Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
 

On Jan 10, 11:34 pm, art wrote:
We haven't moved forward a bit on that first sentence of the other
post which is " what created the reflecting voltage" of this resonant
radiator when it is a fractional wavelength or a electrically full wave length?

The characteristic impedance of the horizontal wire above ground is in
the neighborhood of 600 ohms. The "load" impedance at the end of the
wire can be considered to be infinite. The reflection coefficient at
the tip of a dipole is 1.0, i.e. all the forward voltage is reflected
in phase. This is true no matter what the length of the dipole. The
round trip delay that the forward wave makes can be used to get a fair
approximation of the feedpoint impedance using transmission line
equations and assigning an appropriate value to the alpha loss factor
which not only includes real losses but also "losses" due to
radiation.
--
73, Cecil, w5dxp.com

Standing morphing to travelling waves, and other stupid notions
 

On Jan 10, 11:45 pm, "AI4QJ" wrote:
But: The closer standing wave ratio of the illusionary is to 1:1, the closer
we are to antenna resonance so the illusion has more significance than, say
a mirage in the desert. ;-)

By "illusionary", I certainly didn't mean "imaginary". A magician's
act contains illusions based on real events. It's just that the
audience doesn't comprehend what is really happening. That's exactly
what is occurring here with standing waves. The standing waves, like
the magician's illusions, certainly have a real existence but many of
the conclusions about standing waves that are presented here are based
on the illusions created by those real standing waves (which do not
meet the definition for EM, i.e. photonic waves).
--
73, Cecil, w5dxp.com

Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
 

On 11 Jan, 06:18, Cecil Moore wrote:
On Jan 10, 11:34 pm, art wrote:

We haven't moved forward a bit on that first sentence of the other
post which is " what created the reflecting voltage" of this resonant
radiator when it is a fractional wavelength or a electrically full wave length?

The characteristic impedance of the horizontal wire above ground is in
the neighborhood of 600 ohms. The "load" impedance at the end of the
wire can be considered to be infinite. The reflection coefficient at
the tip of a dipole is 1.0, i.e. all the forward voltage is reflected
in phase. This is true no matter what the length of the dipole. The
round trip delay that the forward wave makes can be used to get a fair
approximation of the feedpoint impedance using transmission line
equations and assigning an appropriate value to the alpha loss factor
which not only includes real losses but also "losses" due to
radiation.
--
73, Cecil, w5dxp.com

Thanks for the reply Cecil which has opened my eyes regarding the
trend of your thoughts.
Try to change your thinking to the following. An alternating current
is created by a generator
that moves in a circular fashion. The + and _ functions are a
mathematical tool obtained by the sine .cosine etc. This is a measure
ONLY of the amplitide only at a particular point in time. If you put a
scope on it you will see a wave like function only because your eyes
e.t.c.
is not fast enough to take more samples at the point in question. Thus
it is an illusion to think of forward travel. Another way of looking
at it is to stand in the center of a football field and watch the
spectators stand up in sequence. At any point of what you are viewing
you /
your eye mechanism,are seing a movement upwards at a single position
at a single point in time.
At no time is there anything moving forward thus this reflection of
yours cannot occur.
I think we can end out interchange at this point
Very best regards
Art Unwin KB9MZ....xg(uk)

Standing morphing to travelling waves, and other stupid notions
 

Cecil Moore wrote:
On Jan 9, 11:22 pm, Roy Lewallen wrote:
Just what is a "wave", anyway? Are there different "kinds" of
electromagnetic wave?

Take a look at the E-field, H-field, and direction of travel for an EM
(photonic) wave. An RF standing wave does not behave like an EM wave
nor does it meet the definition of an EM wave which can be represented
by a Poynting vector. The Poynting vector for an RF standing wave has
a magnitude of zero and no direction.
--
73, Cecil, w5dxp.com

Cecil,

That is flat out wrong. For a plane wave the E and H fields are
perpendicular for either traveling waves or standing waves. For a
coaxial cable operating in the normal TEM mode, the E field is radial
and the H field is circular around the center conductor. Again, the E
field and H field are always perpendicular. Unless one or both of the
fields are exactly zero, the Poynting vector will be nonzero. It will
have a magnitude and direction.

I suppose what you are looking at is some sort of time average. In that
case the average of the Poynting vector at a single point in space may
be different for standing waves and traveling waves. However, that
information is essentially useless. The only thing with physical
reality, related to Poynting vectors, is the integral of the Poynting
vector over a closed surface. Equivalently, the only thing with physical
reality is the divergence of the Poynting vector.

In the lossless cases we are typically discussing, the time-averaged
integral or the divergence is exactly zero for either the traveling wave
case or the standing wave case. The Poynting vector is no help in making
any sort of distinction at all.

73,
Gene
W4SZ

Standing morphing to travelling waves, and other stupid notions
 

Cecil Moore wrote:
On Jan 10, 10:59 am, Gene Fuller wrote:
. It is really amazing that you can make up so many requirements that
are
completely unknown to the rest of the world. Is that a Mensa thing?

Methinks you need to study and comprehend the nature of photons and
photonic waves.
--
73, Cecil, w5dxp.com

Cecil,

I have been doing that for decades. Is there some tutorial material I
seemed to have overlooked? (other than RRAA, of course) I already have
tons of books on physics, engineering, and optics.

What do you recommend as the definitive reference on "the nature of
photons and photonic waves"?

73,
Gene
W4SZ

Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
 

Cecil Moore wrote:
On Jan 10, 10:55 am, Gene Fuller wrote:
. You never give up, do you? Even when you are caught in an utter
lie. You
know exactly what the capacitors are for, and it isn't to control
transmission line reflections from open ends of the line.

I'm sorry, Gene, but I cannot alleviate your ignorance with one
posting. Given a voltage phasor and a current phasor with a phase
angle between them, there is absolutely no way to distinguish between
a mismatch and a reflection. The purpose of those power factor
capacitors on the power line poles is to turn those transmission lines
into money-making traveling wave delivery systems rather than allow
money-losing standing wave systems. Please stop your emoting long
enough to realize what I have said is true.

If the capacitors were not there, the inductive loads would cause
reflections just as they do on an RF transmission line. The only
difference is that the 60 Hz transmission line is a small fraction of
a wavelength. If you scaled the 60 Hz system to 6 MHz, all the same
laws of physics would apply and the similarities would be readily
apparent.
--
73, Cecil, w5dxp.com

Cecil,

I am glad to see you have now acknowledged the real purpose of the
capacitors. You avoided a direct response to my comment, of course, but
progress is being made.

8-)

73,
Gene
W4SZ

Standing morphing to travelling waves. was r.r.a.a LaughRiot!!!
 

Gene Fuller wrote:
"You know exactly what capacitors are for, and it isn`t to control
transmission line reflections from open ends of the line."

When you open a circuit at an instant when current is flowing, the
transient created can be large. Natural phenomena also create injurious
spikes on a power line. Capacitors absorb transient current reducing and
delaying a voltage rise which gives overvoltage protection a chance to
operate.

Lightly loaded induction motors cause power factor to lag, demanding
additional current. Capacitors to correct large amounts of lagging
current often take the form of over-excited unloaded induction machines
(rotory capacitors) which produce an offsetting leading power factor.

Power loss in power lines is proportional to the square of the current,
whatever the cause, so power factor correction aims at to reduce current
in the line.

Best regards, Richard Harrison, Kb5WZI

Standing morphing to travelling waves, and other stupid notions
 

Cecil Moore wrote:

On Jan 10, 9:23 pm, Jim Kelley wrote:

A standing wave is an amplitude vs position envelope.


Sorry, that is a false statement.

No, in the most general sense, it is a precisely accurate statement.

Please reference "Fields and Waves
in Communication Electronics" by Ramo, Whinnery, and Van Duzer, page
343.

Ah. Apparently the only book you know of that contains the
description of a standing wave.

The equation for the standing wave voltage is: Ez = Efor*e^j(wt-
Bz) + Eref*e^j(wt+Bz)

You must belong to the Standing Wave Equation of the Week Club. Nice
letter choices. :-)

The equation for a standing wave *envelope* does not contain an
(omega*t) term.

That right. As I said, it is a function of amplitude vs postion.

The equation for the *standing wave* indeed does
obviously contain (omega*t) terms since the equation for a standing
wave is the sum of the two component traveling waves each containing
an (omega*t) term.

And when Ramo and Whinnery, for example, plots standing wave current
on a vertical radiator, for example, why do you suppose it looks like
an amplitude vs. position curve?

If the (omega*t) term is omitted it is an envelope equation, not a
wave equation.

Ah. So according to Cecil, we have a new definition for a wave which
now stipulates that it must only be expressed as a function of time.

If you only knew how ridiculous you sound.

ac6xg

Standing morphing to travelling waves, and other stupid notions
 

On Jan 11, 12:10 pm, Gene Fuller wrote:
What do you recommend as the definitive reference on "the nature of
photons and photonic waves"?

I personally like "Optics" by Hecht and his idea that standing waves
maybe shouldn't be called waves at all. EM waves move energy and
conserve momentum. Standing waves don't.
--
73, Cecil, w5dxp.com

Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!
 

art wrote
Thanks for the reply Cecil which has opened my eyes regarding the
trend of your thoughts.
Try to change your thinking to the following.

big snip

At no time is there anything moving forward thus this reflection of
yours cannot occur.
I think we can end out interchange at this point
Very best regards
Art Unwin KB9MZ....xg(uk)

Now this is gonna be a hoot, watching Art and Cecil exchange
technical repartees.

Mike W5CHR