On Dec 17, 7:10 pm, Cecil Moore wrote:
Gene Fuller wrote:
As usual you have twisted the question so that you can provide some type
of answer. You still have not answered the original question posed by
Keith.

What was that question? I suspect the question was irrelevant
because Keith didn't understand what phase shift I was talking
about. I also suspect that Keith is beginning to understand
what I am talking about. His silence seems a little strange.

Snow storm - ski
ski - sleep
ISP then breaks DSL - no conectivity
ISP breaks PC IP stack while restoring connectivity - time spent
fixing IP stack
time spent fixing IP stack - employer's work not getting done
employer's work not getting done - reduction of free time
reduction of free time - no r.r.a.a

....Keith

Jim Kelley wrote:
Let me ask you this: how would you go about calculating the phase shown
on your Standing Wave Current graph, and what meaning if any does it
hold for you?

Kraus already did it for us. Note the relative phase
graph.

http://www.w5dxp.com/krausdip.jpg

The phase shown on my Standing Wave Current graph is
the phase relative to the source phase. For a pure
standing wave on a 1/4WL wire, the standing wave current
phase is everywhere equal to the source current phase.
That's why it cannot be used to "measure" the delay
through a wire or through a coil.
--
73, Cecil http://www.w5dxp.com

Gene Fuller wrote:
If the currents were referenced to the source phase,
they would not change when the source phase was changed.

You cannot be serious.
--
73, Cecil http://www.w5dxp.com

On Tue, 18 Dec 2007 22:03:12 -0500, "AI4QJ" wrote:

I am trying OpenDX right now. I am new to x windows and I am trying to
figure out a windows interface called cygwin...stay tuned, this could take a
while.

Hi Dan,

The trick with cygwin is that the interface you connect to first, and
download, is a package manager. Once you have that installed, you
then need to run it and select the right packages - mostly X11 and
XFree86.

Welcome to _Nix.

73's
Richard Clark, KB7QHC

Keith Dysart wrote:
But the rules for black boxes do not allow measurements
on the inside. This is how they help clarify the thinking.

I've not disagreed about anything happening outside
the black boxes. I am only interested in what is
happening inside so I am getting rid of the black
boxes. They are a silly unnecessary handicap.

since the problem can be solved without the information.

You haven't solved the problem yet with no black box.

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

What is the phase shift between Vfor1 and Vfor2? I
solved it for you already.
--
73, Cecil http://www.w5dxp.com

Keith Dysart wrote:
But the rules for black boxes do not allow measurements
on the inside. This is how they help clarify the thinking.

So instead of sweeping technical facts under the rug,
you hide them in a black box. In both cases, the only
apparent purpose is to maintain ignorance.

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.

So I ask you once again, given the following two stubs:

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

--43.4 deg 600 ohm line--+--46.6 deg 600 ohm line--open
Vfor1--|--Vfor2

What are the phase shifts between Vfor1 and Vfor2 for
the two cases?
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
If the currents were referenced to the source phase,
they would not change when the source phase was changed.

You cannot be serious.

I am dead serious. You need to think about this a bit more.

Why would something "referenced to the source phase" change when that
source itself was changed? This is no different than the elementary
example of walking in a train car. One's speed relative to the seats
does not change simply because the train is traveling at a different
speed on the rails.

What does your IEEE dictionary say about the meaning of "referenced to"?

73,
Gene
W4SZ

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:
Why would something "referenced to the source phase" change when that
source itself was changed?

In my EZNEC examples the source current reference
phase is zero and all the currents at the various
points are referenced to that zero source phase.

If the source current phase is changed, the phase
of all the currents at the various sampling points
change.

In TravWave.EZ, the current is sampled by a zero
ohm load in segment 10 of the wire.

Source phase Seg 10 phase
0 deg -47.82 deg
-10 deg -57.82 deg
+10 deg -37.82 deg

The current in Seg 10 is clearly referenced to the
phase of the source and obviously lags the source
phase by 47.82 degrees.
--
73, Cecil http://www.w5dxp.com

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