On 13 Nov 2003 06:02:50 GMT, (Tdonaly) wrote:

For those of us who like to lurk, such discussions can be entertaining, but are
essentially worthless, since they usually only consist of pronouncements
from on high unaccompanied by anything resembling logic or proof. Some
baseless technical rhetoric can be thought-provoking, however, just as some
religious beliefs are. Too bad most of it isn't.

Hi Tom,

Quite true. On the other hand, there is always an element of
substance to be investigated, or to reinvigorate long unexercised
issues. You said as much, but I don't mind putting some work into
these things to test the perspective of their impact.

The issue of lumped versus distributed loads has enough of that
perspective to merit discussion. It is too bad it is attended with
such a circus mentality. Further, it also illustrates how poor
planning, testing, and specification can seriously prejudice an
outcome. Even if the topics are specious, it can be shown that their
conclusive proofs are often spun from sheer imagination or frauds (aka
fractal claims). These tests of logic are often more important than
the lack of substance (look at all the folderol of photons, tachyons
and such metaphysical guff).

For instance, it motivated Mark to enquire into how much effect moving
the solenoid could have (which my model confirmed in its own tortured
way). It has also motivated Yuri to perform measurements with more
care to details and greater coverage (not just two data points). Roy
emerged to do some bench work (he may yet change his mind, but I
suppose that is stretching my luck ;-)

All fairly typical behaviors for our supposed avocation; but growing
rarer with the haughty attitude that mental gymnastics can answer it
all. To this point I've finished viewing one of Robert Pease's Online
seminars (Use and Mis-use of Amplifiers) and his single thumped home
admonition was to "Eschew SPICE."

For those who want the straight skinny from a battle hardened bench
designer, I recommend his online work at:
http://www.national.com/rap/
on the other hand, for those looking for cut-and-paste greek
citations, they will be put against the wall. :-)

Where's my bazooka?

73's
Richard Clark, KB7QHC

Given the length and diameter of the top and bottom antenna sections, and
the LENGTH and DIAMETER of the loading coil, program LOADCOIL will calculate
coil inductance and the number of turns needed to resonate the antenna to
any required 1/4-wave frequency.


The program allows the coil to slide up and down the antenna to optimise
radiating efficiency versus physical implementation. The inductance value,
number of turns and wire gauge are automatically varied to maintain 1/4-wave
resonance versus height.


As a self-check on resonance and other results, the base feedpoint Zin is
calculated. Zin can be used in another program to calculate tuner L and C
settings. A base loading coil can be conveniently included in a tuner.


The distribution of current along the antenna, including along the coil
especially if it is a long helix, and phase relationships, are necessarily
taken into account to estimate loss and radiation resistances. But such data
is not outputted because it's of no practical use to anybody and not worth
the screen space.


The simple radiation pattern of short vertical antennas is already very well
known.


Download program LOADCOIL in a few seconds from website below and run
immediately.
----
=======================
Regards from Reg, G4FGQ
For Free Radio Design Software
go to http://www.g4fgq.com
=======================

On Thu, 13 Nov 2003 06:57:17 GMT, Richard Clark
wrote:

[interesting comments snipped]
|
|All fairly typical behaviors for our supposed avocation; but growing
|rarer with the haughty attitude that mental gymnastics can answer it
|all. To this point I've finished viewing one of Robert Pease's Online
|seminars (Use and Mis-use of Amplifiers) and his single thumped home
|admonition was to "Eschew SPICE."
|
|For those who want the straight skinny from a battle hardened bench
|designer, I recommend his online work at:
|http://www.national.com/rap/
|on the other hand, for those looking for cut-and-paste greek
|citations, they will be put against the wall. :-)

No, they'll just swithch to the Taguchi method.