colinear representation in NEC
 

Jim Kelley wrote:
It's no coincidence that the phase of the standing wave varies by 90
degrees along the length of a 90 degree standing wave antenna.

But it doesn't, Jim. Both Kraus and EZNEC agree that
standing wave current phase varies by only ~3 degrees
over the entire length of a 180 degree wire dipole
(referenced to the phase at the feedpoint).

If you slide a current probe up and down a 1/2WL wire
dipole, you will find that the phase referenced to
the phase at the feedpoint barely changes and cannot
be used to determine position on the dipole. The
position along the dipole is contained in the amplitude.
The ARCCOS of the relative amplitude will yield the
position along the dipole.

Please read what Gene Fuller said:

Gene Fuller, W4SZ wrote:
In a standing wave antenna problem, such as the one you describe,
there is no remaining phase information. Any specific phase
characteristics of the traveling waves died out when the startup
transients died out.

Phase is gone. Kaput. Vanished. Cannot be recovered. Never to be
seen again.

The only "phase" remaining is the cos (kz) term, which is really
an amplitude description, not a phase.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

colinear representation in NEC
 

Jim Kelley wrote:
It's no coincidence that the phase of the standing wave varies by 90
degrees along the length of a 90 degree standing wave antenna.

Here's the phase of the standing wave along 90 degrees
of monopole as reported by EZNEC. Clearly, your assertion
is false as the current phase varies by only 2.62 degrees
between segment 1 and segment 10.

1/4WL Vertical over real gnd 4/7/2009 7:33:02 AM
--------------- CURRENT DATA ---------------
Frequency = 7.2 MHz
Wire No. 1:
Segment Conn Magnitude (A.) Phase (Deg.)
1 Ground 1 0.00
2 .97418 -0.40
3 .92577 -0.80
4 .85611 -1.14
5 .76657 -1.44
6 .65894 -1.71
7 .53532 -1.96
8 .39796 -2.20
9 .24889 -2.42
10 Open .08785 -2.62

--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

colinear representation in NEC
 

Cecil Moore wrote:
Jim Kelley wrote:
It's no coincidence that the phase of the standing wave varies by 90
degrees along the length of a 90 degree standing wave antenna.

But it doesn't, Jim. Both Kraus and EZNEC agree that
standing wave current phase varies by only ~3 degrees
over the entire length of a 180 degree wire dipole
(referenced to the phase at the feedpoint).

You're always trying to drag other people into your messes. So now, in
addition to waves of average power and the 4th mechanism of reflection,
we have waves that don't change phase. :-)

Fine business OM.

ac6xg

colinear representation in NEC
 

Jim Kelley wrote:
So now, in we have waves that don't change phase. :-)

Yes, and w7el has verified that fact either on this
newsgroup or another newsgroup. If you have EZNEC,
you can easily verify it for yourself - anyone can.

Here's what Hecht said in "Optics" regarding standing
wave phase: "It (the standing wave phasor) doesn't
rotate at all, and the resultant wave it represents
doesn't progress through space - its a standing wave."
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

colinear representation in NEC
 

Cecil Moore wrote:
Jim Kelley wrote:
So now, in we have waves that don't change phase. :-)

Yes, and w7el has verified that fact either on this
newsgroup or another newsgroup. If you have EZNEC,
you can easily verify it for yourself - anyone can.

It's absurd to talk about waves that don't change phase, Cecil. If 'it'
does not change phase in some dimension, then 'it' is not a wave. Again
I refer you to a table of sines.

Here's what Hecht said in "Optics" regarding standing
wave phase: "It (the standing wave phasor) doesn't
rotate at all, and the resultant wave it represents
doesn't progress through space - its a standing wave."

Hecht knew exactly what he was talking about. It's not always evident
that you know exactly what Hecht is talking about.

ac6xg

colinear representation in NEC
 

Jim Kelley wrote:
Cecil Moore wrote:
Jim Kelley wrote:
So now, in we have waves that don't change phase. :-)

Yes, and w7el has verified that fact either on this
newsgroup or another newsgroup. If you have EZNEC,
you can easily verify it for yourself - anyone can.

It's absurd to talk about waves that don't change phase, Cecil. If 'it'
does not change phase in some dimension, then 'it' is not a wave. Again
I refer you to a table of sines.

Here's what Hecht said in "Optics" regarding standing
wave phase: "It (the standing wave phasor) doesn't
rotate at all, and the resultant wave it represents
doesn't progress through space - its a standing wave."

Hecht knew exactly what he was talking about. It's not always evident
that you know exactly what Hecht is talking about.

ac6xg

There's not much point in arguing with Cecil, Jim. He won't stop
playing the one-note samba until he's too old to whistle the tune.
73,
Tom Donaly, KA6RUH

colinear representation in NEC
 

Jim Kelley wrote:
It's absurd to talk about waves that don't change phase, Cecil. If 'it'
does not change phase in some dimension, then 'it' is not a wave.

Yes, my point exactly and that's what a couple of my
references say - that standing waves are not waves at
all. I'm glad that we agree that a standing wave does
not meet the definition of a wave.

"College Physics", by Bueche and Hecht:
"These ... patterns are called *standing waves*, as
compared to the propagating waves considered above.
They might better not be called waves at all, since
they do not transport energy and momentum."

"Electrical Communication", by Albert:
"Such a plot of voltage is usually referred to as a
*voltage standing wave* or as a *stationary wave*.
Neither of these terms is particularly descriptive
of the phenomenon. A plot of effective values of
voltage, appearing as in Fig. 6(e), *is not a wave*
in the usual sense. However, the term "standing wave"
is in widespread use."

Please contact w7el and ask him if the total current
on a 90 degree monopole changes by 90 degrees over
its length. Please tell us what he says.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

colinear representation in NEC
 

Tom Donaly wrote:
There's not much point in arguing with Cecil, Jim. He won't stop
playing the one-note samba until he's too old to whistle the tune.

No technical content - just an ad-hominem attack.
Sometimes I feel like Galileo up against the Catholic
priests. Like Galileo, I may not live to see the
technical facts accepted by you gurus.

Tom, you cannot seriously assert that the standing wave
current changes by 90 degrees in 90 degrees of monopole
when simply mathematics proves that is not the case.

For a pure standing wave, Io*cos(kx) is the amplitude.
cos(wt) is the phase. It is obvious that the phase of
a standing wave doesn't change with (x) - it only changes
with (t). What is it about Gene Fuller previous posting
with which you disagree?

Gene Fuller, W4SZ wrote:
In a standing wave antenna problem, such as the one you describe,
there is no remaining phase information. Any specific phase
characteristics of the traveling waves died out when the startup
transients died out.

Phase is gone. Kaput. Vanished. Cannot be recovered. Never to be
seen again.

The only "phase" remaining is the cos (kz) term, which is really
an amplitude description, not a phase.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

colinear representation in NEC
 

Jim Kelley wrote:
So now, in
addition to the 4th mechanism of reflection, ...

Three years ago, I removed that 4th mechanism of
reflection from my energy article in favor of
"redistribution" instead of "reflection". About
a year ago, I told you that and predicted that
you would regurgitate that same old dead horse
sometime in the future. Thanks for proving me
correct in my prediction.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

colinear representation in NEC
 

On Wed, 08 Apr 2009 17:17:50 -0500, Cecil Moore
wrote:
Sometimes I feel like Galileo

A doddering pro-hominem defense by consuming a corpse's reputation as
a Nobel laxitive.