Cecil Moore wrote:

I(x,t) = Imax sin(kx) cos(wt)

For any point location 'x', it can be seen that the standing
wave current is not "flowing" in the ordinary sense of the word
but rather, is just oscillating in place at that fixed point.

According to the equation you provide above, for any point location
'x', the phase of the current varies continuously with t. Presumably
that is what it means to just oscillate in place.

73, ac6xg

Jim Kelley wrote:
Cecil Moore wrote:

I(x,t) = Imax sin(kx) cos(wt)

For any point location 'x', it can be seen that the standing
wave current is not "flowing" in the ordinary sense of the word
but rather, is just oscillating in place at that fixed point.

According to the equation you provide above, for any point location 'x',
the phase of the current varies continuously with t. Presumably that is
what it means to just oscillate in place.

Of course, that's what it means. It doesn't move right or left.
I(x,t) = Imax sin(kx) cos(-wt) would be just as accurate a
description. One cannot even tell which way the standing-wave
phasor is rotating. This equates to putting the source
on either end of a lossless stub without anything changing.
Standing-wave current phase is unchanging up and down a lossless
stub. Standing-wave current phase changes hardly at all up and
down a stub with losses or a wire 1/2WL dipole. That current
cannot be used to obtain a valid delay through a wire or a coil.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Jim Kelley wrote:

Cecil Moore wrote:

I(x,t) = Imax sin(kx) cos(wt)

Standing-wave current phase changes hardly at all up and
down a stub with losses or a wire 1/2WL dipole.

That is correct to the same extent that t in the equation above
"changes hardly at all" with time.

73, ac6xg

Jim Kelley wrote:
Cecil Moore wrote:
Jim Kelley wrote:

Cecil Moore wrote:

I(x,t) = Imax sin(kx) cos(wt)

Standing-wave current phase changes hardly at all up and
down a stub with losses or a wire 1/2WL dipole.

That is correct to the same extent that t in the equation above "changes
hardly at all" with time.

t changes hardly at all referenced to the source current
phase which is what we are talking about. Please don't
try to feign ignorance of that fact. What I don't get is
why people like you have to distort the technical facts.
What do you possibly have to gain through distortion and
diversion?
--
73, Cecil http://www.w5dxp.com

Jim Kelley wrote:
Cecil Moore wrote:
Jim Kelley wrote:

Cecil Moore wrote:

I(x,t) = Imax sin(kx) cos(wt)

Standing-wave current phase changes hardly at all up and
down a stub with losses or a wire 1/2WL dipole.

That is correct to the same extent that t in the equation above "changes
hardly at all" with time.

The phase is referenced to the source phase, as it is in EZNEC,
but you already knew that and just want to perform your usual
diversions away from the technical facts.

I have said at least a dozen times that the current phase
I am talking about is the same as EZNEC reports. If you don't
like what EZNEC reports, take it up with Roy.

For those who don't understand Jim's diversion above, EZNEC
sets t=zero as a reference and then reports the phase. Jim
knows that and is just trying to hoodwink the uninitiatated.
His motives for such remain a mystery.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:

Jim Kelley wrote:

Cecil Moore wrote:

Jim Kelley wrote:

Cecil Moore wrote:

I(x,t) = Imax sin(kx) cos(wt)


Standing-wave current phase changes hardly at all up and
down a stub with losses or a wire 1/2WL dipole.


That is correct to the same extent that t in the equation above
"changes hardly at all" with time.


The phase is referenced to the source phase, as it is in EZNEC,
but you already knew that and just want to perform your usual
diversions away from the technical facts.

Actually, I'm trying to figure out what technical meaning there is to
be obtained from your repeated observation "Standing-wave current
phase changes hardly at all up and down a stub with losses or a wire
1/2WL dipole." The phase of the standing wave varies with position
from one perspective, and with time from another, and with amplitude
from yet another. If you hold t fixed, then amplitude and position
remain variable. This is a revelation?

I have said at least a dozen times that the current phase
I am talking about is the same as EZNEC reports. If you don't
like what EZNEC reports, take it up with Roy.

One should be careful not to invite comparisons to a craftsman holding
his tools responsible for poor craftsmanship. ;-)

73, ac6xg

Jim Kelley wrote:


Cecil Moore wrote:

. .
The phase is referenced to the source phase, as it is in EZNEC,
but you already knew that and just want to perform your usual
diversions away from the technical facts.

The current reported by EZNEC isn't referenced to source phase. The
phases of all currents and voltages -- wire, source, and load -- are all
referenced to the same arbitrary point. Source phase can be assigned by
the user to any value relative to this point.

Actually, I'm trying to figure out what technical meaning there is to be
obtained from your repeated observation "Standing-wave current phase
changes hardly at all up and down a stub with losses or a wire 1/2WL
dipole." The phase of the standing wave varies with position from one
perspective, and with time from another, and with amplitude from yet
another. If you hold t fixed, then amplitude and position remain
variable. This is a revelation?

I have said at least a dozen times that the current phase
I am talking about is the same as EZNEC reports. If you don't
like what EZNEC reports, take it up with Roy.

As far as I can tell, Cecil has never been quite able to understand just
what EZNEC reports. EZNEC doesn't need several different definitions of
current to suit the theory du jour or to do its job, so it doesn't
report "standing wave current" or other fruits of The Gifted One's
overly fertile imagination. It simply reports current. Anyone not
acquainted with this concept can refer to any basic text on electricity
or physics. What EZNEC reports is exactly what you'll find there.

Roy Lewallen, W7EL

Roy Lewallen wrote:
Jim Kelley wrote:

Cecil Moore wrote:
. . The phase is referenced to the source phase, as it is in EZNEC,
but you already knew that and just want to perform your usual
diversions away from the technical facts.

The current reported by EZNEC isn't referenced to source phase. The
phases of all currents and voltages -- wire, source, and load -- are all
referenced to the same arbitrary point. Source phase can be assigned by
the user to any value relative to this point.

The phase assigned by the user to the source obviously becomes
the default reference phase. What on earth do you have to gain
by obscuring that technical fact?

If the user doesn't do anything, the source phase defaults to zero
and all current measurements are referenced to that zero source
phase. Are you so determined to discredit me that you are willing
to sacrifice your integrity in the process?

Do you deny that there is virtually no phase shift in the current
up and down a 1/2WL dipole referenced to the source current. If you
are up to that denial, please argue with Kraus's graphic. Take a look
at the phase angles at:

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

Unfortunately, Kraus agrees with EZNEC and that current is
exactly what you used to make your meaningless measurements
of current phase through a loading coil. So please look at
Kraus's graph and tell us again how that current with unchanging
phase can be used to measure phase shift through a loading coil.

As far as I can tell, Cecil has never been quite able to understand just
what EZNEC reports. EZNEC doesn't need several different definitions of
current to suit the theory du jour or to do its job, so it doesn't
report "standing wave current" or other fruits of The Gifted One's
overly fertile imagination. It simply reports current.

My point exactly! If the antenna being modeled is a standing-wave
antenna, EZNEC reports standing-wave current.

If the antenna being modeled is a traveling-wave antenna, EZNEC
reports traveling-wave current. Roy apparently doesn't want anyone
to know this fact.

So Roy, why would the phase shift through a coil be different
when it is used in a 1/2WL dipole vs using it in a rhombic
at the same frequency??? Magic???

Roy has threatened to take EZNEC away from me for using it to
demonstrate traveling-wave current through a loading coil. Here
is what EZNEC says about the delay through that loading coil.

http://www.w5dxp.com/coil512.ez

Click on "Load Dat" and observe what Roy is so afraid that
someone besides me is going to discover.
--
73, Cecil http://www.w5dxp.com

Roy Lewallen wrote:
The current reported by EZNEC isn't referenced to source phase.

If the source phase is set to zero and I want EZNEC to reference
the antenna currents to 77 degrees, how would I go about that?
--
73, Cecil http://www.w5dxp.com

Roy Lewallen wrote:
The current reported by EZNEC isn't referenced to source phase. The
phases of all currents and voltages -- wire, source, and load -- are all
referenced to the same arbitrary point. Source phase can be assigned by
the user to any value relative to this point.

I'm sorry, Roy, I just changed the source phase in a single
source system and changed nothing else. The reported phase of
the antenna currents changed in step with the source phase.
Since all you did was provide a GUI interface to NEC, might
it be possible that you don't understand how NEC works?
--
73, Cecil http://www.w5dxp.com