Cecil Moore wrote:


It seems that whatever part of the system you don't
understand, you draw a black box around it so you
don't have to understand it.


Cecil,

Interesting comment, especially since you frequently reference
s-parameter analysis.

A direct quote from AN-95-1, the slide version, is:

Two-port, three-port, and n-port models simplify the input / output
response of active and passive devices and circuits into "black boxes"
described by a set of four linear parameters.

If you deny the legitimacy of "black boxes" do you need to give up the
use of s-parameters?

73,
Gene
W4SZ

Gene Fuller wrote:
A direct quote from AN-95-1, the slide version, is:

Two-port, three-port, and n-port models simplify the input / output
response of active and passive devices and circuits into "black boxes"
described by a set of four linear parameters.

Thank you, Gene. That contradicts what you said before
about the black box not being allowed to have two of
the four terminals on the other side. Play silly games
with the facts and you tend to get caught.

If you deny the legitimacy of "black boxes" do you need to give up the
use of s-parameters?

No, you need to give up your assertion that a four-
terminal black box doesn't have two terminals on
the other side. Your black box and HP's are two
entirely different concepts.

HP puts a black box around a 4-terminal network to
enhance understanding of the contents of the black
box. You put a black box around a stub to promote
ignorance of the contents of the black box.

I have said before. Specify that the black boxes be
supplied with the four measured s-parameters stamped
on them and I can probably tell you which box is which
without even applying a signal.

Or, more logically, forget the black box entirely since
it is totally irrelevant to the subject being discussed.

Exactly what is it that you think you have proved by
using black boxes. Please be specific.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
A direct quote from AN-95-1, the slide version, is:

Two-port, three-port, and n-port models simplify the input / output
response of active and passive devices and circuits into "black boxes"
described by a set of four linear parameters.

Thank you, Gene. That contradicts what you said before
about the black box not being allowed to have two of
the four terminals on the other side. Play silly games
with the facts and you tend to get caught.

If you deny the legitimacy of "black boxes" do you need to give up the
use of s-parameters?

No, you need to give up your assertion that a four-
terminal black box doesn't have two terminals on
the other side. Your black box and HP's are two
entirely different concepts.

HP puts a black box around a 4-terminal network to
enhance understanding of the contents of the black
box. You put a black box around a stub to promote
ignorance of the contents of the black box.

I have said before. Specify that the black boxes be
supplied with the four measured s-parameters stamped
on them and I can probably tell you which box is which
without even applying a signal.

Or, more logically, forget the black box entirely since
it is totally irrelevant to the subject being discussed.

Exactly what is it that you think you have proved by
using black boxes. Please be specific.

I said no such thing about "black boxes" being unable to have more than
two terminals. What I said is that the "black boxes" defined by Keith
and Roy have only two terminals.

If you want to drift off into some other irrelevant chatter, go right
ahead. It might make you feel good, but it won't change the real world.

Gene Fuller wrote:
I said no such thing about "black boxes" being unable to have more than
two terminals. What I said is that the "black boxes" defined by Keith
and Roy have only two terminals.

But the "black boxes" defined by me have either two
terminals or four terminals. Here they are again:

--43.4 deg 600 ohm line--+--10 deg 100 ohm line--open

--43.4 deg 600 ohm line--+--46.6 deg 600 ohm line--open

--43.4 deg 600 ohm line--+--j567 impedor

The black boxes are drawn around the '+' point just as
I said before. That makes the first two examples four-
terminal networks and the last example a two-terminal
network.

Now tell us again how s11, s12, s21, and s22 are identical
for those three black boxes.
--
73, Cecil http://www.w5dxp.com

Gene Fuller wrote:
If you want to drift off into some other irrelevant chatter, go right
ahead. It might make you feel good, but it won't change the real world.

As if imaginary black boxes exist in the real world. :-)
Get real, Gene. Any black box you provide, I can open.
--
73, Cecil http://www.w5dxp.com

Gene Fuller wrote:
Cecil Moore wrote:


It seems that whatever part of the system you don't
understand, you draw a black box around it so you
don't have to understand it.


Cecil,

Interesting comment, especially since you frequently reference
s-parameter analysis.

A direct quote from AN-95-1, the slide version, is:

Two-port, three-port, and n-port models simplify the input / output
response of active and passive devices and circuits into "black boxes"
described by a set of four linear parameters.

If you deny the legitimacy of "black boxes" do you need to give up the
use of s-parameters?

This is simply a diversion to deflect the discussion away from the
sticky questions about "electrical degrees" which his theory is unable
to resolve. Phase reference is another, and we can expect more.

Roy Lewallen, W7EL

Roy Lewallen wrote:
This is simply a diversion to deflect the discussion away from the
sticky questions about "electrical degrees" which his theory is unable
to resolve. Phase reference is another, and we can expect more.

There were no black boxes in the original example so the
black box was the original diversion. Coming back from that
diversion, can you calculate the current amplitude and phases
in the original example? I would be very surprised if you
could do it. I would be even more surprised if you did it
and published the results. Roy, here's your chance to nail
me to the wall. Simply prove that the phase shift between
Vfor1 and Vfor2 below is something other than 36.6 degrees.
(All of Roy's worshipers hold their breath for a response. :-)

This is not "my" theory - this is standard distributed
network reflection theory that I learned at Texas A&M
in the 50's. And the theory is certainly capable of
resolving the electrical degree problems.

Here's the original example again - no black box necessary.

--43.4 deg 600 ohm line--+--10 deg 100 ohm line--open
Vfor1--|--Vfor2

Assuming 100v at 0 deg incident upon the open at the
end of the stub, what is the phase shift between
Vfor1 and Vfor2?

Vfor2 = 100v at -10 deg
Vfor1 = 143.33v at -46.4 deg

The phase shift between Vfor1 and Vfor2 is 36.6 degrees just
as predicted originally. Roy, you are always advising me to
use voltages so I did. The results are easy to verify if you
know how. But I don't think you know how.

Everyone is invited to use any valid model you want to and
prove me either right or wrong.

I predict that Roy will be silent on this subject and rely
on his political power to try to suppress those results.
The emperor has no clothes. The emperor's worshipers have
no clothes.
--
73, Cecil http://www.w5dxp.com