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Richard Clark · March 27th 07, 09:41 PM posted to rec.radio.amateur.antenna

On Tue, 27 Mar 2007 02:47:04 -0500, (Richard
Harrison) wrote:

Richard Clark, KB7QHC wrote:
"There is a continuum of phase relationships expressed in degrees
between 0 and 360."

We are discussing transmission lines and assuming near perfection.
Indeed the phase of the wave depends on that of the generator when it
was launched and the phase of the generator continues to advance with
time, but a good line enforces its Zo, a resistance.

Hi Richard,

This is, of course, contingent only when the line is terminated in its
characteristic Z. Otherwise, given the premise of this thread, that
is not true. However, you do amend by:

The transmission line treats the wave reflected from a discontinuity
exactly the same as it does the incident wave.

The reflected wave is identical with the incident wave except that it is
traveling toward the generator.

However, this presumes one of those one or two degree (0 & 180)
solutions originating from either a short or an open that you
explicitly introduce.

There are two phasing conditions between the voltage and current on an
ideal transmission line, 0 degrees and 180 degrees.

Actually, there are 360 degrees to consider, of which 0 & 180 make up
slightly more than 0.5% of the complete picture. The length of the
line presents this continuum to the unmatched source, and the source
suffers by degree of phase relationships.

The solution to this perceived suffering, of course, is to introduce a
match. This serves two functions against a mismatched load:
1. Delivery of optimal power;
2. Reduce the risk of added heat burden to the source.

73's
Richard Clark, KB7QHC