Richard Harrison wrote:
If I recall, he said a short on a line vitiates capacitance at that
point. It shorts it out.

But there is NO actual short. The ratio of voltage to current is not
even zero. The ratio of voltage to current at a Z0-match point is Z0.

The discontinuity is essential to the turnaround.

Exactly! That's how b1 = s11*a1 + s12*a2 gets to equal zero. s11*a1 and s12*a2
are both reflections from the physical impedance discontinuity. No "virtual
short" required. s11*a1 and s12*a2 are reflections that are equal in magnitude
and opposite in phase.
--
73, Cecil http://www.qsl.net/w5dxp
"One thing I have learned in a long life: that all our science, measured against
reality, is primitive and childlike ..." Albert Einstein



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----

Cecil, W5DXP wrote:
"The ratio of voltage to current at a Zo-match point is Zo."

There is one voltage at a match point produced by the waves arriving
from opposite directions.

There is one power, the power delivered by the transmitter, feeding the
match point. The same power total flows from the match point to the
load. It`s the forward power minus the reflected power.

Though there is but one voltage at the match point, it is clear that the
currents in lines connected at the match are not equal because the Zo`s
of the connected lines are not equal.

We need the reflected power to reconcile our mismatch. The mismatch is a
catalyst that makes a reflection happen.

Say Zo is 150 ohms. 100 watts into Zo is 123.5 volts. 10 watts facing
the 100 watts presents 38.7 volts. Power direction is determined by the
123.5 volt source, not by the 38.7 volt reflection, at the match point.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:
Say Zo is 150 ohms. 100 watts into Zo is 123.5 volts.

I get 122.5 volts. :-)

10 watts facing
the 100 watts presents 38.7 volts. Power direction is determined by the
123.5 volt source, not by the 38.7 volt reflection, at the match point.

Essentially all you are saying is that net energy flows from the source
to the load. I agree but it has nothing to do with "facing off". Coherent
voltage waves flowing in opposite directions are unaffected by each other.
Coherent voltage waves flowing in the same direction merge into one wave.
The events that happens at an impedance discontinuity are reflections which
causes coherent waves to flow in the same direction and therefore merge. It
is explained in my part 1 article on my web page.
--
73, Cecil http://www.qsl.net/w5dxp
"One thing I have learned in a long life: that all our science, measured against
reality, is primitive and childlike ..." Albert Einstein



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----

Cecil, W5DXP wrote:
"I get 122.5 volts."

Dang cheap Chinese calculator operator!
Cecil is correct.

Cecil also wrote:
"Coherent voltage waves flowing in opposite directions are unaffected by
each other."

I agree, except at an impedance bump which shakes things up. Incoherent
voltage waves flowing in opposite directions are also unaffected by each
other. :-)

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:

Cecil, W5DXP wrote:
"I get 122.5 volts."

Dang cheap Chinese calculator operator!
Cecil is correct.

Cecil also wrote:
"Coherent voltage waves flowing in opposite directions are unaffected by
each other."

I agree, except at an impedance bump which shakes things up.

Yes, and what we are discussing is exactly how an impedance bump
shakes things up.
--
73, Cecil http://www.qsl.net/w5dxp
"One thing I have learned in a long life: that all our science, measured against
reality, is primitive and childlike ..." Albert Einstein



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----