On 22 Sep, 16:47, art wrote:
On 22 Sep, 16:02, "Richard Fry" wrote:

"art" wrote O.K. I may have muddied things. I hold to the fact that a one
wavelength dipole will always radiate at a higher efficiency than a
1/2 wave dipole.

_________

Please post your definition of "efficiency," in this context.

RF

Power in vs power out of a system. I know how to do this for a
parallel circuit ala
a tank circuit where energy is released in equilibrium fashion. For a
half wave dipole
you can't have two energy containers so you may or may not be heading
for excess end effects because of high voltage looking for where it
has to go. (Personally I don't know how a half wave radiates because
that form vuews the cyclic current continually radiating as the time
variant which is contrary to all other radiations i.e. a spark plug,
ahydregen bomb which is a bigger container that a flyback transformer
and a bigger container will always beat a small container with respect
to out going accelleration of energy, particles or plasma which ever
you may prefer)without any known proof.I believe that is why the quad
was designed to get away from the spark plug type emmissions at the
ends of the radiator.
On the other side of the coin, since both a quad and a 1/2 wave dipole
is assumed to be suitable drivers for a yagi array both must be bi
directional so gain is applicable when comparing these radiators I
would would think!
Best regards
Art

Richard , I have been reviewing antenna fundamentals as per the
engineering
handbook by Jasik second edition where it states
"The method of computing radiation patterns foir thin linear radiators
is basic regardless of length or complexity of shape " if one assumes
that the current from point to point is sinosoidal. This statment is
consistent with the present assumption that the time variant current
is sinosoidal at every point along the length of the antenna.
Well I have clearly shown for a parallel circuit you cannot pursue
this assumption anymore even tho the books state otherwise. The books
are not incorrect if the mathematics produced by such a assumption is
correct which mathematicians often do when there is an absence of
knoweledge to the contrary. What I am declaring is the tank circuit
ala parallel circuit which demands a full wave length antenna is the
most efficient because the assumption by mathematicians is incorrect.
Following Gauss's laws for static and enlarging the format to a
dinamic situation i.e. time varient then the demand is for a
arrangement in "equilibrium" which cannot be attained with anything
other that a full wave length. Following this logic mathematically it
concurrs with Maxwells laws and any computor program will move away
from any half wave radiator if you ask for maximum gain and allow it
to computeaway from a planar arrangement under Maxwells laws.( By the
way I always refer to a full wavelength radiator which by no means
infers
a center feed. In my case I usually follow the end fed aproach because
of a dual windings but in opposite directions)
If Maxwell had in his portfolio an expanded Gaussuian law for making
his jigsaw complete the overall picture would have been completed in
no time. Unfortunately he did not have this at hand but instead used
Faraday and others input
to arrive at the correct answer but with gaps in the info provided. It
is for that reason I persued this analogy which is new and contrary
with existing assumptions even tho the eventual answers are the same.
BUT the analogy of assumption of time varient current of itself
produces radiation is incorrect at least for a parallel circuit,
aspark plug with a flyback transformer or even the emmisions of a
nuclear explosion. I don't think there is a need to dither on the
subject anymore since nobody knows how a fractional wavelength antenna
really works whereas I am promoting a view of an arrangement in
equilibrium and the commonly used approach by Gauss and others with
respect to a closed arbitary field. Enjoyed the discussion tho, very
thought provoking.
Regards
Art
antennas