Reg Edwards wrote:
So KISS ! In plain unabbreviated English.

That's exactly what I try to do, Reg. But everyone keeps asking me to
prove my concepts using Maxwell's equations, as if that was possible
on an ASCII newsgroup. My attitude is: If they are incapable of
arguing concepts, then they probably don't know what they are talking
about anyway. When I ask for a conceptual thumbnail sketch and am refused,
that's exactly what I assume. Even Einstein was capable of presenting his
relativity concepts in a language that most technical people could understand.
--
73, Cecil http://www.qsl.net/w5dxp



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(Richard Harrison) wrote in message ...
Art Unwin wrote:
"It is in this area that I view stagger tuning or coupling to be
efficient in character."

This is a struggle against nature. Like the double-tuned stagger
frequency transformer, the wider the frequency separation, the less the
coupling.

Richard it is no use bringing up the subject that you have told Art
e.t.c.
As far as I am concerned you do not have the faintest idea of what my
antenna consists of ...or..you don,t know what you are talking about
However you are in good company as the whole idea has been trashed by
the newsgroup and without dissention it was agreed that I have no
credability
Can't type either) So why are you bringing up the idea again of
antenna coupling?
That particular horse is dead.
You would be better off looking at your books and pulling out a
statement verbatum regarding a conjugate match or the date of Termans
birthday than trying to bait me on a subject where I have already
received a hiding from resident gurus and bypassers alike.

Art.



Another item promotes coupling in a transformer. It is placement of the
coils so they share flux. An opposite phenomenon is at work for Art, as
I`ve told him for the nth time. A small loop has a null in its radiation
perpendicular to the plane of the loop. Art`s loop shares the plane of
his dipole. The loop is suspended form the dipole and actually shares
conductor.

The dipole has maximum desired radiation perpendicular to the plane
containing the loop. At horizontal and low-angle directions to the
earth, this is the direction of the loop`s null. No way could radiation
from the loop reinforce dipole radiation.

In a yagi, the reflector is tuned lower in frequency and the director is
tuned higher in frequency than the driven element. The purpose of this
detuning is to get proper phasing between the elements so that director
directs and the reflector reflects and not vice versa. But, in the case
of the yagi, radiation of all the rods is in the same plane that they
share and that contains the desired direction of signal transmission /
reception.

In a dipole which shares conductor with one side of a suspended loop,
the only possible loop contribution to the dipole`s radiation is
straight up, or straignt down, or toward the ends of the dipole. This
could help it approach an isotropic antenna more closely. The isotropic
has about 2 db less gain than a dipole alone. Or, a slight gain toward
the earth, the zenith, or the dipole ends might be realized, as stated
before.

Best regards, Richard Harrison, KB5WZI

W5DXP wrote:

Jim Kelley wrote:
You're arguing with me about it right now in another thread! :-)

If you really believe that, Jim, you are *extremely* mentally ill.
Go obtain some medication for your problem and get back to us.

My joke was apparently too subtle. It is impossible for me to be
reading this thread "right now" while arguing with Jim "right now"
on another thread. Sorry, it was a poor attempt at a play on the
words, "right now". I certainly don't think Jim is mentally ill.
--
73, Cecil http://www.qsl.net/w5dxp



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Cecil wrote,

My joke was apparently too subtle. It is impossible for me to be
reading this thread "right now" while arguing with Jim "right now"
on another thread. Sorry, it was a poor attempt at a play on the
words, "right now". I certainly don't think Jim is mentally ill.
--
73, Cecil http://www.qsl.net/w5dxp




No, but he will be if he keeps arguing with you. Most of
the rest of us value our mental health too much to argue an
infinite thread with an obsessed Texan.
73,
Tom Donaly, KA6RUH

Cec, from where do you get all your energy?

Is it from fire water you have now stopped trading for buffalo hides from
the injuns?
---
Reg

Art Unwin wrote:
"As far as I am concerned you do not have the faintest idea what my
antenna consists of ...or,,you don`t know what you are talking about."

How does Art`s antenna differ from Fig 10(A) on page 26-9 of the 19th
edition of the ARRL Antenna Book?. In that figure, the input of the "T"
is inductive until the series capacitance brings it into resonance.

The tuning section of Fig 10(A) forms a small loop. See Fig 4 on page
5-3 of the same Antenna Book for the small loop radiation pattern. Also,
see Fig 12 on page 2-8 for the dipole radiation pattern. Note that lobes
are perpendicular to the wire and plane of the dipole, and perpendicular
to the axis of the small loop. There are nulls perpendicular to the wire
and plane of the loop.

The loop`s null can`t help the dipole`s lobe. It can`t hurt it either,
other than by radiating some energy that might otherwise have gone into
the dipole. As the loop is small ( 0.1 lambda is one definition), its
contribution to radiation may be small. As the loop size grows, so will
its radiation, and its null will decline.

How does Art`s antenna differ from a T-matched dipole?

Best regards, Richard Harrison, KB5WZI

Reg Edwards wrote:
Cec, from where do you get all your energy?

A congenital insatiable thirst for knowledge. I asked my
first grade teacher, "Why is one plus one equal to two?"
She didn't know. I finally got my answer years later when
I took a "Foundations of Mathematics" college course.
--
73, Cecil, W5DXP

Dr Slick.
When the term efficiency is used on this newsgroup
it always leads to dissention.
As Roy pointed out efficiency is a ratio between two factors
X and Y only. Unfortunately in this newsgroup
people have a tendency to use Y in their derivation of efficiency
which results in people talking past each other.
I suspect we have a bit of that in this thread
Have a great day
Art




(Dr. Slick) wrote in message . com...
(Art Unwin KB9MZ) wrote in message om...
Roy Lewallen wrote in message ...
I hope you'll pardon me for amplifying this a little.

If you put X watts into the primary of a transformer and extract Y watts
from the secondary, the efficiency is Y/X by definition.

Yes Roy. The specifics of what is being discussed is all important
when looking at answers as well as what terms are being used to
measure 'efficiency' and to what ends.


Roy is correct. And if both transmit and receive antennas were
directional Yagis pointed at each other instead of regular dipoles,
the efficiency would go up.



As you are surely awawe I too look at antennas as transformers or
coupled circuits and thus the primary contributes very much in its own
way as far as radiation as does the secondary. Thus 'efficiency' as a
criteria of 'value'
is all important when using it as a term since as you point out it is
a ratio of two terms both of which have to be made very clear for the
term efficiency to be made clear
Thus in stagger tuning it is important to define your requirements in
terms of bandwidth (dual frequency radiation) or max gain ( dual
radiators on the same frequency),the above bearing little difference
to old time receiver designwith multiple I.F. cans. It is in this
areana that I view stagger tuning or coupling
as being efficient in charactor. If I am incorrect in the above
assumptions I would welcome any correction from those well versed
inthe field.
Best regards
Art



Broadbandedness by itself is not a measure of efficiency. You
may still be very inefficient, over many octaves!


Slick

If you put X watts into one antenna and extract Y watts from an antenna
coupled to it, and measure the efficiency of the "transformer" the same
way as you did the conventional transformer, you'll find it has lousy
efficiency. Why? Because a goodly fraction of the power you applied to
the "primary" antenna never gets to the "secondary" antenna because it's
radiated instead. As far as the "secondary" is concerned, it might as
well have been converted to heat.

If you look at the impedance of the "primary" antenna, you'll find an
excess of resistance -- just enough, in fact, to account for the "lost"
(radiated) power.

This isn't a statement about how well coupled antennas function as
antennas, whose purpose is to radiate after all. It's a statement about
how well they function as a transformer. Poorly.

Roy Lewallen, W7EL

Dr. Slick wrote:
(Art Unwin KB9MZ) wrote in message m...

1. Two antennas (also called transducers) placed close together
actually can be considered a transformer, albeit a very inefficient
one.

Humm...By antenna I assume it also means a radiator. This would
suggest
that a stagger tuned radiators would fall into the catagory discussed
above.
Now I have a problem with that statement, because I very much see it
as a transformer which is VERY efficient and not as you stated "albiet
a very inefficient one".
Can you explain to me how a stagger tuned antenna migrate into
inefficient radiators?
Seems to me that Thevenin's theorem would show this as being
incorrect !




Well, two identical antennas spaced a few wavelengths apart can
be considered a transformer, but very inefficient compared to a "real"
transformer with identical primary and secondary turns, with an
appropriate toroid core. This would be because the core material will
increase the magnetic flux density, and will increase the coupling
between the two windings/transducers.

Point is, the farther apart the antennas are, the less efficient
of a "transformer" they will be.

I'm not familiar with stagger tuned antennas, although the name
would suggest that it is tuned for multiple resonances, so that the
antenna will be broadband.



Slick

Dr Slick.
When the term efficiency is used on this newsgroup
it always leads to dissention.
As Roy pointed out efficiency is a ratio between two factors
X and Y only. Unfortunately in this newsgroup
people have a tendency to use Y in their derivation of efficiency
which results in people talking past each other.
I suspect we have a bit of that in this thread
Have a great day
Art




(Dr. Slick) wrote in message . com...
(Art Unwin KB9MZ) wrote in message om...
Roy Lewallen wrote in message ...
I hope you'll pardon me for amplifying this a little.

If you put X watts into the primary of a transformer and extract Y watts
from the secondary, the efficiency is Y/X by definition.

Yes Roy. The specifics of what is being discussed is all important
when looking at answers as well as what terms are being used to
measure 'efficiency' and to what ends.


Roy is correct. And if both transmit and receive antennas were
directional Yagis pointed at each other instead of regular dipoles,
the efficiency would go up.



As you are surely awawe I too look at antennas as transformers or
coupled circuits and thus the primary contributes very much in its own
way as far as radiation as does the secondary. Thus 'efficiency' as a
criteria of 'value'
is all important when using it as a term since as you point out it is
a ratio of two terms both of which have to be made very clear for the
term efficiency to be made clear
Thus in stagger tuning it is important to define your requirements in
terms of bandwidth (dual frequency radiation) or max gain ( dual
radiators on the same frequency),the above bearing little difference
to old time receiver designwith multiple I.F. cans. It is in this
areana that I view stagger tuning or coupling
as being efficient in charactor. If I am incorrect in the above
assumptions I would welcome any correction from those well versed
inthe field.
Best regards
Art



Broadbandedness by itself is not a measure of efficiency. You
may still be very inefficient, over many octaves!


Slick

If you put X watts into one antenna and extract Y watts from an antenna
coupled to it, and measure the efficiency of the "transformer" the same
way as you did the conventional transformer, you'll find it has lousy
efficiency. Why? Because a goodly fraction of the power you applied to
the "primary" antenna never gets to the "secondary" antenna because it's
radiated instead. As far as the "secondary" is concerned, it might as
well have been converted to heat.

If you look at the impedance of the "primary" antenna, you'll find an
excess of resistance -- just enough, in fact, to account for the "lost"
(radiated) power.

This isn't a statement about how well coupled antennas function as
antennas, whose purpose is to radiate after all. It's a statement about
how well they function as a transformer. Poorly.

Roy Lewallen, W7EL

Dr. Slick wrote:
(Art Unwin KB9MZ) wrote in message m...

1. Two antennas (also called transducers) placed close together
actually can be considered a transformer, albeit a very inefficient
one.

Humm...By antenna I assume it also means a radiator. This would
suggest
that a stagger tuned radiators would fall into the catagory discussed
above.
Now I have a problem with that statement, because I very much see it
as a transformer which is VERY efficient and not as you stated "albiet
a very inefficient one".
Can you explain to me how a stagger tuned antenna migrate into
inefficient radiators?
Seems to me that Thevenin's theorem would show this as being
incorrect !




Well, two identical antennas spaced a few wavelengths apart can
be considered a transformer, but very inefficient compared to a "real"
transformer with identical primary and secondary turns, with an
appropriate toroid core. This would be because the core material will
increase the magnetic flux density, and will increase the coupling
between the two windings/transducers.

Point is, the farther apart the antennas are, the less efficient
of a "transformer" they will be.

I'm not familiar with stagger tuned antennas, although the name
would suggest that it is tuned for multiple resonances, so that the
antenna will be broadband.



Slick

Reg Edwards wrote:

Here in Euro-side an amateur radio ticket can be obtained without ever
having heard of it. And what with present educational standards that's
nearly all of us.

The trouble with Guru's displaying their knowledge on this newsgroup is
failure to appreciate the technical standing of their 'pupils'. Yet as often
as not the manner in which questions are asked are a dead giveaway. For a
reply to be of value it is necessary for the Guru to 'tune in' to the
recipient, ie., become resonant in same sort of language.

Too seldom is any thought given to it. As a result I would guess many
questioners become so confused or overloaded with haggling between the
'experts' they don't bother reading to the end of the thread, possibly to
consider packing up the hobby. It is impossible for a novice in a particular
subject to distinguish wheat from chaff, or to choose between one old-wive's
tale and another. Confusion reigns!

My assessment as one of the "less washed" is that I can kind of
understand some of what is being argued.

But too much pouncing on minutaia, too much of what sounds like the
antagonists saying the same thing in a different way, and too much
personal junk all over the place, and it ends up doing everyone no good
at all, especially the antagonists. But of course, it doesn't really
matter what I think. I suspect that despite some aggravation and
digestive tract angst, they are enjoying it.

In the end, it is just a Warholesqe repetitive, stretched out artwork.



So KISS ! In plain unabbreviated English.


Or (ironically enough -- Occam's Razor!!-- 8^)

- Mike KB3EIA -