On Jun 25, 5:53*am, dave wrote:
try it! *you will read the exact same voltage on either side of that
connection point!

I already told you that only applies to the total voltage and total
current. You will NOT read the same forward voltage on either side,
you will NOT read the same forward current on either side, you will
NOT read the same reflected voltage on either side, and you will NOT
read the same reflected current on either side. The total voltage and
total current are the results of the superposition of the four
component voltages and currents that obey the rules of wave reflection
mechanics. Recognizing the interference patterns when two phasor
voltages are superposed is the key to understanding exactly what is
happening to the energy in the waves. At an impedance discontinuity in
a transmission line some distance from any active source, the average
destructive interference power in one direction MUST equal the average
constructive interference power in the opposite direction in order to
avoid a violation of the conservation of energy principle.

So why isn't the forward current flowing into the impedance
discontinuity equal to the forward current flowing out of the
impedance discontinuity? The answer to that question will solve Walt's
apparent contradiction between voltages and powers. Look at the Z0-
match again.

source--50 ohm--+--1/2WL Z050 ohm--50 ohm load

The total current on the 50 ohm side of point '+' is equal to the
total current on the Z050 ohm side but the current on the 50 ohm side
is a flat traveling wave *constant* current while the current on the
Z050 ohm side is a standing-wave current maximum, i.e. the total
current on the Z050 ohm side is a *variable* that changes with a
change in the measurement point. A variable current is NOT the same as
a constant current.

The total voltage on the 50 ohm side is a flat traveling wave
*constant* voltage while the voltage on the Z050 ohm side is a
standing wave voltage minimum, i.e. the total voltage on the Z050 ohm
side is a *variable* that changes with a change in the measurement
point.

The power on the 50 ohm side is V*I where V and I are constant values.
The power on the Z050 ohm side is V*I*cos(A) where A is the angle
between the current phasor and the voltage phasor and, because of the
standing waves, all three parameters vary with location on the
feedline.
--
73, Cecil, w5dxp.com

On Jun 25, 1:18*pm, Cecil Moore wrote:
On Jun 25, 5:53*am, dave wrote:

try it! *you will read the exact same voltage on either side of that
connection point!

I already told you that only applies to the total voltage and total
current. You will NOT read the same forward voltage on either side,
you will NOT read the same forward current on either side, you will
NOT read the same reflected voltage on either side, and you will NOT
read the same reflected current on either side.

when someone gives me a voltmeter i can touch to that connection point
and measure the 4 components then we can talk. as far as designing
anything i need i can do it without giving those s parameters or your
4 components a second thought. it is very easy to transform and
combine the impedances to tell me what the load seen by the
transmitter is, or to figure out the needed stub for providing a
proper match without all that stuff.

On Jun 26, 6:43*am, dave wrote:
when someone gives me a voltmeter i can touch to that connection point
and measure the 4 components then we can talk.

I could design an expensive device that will do exactly that but it is
a lot easier to just calculate the values using Mathcad.
--
73, Cecil, w5dxp.com