dykesc wrote:
On Jun 3, 2:17 pm, dave wrote:

http://ytdp.ee.wits.ac.za/smithchart.pdf

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=8763

I don't run Linux Dave. Is there a Windows version? Meanwhile I am
going at it manually with a Smith Chart. At multiple frequencies this
will take some time.

Dykes AD5VS


you can do it with an Excel Spreadsheet..

You know that at "match" the impedance looking into the tuner from the
antenna is the conjugate of the impedance looking into the antenna from
the tuner.

If you assume your transmitter is 50+j0 ohms (not a good assumption..
but you could make it closer to being so by putting a 10dB pad between
Tx and tuner, for instance)

Then, you calculate what the impedance the tuner is using the L and C
values (I assume it's a series L and a shunt C) ... you'll either have:

TxR plus L, shunted by C
or TxRshunted by C, then series L

A spreadsheet like XLZIZL does it in a flash.

On Jun 4, 11:09*am, Jim Lux wrote:

you can do it with an Excel Spreadsheet..

A spreadsheet like XLZIZL does it in a flash.

Thanks Jim. I found and downloaded XLZIZL

73
Dykes AD5VS

dykesc wrote:
On Jun 3, 2:17 pm, dave wrote:

http://ytdp.ee.wits.ac.za/smithchart.pdf

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=8763

I don't run Linux Dave. Is there a Windows version? Meanwhile I am
going at it manually with a Smith Chart. At multiple frequencies this
will take some time.

Dykes AD5VS


RF Cafe has one that uses Excel. www.rfcafe.com

On Jun 4, 2:13*pm, dave wrote:

RF Cafe has one that uses Excel. *www.rfcafe.com

Thanks Dave. I just downloaded it.

From: dykesc
Date: Wed, 3 Jun 2009 Time: 10:57:52

I am trying to validate impedance values I am measuring with my
MFJ-259B. I want to do this by using my MFJ-993B auto tuner. The tuner
uses a simple L network to create the conjugate match. I want to take
the final inductance, capacitance and swr values from the auto tuner
digital display after matching is completed and back calculate the
impedance that the tuner is seeing. Is there an online calculator that
will do this?

Many thanks for replys.


Is this any help?

http://www.wy2u.com/

Scroll down to "Electrical / Electronic Engineering Links" and click on
"L/C Impedance Matching Design Tool"

--
73
Ian, G3NRW

On Jun 4, 2:10*am, Ian Wade G3NRW wrote:

Is this any help?

http://www.wy2u.com/

Scroll down to "Electrical / Electronic Engineering Links" and click on
"L/C Impedance Matching Design Tool"

--
73
Ian, G3NRW

Thanks Ian. That is the type of calculator I am looking for. However,
this one requires both source and load impedance as input. I am
looking for one that will allow you to specify the source impedance
(50+j0), fill in the capacitor and inductor values, and then tell you
what the matched load side impedance is.

dykesc wrote:
I am
looking for one that will allow you to specify the source impedance
(50+j0), fill in the capacitor and inductor values, and then tell you
what the matched load side impedance is.

That is a trivial problem. What configuration?
What does the schematic look like?
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

On Jun 4, 11:30*am, Cecil Moore wrote:

That is a trivial problem. What configuration?
What does the schematic look like?

The auto tuner is a simple LC network (series inductor, shunt
capacitor) Cecil. It reports the inductor and capacitor values and the
side of the network the shunt capacitor is on (transmitter or
antenna). Of course it reports final SWR as well.

For instance, at 28.7Mhz it matched with an inductor value of 0.17
microhenries and 0 pF at an SWR of 1.0 (1:1).

My MFJ-259B reported 25-j11 at 28.7 Mhz which obviously is not in
agreement with the auto

Thanks Cecil

Dykes AD5VS

On Thu, 4 Jun 2009 09:19:42 -0700 (PDT), dykesc
wrote:

That is the type of calculator I am looking for. However,
this one requires both source and load impedance as input. I am
looking for one that will allow you to specify the source impedance
(50+j0), fill in the capacitor and inductor values, and then tell you
what the matched load side impedance is.

The source code is at:
http://www.hoflink.com/~mkozma/match19cb.html
which, if you can follow the design and make your own changes, should
be ammenable to your needs.

73's
Richard Clark, KB7QHC

On Jun 4, 12:06*pm, Richard Clark wrote:

The source code is at:http://www.hoflink.com/~mkozma/match19cb.html
which, if you can follow the design and make your own changes, should
be ammenable to your needs.

73's
Richard Clark, KB7QHC

Thanks Richard. I found the source code. I have done a little
programing long ago, but modifying the code there would be a little
much for me I'm afraid.

73
Dykes AD5VS