Hi Rich I will try to use my words carefully as I am optomistic
that we are getting close to my long term bogey.


"Richard Clark" wrote in message
...
On Thu, 04 Mar 2004 22:31:40 GMT, "aunwin"
wrote:
...
give the pros and cons between a series
circuit and a parallel circuit from which to base a radiator ?
...
Just to give you a start a series circuit radiator is a dipole.

And we will
say a parallel circuit radiator is one with at least one capacitive
lumped
circuit and one inductive lumped circuit in parallel.
...
Here is a start
A dipole provides a lot of signals at the same time( good)
A parallel circuit can only supply one signal at a time (bad )
Get the idea?

Hi Art,
A dipole is the most efficient antenna.

Well I know that is your position but what are you comparing it with and
what parameters
are you focussing on to form an efficiency term ?


The parallel circuit offers loss to an already most efficient
antenna..

Well looking at them separately rather than adding one to another.
What losses are you refering to in a parallel circuit assuming that the
circuit is resonant?. Is it of magnitude that one gets when adding an
impedance matching unit say on a 160 metre style shortened dipole or similar
antenna?

A dipole is simple to load and often requires no matching.

Yes, that is true and very important, possibly a good reason to make it a
standard in all its different aspects with respect to ground and radiation
foot print.


The parallel circuit is difficult to load and always requires
matching.

No........ The parallel circuit need not require any external matching
system which is a huge plus.


A dipole offers a standard of gain.

Anything can be adopted as a standard to compare to so this is a non runner.


The parallel circuit offers no change in gain except the prospect of
reducing it through making the antenna smaller to become a resonant
system.


As a dipole moves away from its resonant point gain losses occur,
swr increases and limits the frequency span of use.
A parallel circuit which provides movement of the resonant point
has no loss in gain, minimul change in SWR and thus less constraint on
frequency span that can be used.

Shortening comment I fully agree with, that eventually can open many doors.


A dipole is a simple construction.

I fully agree


The parallel circuit adds complexity which raises the prospects of
mechanical and electrical failure.

Yes, you are of my generation that was brought up on the idea of less moving
parts. But our generation has made such huge advances in Quality control
together with the introduction of solid state construction that we now have
a throw away economy.
In ham radio we now see solid state construction with high intricasy of
moving parts, in radios, remote matching systems and yes even with antennas
such as the IR antenna. Our generation is now in the minority on that
subject.



A dipole offers hazardous potentials at its tips.

True but it has not been of sufficient danger for manufacturers to place a
warning tag at each end.


A parallel circuit double that danger by offering hazardous potentials
at both its tips and its drive point.


Should be zero change in drive point at the antenna input port
and should provide less voltage hazards as it would tend to lower voltages
and increase current which is the prime requirement for radiation. This
point is one of the main points I fail to understand
why the group will not embrace.

A dipole requires isolation/insulation at its tips due to high
potentials.

Repeat

A parallel circuit requires isolation/insulation at its drive point
AND its tips due to high potentials.

Is that the idea? I presume you can distinguish good/bad.

73's
Richard Clark, KB7QHC

Yes Richard I think that narrows the issue down very nicely and prevents
mischevious comments that foster disarray.

Obviously enclosed in the above there is something that I am tripping over
thru the years and I have no doubt that you will eventually point to it and
here I must put up or shut up.
Even if it is demonstrated where I am in error it is a positive for me in a
learning cycle.
Could we now focus on those points that we disagree and push the others
aside and only return to them if it is pointed out that we were both wrong.
You continue with the lead as it is working nicely.
Thanks so much for aproaching with an open mind in a true academic fashion
which will eventually arrive at the main point of contention that I have
failed to grasp before intential spoilers
arrive as they have done with forums such as.......well you know what I mean
Best regards
Art