Loading Coils; was : Vincent antenna
 

On Sun, 02 Dec 2007 14:23:33 -0800, John Smith
wrote:

"Skips along", as in some portion of the signal is coupled to adjacent
turns

As you admit this is a struggle of concepts, are we talking about
picoSeconds?

73's
Richard Clark, KB7QHC

Loading Coils; was : Vincent antenna
 

Richard Clark wrote:

...
As you admit this is a struggle of concepts, are we talking about
picoSeconds?

73's
Richard Clark, KB7QHC

Richard:

I have no horse in this race ... I am just interested in the discussion.

Warm regards,
JS

Loading Coils; was : Vincent antenna
 

"AI4QJ" wrote in
:

....
With the coil in series with its internal resitance, the phase angle
of the current will be the same throughout all components in the
circuit. Of course with parallel components, the vector sums of the
current though each component must follow kirchoff's law. In parallel

Then you are doing a lumped element approximation.

It is probably adequate for analysis of a short loading coil.

That is probably not a suitable method to analyse a helically loaded
monopole (where the monopole consists of nothing but a helix).

Owen

Loading Coils; was : Vincent antenna
 

Owen Duffy wrote:
"AI4QJ" wrote in
:

...
With the coil in series with its internal resitance, the phase angle
of the current will be the same throughout all components in the
circuit. Of course with parallel components, the vector sums of the
current though each component must follow kirchoff's law. In parallel

Then you are doing a lumped element approximation.

It is probably adequate for analysis of a short loading coil.

That is probably not a suitable method to analyse a helically loaded
monopole (where the monopole consists of nothing but a helix).

Owen

Interesting ... a thought jumps to mind, an equation to determine the
"most efficient" pitch/dia-to-length helix, with freq being the
determining factor ... esoteric? Maybe. Ahh, perhaps I just wish a
break in exoteric knowledge.

Regards,
JS

Loading Coils; was : Vincent antenna
 

On Sun, 02 Dec 2007 17:59:18 -0800, John Smith
wrote:
As you admit this is a struggle of concepts, are we talking about
picoSeconds?
I have no horse in this race ... I am just interested in the discussion.

Then you shouldn't lay down on the track.

73's
Richard Clark, KB7QHC

Loading Coils; was : Vincent antenna
 

On Sun, 02 Dec 2007 22:32:50 GMT, Cecil Moore
wrote:

In what, about 2-4 ns?

No, it increases the VF by roughly 2x in a typical coil.
Why don't you already know that fact?

So, 4-8 nS?

Loading Coils; was : Vincent antenna
 

Richard Clark wrote:

[quite normal chit--for him]
73's
Richard Clark, KB7QHC

Don't attempt to jockey another mans' ride, nor temp him to another
race/horse ...

JS

Loading Coils; was : Vincent antenna
 

On Sun, 02 Dec 2007 20:58:45 -0800, John Smith
wrote:

Don't attempt to jockey another mans' ride, nor temp him to another
race/horse ...

Last month when I was in Africa's airports, I heard better English
there than I heard when I landed at Dulles. Are you trying to place a
bet, or complaining about your shorts?

73's
Richard Clark, KB7QHC

Loading Coils; was : Vincent antenna
 

Richard Clark wrote:
On Sun, 02 Dec 2007 20:58:45 -0800, John Smith
wrote:

Don't attempt to jockey another mans' ride, nor temp him to another
race/horse ...

Last month when I was in Africa's airports, I heard better English
there than I heard when I landed at Dulles. Are you trying to place a
bet, or complaining about your shorts?

73's
Richard Clark, KB7QHC

Richard:

In all the world, the only person I've run into that even strikes me as
the "type" of personality as you possess is my mother in law, thank gawd
she has little use for shakespeare--gawd bless her soul ... LOL

Regards,
JS

Loading Coils; was : Vincent antenna
 

On Dec 2, 2:02 pm, Cecil Moore wrote:
...
In a traveling-wave environment, the phase changes
every inch around the circuit and I can calculate
that phase change...

OK, I live in a very cold environment (freespace) and I've discovered
I can make and use high-temperature superconductors here, so I can
wind very small coils that still have high Q. In fact, the Q is
practically infinite, even for small coils. I've made a dipole from
0.1 inch diameter wire, 16 feet long total (192 inches). Four feet
from each end I've put a coil of about 390 turns (gets a bit hard to
keep track of the count) of very fine wire in a helix 0.1 inches
diameter and 0.2 inches long. This seems to give me resonance at
3.9MHz, though a rather nasty low feedpoint impedance. Master guru,
can you tell me please the travelling-wave phase change from one end
of one of those coils to the other end of the same coil, at 3.9MHz, in
the described environment? And can you tell me why I should care
about that?

I'm also experimenting with capacitively loaded long antennas, and I
have another dipole that's 180 feet long, also made from 0.1" diameter
wire. I've put tiny capacitors 45 feet in (25% of the total length)
from each end, and adjusted them for resonance at 3.9MHz. This yields
a much easier to feed feedpoint impedance. They are, like the coils,
the same diameter as the wire, and about 0.04 inches long. Master
guru, can you tell me please the travelling-wave phase change from one
end of one of those capacitors to the other end of the same capacitor,
at 3.9MHz, in the described environment? And can you tell me why I
should care about that?

(And how about trying to surprise us all, and quote and answer the
whole thing, not just some select part, huh?)