Dave wrote:

SNIPPED

Art, It has absolutely NOTHING to do with measurements, or with 95 watts
or 5 watts, or antenna patterns, or the reactive components.

It is defining efficiency properly!

Net radiated power divided by power input is Efficiency. Measure it or
calculate it any way you want!

An antenna with -3 dB loss is a 50% efficient antenna independent of the
actual input power. Choose any power input you like. An antenna with -3
dB loss is a 50% efficient antenna regardless of gain, directivity,
antenna patterns, patents, claims, marketing Bull S--t, or anything else.

Put your favorite antenna inside a sphere of any suitable diameter that
contains the antenna. The total rf power coming out of the sphere
divided by the total rf power into the antenna [sphere] is the antenna
efficiency. There is NO OTHER definition!

Reducing power in the back and side lobes has absolutely NOTHING to do
with efficiency. It has to do with directivity.

Design of a Yagi, traps, conductors, element spacing etc. will produce
variations in gain, directivity, efficiency [variations in losses,
heat]. Practically, the difference in efficiency between a 90% efficient
antenna and a 98% efficient antenna is swamped by variations in the path
loss physics.

I spent years of my life designing rf systems for telemetry from space
vehicles through reentry to a ground station. Data integrity at the
ground station was and still is the dominating requirement. Based on
allowable data error rates, the total path equation required S/N ratios
of 12 dB or more. The solution is a systems solution where the minor
variations in antenna efficiency get lost in the calculations.


Art doesn't care about reality, he thinks he can create a new one which
ignores physics. You are wasting your time.

I am plonking this thread, and art.

tom
K0TAR

Tom Ring wrote:
Dave wrote:
...
I am plonking this thread, and art.

tom
K0TAR

Ahhhh. Mr. Tom Ring. I would almost bet he shares much in common with
the average IBM employee!

Graduated with a C+ grade point average!

JS

Tom it is no good plonking me for what david is saying because he is
not quoting me, in fact some of it is a requote of what he said not me.
I think he is creating a straw man that he can argue with, is that what
you call reality? He has spent most of his time in space and I believe
him

Tom Ring wrote:
Dave wrote:

SNIPPED

Art, It has absolutely NOTHING to do with measurements, or with 95 watts
or 5 watts, or antenna patterns, or the reactive components.

It is defining efficiency properly!

Net radiated power divided by power input is Efficiency. Measure it or
calculate it any way you want!

An antenna with -3 dB loss is a 50% efficient antenna independent of the
actual input power. Choose any power input you like. An antenna with -3
dB loss is a 50% efficient antenna regardless of gain, directivity,
antenna patterns, patents, claims, marketing Bull S--t, or anything else.

Put your favorite antenna inside a sphere of any suitable diameter that
contains the antenna. The total rf power coming out of the sphere
divided by the total rf power into the antenna [sphere] is the antenna
efficiency. There is NO OTHER definition!

Reducing power in the back and side lobes has absolutely NOTHING to do
with efficiency. It has to do with directivity.

Design of a Yagi, traps, conductors, element spacing etc. will produce
variations in gain, directivity, efficiency [variations in losses,
heat]. Practically, the difference in efficiency between a 90% efficient
antenna and a 98% efficient antenna is swamped by variations in the path
loss physics.

I spent years of my life designing rf systems for telemetry from space
vehicles through reentry to a ground station. Data integrity at the
ground station was and still is the dominating requirement. Based on
allowable data error rates, the total path equation required S/N ratios
of 12 dB or more. The solution is a systems solution where the minor
variations in antenna efficiency get lost in the calculations.


Art doesn't care about reality, he thinks he can create a new one which
ignores physics. You are wasting your time.

I am plonking this thread, and art.

tom
K0TAR

David, you are doing a lot of reading of different posters and then
placing them under my name. I have no idea of what you are trying to
project with this accumulation of various postings from various people
tho I cqan see that you are getting mad as hell over something.
cool down

Dave wrote:
art wrote:

Dave wrote:

If a simple dipole is fed with 100 watts and radiates 95 watts, it is 95% efficient.


David if you had a dipole that had inherrent directional capabilities
would you consider
that as a possible choice for better efficiency ? Where does the 95%
number come from and where did the 5% go so. Did turners post influence
your guess at that number? is he worth copying? Others can get an idea
what you are talking about ie. parameters of use for which you are
applying the 95% figure to. It is possible that we can at least one
negative from the discusion in search of the kernel of info. Does the
dipole become more or less efficient as it moves away from its design
frequency as it becomes "detuned" Give me some meat

SNIPPED

Art, It has absolutely NOTHING to do with measurements, or with 95 watts or 5
watts, or antenna patterns, or the reactive components.

It is defining efficiency properly!

Net radiated power divided by power input is Efficiency. Measure it or calculate
it any way you want!

An antenna with -3 dB loss is a 50% efficient antenna independent of the actual
input power. Choose any power input you like. An antenna with -3 dB loss is a
50% efficient antenna regardless of gain, directivity, antenna patterns,
patents, claims, marketing Bull S--t, or anything else.

Put your favorite antenna inside a sphere of any suitable diameter that contains
the antenna. The total rf power coming out of the sphere divided by the total rf
power into the antenna [sphere] is the antenna efficiency. There is NO OTHER
definition!

Reducing power in the back and side lobes has absolutely NOTHING to do with
efficiency. It has to do with directivity.

Design of a Yagi, traps, conductors, element spacing etc. will produce
variations in gain, directivity, efficiency [variations in losses, heat].
Practically, the difference in efficiency between a 90% efficient antenna and a
98% efficient antenna is swamped by variations in the path loss physics.

I spent years of my life designing rf systems for telemetry from space vehicles
through reentry to a ground station. Data integrity at the ground station was
and still is the dominating requirement. Based on allowable data error rates,
the total path equation required S/N ratios of 12 dB or more. The solution is a
systems solution where the minor variations in antenna efficiency get lost in
the calculations.

Dave wrote:
If a simple dipole is fed with 100 watts and radiates 95 watts, it is 95% efficient.

David if you had a dipole that had inherrent directional capabilities
would you consider
that as a possible choice for better efficiency ? Where does the 95%
number come from and where did the 5% go so. Did turners post influence
your guess at that number? is he worth copying? Others can get an idea
what you are talking about ie. parameters of use for which you are
applying the 95% figure to. It is possible that we can at least one
negative from the discusion in search of the kernel of info. Does the
dipole become more or less efficient as it moves away from its design
frequency as it becomes "detuned" Give me some meat





snip/s/ DD

art wrote:

Some time ago I mentioned how inefficient Yagi design
antennas were thinking more in the way of how little of
the radiation used got to its required direction.
At that time people said the antenna was efficient though
they wanted to talk about
actual radiation efficiency and the sniping began
.Nobody but nobody came back with the radiation
efficiency of a Yagi as they saw the question, they
just wanted to throw stones.Imagine that antennas
was not what the experts wanted to talk about and
the newsgroup took a turn for the worst
So I join in with the thoughts of radiation efficiency
of a yagi unless you prefere to give up this antenna
newsgroup. But before you scream out and throw
stones again I will referr to efficiency as most of the
members of this group what's left of them think of the term.
So let's look at that if that is what you preferr..

The basic small yagi has three elements one driven,
one a reflector and one a director yet only one
element has a truly resistive impedance whereas
the other two do not. Since two elements out of the
three are producing reactive impedances and wherein
the reactive portions of impedance is pure waste
pray tell me how one can consider a yagi as efficient?
And please, please don't waste time on "I don't understand"
otherwise everything drops down to the subject of spark noise
which was really decided by hams a long while ago.
On the other side of the coin, if the reactive portion of an
impedance is not waste then why is LCR
type mesh circuitry only revolve around lumped circuitry?
HINT add up the power emminating from each element
P =I sq times real resistance for those who are just followers.

There again maybe it is best that you be honest and say
you don't understand! Better that than join those who have
nothing to say about antennas!

art wrote:
Some time ago I mentioned how inefficient Yagi design
antennas were thinking more in the way of how little of
the radiation used got to its required direction.
At that time people said the antenna was efficient though
they wanted to talk about
actual radiation efficiency and the sniping began
.Nobody but nobody came back with the radiation
efficiency of a Yagi as they saw the question, they
just wanted to throw stones.Imagine that antennas
was not what the experts wanted to talk about and
the newsgroup took a turn for the worst
So I join in with the thoughts of radiation efficiency
of a yagi unless you prefere to give up this antenna
newsgroup. But before you scream out and throw
stones again I will referr to efficiency as most of the
members of this group what's left of them think of the term.
So let's look at that if that is what you preferr..

The basic small yagi has three elements one driven,
one a reflector and one a director yet only one
element has a truly resistive impedance whereas
the other two do not. Since two elements out of the
three are producing reactive impedances and wherein
the reactive portions of impedance is pure waste
pray tell me how one can consider a yagi as efficient?
And please, please don't waste time on "I don't understand"
otherwise everything drops down to the subject of spark noise
which was really decided by hams a long while ago.
On the other side of the coin, if the reactive portion of an
impedance is not waste then why is LCR
type mesh circuitry only revolve around lumped circuitry?
HINT add up the power emminating from each element
P =I sq times real resistance for those who are just followers.

There again maybe it is best that you be honest and say
you don't understand! Better that than join those who have
nothing to say about antennas!

My cat has mittens.
MK