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Old June 4th 09, 06:29 PM posted to rec.radio.amateur.antenna
Jerry[_5_] Jerry[_5_] is offline
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First recorded activity by RadioBanter: Jun 2008
Posts: 133
Default Using Tuner to Determine Line Input Impedance


"dykesc" wrote in message
...
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.

Hi dykesc

I may be missing something. But, if the objective it to learn if the
local 105 MHz signal is actually introducing error into your impedance
measurement, only a few Smith Chart Polts are needed. You know the path (on
the Chart) the shunt reactance will have taken while being adjusted to make
a "match". You also know the path the series reactance took. Start from
the Chart center and move the impedance along the circles of constant
resistance for the series reactor. Move along the circles of constant
admittance for the shunt reactance. When the Xc and Xl are both known, and
you know which is closest to the "transmitter", it seems that a "program" is
unnecessary. What am I mising?

Jerry KD6JDJ