On Sep 3, 11:30*pm, Owen Duffy wrote:
"Jerry" wrote innews:s5Ivk.448$sq3.441@trnddc07:
...

* I realize that you have asked this question to Richard, who is far
* better
prepared to answer than I am. * But, it seems that you are confused
about how two sine waves add. *Maybe I am wrong, and you do know how
two sine wave voltages generated at different times and are connected
in series combine to being other than 180 degrees from terminal to
terminal.
* All the 208 power lines I am familiar with *are* 208 from terminal
* to
terminal when each leg is 120 "terminal to center". * Where did you
get the "240"?

* * * * * * * * * * * *Jerry * KD6JDJ

Jerry, in the three wire system with 180° phase difference between Line1
and Line2 wrt Neutral (the centre wire) the voltage Line1 wrt Line2 is
exactly twice the Line1 to Neutral voltage.

You probably don't use the word Neutral over there, it is the word used
for four wire three phase systems and it is equally applicable for a
three wire two phase system where the Neutral wire carries the
"imbalance" current.

None of this is a good analogy to a two wire open transmission line at
radio frequencies, principally because the length of conductors at power
frequencies is usually a very small part of a wavelength and can be
approximated well using a simpler analytical model than the traditional
'Telegrapher's' equations applied to transmission lines.

Those who resort to explaining radio frequency transmission lines and
transformers using 60Hz models need to justify the accuracy / limits of
the approximation. The low frequency model does not explain high
frequency roll-off in RF transformers and inductors, so it is clearly
incomplete.

Almost all of this discussion is using lumped circuit analysis (a low
frequency model) to explain not just transmission lines, but conductors
with significant mutual coupling (the nominal radiator and its feedline).

Owen



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I found it difficult to go beyond the simplistic 60 Hz analogy in this
discussion to best decribe my concept (when writing on usenet). All
one can hope for is that the general idea comes out and hope people
realize that the variables you mention do exist as well and do not
detract from the very fundamental concepts.