Hello Group,

If I have an RG-58 coax and it is shorted at the load end. At the electrical
1/8 wave lenght what would be the impedance seen at the other end?

I understand that a shorted 1/4 wave length reflects an open, but was
interested in what happens at the 1/8 wave frequency.

Tnx de KJ4UO

The impedance would be +j50 ohms, that is, 50 ohms of inductive
reactance. If you open the far end, you'll see -j50 ohms, that is, 50
ohms of capacitive reactance, at the input.

Roy Lewallen, W7EL

PDRUNEN wrote:

Hello Group,

If I have an RG-58 coax and it is shorted at the load end. At the electrical
1/8 wave lenght what would be the impedance seen at the other end?

I understand that a shorted 1/4 wave length reflects an open, but was
interested in what happens at the 1/8 wave frequency.

Tnx de KJ4UO

Roy,

Many years ago an article was published showing nomographs for using 1/8
wave lines for universal impedance matching. Do you recall where and when
that appeared, by any remote chance? I know you can do all this with
computer programs now, but I can't easily carry a computer or software into
many of the places I go.

--
Crazy George
W5VPQ
Remove N O and S P A M imbedded in return address

"Roy Lewallen" wrote in message
...
The impedance would be +j50 ohms, that is, 50 ohms of inductive
reactance. If you open the far end, you'll see -j50 ohms, that is, 50
ohms of capacitive reactance, at the input.

Roy Lewallen, W7EL

PDRUNEN wrote:

Hello Group,

If I have an RG-58 coax and it is shorted at the load end. At the
electrical
1/8 wave lenght what would be the impedance seen at the other end?

I understand that a shorted 1/4 wave length reflects an open, but was
interested in what happens at the 1/8 wave frequency.

Tnx de KJ4UO

Crazy George wrote:
... I can't easily carry a computer or software into
many of the places I go.

Everyone else does.



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Sorry, I don't recall having seen that.

Roy Lewallen, W7EL

Crazy George wrote:

Roy,

Many years ago an article was published showing nomographs for using 1/8
wave lines for universal impedance matching. Do you recall where and when
that appeared, by any remote chance? I know you can do all this with
computer programs now, but I can't easily carry a computer or software into
many of the places I go.

--
Crazy George
W5VPQ
Remove N O and S P A M imbedded in return address

Hi Roy, see you're still at it! Just stopped by to say
hello; hope you're doing well.

Regards,
Jack
WB3U


On Tue, 11 May 2004 17:55:48 -0700, Roy Lewallen
wrote:

The impedance would be +j50 ohms, that is, 50 ohms of

PDRUNEN wrote:
If I have an RG-58 coax and it is shorted at the load end. At the electrical
1/8 wave lenght what would be the impedance seen at the other end?

I understand that a shorted 1/4 wave length reflects an open, but was
interested in what happens at the 1/8 wave frequency.

For lossless coax, it would be purely reactive, close to +jZ0. Questions
like that are easy when one understands the Smith Chart.
--
73, Cecil http://www.qsl.net/w5dxp



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For lossless coax, it would be purely reactive, close to +jZ0. Questions
like that are easy when one understands the Smith Chart.
--
73, Cecil

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

They are even easier WITHOUT the unessessary over-complication of the chart.

A student's valuable time is much better spent learning about transmissiom
lines instead of how to use an antique chart. The answer can be worked out
in the head in less than a second. Tan(45) = 1.0000000 and therefore X =
Zo.

Sorry to hear about your pH problem. Isn't there an ant-acid preparation
available in this modern day and age?

----
Reg, G4FGQ

Reg Edwards wrote:
They are even easier WITHOUT the unessessary over-complication of the chart.

Why do you think the chart is "over-complicated". I have one with the
R,X values and only the to/from wavelength circles outside. I deleted
everything else from the Smith Chart program.

What I find convenient is to carry the image of the Smith Chart around
in my head. I'm more of a visual person than a formula person and that
image has helped me tremendously.

A student's valuable time is much better spent learning about transmissiom
lines instead of how to use an antique chart. The answer can be worked out
in the head in less than a second. Tan(45) = 1.0000000 and therefore X =
Zo.

How about 0.07 wavelength in your head? :-) I can glance at a Smith Chart
faster than you can pick up a calculator.

Sorry to hear about your pH problem. Isn't there an ant-acid preparation
available in this modern day and age?

Prilosec OTC works well. Then I can drink twice as much as usual [hic].
--
73, Cecil http://www.qsl.net/w5dxp



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Reg, G4FGQ wrote:
"Isn`t there an ant-acid preparation avbailable in this day and age?"

I read in "Spectrum" that J.C. Maxwell took bicarbonate of soda but died
of stomach cancer, regardless.

Best regards, Richard Harrison, KB5WZI