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Old May 13th 11, 09:09 PM posted to rec.radio.amateur.antenna
Cecil Moore Cecil Moore is offline
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First recorded activity by RadioBanter: Aug 2006
Posts: 572
Default Transmitter Output Impedance

On May 11, 3:09*pm, walt wrote:
Cecil, you are correct!!!


Thanks Walt, it would be interesting to see what else about which I am
correct. W7EL has a food-for-thought publication with one section
about reflections from the source. His source has a 50 ohm source
impedance, by design, so any dynamic load pulling experiment should
result in zero reflections from the source. Question is, does it?

http://eznec.com/misc/Food_for_thought.pdf

The "forward and reverse power section" is at the bottom of the page.
Using the dynamic load pulling method, do the results always indicate
50 ohms for the source impedance no matter what is the load and/or the
transmission line length? If not, the method yields invalid results.

IMO, it is a gross error to presume that all redistribution of energy
is a result of reflections. In W7EL's example, there are no
reflections from the source yet it is obvious that energy is being
redistributed from the source back toward the load in some cases but
not in other cases. IMO, destructive/constructive interference must be
taken into account in order to explain the results. Yet, no one except
yours truly has even mentioned interference effects as a method of
redistributing energy.

Anyone interested in understanding the role of interference at
impedance discontinuities in transmission lines is welcome to read my
article at:

http://www.w5dxp.com/energy.htm
--
73, Cecil, w5dxp.com
"Halitosis is better than no breath at all.", Don, KE6AJH/SK