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Old August 28th 03, 05:20 PM
Richard Clark
 
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On Thu, 28 Aug 2003 05:58:09 -0500, W5DXP
wrote:

Richard Clark wrote:
"...the generator impedance is 100+0j ohms, and the line is 5.35
wavelengths long."


What does the generator impedance have to do with line losses?


Hi Cecil,

From Chapman (you following this George?) page 28:

"It is reasonable to ask at this point how, for the circuit of
Fig. 3-1(b), page 18, on which the above analysis is based, there
can be voltage and current waves traveling in both directions on
the transmission line when there is only a single signal source.
The answer lies in the phenomenon of reflection, which is very
familiar in the case of light waves, sound waves, and water waves.
Whenever traveling waves of any of these kinds meet an obstacle,
i.e. encounter a discontinuous change from the medium in which
they have been traveling, they are partially or totally
reflected."
...
"The reflected voltage and current waves will travel back along
the line to the point z=0, and in general will be partially
re-reflected there, depending on the boundary conditions
established by the source impedance Zs. The detailed analysis of
the resulting infinite series of multiple reflections is given in
Chapter 8."

The Challenge that I have offered more than several here embody such
topics and evidence the exact relations portrayed by Chapman (and
others already cited, and more not). The Challenge, of course, dashes
many dearly held prejudices of the Transmitter "not" having a
characteristic source Z of 50 Ohms. Chapman also clearly reveals that
this characteristic Z is of importance - only to those interested in
accuracy.

Those hopes having been dashed is much evidenced by the paucity of
comment here; and displayed elsewhere where babble is most abundant in
response to lesser dialog (for the sake of enlightening lurkers no
less). Clearly those correspondents hold to the adage to choose
fights you can win. I would add so do I! The quality of battle is
measured in the stature of the corpses littering the field. :-)

So, Cecil (George, Peter, et alii), do you have an answer? Care to
take a measure at the bench? As Chapman offers, "just like optics."
Shirley a man of your erudition can cope with the physical proof of
your statements. ;-)

The only thing you and others stand to lose is not being able to
replicate decades old work. Two resistors and a hank of line is a
monumental challenge.

73's
Richard Clark, KB7QHC