Ok, I'll bite once more since you have put so much work into
that post.... :/

MK, that is the whole point, that you portray missing or not appreciating.

Yes. It is quite true. I don't really appreciate the importance of
knowing
if the current tapers across a coil or not. Even if I did, what could I
do about
it? But you can consider this a personal problem...

It might not matter to you, but I am sure many would benefit from knowing
more precisely what is REALLY going on and then use or correct their design
methodology.

How are you going to to fix what is not broke? There is nothing wrong
with the current state of mobile whip design. I don't see how it can be

improved without going to unpractical measures. Deciding whether or
not there is current taper across the coil is not going to help you
improve a mobile antenna one whit.
Now, I'll agree there might be other app's where it could be useful to
be aware of this, but not for mobile whips.

I think it is fine for you to ignore this and poh-poh it. But I know how
huge difference it made in my 160m mobile antenna when I extended the whip
to the front bumper with wire.

No kidding.... I've never heard of adding a longer whip to improve a
mobile antenna. :/ What does coil current taper have to do with this?
I could have told you about adding longer whips way before you even
thought
about current taper. I've never needed current taper technology to
know
that adding a longer top whip to a short mobile antenna will generally
improve
performance.
Have you ever tried Reg's "vertload"? You can play "what if" till the
cows
come home... I often have...

The lesson is, the higher you place the coil on the
radiator, the more turns you need to reresonate the radiator, the high
current portion of the antenna current distribution curve gets "stretched
up", better efficiency (larger area under the overall curve).

And this lesson is new? Get a grip...I've been aware of this for years.

And I think most others have been too...


This all is supported by reality, except "gurus" who insist that the current
is (about) the same across the coil and they make (theoretically) antenna
current to be higher across the tip and "more" efficient than it is.

You can't fool a field strength meter. It makes no difference whether
one
believes there is a taper or not, the antenna is still going to perform
the
same for a given coil height on a given height mast.


It is known how profound effect had replacement of loading stubs by coils in
the KLM 3 el. 80 m loaded Yagi. Better gain, huge improvement in the F/B and
pattern. Has been done and described. And this is just replacing the same
inductance value stub with coil, where delta current from stub wires was
enough to throw monkey wrench in the Yagi performance. Now consider larger
error from the wrong assumption or calculation caused by wrong current
magnitudes and distribution.

Not a very good example. Sure, replacing inferior stubs, or whatever
methods
of linear loading are usually going to be improved by changing to coil
loading.
No big surprise. If doing this makes a large improvement in f/b,
pattern, etc,
sounds like it was a poor design from the git go... I still don't
follow how
knowing about current taper is going to help you much here. How will
you
apply this knowledge? Will this "improved coil taper technology"
improve
performance more than 1 db? At this point, I won't be holding my
breath.


Heloooo guys!
Measure, feel, whatever, the frickin' current across the loading coil and
then come back and tell the world why it IS different, but IT CAN'T be so,
because you said so in the beginning and you just can't admit being wrong.

Dunno...I think you have me confused with someone who really gives a
hoot.
I could care less if you are right or wrong. What I want to know is how
is this
"knowledge" going to improve a mobile whip. ?
I'll grant you that there may well be cases where knowledge of this
could
be useful. Mainly when modeling very complex antennas.
But as far as the basic mobile whip, knowing about current taper across

the coil is not going to help you improve the antenna one bit.
Trying to say that it showed you that you need to add a longer
capacitive
whip to a 160m antenna is silly.
You can run "vertload" and see the appx best place for the coil very
quickly. No current taper technology will be used, yet it will be quite
accurate for most all uses.
This coil taper effect you have spent months trying to prove may seem
very important to you, but to me it's fairly ho-hum..."snore" It's
been shown
that the possible errors in modeling are going to be generally small
and usually under 1 db in most cases.
There may be something useful to come out of all this, but it ain't
going
to be an improvement of mobile antenna design. I think it's safe to
say you can take that to the bank. The optimum location of a coil
on a short whip is already well known and etched in fairly hard
material. Deciding there is current taper across the coil is not
going to change this.
MK