading too many missives from our White House's
pronouncements on the conduct of the war....

Anger comes by way of the Old French anquisse, or the Modern French
angoisse, derived from the Latin augustia meaning compression. Most
folks do not smile in anticipation of anguish becoming their "sense of
purpose." Not unless you are a fundamentalist perhaps.

Who would'a' thunk that this thread could be such a trove of language
instruction? ;-)

73's
Richard Clark, KB7QHC

On Fri, 03 Jun 2005 08:52:00 -0700, Richard Clark
wrote:

Most
folks do not smile in anticipation of anguish becoming their "sense of
purpose." Not unless you are a fundamentalist perhaps.

From my copy of the "Concise Dictionary of the English Language"
(available at project Gutenberg):

Angre ... affliction, sorrow, wrath, pain, inflammation ... by way of
the Icelandic angr.

Angren ... to annoy, injure, make angry ... by way of the Icelandic
angra.

Angwisch ... anguish

anguyssh ... angoise

anguise ... anguisse ... angustia, tightness from angere, to squeeze.

Amusingly enough, every one of these terms encountered in line are
directly following:

Angles ... the English, the people of 'Angul' a district of Holstein
.... Englis.

What a larf (or for the rest of the English speaking world, Hoot).

73's
Richard Clark, KB7Q aich C