On Sat, 22 Sep 2007 19:18:24 -0700, art wrote:

Richard , I have been reviewing antenna fundamentals as per the
engineering
handbook by Jasik second edition where it states

Equation (1-1)

efficiency = power radiated by antenna / power accepted by antenna

There is absolutely nothing stated here about "Gain" because radiation
is in every direction. An antenna is a passive device, it cannot
exhibit gain. Johnson and Jasik sez: "if one has a lossless antenna,
the directivity and gain are identical."

Equation (1-2): "The total power radiated from the antenna is" the
measurement of radiation intensity in watts/sr in every direction from
an antenna.

Equation (1-4): "Directivity is the measure of the ability of an
antenna to concentrate radiated power in a particular direction."
which is a sub-portion of the total radiation.

We can measure the total power of all radiation (EZNEC provides this);
we can measure the power accepted by an antenna (EZNEC provides this);
we can measure the power in a particular direction (EZNEC provides
this).

"The method of computing radiation patterns foir thin linear radiators
is basic regardless of length or complexity of shape "

There is for EVERY length.

"if one assumes
that the current from point to point is sinosoidal.

"for the case of a thin half-wave radiator which can be assumed to
have a sinusoidal current distribution"

This statement is NOT about efficiency and it specifically recites
what can be said about:
1. radiation patterns;
2. radiation resistance;
3. "gain" (directivity);
4. input Z.

We, in this group, quite typically express ALL of these qualities for
ANY antenna on the basis of SPECIFIC physical dimensions and
frequency. When we do, there is barely a half dB variation in any
answer, and often better when all SPECIFIC physical dimensions and
frequency are provided by the claim maker.

As you often fail to provide this SPECIFIC information, then your
claims descend into the category of myth and superstition (you can
call it hope and desire).

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.

This is superstition.

This Voodoo can be easily tested. The first part of equation (1-1)
from the authors you quote demand you supply the SPECIFIC power
accepted by an antenna. You also fail to supply the second part of
equation (1-1) that states the SPECIFIC power radiated by the antenna.

Voodoo = 100%

So, to SPECIFIC counter proofs:

A half wave antenna in free space:
length = 33.43 feet
wire diameter = #12 wire
frequency = 14.28127 MHz
input Z = 72.12 ±j0.00 Ohms
Power accepted by antenna = 100W
Power radiated by antenna = 100W
Efficiency = 100%

Absolutely same antenna in free space at its full wavelength
frequency:
length = 33.43 feet
wire diameter = #12 wire
frequency = 28.463975 MHz
input Z = 4257 ±j0.00 Ohms
Power accepted by antenna = 100W
Power radiated by antenna = 100W
Efficiency = 100%

BOTH antennas exhibit radiation patterns IDENTICAL to Johnson and
Jasik. BOTH antennas exhibit input Zs IDENTICAL to Johnson and Jasik.
BOTH antennas exhibit radiation patterns IDENTICAL to Johnson and
Jasik. BOTH antennas exhibit radiation resistances IDENTICAL to
Johnson and Jasik. BOTH antennas exhibit radiation gain (directivity)
IDENTICAL to Johnson and Jasik.

When either of these two are off-center fed the efficiency DOES NOT
CHANGE:
Power accepted by antenna = 100W
Power radiated by antenna = 100W
Efficiency = 100%

nobody knows how a fractional wavelength antenna
really works

Total ignorance reveals:
Voodoo = 100%

Equation (1-1) and (1-2) are for any size antenna. All of this stuff
is in the FIRST TWO PAGES OF THE BOOK.

On the very first page of "Fundamentals of Antennas"
"If the current distribution on a wire is known ...
then the radiation pattern and the radiated power
can be computed."

Marconi could measure current distribution 100 years ago.

The authors, of course, give treatments for antennas of all sizes,
otherwise the book would only be three pages long.

Arthur, stop coloring the pages with your crayons long enough to try
reading at least these three pages. :-0

73's
Richard Clark, KB7QHC

"Richard Clark" wrote ...
On Sat, 22 Sep 2007 19:18:24 -0700, art wrote:

Richard , I have been reviewing antenna fundamentals as per the
engineering
handbook by Jasik second edition where it states

Equation (1-1)

Massive snip of good stuff

Arthur, stop coloring the pages with your crayons long enough to try
reading at least these three pages. :-0

73's
Richard Clark, KB7QHC

Richard: I love to watch you tilt at windbags!!!!

Mike W5CHR

On Sep 23, 11:18 am, art wrote:
In comparing two antennas with similar omni direction radiation field
I state that gain in the field is indicative of increased radiadion ...

....yes, but radiation only in limited az/el sectors, at the expense of
loss of radiation in the other sectors.

The field gain in a particular direction is due to the change in
pattern shape, not an increased radiation efficiency of the "better"
antenna.

For the same input power accepted by different antennas, the total
power radiated into the volume of space is the same, no matter what
the shapes of their respective radiation envelopes.

"Jimmie D" wrote in message
...

"Walter Maxwell" wrote in message
...
On Sat, 22 Sep 2007 19:19:18 -0700, wrote:

On Sep 22, 5:40 pm, 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.

If it does, I doubt it's enough to measure on the air..

The example I gave as for an instance was a quad
versus a 1/2 wave dipole.
This is readily seen by any operator empirically.

I've never seen it here. For that reason, I hardly use loops.
Neither vertically oriented, or horizontal as for NVIS use.
I don't see them as worth the extra trouble. Being I tested
them on 75m using NVIS paths, a noticable difference in
efficiency should have been readily apparent. It wasn't.
In fact, I usually has slightly better performance using the
dipoles, which I think was due to the bulk of the max current
portions of the antenna being higher above ground in general.
The loop sagged a bit in areas, and wasn't all that high above
ground. The more wire near the ground, the more ground loss
in general.

Mathematically it is
proven that way also even tho both are in accordance to Maxwell's
laws.

Where is the math? You should find a very slight difference
at best..
It's common knowledge that even a short piece of wire 1/10
of a wave long will radiate nearly all the power that is applied
to it.
You can go lots shorter than that if you want.
If even a short piece of wire will radiate nearly all the power
applied to it, what is the point on harping about some magical
properties of a full wave length of wire?
Art, you are starting to bark at the moon I'm afraid...

I was going to comment on some of your other posts, but I
think I'll spare you the increase in blood pressure.
All I can say is that you are starting to wander off in
mumbo jumbo land again..
Replacing known science with conjured mumbo jumbo is no
way to live.
MK





Art, it distresses me to read the misleading statements you profess to be
true in your posts.

There is no difference in the 'efficiencies' between a full-wave and a
half-wave dipole. Let's assume the wire
size and conductivity of each dipole is such that we can say they both
radiate 98 percent of the power
delivered to them. Let's also say that the same amount of power is
delivered to both dipoles. What now is the
difference in the radiation between the two dipoles?

The only difference is in the SHAPE of the radiation patterns--the
full-wave dipole will have a somewhat
narrower lobe in the direction broadside to the dipole than that of the
half-wave dipole, therefore deriving
slightly more gain IN THAT DIRECTION than that of the half-wave, but with
less gain than the half-wave in all
other directions. Consequently, the total integrated power in either
radiation pattern will be exactly the
same!!!

If you want to express the mathematics of the conditions I described here
according to J.C.Maxwell's
equations, you will find that Maxwell's equations fit the conditions
EXACTLY.

Walt, W2DU

If any difference at all exist it is that the full wave antenna would be
ever so slightly less efficient due to the ohmic losses of the extra wire.

Jimmie

don't claim that until you have modeled it in full. it may actually have
lower currents spread out over the longer wire thus giving smaller I^2*R
losses. consider this 'obvious' case... 1V across 100' of wire that
measures 1ohm... draws 1A... power dissipation is 1^2*1 for 1watt.... now i
double the length of the wire expecting to get more heat... now there is 1V
across 200' of wire, but the resistance is now 2ohms... I is now .5A, .5^2*2
= .5watts. those squared terms will get you every time.

On 23 Sep, 11:45, "Jimmie D" wrote:
"Walter Maxwell" wrote in message

...





On Sat, 22 Sep 2007 19:19:18 -0700, wrote:

On Sep 22, 5:40 pm, 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.

If it does, I doubt it's enough to measure on the air..

The example I gave as for an instance was a quad
versus a 1/2 wave dipole.
This is readily seen by any operator empirically.

I've never seen it here. For that reason, I hardly use loops.
Neither vertically oriented, or horizontal as for NVIS use.
I don't see them as worth the extra trouble. Being I tested
them on 75m using NVIS paths, a noticable difference in
efficiency should have been readily apparent. It wasn't.
In fact, I usually has slightly better performance using the
dipoles, which I think was due to the bulk of the max current
portions of the antenna being higher above ground in general.
The loop sagged a bit in areas, and wasn't all that high above
ground. The more wire near the ground, the more ground loss
in general.

Mathematically it is
proven that way also even tho both are in accordance to Maxwell's
laws.

Where is the math? You should find a very slight difference
at best..
It's common knowledge that even a short piece of wire 1/10
of a wave long will radiate nearly all the power that is applied
to it.
You can go lots shorter than that if you want.
If even a short piece of wire will radiate nearly all the power
applied to it, what is the point on harping about some magical
properties of a full wave length of wire?
Art, you are starting to bark at the moon I'm afraid...

I was going to comment on some of your other posts, but I
think I'll spare you the increase in blood pressure.
All I can say is that you are starting to wander off in
mumbo jumbo land again..
Replacing known science with conjured mumbo jumbo is no
way to live.
MK

Art, it distresses me to read the misleading statements you profess to be
true in your posts.

There is no difference in the 'efficiencies' between a full-wave and a
half-wave dipole. Let's assume the wire
size and conductivity of each dipole is such that we can say they both
radiate 98 percent of the power
delivered to them. Let's also say that the same amount of power is
delivered to both dipoles. What now is the
difference in the radiation between the two dipoles?

The only difference is in the SHAPE of the radiation patterns--the
full-wave dipole will have a somewhat
narrower lobe in the direction broadside to the dipole than that of the
half-wave dipole, therefore deriving
slightly more gain IN THAT DIRECTION than that of the half-wave, but with
less gain than the half-wave in all
other directions. Consequently, the total integrated power in either
radiation pattern will be exactly the
same!!!

If you want to express the mathematics of the conditions I described here
according to J.C.Maxwell's
equations, you will find that Maxwell's equations fit the conditions
EXACTLY.

Walt, W2DU

If any difference at all exist it is that the full wave antenna would be
ever so slightly less efficient due to the ohmic losses of the extra wire.

Jimmie- Hide quoted text -

- Show quoted text -

Give me the proof not a opinion when there are so many .
Art KB9MZ

On 23 Sep, 12:02, "Dave" wrote:
"Jimmie D" wrote in message

...





"Walter Maxwell" wrote in message
.. .
On Sat, 22 Sep 2007 19:19:18 -0700, wrote:

On Sep 22, 5:40 pm, 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.

If it does, I doubt it's enough to measure on the air..

The example I gave as for an instance was a quad
versus a 1/2 wave dipole.
This is readily seen by any operator empirically.

I've never seen it here. For that reason, I hardly use loops.
Neither vertically oriented, or horizontal as for NVIS use.
I don't see them as worth the extra trouble. Being I tested
them on 75m using NVIS paths, a noticable difference in
efficiency should have been readily apparent. It wasn't.
In fact, I usually has slightly better performance using the
dipoles, which I think was due to the bulk of the max current
portions of the antenna being higher above ground in general.
The loop sagged a bit in areas, and wasn't all that high above
ground. The more wire near the ground, the more ground loss
in general.

Mathematically it is
proven that way also even tho both are in accordance to Maxwell's
laws.

Where is the math? You should find a very slight difference
at best..
It's common knowledge that even a short piece of wire 1/10
of a wave long will radiate nearly all the power that is applied
to it.
You can go lots shorter than that if you want.
If even a short piece of wire will radiate nearly all the power
applied to it, what is the point on harping about some magical
properties of a full wave length of wire?
Art, you are starting to bark at the moon I'm afraid...

I was going to comment on some of your other posts, but I
think I'll spare you the increase in blood pressure.
All I can say is that you are starting to wander off in
mumbo jumbo land again..
Replacing known science with conjured mumbo jumbo is no
way to live.
MK

Art, it distresses me to read the misleading statements you profess to be
true in your posts.

There is no difference in the 'efficiencies' between a full-wave and a
half-wave dipole. Let's assume the wire
size and conductivity of each dipole is such that we can say they both
radiate 98 percent of the power
delivered to them. Let's also say that the same amount of power is
delivered to both dipoles. What now is the
difference in the radiation between the two dipoles?

The only difference is in the SHAPE of the radiation patterns--the
full-wave dipole will have a somewhat
narrower lobe in the direction broadside to the dipole than that of the
half-wave dipole, therefore deriving
slightly more gain IN THAT DIRECTION than that of the half-wave, but with
less gain than the half-wave in all
other directions. Consequently, the total integrated power in either
radiation pattern will be exactly the
same!!!

If you want to express the mathematics of the conditions I described here
according to J.C.Maxwell's
equations, you will find that Maxwell's equations fit the conditions
EXACTLY.

Walt, W2DU

If any difference at all exist it is that the full wave antenna would be
ever so slightly less efficient due to the ohmic losses of the extra wire.

Jimmie

don't claim that until you have modeled it in full. it "may"



What does "may" infere? Is it it 'may' or 'may not' or 'I am not sure'
or 'I don't know'?
I am not willing to procede with what you say unless you can be more
difinitive.
What does a house built on sand do?


snip
ragards
Art KB9MZ....XG

Jimmie D wrote:

On 23 Sep, 12:02, "Dave" wrote:
don't claim that until you have modeled it in full. it "may"

Who said "may", not me Jimmie

The attributions indicate that Dave said "may".
--
73, Cecil http://www.w5dxp.com

I am sorry to read this. I had hoped I had stumbled upon a perpetual motion
machine.

"Jimmie D" wrote in message
...
[snip]

No that is the point. An antenna can radiate no more energy than you put
into it. If you do something to increase the field intensity in one
direction the field intensity must decrease in other directions. Nothing
to debate, it is a proven fact. A fact you will never accept because if
you do you will also have to accept the your guassian antenna is just a
delusion.

It is a real shame that you have chosen a knowledge of antennas to be such
an important measuring stick for the value of your existence.

John, N9JG wrote:
I am sorry to read this. I had hoped I had stumbled upon a perpetual motion
machine.


Keep the faith baby! You just might have, he

http://www.dailymail.co.uk/pages/liv...page_id=19 65

Regards,
JS

On Sep 24, 7:16 pm, "Jimmie D" wrote:
"art" wrote in message

ups.com...

On 23 Sep, 07:29, "Jimmie D" wrote:
"art" wrote in message

roups.com...

On 22 Sep, 07:22, "Richard Fry" wrote:
"art" wrote

The most efficient radiator is one wave length long where
it is considered to be in equilibrium with a parallel electrical
cuircuit.
For most efficient radiation both the capacitance and the
inductance must act as a energy storage such that when
the terminals are shorted the energy is released in a burst
such that radiation can begin. ... In the case of a fractional
wave length radiator the pendulum type radiation is not
available for radiation

___________

Note (for one example of many) that in an antenna system consisting of
a
1/2-wave, center-fed dipole driven by a matched, balanced transmission
line,
the dipole itself radiates virtually all of the r-f energy present at
the
antenna feedpoint.

The radiation efficiency of a system as in the above example, but
using a
full wave dipole is no better than the 1/2-wave version, other things
equal.
The full wave version just has a different radiation pattern.

RF

I don't know what your credentials are for you to make such a
statement but it is a free world after all!
A quad radiator is a wave length radiator with a gain more than a half
wave as one sample.
Computor programing confirmes more radiation from full wave antennas
and mathematics according to Maxwell,s rules substantiate it. I can
understand not believing computor programs but I am very interested in
any mathematical data that would support your stand which is contrary
to the mathematics that I and others support.
What you are stating is that an attena in a series cuircit format
produces the same radiation as a parallel or tank cuircuit. I am more
than eager to read the contrary mathematical proof that is contrary to
the mathematics that I hold true. You may have hit on the true
explaqnation of radiation which Einstein, Planck and many others went
to their grave without solving it
Regards
Art KB9MZ.....XG

I dont know his credentials either but Richard is absolutly correct.
Efficency is the ability to radiate the signal and not turn it into
infra-red energy and has nothing to do with gain.

The Math:
Efficiency = (power applied to the antenna system - power turned into
heat
by the antenna system)/power applied to the antenna system.

Doesnt take a computer, doesnt take Maxwell or Einstien to explain. 5th
grade math works pretty well in this case.

The best thing the OP can do for his existing antenna is install a good
ground system and impedance matching networks, antenna tuner. If I were
really serious about it I would invest in an antenna analyzer so I would
know when my antenna is tuned for optimum match to my radio and log the
settings of my tuner. With the ground system and antenna type he has I am
sure the ground resistance is soaking up most of his signal. He would
surely
benifit from improving his ground system.

Jimmie- Hide quoted text -

- Show quoted text -

In comparing two antennas with similar omni direction radiation field
I state that gain in the field is indicative of increased radiadion
but that is a side issue brought up as often is in this newsgroup in
tha absence of a point by point debate.

No that is the point. An antenna can radiate no more energy than you put
into it. If you do something to increase the field intensity in one
direction the field intensity must decrease in other directions. Nothing to
debate, it is a proven fact. A fact you will never accept because if you do
you will also have to accept the your guassian antenna is just a delusion.


If you look at the field of a antenna that isr radiating an equal
amount in all direction
the volume of the radiation consists of usefull energy in the form of
radiation.
If another antenna with the same energy input provides a radiation
field in all
directions that is equal but at a larger radius than the prior antenna
field the the latter antenna has gain
over the prior antenna.
If you compare any fractional ground mounted antenna with a full wave
antenna the radius of the field
willhave a difference of aprox 3 db and the resistive impedance will
have a ratio of two to one.Note that gain is a measure of one radiator
level against another and is no way a distorted field of radiation
that has been manipulated by an additional near by radiator.
A ground plane does nothing more than balancing the circuit provided
such that current does not meander back thru the feed line and a
ground plane is only necessary for a fractional wavelength circuit to
balance the circuit as a whole. It eats up energy that would normally
provide radiation in a circuit such as a full wave radiator. Without a
good ground plane the impedance to a fractional wave length is
difficult and usually not efficient and a lot less than that of a
radiator that does have a good ground plane which is around30 ohms
resistive which is 1/2 of the resistive impedance of a full wave
radiator.
As far as the Gaussian antenna it is not an illusion to those with an
engineering background.
For those without an engineering background to enable them to follow
the logic do not have
the know how to discredit anything and certainly can not measure the
quality of life of those
with understanding.
If you cannot follow the science of antennas then you are doomed to
be a follower, never a leader.
and certainly not a judge.
I'm gone for a month or so and will not be using this newsgroup during
that time.
Will be back in the fall

Art


It is a real shame that you have chosen a knowledge of antennas to be such
an important measuring stick for the value of your existence.

Jimmie

Jimmie