Standing-Wave Current vs Traveling-Wave Current
 

Art wrote:
"So I added a time varient to a static field which provided a direct
connection to Maxwell`s laws."

It is said that Maxwell began with Faraday`s law of electromagnetic
induction, which seems reasonable, as the voltage in one loop of wire
inductively coupled to another is proportional to the derivative dphi/dt
of current produced magnetic flux from the primary loop.

Induced voltage does not arise at a single point on the loop but is the
sum of all the infinitesimal bits of voltage distributed around the
loop. Maxwell developed his first field equation from this start.

Faraday`s law already deals with a time varying current to obtain
induction.

Different derivations are possible but Maxwell`s equations can express
all known electromagnetic conditions at once.

Oliver Heaviside made it his job to study Maxwell`s "Electromagnetic
Theory", learn its mathematics, and reduce it to vector analysis.
Heaviside published his results beginning a series of papers in 1887 in
a British publication, "The Electrician", in a very understandable way.
This has been called the start of modern communication engineering.

Art also wrote:
"The result for equilibrium must be a tank circuit where all energy is
interchanged between the energy storage tanks (inductance and
capacitance)"

True that an EM wave exchanges its energy between an electric field and
a magnetic field. Not true that a tank circuit type antenna is needed to
launch or capture EM waves. An isolated wire, resonant or non-resonant
is all that`s needed if it carries alternating current.

Nor are explosives needed to generate radio waves. Less disruptive
methods are quite acceptable.

Art also wrote:
"The bottom line is that for best efficiency for the unit volune
supplied to an array must be in equilibrium."

The above doesn`t square with what I`ve seen.
Efficiency is output over input. Antenna efficiency is usually Radiation
Resistance / Radiation Resistance + Loss Resistance. For the most
antenna for the money, Terman suggests the Yagi or the Corner Reflector.

Enough debunking for tonight.

Best regards, Richard Harrison, KB5WZI

Standing-Wave Current vs Traveling-Wave Current
 

"Richard Harrison" wrote in message
...
Art wrote:
"So I added a time varient to a static field which provided a direct
connection to Maxwell`s laws."

It is said that Maxwell began with Faraday`s law of electromagnetic

can we do this... Maxwell did not write 'laws'. all of my references refer
to "Maxwell's equations". Maxwell collected laws from Faraday, Gauss, Ohm,
Ampere, and probably a few others and as far as I know added just the
displacement current concept to turn them into a concise description of time
varying electromagnetic phenomenon that has never been disproved. This set
of equations is indeed what all antenna, feedline, waveguide, motors, power
transmission, and related electromagnetic phenomenon are modeled with
successfully in all environments that we have experienced. (neglecting
things like black holes anyway) This includes diamagnetic, paramagnetic,
ferromagnetic, insulators, conductors, dielectrics, and even the new man
made negative refractive index materials. it is not necessary to add a new
'time varient' part to any of Maxwell's equations, they already contain all
the time variant parts that are needed to explain any electromagnetic fields
you can come up with.

Standing-Wave Current vs Traveling-Wave Current
 

"Keith Dysart" wrote in message
...
Thanks for offering the two capacitor/one capacitor view of the middle
of the line. It took a bit of time to decide whether the commingling
of the charge in the single capacitor at the middle of the line would
solve my dilemma.

So I considered this one capacitor in the exact center of a perfect
transmission line. It is the perfect capacitor, absolutely
symmetrical. So as the exactly equal currents flow into it on
the exactly symmetrical leads, the charge is perfectly balanced
so that the charge coming from each side exactly occupies its
side of the conductor. As the two flows of charge flow over
the perfectly symmetrical plates, they meet in the exact
center, and flow no more. I conclude that a surface can
be found exactly in the center of this capacitor across
which no charge flows. Thus (un)happily returning me exactly
to where I was before; there is a line across which no
charge, and hence no energy, flows.

absolutely correct. no charge flows through the insulator of a capacitor.
you don't have to try hard to set up this condition, it is true of any
capacitor that has no resistive losses. the concept you are struggling with
is called the 'displacement current'. This is the unique concept that
Maxwell added to the laws of Gauss, Faraday, et al when he compiled his set
of electromagnetic equations. once you understand that then all will become
clear.

2. I don't understand the mechanism which causes waves to bounce.

I take this to imply that you are not happy with the simple "like
charge
repels"?


waves do not bounce. waves superimpose on each other, but the original
waves that meet in a homogenious, linear medium DO NOT INTERACT in any way.
they each proceed happily on their way without any change. it is only due
to the limited capability of your measurement instruments to measure the
superimposed field that results that causes the confusion. if you could
easily separate out the forward and reflected waves it would become
intuitively obvious... however the poor instruments (swr meters and other
'power' meters) that have caused the confusion and resulted in the misnomer
'standing wave'. It is of course not a 'wave', nor does it 'stand'... it is
just the result of superposition of 2 waves traveling in opposite
directions.



So the (poorly developped) "charge bouncing" explanation
seems like a way out, but I certainly would appreciate
other explanations for consideration.

you don't need a 'way out' you need to go back to basics and learn the
proper explanation.

A large part of the argument seems to revolve around a single point in a
perfect transmission line, where the current is exactly zero. This is an
infinitesimal point on a perfect line, so some anomalous things might be
expected to happen there.

but the current, or voltage, is only zero because of the superimposed
oppositely traveling waves. it is only your poor measurement instrument
that only responds to the superimposed waves that causes the confusion.


there. that ought to cause enough controversy to push this thread over the
1000 mark pretty quick! the wx is bad and i needed something to do today
anyway since i can't go out and work on my maxwell compliant antennas.

Standing-Wave Current vs Traveling-Wave Current
 

On 11 Jan, 05:00, "Dave" wrote:
"Richard Harrison" wrote in message

...

Art wrote:
"So I added a time varient to a static field which provided a direct
connection to Maxwell`s laws."

It is said that Maxwell began with Faraday`s law *of electromagnetic

can we do this... Maxwell did not write 'laws'. *all of my references refer
to "Maxwell's equations". *Maxwell collected laws from Faraday, Gauss, Ohm,
Ampere, and probably a few others and as far as I know added just the
displacement current concept to turn them into a concise description of time
varying electromagnetic phenomenon that has never been disproved. *This set
of equations is indeed what all antenna, feedline, waveguide, motors, power
transmission, and related electromagnetic phenomenon are modeled with
successfully in all environments that we have experienced. *(neglecting
things like black holes anyway) *This includes diamagnetic, paramagnetic,
ferromagnetic, insulators, conductors, dielectrics, and even the new man
made negative refractive index materials. *it is not necessary to add a new
'time varient' part to any of Maxwell's equations, they already contain all
the time variant parts that are needed to explain any electromagnetic fields
you can come up with.

I added a time varient to GAUSSIAN law to make it the same as
Maxwellian laws, not the other way around as you are inferring.
Before Maxwell came a long there were multiple laws stated many
different ways.
Maxwell saw that many of these laws tho written differently condensed
to the same thing.
So he condensed these multiple laws to a few but an no time did debunk
the laws that already were in situ. All of these multiple laws as with
Maxwell were built on the shoulders of Newton
and those that contributed before him, all of which are derived around
the pivot of gravity
and equilibrium

Standing-Wave Current vs Traveling-Wave Current
 

On Thu, 10 Jan 2008 18:52:28 -0800 (PST)
Keith Dysart wrote:
snip............

I would really appreciate seeing some other possible explanations.

One other one which I have seen and am not confortable with is the
explanation that energy in the waves pass through the point in
each direction and sum to zero. But this is indistinguishable from
superposing power which most agree is inappropriate. As well, this
explanation means that P(t) is not equal to V(t) times I(t),
something that I am quite reluctant to agree with.

The other explanation seen is that the voltage waves or the
current waves travel down the line superpose, yielding a total
voltage and current function at each point on the line which
can be used to compute the power. With this explanation, P(t)
is definitely equal to V(t) time I(t), which I do appreciate.
The weakness of this explanation is that it seems to deny
that the wave moves energy. And yet before the pulses collide
it is easy to observe the energy moving in the line, and if
a pulse was not coming in the other direction, there would
be no dispute that the energy travelled to the end of the
line and was absorbed in the load. Yet when the pulses
collide, no energy crosses the middle of the line. Yet
energy can be observed travelling in the line before
and after the pulses collide.

So...

I can give up on pulses (or waves) moving energy. I am not
happy doing that.
I can give up on P(t) = V(t) * I(t). I am not happy doing
that either.

So the (poorly developped) "charge bouncing" explanation
seems like a way out, but I certainly would appreciate
other explanations for consideration.

Hi Keith,

I think you are putting too much emphasis on the measurement of energy in the pulse, or maybe not enought, depending upon how you are making and using the measurements.

I hope you agree that the transmission line you are pulsing has no standing waves. If not, then the pulse must be a treveling wave. If it is a traveling wave, the impedance of the wave will be the impedance of the transmission line, except where the two pulses cross paths. At the crossing point, the impedance will jump to infinity, Z = v/i = v/zero = infinity.

How about the energy/power levels? Except at the center, as the pulse passes, current and voltage can be measured, so power is being delivered from one section of the line to a second section more distant from the source. The energy delivered by the power equation can be measured by U = (v^2)/r = (i^2)*r where r is the Zo if the transmission line.

Where the two pulses cross, the energy level must be the sum of the two energy levels, which would be 2U = 2*(v^2)/r (assuming two pulses of equal voltage). As you have pointed out, power would not flow at the point of wave first meeting, spreading from the meeting point back towards the two sources a distance equal to the square pulse width. Energy is present however, measured as U = (v^2)/r.

The transmission line can be considered as a lineal capacitor, so U = (CV^2)/2, where C is the capacitance per unit length. If the waves "bounce", and occupy physical space for a period of time, they should comingle, stop, and fill the capacitor during that time. If so,

2U = C*V'^2
= 2*(V^2)/r where v is the voltage of a single pulse and V' = 1,414*v = voltage observed at point of crossing.

At a disconinuity, we find a doubling of the voltages, not an increase of 1.414. This leads me to believe that the crossing pulses never stop in a physical sense. They do stop in the sense that power is not delived through the center point.

73, Roger, W7WKB

Standing-Wave Current vs Traveling-Wave Current
 

On 11 Jan, 08:15, Roger Sparks wrote:
On Thu, 10 Jan 2008 18:52:28 -0800 (PST)Keith Dysart wrote:

snip............







I would really appreciate seeing some other possible explanations.

One other one which I have seen and am not confortable with is the
explanation that energy in the waves pass through the point in
each direction and sum to zero. But this is indistinguishable from
superposing power which most agree is inappropriate. As well, this
explanation means that P(t) is not equal to V(t) times I(t),
something that I am quite reluctant to agree with.

The other explanation seen is that the voltage waves or the
current waves travel down the line superpose, yielding a total
voltage and current function at each point on the line which
can be used to compute the power. With this explanation, P(t)
is definitely equal to V(t) time I(t), which I do appreciate.
The weakness of this explanation is that it seems to deny
that the wave moves energy. And yet before the pulses collide
it is easy to observe the energy moving in the line, and if
a pulse was not coming in the other direction, there would
be no dispute that the energy travelled to the end of the
line and was absorbed in the load. Yet when the pulses
collide, no energy crosses the middle of the line. Yet
energy can be observed travelling in the line before
and after the pulses collide.

So...

I can give up on pulses (or waves) moving energy. I am not
happy doing that.
I can give up on P(t) = V(t) * I(t). I am not happy doing
that either.

So the (poorly developped) "charge bouncing" explanation
seems like a way out, but I certainly would appreciate
other explanations for consideration.

Hi Keith,

I think you are putting too much emphasis on the measurement of energy in the pulse, or maybe not enought, depending upon how you are making and using the measurements. *

I hope you agree that the transmission line you are pulsing has no standing waves. *If not, then the pulse must be a treveling wave. *If it is a traveling wave, the impedance of the wave will be the impedance of the transmission line, except where the two pulses cross paths. *At the crossing point, the impedance will jump to infinity, Z = v/i = v/zero = infinity.

How about the energy/power levels? *Except at the center, as the pulse passes, current and voltage can be measured, so power is being delivered from one section of the line to a second section more distant from the source. *The energy delivered by the power equation can be measured by U = (v^2)/r = (i^2)*r where r is the Zo if the transmission line.

Where the two pulses cross, the energy level must be the sum of the two energy levels, which would be 2U = 2*(v^2)/r (assuming two pulses of equal voltage). *As you have pointed out, power would not flow at the point of wave first meeting, spreading from the meeting point back towards the two sources a distance equal to the square pulse width. Energy is present however, measured as U = (v^2)/r.

The transmission line can be considered as a lineal capacitor, so U = (CV^2)/2, where C is the capacitance per unit length. *If the waves "bounce", and occupy physical space for a period of time, they should comingle, stop, and fill the capacitor during that time. If so,

2U = C*V'^2
* *= 2*(V^2)/r where v is the voltage of a single pulse and V' = 1,414*v = voltage observed at point of crossing. *

At a disconinuity, we find a doubling of the voltages, not an increase of 1.414. *This leads me to believe that the crossing pulses never stop in a physical sense. *They do stop in the sense that power is not delived through the center point.

73, Roger, W7WKB- Hide quoted text -

- Show quoted text -

Roger you are conversing with old men most of which oppose change.
Having been taught some fifty years ago they want to protect those
teachings the originators of which are all dead.
Thus regardless of what has happened and discovered or intruded upon
by inquiring minds they wish to stay in the past.In the past, statics
was viewed as a subset of electro-dynamics and the old timers want it
to stay that way. By starting with Gauss and adding a time varient I
added a visual to Maxwell that was missing from his equations because
Gauss was not the leading
contributor to the time varient theme. It is this that the old timers
are resisting because it brings away the thought that statics is just
a subset. Thus you see that there is inherrent resistance to the
mathematics that supplies a visual to Mawellian equations. It took
Richard several months to accept the legitimacy of the mathematics
involved in the steps I took. As yet nobody else has admitted to the
legitamacy of the mathematics. Thus protecting the notion of static
being just a subset. This manoever has placed ham radio into a
quagmire from which they cannot extricate themselves and thus advance
to analyse the intricacies of propagation.
Who would have believed that ham radio would take to task of a Doctor
working at MIT on space reseach for NASA for faulty use of mathematics
to prove the relavence of statics?
Can science really be held up while old men are still living?
Art Unwin KB9MZ...XG

Standing-Wave Current vs Traveling-Wave Current
 

roger chimed in with:

I hope you agree that the transmission line you are pulsing has no standing
waves. If not, then the pulse must be a treveling wave. If it is a
traveling wave, the impedance of the wave will be the impedance of the
transmission line, except where the two pulses cross paths. At the
crossing point, the impedance will jump to infinity, Z = v/i = v/zero =
infinity.


argh, another misconception!.. the impedance of a transmission line doesn't
change! and the impedance seen by a single traveling wave never changes
either. the measured ratio of voltage to current at a point on the line can
change as a result of the superposition of traveling waves. but again, that
is just a result of cheap instrumentation that can't resolve the component
waves.

Standing-Wave Current vs Traveling-Wave Current
 

On Fri, 11 Jan 2008 08:15:09 -0800, Roger Sparks
wrote:

They do stop in the sense that power is not delived through the center point.

Hi Roger,

I'm not sure if this is original to you, or one of those conceits that
is being passed around; but how, short of tagging energy (power?), can
you tell its origin? In other words, delivery by return, or
completion of the path needs to be separable by some information about
the origin that to this point has been missing from the discussion.

If energy can be tagged with a return address, what is that tag?

73's
Richard Clark, KB7QHC

Standing-Wave Current vs Traveling-Wave Current
 

On Fri, 11 Jan 2008 17:19:28 GMT
"Dave" wrote:

roger chimed in with:

I hope you agree that the transmission line you are pulsing has no standing
waves. If not, then the pulse must be a treveling wave. If it is a
traveling wave, the impedance of the wave will be the impedance of the
transmission line, except where the two pulses cross paths. At the
crossing point, the impedance will jump to infinity, Z = v/i = v/zero =
infinity.


argh, another misconception!.. the impedance of a transmission line doesn't
change! and the impedance seen by a single traveling wave never changes
either. the measured ratio of voltage to current at a point on the line can
change as a result of the superposition of traveling waves. but again, that
is just a result of cheap instrumentation that can't resolve the component
waves.


Good point. It would have been much better to say something like :"At the
crossing point, the MEASURED impedance will jump to infinity (Z = v/i = v/zero =
infinity) but we have no indication that the impedance of either the wire or the individual pulse changes in any way.".

73, Roger, W7WKB

Standing-Wave Current vs Traveling-Wave Current
 

On Fri, 11 Jan 2008 10:44:19 -0800
Richard Clark wrote:

On Fri, 11 Jan 2008 08:15:09 -0800, Roger Sparks
wrote:

They do stop in the sense that power is not delived through the center point.

Hi Roger,

I'm not sure if this is original to you, or one of those conceits that
is being passed around; but how, short of tagging energy (power?), can
you tell its origin? In other words, delivery by return, or
completion of the path needs to be separable by some information about
the origin that to this point has been missing from the discussion.

If energy can be tagged with a return address, what is that tag?

73's
Richard Clark, KB7QHC

Current is the tag, and the address is "past" and "future". Measurement is always "present", but we like to make predictions about what will happen in the future, and trace what has happened in the past. With the electromagnetic equations, we are quite good at making those extrapolations from present measurements.

At the crossing point, we can not measure current, so the power equation of P = V * I fails. There is no power at this point that we can measure. We can measure instantaneous voltage but don't know which equation to use to determine energy, U = (CV^2)/2 or SumU = Sum((V^2)/r). Only if we make many measurements over time can we learn the shape of the voltage over time, and thereby deduce which equation to use.

73, Roger, W7WKB






At the crossing poiont