1/4WL XMFR Vectors

W6RCecilA

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Jun 20, 1998, 3:00:00 AM6/20/98

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I have created a graphic of the vectors associated with a quarter-wave
series section transformer. Anyone interested in the subject, please
review what I posted and point out any error I might have made. Once
any errors are corrected, this graphic should give all of us a common
picture about which to talk. I made it 8"x10" and therefore easy to
print. Advanced thanks for any input y'all can give me.
--
73, Cecil, W6RCA http://people.delphi.com/CecilMoore/qwlxmfr.htm

Gary Coffman

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Jun 21, 1998, 3:00:00 AM6/21/98

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You have the vectors at the source end of the 300 ohm section drawn
in the wrong direction. They should be longitudinal with the line, just as
you show them at the load end. All current and voltage waves move
longitudinally on the line. They can't move off at right angles to the line.

W6RCecilA

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Jun 21, 1998, 3:00:00 AM6/21/98

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Gary Coffman wrote:
> You have the vectors at the source end of the 300 ohm section drawn
> in the wrong direction. They should be longitudinal with the line, just as
> you show them at the load end. All current and voltage waves move
> longitudinally on the line. They can't move off at right angles to the line.

Gary, there were errors on the original but that wasn't one of them. A vector
can have any phase on a horizontal wire and the phase is just an arbitrary
reference point. You statement is just plain stupid. Please reference the
updated diagram dated 6-21-98. On the original I forgot I was dealing with
a 1/4WL instead of a 1/2WL series section.

W6RCecilA

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Jun 21, 1998, 3:00:00 AM6/21/98

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DavidC wrote:
>
> Someone recently wrote to someone else on this newsgroup:

> > You statement is just plain stupid.
>

> OK guys, please play nice or you will be sent to summer school and assigned
> to read and submit a book report on "Everything I Need To Know I Learned In
> Kindergarten". :-)

Note that I didn't call the person stupid - just the statement. Saying
that a vector cannot have a phase angle of 90 degrees in a horizontal
wire is a stupid statement.

DavidC

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Jun 22, 1998, 3:00:00 AM6/22/98

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Someone recently wrote to someone else on this newsgroup:
> You statement is just plain stupid.

OK guys, please play nice or you will be sent to summer school and assigned
to read and submit a book report on "Everything I Need To Know I Learned In
Kindergarten". :-)

73, DavidC AA1FA

W6RCecilA

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Jun 22, 1998, 3:00:00 AM6/22/98

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W6RCecilA wrote:
> A vector can have any phase on a horizontal wire and the phase is
> just an arbitrary reference point.

Bart pointed out that the confusion may be between spatial
vectors and temporal vectors, i.e. phasors, and of course,
the phase of a temporal vector has nothing to do with the
physical orientation of the wire that is carrying it.
Thanks Bart, and I apologize to Gary for calling his statement
"stupid". We all make stupid statements from time to time.
--
73, Cecil, W6RCA http://people.delphi.com/CecilMoore/qwlxmfr.htm

Gary Coffman

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Jun 22, 1998, 3:00:00 AM6/22/98

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On Mon, 22 Jun 1998 07:11:36 -0700, W6RCecilA <w6...@ibm.net> wrote:
>W6RCecilA wrote:
>> A vector can have any phase on a horizontal wire and the phase is
>> just an arbitrary reference point.
>
>Bart pointed out that the confusion may be between spatial
>vectors and temporal vectors, i.e. phasors, and of course,
>the phase of a temporal vector has nothing to do with the
>physical orientation of the wire that is carrying it.
>Thanks Bart, and I apologize to Gary for calling his statement
>"stupid". We all make stupid statements from time to time.

Apology accepted, Cecil. Since we had been talking about
voltage and current waves in the forward and reverse directions,
I naturally assumed that's what you were trying to draw. Phasors
are a different animal. I would note that it is conventional to
have T0 (0 degrees) on the left, and have it increment toward
the right. Putting T0 on the right added to the confusion.

W6RCecilA

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Jun 22, 1998, 3:00:00 AM6/22/98

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Gary Coffman wrote:
> I would note that it is conventional to
> have T0 (0 degrees) on the left, and have it increment toward
> the right. Putting T0 on the right added to the confusion.

I've been doing DSP unit circles for so long with Ų degrees to
the right and the vector rotating counter-clockwise that I have
a hard time remembering the other conventions.

W6RCecilA

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Jun 24, 1998, 3:00:00 AM6/24/98

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Gary Coffman wrote:
> I would note that it is conventional to
> have T0 (0 degrees) on the left, and have it increment toward
> the right. Putting T0 on the right added to the confusion.

Well, "Transmission Lines and Networks" by Walter C. Johnson shows
the rotating vector with t=Ø to the right and omega*t increasing
counter-clockwise just like the unit circle. This seems to be
standard graphics for the e to the j*omega*t signals illustrated
in my diagram.
--
73, Cecil, W6RCA http://people.delphi.com/CecilMoore/qwlxmfr.htm