"Reg Edwards" wrote in message ...

When the line is not lossless, ie., it has appreciable
attenuation in dB per 1/4-wavelength, then the ratio is
'distorted' and has a phase angle. So negative values
of indicated SWR can be expected at some values of |
Vmax | / | Vmin |


What are you talking about? If it have losses, and they
are dissipative losses, the amplitude of the voltage will
decrease due to voltage drops. That would be moving AWAY
from having a greater reflected voltage than an incident one.

But, that's impossible anyways with a passive network.

The concept of Negative SWRs is rubbish.

SWR is calculated from the square of | rho |. As I've
said before, immediately | rho | is squared, half the
information it contains is junked. Any
discussion/argument about power waves following
rho-squared on a lossy (a real ) line is meaningless
piffle.

Anybody who writes books about power waves, selling
them to make a living, is obtaining money under false
pretences.

On the other hand we should be kind to otherwise
unemployed Ph.D's. They too have wive's and kid's to
clothe, feed and provide a roof over their heads.
That's life!
---
Reg.

Remind me not to be YOUR book when it comes out!



The ratio Pref/Pfwd is directly related to the ratio [rho].

Pref/Pfwd = [rho]**2 Absolute value brackets are a must!


Consider that after the absolute value brackets, the phase information
is gone. But since we are going to a ratio of average (RMS)
values OR peak values of power, it doesn't matter.

In other words, if you use V**2/R, the "V" can be either peak or
RMS, it doesn't matter, because it is a ratio. And of course, the "R"
doesn't matter either. And of course, the phase information is gone
with
the absolute value brackets.

If you agree that the Pref/Pfwd ratio cannot be greater than 1
for a passive network, then neither can the [Vref/Vfwd]= rho be
greater
than 1 either.

Some people wanna rewrite some books here.


Slick

If the loss per unit wavelength is large enough, and you produced a plot of
voltage vs. distance x. The voltage maximum would be at the source, and the
voltage minimum at the load. Try a thousand miles or so of RG58 at 60 Hz.
I suspect that to see anything that looks like a standing wave you would
have to look at dV/dx. Remember, I can always define a lossier line.

Tam/WB2TT