"Brian Kelly" wrote in message
...
On Mar 7, 6:09 pm, Art Unwin wrote:
On Mar 7, 4:45 pm, "Dave" wrote:







"Art Unwin" wrote in message

...

On Mar 7, 2:08 pm, (Richard Harrison) wrote:
I disagree. Laws written are all based on the assumption of
equilibrium and that includes
Maxwell's laws. These laws hav e zero refernce to size as such though
many would seek

because contrary to what those male enhancement product adds tell you,
size
doesn't matter.

for the word volume. Pertinent factors are wave length of frequency in
The problem here is that amateur radio is wellded to the yagi design
which is not one of equilibrium

WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the
simple
half wave dipole WAS a prefect example of equilibrium! NOW it isn't???
have you had a new revelation while i had your old email address
plonked??

David,
You admit to not understanding the term "equilibrium" so what do you
care what I say and in what content.
If you consider a half wave dipole as being in equilibrium you have to
consider the electrical circuit
consisting of a capacitance from the antenna to ground or the route
thru the center of of the radiator, both of thes circuits
can be considered as being in equilibrium. However, on this newsgroup
a fractional wavelength radiator is considered as an open circuit for
some reason and thus under those circumstances the half wave dipole is
not in equilibrium.
Now your views on radiation is all over the place so it is very hard
for me to determine the context of what you say.
Art

Long before we rode our dinosaurs to club meetings the bright lights
had completely agreed that the strength of radio signals at far off
places was a function of the integral of i·dl where dl is the bigness
of the aerial. Maybe it's in Sears and Zemansky. I dunno . . nor do I
really care.

w3rv

Antennas for All Applications, 3rd Edition, Kraus & Marhefka, McGraw-Hill,
page 12.

Begin quote

Regardless of antenna type, all involve the same basic principle that
radiation is produced by accelerated (or decelerated) charge. The basic
equation of radiation may be expressed simply as

IL = Qv (A m / s)

where

I = time-changing current, A/s
L = length of current element, m
Q = charge, C
v = time change of velocity which equals the acceleration of the charge, m/s

Thus, time-changing current radiates and accelerated charge radiates. For
steady-state harmonic variation, we usually focus on current. For transients
or pulses, we focus on charge. The radiation is perpendicular to the
acceleration, and the radiated power is proportional to the square of IL or
Qv.

end quote

Cheers,
John