"Cecil Moore" wrote in message
...
Tam/WB2TT wrote:
I am not quite sure what you are saying. But, I ran a SPICE simulation
of
the following:
1V 1MHz source with resistor R0 feeding a 50 Ohm 250 ns transmission
line
shorted at the far end. Independent of R0, in steady state the voltage
at
the input end of the transmission line will be 1V. The effect of R0 is
to
limit how long it takes to reach steady state. For R0 = 50 Ohms, it is
one
cycle; for R0 = 500 Ohms, it is about 8 cycles, as eyeballed off the
waveform display.

Does SPICE report the steady-state forward and reflected waves
or just the superposition of those two waves? We all know what
they look like when superposed. The question is whether the
identity of the forward and reflected waves disappear after
they are superposed. To the best of my knowledge, the very
existence of standing waves requires the existence of a forward-
traveling wave and a rearward-traveling wave.

I have asked for examples of standing waves void of rearward-
traveling waves and none has been forthcoming.
--
73, Cecil http://www.qsl.net/w5dxp
It shows the composite voltage waveform, and the net current. Exactly what a
Bird wattmeter would do. Of course the Bird only shows you steady state,
Spice (SWCAD) swhows how you got there.

Tam/WB2TT