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Old June 10th 05, 01:38 PM
Cecil Moore
 
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Roy Lewallen wrote:
If you put the perfect voltage source and the source resistor into a box
and label it "Source", you have a Source whose impedance perfectly
matches the transmission line. It's a Z0-matched system.


This is exactly like the ham who puts up a random length dipole,
feeds it through a 9:1 balun using 450 ohm ladder-line, and
declares that he has a Z0-match.

50 ohm
100v
source--+--1/2WL 50 ohm feedline--+--200 ohm load

Measuring the 50 ohm SWR at your source output yields 4:1.
Measuring the 200 ohm SWR at your source output yields 1:1.
It is *NOT* Z0-matched to the 50 ohms inside your source.

In a lossless system, a Z0-match to the source impedance
would imply a conjugate match and maximum power transfer.
Your example obviously does not transfer maximum power.
--
73, Cecil http://www.qsl.net/w5dxp

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