On Dec 5, 6:38*pm, John Smith wrote:
Art Unwin wrote:
... So what exactly forces a time varying current
to take an alternate route of travel from the center of a conductor
when the resistance is so low compared to other routes that could be
taken.?
*Note : center resistance is lower than that on the surface because
skin depth (opposing eddy currents) cannot form.
Art
I think that question is probably best answered with a question(s) ...
What is a thin element?; *What is a thick element? *What is the surface
area of the element(s) in question?; what are the power densities
involved?; *Does the surface quality of the element cause these
measurements to vary?; *In all cases ever recorded, is it ALWAYS the
level you gave, i.e., no anomalies?
I have always thought 1/4 copper tubing with a tenalized SS welding wire
of heavy gage though its center was superior at high power, a lot get by
with much thinner elements. *On 10m and lower, I would, generally, use
heavy wall copper pipe of 1/2", or so ... on wifi antennas, I use 1/8
heavy wall brass hobby tubing--I suspect no advantage over thin wall.
I would love access to facilities to investigate this, that lacking, I
would love data I could trust ... what do you find so interesting that
rf might be forced deeper into the surface of elements? *I assume from
all my readings and studies that rf prefers the surface--the higher the
freq(s) the more the phenomenon is noted/enforced.
Regards,
JS
Well John the impedance gets lower as the percent of the wavelength
goes down
Exercising limits when the radiation surface is zero then so is the
radiation
The point I am stating is that a fractional wavelength is less that a
wavelength
and copper losses thru the center is less than an ohm so where is
there a lesser
impedance route fot the current to travel to become a closed circuit
without radiating?
I am just making the point again that antenna knoweledge on this
newsgroup is very sparce
Most do not accept I sq R jn all cases,and most will not accept the
existence of a Faraday cage!
RF does prefer to exist on the surface if and only if contra forces
cannot be over come.
But then "engineers are not scientists" according to one poster so
perusal of white papers is not necessary
as the truth is unimportant. So the single question again........
What is the lowest resistance part from the top of a fractional
wavelength antenna to obtain a closed circuit?
Simple and to the point and no word games as the application of true
true science is indicated to those thus qualified
Art