"Art Unwin" writes...
I am still of the belief that on a fractional wave antenna
the current travels on both the outside and the inside of
the radiator. This puts me in opposition to the multitude
of "washed" hams who resist change even tho as yet
I have not been proved as being in error.
___________

Believe as you personally wish, Art.

But note that your belief is not supported either by theo-
retical or practical physics, or decades of field experience.

Instead of challenging the readers of your posts to prove
that you are wrong, you might take the time to research and
show SCIENTIFICALLY that you are right (if you can do so).

RF

On Oct 31, 7:13*pm, "Richard Fry" wrote:
"Art Unwin" writes...
I am still of the belief that on a fractional wave antenna
the current travels on both the outside and the inside of
the radiator. This puts me in opposition to the multitude
of "washed" hams who resist change even tho as yet
I have not been proved as being in error.

___________

Believe as you personally wish, Art.

But note that your belief is not supported either by theo-
retical or practical physics, or decades of field experience.

Instead of challenging the readers of your posts to prove
that you are wrong, you might take the time to research and
show SCIENTIFICALLY that you are right (if you can do so).

RF

So what do you believe ?

So what do you believe ?


Art,
I believe we will never get a 'straight' answer from you. Does
that make me a 'washed' ham or an 'unwashed' one? Beats me, I don't
know.
- 'Doc

Art Unwin wrote:
"I am still of the belief that on a fractional wave antenna the current
travels on both the outside and the inside of the radiator."

That`s so at DC but not at HF.

HF only travels on the outside layer of a conductor as more
current-opposing flux lines encircle the conductor`s center than
encircle the conductor`s surface or outer layer. See Fig. 2-10 on page
22 of Terman`s 1955 opus.

Art also is confused about current distribution on resonant antennas of
various lengths. Terman can help there too. On page 866 Terman wrote:
"The current distribution as observed in such a resonant wire (1/2-wave
open at both ends) serving as an antenna ordinarily approximates very
closely the distribution that would be obtained on the assumption of
zero loss. provided the wire length does not exceed 8 to 10 wavelengths.
The current distribution, accordingly has the character illustrated in
Fig. 23-3."
Also on page 866:
"----to a first approximation the current distribution can be taken as
that for a line with zero losses; it then has the characteristics
discussed in Sec.4-5."

Page 91, Fig. 4-3 shows the vectors (phasors) E1 & E2 at an
open-circuited load as happens at the antenna tips, Conduction current
ends at the conductor tip. Current interruption collapses the magnetic
field and induces an opposite current causing a zero sum current at the
tip, but the induced voltage is of the same polarity as the incident
votage making a voltage double at the antenna tip. Energy is conserved.

Best regards, Richard Harrison, KB5WZI

On Nov 14, 3:11*pm, (Richard Harrison)
wrote:
Art Unwin wrote:

"I am still of the belief that on a fractional wave antenna the current
travels on both the outside and the inside of the radiator."

That`s so at DC but not at HF.

HF only travels on the outside layer of a conductor as more
current-opposing flux lines encircle the conductor`s center than
encircle the conductor`s surface or outer layer. See Fig. 2-10 on page
22 of Terman`s 1955 opus.

Art also is confused about current distribution on resonant antennas of
various lengths. Terman can help there too. On page 866 Terman wrote:
"The current distribution as observed in such a resonant wire (1/2-wave
open at both ends) serving as an antenna ordinarily approximates very
closely the distribution that would be obtained on the assumption of
zero loss. provided the wire length does not exceed 8 to 10 wavelengths.
The current distribution, accordingly has the character illustrated in
Fig. *23-3."
Also on page 866:
"----to a first approximation the current distribution can be taken as
that for a line with zero losses; it then has the characteristics
discussed in Sec.4-5."

Page 91, Fig. 4-3 shows the vectors (phasors) E1 & E2 at an
open-circuited load as happens at the antenna tips, Conduction current
ends at the conductor tip. Current interruption collapses the magnetic
field and induces an opposite current causing a zero sum current at the
tip, but the induced voltage is of the same polarity as the incident
votage making a voltage double at the antenna tip. Energy is conserved.

Best regards, Richard Harrison, KB5WZI * *

Could you give a similar description only this time make it a 5/8
wavelength antenna?

"Art Unwin" wrote in message
...
On Nov 14, 3:11 pm, (Richard Harrison)
wrote:
Art Unwin wrote:

nothing that answered the question.. as expected.

well, art... lets try it even simpler... what term(s) in maxwell's equations
specify the contribution of the weak force? maybe from that we can
determine where they are implemented in art's fantasy about modeling
software.

Art Unwin wrote:
"Could you give a similar description only this time make it a 5/8
wavelength antenna."

My previous resume` regarded current distribution on a 1/2-wave
standing-wave antenna.

A 1/2-wave antenna is resonant, that is it has no reactance, and it is
open-circuited at both ends. Its feed point is in its center, at its
high-current point, and it is a pure resistance.

The 5/8 wavelength antenna consists of a 1/2 wavelength section of
radiation resistance but no reactance plus a 1/8 wavelength section of
small radiation resistance and a large capacitive reactance. To receive
maximum energy, the capacitive reactance must be compensated. A unity
power factor is desirable.

As with the 1/2-wave antenna, current distribution in the 5/8-wave
antenna is controlled by its open-circuited ends. On page 187 of the 3rd
edition of Kraus` "Antennas" he says:
"A sinusoidal current distribution may be regarded as the standing wave
produced by two uniform (unattenuated) traveling waves of equal
amplitude moving in opposite directions along the antenna."

We know there`s radiation and loss as the current travels to and fro
between the open-circuited ends of the antenna, but if unattenuated is
good nough for most purposes for Kraus, it is good enough for me.

Best regards, Richard Harrison, KB5WZI

On Nov 15, 2:07*pm, (Richard Harrison)
wrote:
Art Unwin wrote:

"Could you give a similar description only this time make it a 5/8
wavelength antenna."

My previous resume` regarded current distribution on a 1/2-wave
standing-wave antenna.

snip
"We know that..........." !!!!!!! hmmmm

I don't know who "we" is but for one I don't know
Could you explain who "we" is and on what authority or explanation
has "we": got for such an implausable statement?
I do thank you for responding. Oh what a web we weave when we try....

May be this is why scientists have not yet been able to rationalize
radiation
and we are just left with theories with holes as in cheese.
Industry shows us not just talk about it they show us every day what
happens to a particle
on their conveyor. They even let you show the particle levitated and
revolving.
Industry also shows you that eddy currents occur in a closed loop
circuit
and one must see that the combination of the alternating current flow
and the resulting eddy current can
levitate a particle. They don't just talk about it they can
demonstrate it.
This is much more plausable and reproduceable than wireing a house
with an open circuit to plug into.
Also the old books that you read on both argue that a fractional
wavelength is represented by a series circuit that is not open!
They also say that a full wave antenna is represented by a parallel or
tank circuit and again the circuit is not open!
No wonder radiation has not been explained fully when so many
paradoxes are present. Oh and if my house is wired as an open circuit
asit is time related why on earth would one need fuses and where would
they put them if it is an open circuit?
The idea of two currents opposing each other on the same surface of an
open circuit where the eddy currents is thus cancelled
by revolving in opposite directions and the same thing going for the
time varying current tells me you have discovered the "big bang"
by not placing a fuse in an open circuit.
Kraus was not perfect otherwise he would have improved on his thinking
during his life time
by studying radiation and it's creation.

Regards
Art


We know there`s radiation and loss as the current travels to and fro
between the open-circuited ends of the antenna, but if unattenuated is
good nough for most purposes for Kraus, it is good enough for me.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:
Art Unwin wrote:
"Could you give a similar description only this time make it a 5/8
wavelength antenna."
...
Best regards, Richard Harrison, KB5WZI


Richard:

I certainly don't want to engage in a large argument.

Rather, I would just venture an opinion directly related to my real
world construction experiences, and the results from the same:

If there are notable gains from constructing a 5/8 wave antenna, as
opposed to a 1/2 wave--I have NOT seen them.

It all looks good in EZNEC and/or mmana-gal (or, "on paper"), however,
in real world s-meter/signal-reports, "it" does not.

Perhaps I have experienced a anomaly(s?)

Or, put simply, the extra "hassle" in dealing with these extended
lengths is simply "not worth it!"

Regards,
JS

John Smith wrote:
Richard Harrison wrote:
Art Unwin wrote:
"Could you give a similar description only this time make it a 5/8
wavelength antenna."
...
Best regards, Richard Harrison, KB5WZI

Richard:

I certainly don't want to engage in a large argument.

Rather, I would just venture an opinion directly related to my real
world construction experiences, and the results from the same:

If there are notable gains from constructing a 5/8 wave antenna, as
opposed to a 1/2 wave--I have NOT seen them.

It all looks good in EZNEC and/or mmana-gal (or, "on paper"), however,
in real world s-meter/signal-reports, "it" does not.

Perhaps I have experienced a anomaly(s?)

Or, put simply, the extra "hassle" in dealing with these extended
lengths is simply "not worth it!"

Regards,
JS

I think that we all should remember that it is the "ART" of antenna
design not the "SCIENCE" of antenna design.

Dave WD9BDZ