Loading Coils; was : Vincent antenna
 

Art wrote:
"Were you wearing a uniform supplied by Germany at that time?"

Fortunately not. I was wearing a uniform supplied by the U.S. Navy in
the Pacific theater at that time.

We had no choice when attacked by the Japanese. The U.S. had interrupted
oil to Japan to try to curb their agression and they responded with an
attack on Pearl Harbor.

The English proved their grit during the Battle of Britain. But, it
would have been lost had not lend-lease been provided by the U.S.A.

Even Hermann Goering gave slight praise to British industry when asked
if he needed something else for his Luftwaffe and he replied: "A couple
of Spitfire squadrons would be very nice."

The Luftwaffe`s failure to gain control of the skies during the Battle
of Britain was Hitler`s first defeat and it stained Goering`s
reputation.

Hermann`s nephew was raised in Salt Lake City and commisioned a Captain
in the U.S. Army Airforce where he was considered a uniquely qualified
B-17 pilot assigned to the 303rd Bombardment Group (Hell`s Angels) of
the 8th Air Force based in Molesworth, England, flying missions against
Nazi Germany.
His name was Werner G. Goering. Remember that Eisenhower said that at
least 1/3 of his forces were of German descent. The only mission Werner
was not eager to perform was when he had to bomb Cologne where his
grandmother lived. Hermann`s younger brother, Albert Goering was notable
for helping Jews and other dissidents survive in Germany throughout the
war. He sometimes called upon Herman and received help in this
idealogical problem.

Mostly war is bad sttuff no matter which side you are on. One of my
predecessors, named Harrison signed the Declaration of Independance and
lost his fortune as a result.

Best regards, Richard Harrison, KB5WZI

Loading Coils; was : Vincent antenna
 

AI4QJ wrote:
You are ready to throw me out of the sacred RRAA nesting place?

The next step by the gang of gurus will be to "ploink"
you which means they will program their newsreaders
to shield themselves from your postings of technical
facts which disagree with their old wives' tales.

A few of them believe there is no reflected energy
in a reflected wave.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Richard Harrison wrote:
There is no magic
instantaneous transfer of energy from one turn to another within a coil.

It's not magic and it cannot occur at faster than light
speed. Magnetic coupling between air-core coils does
exist. It is just not of the magical magnitude asserted
by W8JI.

You wouldn't use the same argument on an iron-core
coil, would you, where virtually all of the coil#1
flux does indeed link with coil#N?
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

"AI4QJ" wrote in
:


"AI4QJ" wrote in message
...

note the independence of coil size and location on the
monopole.


The location on the monopole may make a difference. Since a standing
wave is present, the location on the antenna will define the amount of
current in the coil. Mounting near the feedpoint is at a high current

Yes, the complete picture is that:
1. more inductance is needed the further that a single small loading coil
is located from the base; and
2. loss is due to I^2*R, so locating the coil further up decreases
current, but increases required inductance and inherent R.

The above mean that the optimum efficiency is often from a coil located
closer to the middle than to the top or bottom.

It seems reasonable that a stand alone coil can be characterised as a
transmission line having a delay that equates to an electrical length in
degrees, radians, wavelengths or a velocity factor. In fact the
inductance calculator at http://hamwaves.com/antennas/inductance.html is
based on that approach and shows the calculated value of Beta.

But, it is the suggestion by some that the coil simply replaces an
equivalent electrical length of the monopole conductor irrespective of
the coil's location that is inconsistent with 1 above.

A further issue is the accuracy of the estimate of the coil's electrical
length when represented as a transmission line. Using the length of the
wire in the coil (as is sometimes done) is too simplistic. The Corum
paper referenced at the calculator above describes a method that appears
to be more reliable.

Owen

Loading Coils; was : Vincent antenna
 

art wrote:
Cecil,
Nobody here is willing to say they were wrong.

Art, nothing in this posting was written by me. And I, for one,
admitted that "power waves" is a wrong concept about ten years
ago. No ethical person would post an assertion that I still
believe in such.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Richard Clark wrote:
"AI4QJ" wrote:
I believe we are discussing the delay characteristic of current in a coil.

Would you be surprised if Cecil and Art diverged even at this point?
What would be the point of supporting them when they abandon you?

I don't know about Art, Richard, but I detest your trying
to mind fornicate with me. Who is religiously supporting who
is obviously important to you but to some of us, only technical
facts are important. If I believe AI4QJ to be technically correct,
I will support him and vice versa.

I do believe we are discussing the delay characteristic of
current in a coil.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Richard Harrison wrote:
Surely the signal follows the path of the turns on a coil.

Not entirely as adjacent turns do have an effect on
each other so there is a grain of truth in what W8JI
is saying. W8JI's error was in taking that grain of
truth and rationalizing that small grain into an
explanation that is off by at least a magnitude.

It looks like a reasonable rule of thumb is that the
velocity factor of a coil is approximately half what
it would be if the signal followed the wire entirely.
In other words, if one calculates the delay in the
length of wire used to wind the coil, the actual
delay through the coil is likely to be half of that
value.

I follow you and am in some degree of agreement--now let toss there
stones at two of us ... LOL

This is most likely a gray area because of the lack of apparatus
available to most "normal" amateurs, which can do meaningful
measurements ...

Regards,
JS

Loading Coils; was : Vincent antenna
 

John Smith wrote:
However, if
anyone has a view to the contrary, I would be interested in the
specifics ...

In a coil wound on an iron-core toroid, do you believe
the flux follows the wire in the coil and ignores the
iron in the toroid?

Coupling is, of course, not nearly that good in an air-
core coil but coupling exists nonetheless. Some of
the current generated in a coil is through the air-core
transformer action between coils.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
John Smith wrote:
[said, "gray areas exist!]

In a coil wound on an iron-core toroid, do you believe
the flux follows the wire in the coil and ignores the
iron in the toroid?


At designed freqs, permeability of core material, turns
size/spacing--the core OVERWHELMS all other forms of magnetic
coupling--I cannot even begin to think how I would measure EM coupling
between turns in such an environment ...

Coupling is, of course, not nearly that good in an air-
core coil but coupling exists nonetheless. Some of
the current generated in a coil is through the air-core
transformer action between coils.

Air core, EM coupling between turns exists, in what degree--I simply
cannot, probably, afford the equipment to measure ...

As I stated, for at least the most part, we are in agreement ... it
seems only logical ... however, things are not always as they seem (now,
how's that for "wiggle room?" ;-) )

Regards,
JS

Loading Coils; was : Vincent antenna
 

Owen Duffy wrote:
That didn't come out very clearly. As I understand it, Cecil argues that
there is substantial phase change in the forward and reflected wave
components when considering the helix as a transmission line.

Yes, and there's hardly any phase change in the resultant
standing wave when they are superposed because their
phasors are rotating in opposite directions at the same
angular velocity.
--
73, Cecil http://www.w5dxp.com