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Old July 7th 05, 01:17 AM
Wes Stewart
 
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On Wed, 06 Jul 2005 22:27:08 GMT, Owen wrote:

On Wed, 06 Jul 2005 22:07:41 GMT, Owen wrote:


Apparently, the method involves calculation of a factor (let's call it
MR) as MR=|(Zl-Zo*)/(Zl+Zo)|, and the line loss between two points is
given by 10*log((1-MR1**2)/(1-MR2**2)) where MR1 and MR2 are the
values for MR at points 1 and 2.


Sorry, that gives the additional loss "due to SWR" which has to be
added to the matched line loss to obtain the total loss between points
1 and 2.

Zl in the formulas is the impedance (V/I) at the point where MR is
calculated.


I think "Computation of Impedance and Efficiency of Transmission Line
with High Standing-Wave Ratio", W.W. Macalpine, Transactions of the
AIEE, vol. 72, pp 334-339; July, 1953 might be of interest to you.

The same reference is used as the basis for the section
"Transformation of Impedance on Lines With Highh SWR" in the ITT
handbook.