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[AMPS] Feedpoint impedance vs SWR

To: <amps@contesting.com>
Subject: [AMPS] Feedpoint impedance vs SWR
From: measures@vcnet.com (measures)
Date: Sun, 3 Oct 1999 03:04:40 -0700
>
>
>
>I think I am understanding well the measured SWR vs impedance along the
>line question.
>  
>My next question is:   Given, say, a 100 ohm resistive antenna impedance
>(at the antenna terminals) connected to (assumed lossless) 50 ohm coax
>line, of multiple wavelengths, (producing a 2:1 SWR) What is the most
>extreme feed point impedance swing in the line and how far down the line 
>is it?  
> And how can one compute this mathematically, if one does not have
>access to a smith chart?
>
?  My guess is that a quarter wave 50-ohm line would transform the 
100-ohms to [100^2 + 50^2]^0.5 =[10k + 2.5k]^0.5 = 111.8-ohms.  However, 
with a half wavelength of any Z coax, the 100-ohms would not be 
transformed.  

later, Pat. 

-  Rich..., 805.386.3734, www.vcnet.com/measures.  


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