"John Smith" wrote in message
...
I have an old pickett slide around here somewhere--ahhh, like you, never
throw anything away lol....

Warmest regards,
John


The term "old slide rule" is a bit redundant, some would say.
My new slide rule is only about 30 yrs old. Plenty of life left in it.

I agree - like I said - I have nothing but respect for those who figure them
out.

Hal Rosser wrote:

So now you're pickin' on my slide rule? Is nothing sacred??
I like my slide rule. Its more useful than my solar-powered flashlight.
The slide rule works without any power or batteries. :-)
And its accurate to 3 (sometimes 4) significant digits.

Solar powered flashlight? Heck, we have a made up loony lefty here in
Minneapolis who wants people to use electric powered generators to
reduce noise and pollution during emergencies. Morgan Q. E.
Wolfe-Slattery, a true Euphorian.

I have 2 slide rules that I picked up recently, but I miss my easy on
the eyes yellow aluminum Pickett LogLogDeciTrig (I think that's what it
was) that got misplaced during a move a couple decades ago. I also wish
I still had my HP35, 45 and 11C. I do have a working HP25, 15C and 48SX
though.

tom
K0TAR

Hal:

Ok, but that was not pointed towards you... just a general, "Aye!" for
the smith chart... I can't imagine every ham without one on the wall
they just look kewl too, with the world map--and I am quite serious
about that... ... many visitors to a station appreciate it if you
generate a bit of atmosphere for 'em.... nod-and-a-wink

Regards,
John

"Hal Rosser" wrote in message
.. .
I agree - like I said - I have nothing but respect for those who figure
them
out.

"Hal Rosser" wrote in message
news
Hal

It surprises me to read that you consider the Smith Chart difficult to
use. I'd bet that you could figure out how to use one to your benefit
within 20 minutes of asking questions of someone who uses them.

Jerry

Jerry,
You're probably right. I could probably lean how in an afternoon.
I sat down with one I printed out once, and thought I had it figured out.
Then when I needed to use it again, I would need to be retrained.
I remember how to use an MFJ259 from use to use, though. :-)

I just don't have the patience - it just doesn't grab my attention like a
gizmo does.


Hal

First off -- I realize that you are eperienced enough with antenna
analysis to know what is needed for matching them. And, if you did want to
use a Smith Chart, you'd have done it by now. I wont embarrass myself by
telling you anything I know about them. But, they sure can help identify
what kind of impedance is needed for a matching network.
Any impedance with a real resistive value can be plotted on the chart.
Then, its location immediately identifies what reactance will move the
unmatched impedance toward a matched location. I think you already knew
that. I also think you could teach me how to look at matching devices from
a more practical perspective.

Jerry

"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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There is an excellent limited, and free, Smith Chart program at this site:
http://www.janson-soft.de/seminare/dh7uaf/

Scroll down and look for the for the following, download (308 kB), and
unzip. The link below may also work from this posting.

Smith V1.91 (Smith.exe), Smith-Diagramm-Programm (Download hier):
Demo-Version der FH Bern für Win (bis zu 5 Bauteile, L, R, C, Trafo, Stubs
und Trafo-Leitungen mit verschiedenen Wellenwiderständen, kein.

A few moments playing with the program should reveal the simplicity and
power of the Smith Chart. The program was developed at the University of
Applied Science, Berne.

73,

Frank

Jerry Martes wrote:
It surprises me to read that you consider the Smith Chart difficult to
use. I'd bet that you could figure out how to use one to your benefit
within 20 minutes of asking questions of someone who uses them.

The Smith Chart is relatively easy to learn in steps. First step
is to learn how to normalize impedances and plot them on the
Smith Chart. The 1.0 in the center of the chart is the normalized
Z0 of the feedline.
--
73, Cecil http://www.qsl.net/w5dxp

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John Smith wrote:
I should point out, everyone should at least know about a smith and have
used it... kinda gives you a "feel" for the way all the variables work
together... it is a good thing...

For me, the biggest advantage of the Smith Chart is that I can
carry it around in my head. It is a graphical math model of
a transmission line. A picture is worth a thousand calculators.
--
73, Cecil http://www.qsl.net/w5dxp

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Cecil:

I wasn't being cynical, and although I cannot "carry it in my head", it
is good for the example chart, I agree, a picture is worth a thousand
words--I was not poking fun... but hey, it does look kewl.... I am not
above cheap tricks to impress my company... perhaps I admit my failing
here to be poked fun at--but the first time I seen one--was pretty damn
impressed!!! (still am actually)

Warmest regards,
John

"Cecil Moore" wrote in message
...
John Smith wrote:
I should point out, everyone should at least know about a smith and
have used it... kinda gives you a "feel" for the way all the
variables work together... it is a good thing...

For me, the biggest advantage of the Smith Chart is that I can
carry it around in my head. It is a graphical math model of
a transmission line. A picture is worth a thousand calculators.
--
73, Cecil http://www.qsl.net/w5dxp

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"Cecil Moore" wrote in message
...

The Smith Chart is relatively easy to learn in steps. First step
is to learn how to normalize impedances and plot them on the
Smith Chart. The 1.0 in the center of the chart is the normalized
Z0 of the feedline.
--
73, Cecil http://www.qsl.net/w5dxp

The mention of the Smith Chart and slide rules in the same breath brings back a
lot of memories. They put meat and potatoes on the table for me and my family
for many years. I was fortunate to be in the right place at the right time at
the beginning of space exploration, during which time I had the rare priviledge
of developing antenna systems for several different spacecraft while working at
the antenna lab of the RCA Laboratories, and at RCA's Space Center, the RCA
Astro-Electronic Division until I retired in 1980.

The most challenging assignment was developing the antennas that flew on the
World's first weather satellite, TIROS 1, and several of its successors. The
challenge involved developing a transmitting antenna array that would radiate
right-hand circular polarization from two transmitters and left hand circular
from two other transmitters. The four VHF transmitters operated simultaneously
on four separate frequencies in two non-harmonically related bands.

The real challenge was in developing a matching circuit to couple the four
transmitters to the single antenna comprised of two crossed dipoles. The circuit
was constructed entirely of printed circuit stripline transmission line.

The reason for telling you this is that all the calculations during the
development of both the radiators and the matching circuit were performed with
only a slide rule and the Smith Chart. There were no calculators or computers
available at that time. Without the Smith Chart the impedance calculations would
have been so tedious that the project would have failed due to the lack of time
to complete them.

My Dad gave me a simple wooden slide rule when I was thirteen and taking
advanced algebra. Then in my senior class, beginning at fifteen, he gave me an
ivory Kueffel and Esser trig rule. While teaching electronic students in the
Navy during WW2, I acquired another K and E rule, this time a log log decitrig.
Then while developing antennas at RCA in the 50s and 60s I acquired another log
log decitrig, this time an aluminum Picket and Eckel. I still have all of these
rules in my 'antique calculator' museum.

My first calculator was an HP-35, which replaced the slide rules--couldn't
believe I was going from three significant figure precision to nine and greater!
I later acquired an HP-45, then a 55, followed by a 34-C, 15-C, and a 42-S. I
still have batteries fully charged in the last four calculators ready for use.
And even though I have several Smith Chart programs, some of which appear in
Chapter 15 of Reflections, I still use the slide-rule version of the Smith Chart
in solving certain impedance matching problems.

That's the story of my love affair with slide rules and the Smith Chart.

Walt, W2DU

PS--Chapters 10 and 11 in Reflections present a primer in learning how to
understand and use the Smith Chart.