wrote in message ...

And yes, |rho| can be greater than unity for a passive load.

...Keith


Absolute Rubbish.. Could you produce a passive circuit that
will reflect a greater voltage than what you feed it? I'd
LOVE to see that...


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

"Dr. Slick" wrote:

wrote in message ...

And yes, |rho| can be greater than unity for a passive load.

...Keith

Absolute Rubbish.. Could you produce a passive circuit that
will reflect a greater voltage than what you feed it? I'd
LOVE to see that...

Several examples have been presented, but rather than accepting
them, you changed the definition of rho. Perhaps you could build
one of these circuits to determine if modifying the definition
of rho was appropriate.

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

Which I haven't since Pref and Pfwd are just computed numbers and
the result for some circuits is that Pref/Pfwd is greater than 1.
Of course, Pnet is not equal to Pfwd-Pref in these circumstances
so there is no violation of basic physics. It is just that the
computation of Pfwd and Pref does not really produce real powers
(though, again unfortunately, the dimension of the quantity produced
is power).

for a passive network, then neither can the [Vref/Vfwd]= rho be
greater
than 1 either.

....Keith

wrote:
It is just that the
computation of Pfwd and Pref does not really produce real powers
(though, again unfortunately, the dimension of the quantity produced
is power).

Funny how they can heat resistors both at the load end and at the source
end when the source is equipped with a circulator+load.

Incidentally, I've come up with a proof that there are no reflections
at a voltage null in a homogeneous transmission line. Consider a 50
ohm lossless feedline. At a voltage null -

rho = (50-50)/(50+50) = 0 i.e. no reflections in either direction
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Cecil Moore wrote:

wrote:
It is just that the
computation of Pfwd and Pref does not really produce real powers
(though, again unfortunately, the dimension of the quantity produced
is power).

Funny how they can heat resistors both at the load end and at the source
end when the source is equipped with a circulator+load.

Not surprising. The energy comes from the source.

Incidentally, I've come up with a proof that there are no reflections
at a voltage null in a homogeneous transmission line. Consider a 50
ohm lossless feedline. At a voltage null -

rho = (50-50)/(50+50) = 0 i.e. no reflections in either direction

That's what you get when you use the surge impedance and compute
surge rho. Try steady state impedance for steady state rho.

rho = (0-50)/(0+50) = -1 as expected

....Keith

wrote:
That's what you get when you use the surge impedance and compute
surge rho. Try steady state impedance for steady state rho.

rho = (0-50)/(0+50) = -1 as expected

Heh, heh, the steady state impedances are V/I ratios which are results
incapable of causing anything. Your logic is a closed loop. The V/I ratios
cause the rho to be -1. Therefore, rho=-1 causes the appropriate V/I ratios.
Can you name any other result in reality that causes itself? Hint: Only
physical impedance discontinuities can cause reflections. Image impedances
are incapable of causing anything since they are an end result.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Cecil Moore wrote:

wrote:
That's what you get when you use the surge impedance and compute
surge rho. Try steady state impedance for steady state rho.

rho = (0-50)/(0+50) = -1 as expected

Heh, heh, the steady state impedances are V/I ratios which are results
incapable of causing anything. Your logic is a closed loop. The V/I ratios
cause the rho to be -1. Therefore, rho=-1 causes the appropriate V/I ratios.
Can you name any other result in reality that causes itself? Hint: Only
physical impedance discontinuities can cause reflections. Image impedances
are incapable of causing anything since they are an end result.

Was it not only a few days ago that there was agreement that

If it is acceptable to claim that sometimes there is no reflection
at an impedance discontinuity, then it must also be acceptable to
claim that sometimes there is a reflection where there is no
discontinuity.

?

....Keith

Cecil:

[snip]
rho = (50-50)/(50+50) = 0 i.e. no reflections in either direction
--
73, Cecil http://www.qsl.net/w5dxp
[snip]

Hey... that's my line.

That's Mother Nature's reflection coefficient!

At every infinitesimal length along a transmission line rho = (Zo - Zo)/(Zo
+ Zo) = 0.

It's not nice to fool Mother Nature!

--
Peter K1PO
Indialantic By-the-Sea, FL.

wrote in message ...

And yes, |rho| can be greater than unity for a passive load.

...Keith

Absolute Rubbish.. Could you produce a passive circuit that
will reflect a greater voltage than what you feed it? I'd
LOVE to see that...

Several examples have been presented, but rather than accepting
them, you changed the definition of rho. Perhaps you could build
one of these circuits to determine if modifying the definition
of rho was appropriate.



The definition of Rho has been set for "God-knows-how-long!"

Way before you or I were born, i would imagine!

Rho is the magnitude of Gamma, which is the complex voltage
reflection coefficient.

BUT, some people write Gamma is Rho, so just in case, it's wise
to say Power RC = [rho]**2 , with absolute value brackets.

Ok, show us a circuit, I'm waiting to see.



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

Which I haven't since Pref and Pfwd are just computed numbers and
the result for some circuits is that Pref/Pfwd is greater than 1.
Of course, Pnet is not equal to Pfwd-Pref in these circumstances
so there is no violation of basic physics. It is just that the
computation of Pfwd and Pref does not really produce real powers
(though, again unfortunately, the dimension of the quantity produced
is power).


ok, Keith, i look forward with great interest on your
imaginary passive circuit which can reflect more power than
what you feed it (incident power).

I can't wait to hook it up to see more reflected power than
incident on my DAIWA meter, that would be very interesting.


Slick

Dr. Slick wrote:
The definition of Rho has been set for "God-knows-how-long!"

Actually, 'rho' has contradictory definitions. (Z2-Z1)/(Z2+Z1)
is not always the same value as Sqrt(Pref/Pfwd) because of
interference energy.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Slick:

[snip]
I can't wait to hook it up to see more reflected power than
incident on my DAIWA meter, that would be very interesting.


Slick
[snip]

It sure will be an interesting event for your Daiwa when the transmitter
hooked to the other end is keyed!

--
Peter K1PO
Indialantic By-the-Sea, FL.