On Tue, 27 Apr 2010 18:40:22 -0700, Richard Clark
wrote:

On Tue, 27 Apr 2010 16:20:56 -0700, Jeff Liebermann
wrote:

On Tue, 27 Apr 2010 11:22:59 -0700 (PDT), Art Unwin
wrote:

Tom Rauch W8JI has added to his home page a discussion about diversity
antennas

A link might be helpful:
http://www.w8ji.com/polarization_and_diversity.htm

That page is a ramble.

I don't think it was intended to be much more than a discussion of a
specific type of single antenna diversity reception plus something
about stereo-like diversity.

Example: Can someone tell me which line number offers the meaning for
Diversity?

A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion. In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner.

I am not interested in interpretations of Tom, nor
abstractions culled together from disjoint statements.

How about my definition? No matter which scheme is used, a diversity
reception scheme must demonstrate an improvement in availability, BER,
or SNR over a single antenna, or it's not really diversity.

I want to know
where (literally, not figuratively) Tom defines what Diversity is.

He doesn't.

I'm rather confused as to his "stereo diversity" which I guess uses
the listeners ears and brain as the decision switch or decoder. I
think he might be referring to a direct conversion receiver where one
channel is quadrature leading and the other is quadrature lagging,
resulting in a stereo-like effect.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS

On Tue, 27 Apr 2010 21:04:15 -0700, Jeff Liebermann
wrote:

Example: Can someone tell me which line number offers the meaning for
Diversity?

A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion.

So, this is an example of a "straw man" argument (not yours, Tom's): a
solution to a problem that is undefined. There are, thus, many
solutions that none can refute and why Tom's is the sine qua non is
built on a foundation of sand.

In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner.

Well, to Tom's credit, there is ample discussion of that - but that
discussion does not answer the question, which means there is no way
to test for validity.

I am not interested in interpretations of Tom, nor
abstractions culled together from disjoint statements.

How about my definition?

Sorry, Jeff, but unless you are the author of the Wikipedia reference,
I cannot answer your question.

No matter which scheme is used, a diversity
reception scheme must demonstrate an improvement in availability, BER,
or SNR over a single antenna, or it's not really diversity.

I presume the statement above is your definition. Reducing S+N/N
satisfies what you call diversity and provides an example of a
self-referential definition in that you appeal to with "SNR." Self
referential definitions are logical nulls. In other words, does
increasing capture area qualify as diversity for a single antenna? If
so, diversity means less noise or a better signal in comparison. What
is diverse about ordinary directivity? What is the profit in having
two words describe the same thing?

Even with an informal presumption of the meaning of diversity, we can
both agree that diversity is not also directivity.

Or perhaps it is that, and with one characteristic more. This returns
us to the question with some refinement: what is diversity in the face
of directivity? I have a hunch directivity is a distraction, but that
returns us to the original question.

I want to know
where (literally, not figuratively) Tom defines what Diversity is.

He doesn't.

I didn't think so and I was asking because I didn't consider it worth
the effort to search for something so obscured by the baggage of
peripheral discussion.

I'm rather confused as to his "stereo diversity" which I guess uses
the listeners ears and brain as the decision switch or decoder. I
think he might be referring to a direct conversion receiver where one
channel is quadrature leading and the other is quadrature lagging,
resulting in a stereo-like effect.

I will admit this was my interpretation too. Strange how you have to
sift the diamonds out of the horse-****. I had worked in this field
and built quadrature detectors 40 years ago to the same ends as you
describe. Analog TV color detection had been doing it for at least 20
years before that. I suppose there is a metaphor of diversity there,
but it came with the subject of quadrature detection as a solution,
not as a recent invention.

The quad detector is a direct conversion receiver as you say.

For other readers:
The signal is split through two channels each mixed with the same
base-band source, with one feed of the source shifted 90 degrees for
one channel. I suppose here we could drop the input splitter and
simply feed in two antenna drives. The separate mixer outputs feed
separate headphone elements (the classic application way back then)
and the brain perceives the signal as existing in a literal 2D
(binaural) space. The consequence of this perception is a heightened
ability to discriminate one signal from the rest within the bandpass
of reception. The bandpass is perceived as a physical left-to-right
space and because the classic application was through headphones, this
space was also between the ears. For the modern reader, this was like
having a spectrum analyzer in your head.

This is the classic situation of being able to listen to one
conversation in a crowded room full of speakers (the cocktail party
problem) without becoming overwhelmed by overlapping dialog. A simple
test is when you tune to the signal of interest, any off-frequency
signals are perceived as inhabiting this 2D space at a literal
off-center. As no two transmissions occupy the exact same frequency
(Tom explicitly mentions errors as small as a quarter Hertz), then
they lose being at the center of attention. The brain supplies a huge
computational engine that computers have yet to match.

The topic of Quad detection is cool in its own right, but I don't see
how tarting it up with the discussion of Diversity (especially when
the term is one of dim provenance) really adds anything. Quad
detection read more like window dressing than the clincher to the
topic at hand.

73's
Richard Clark, KB7QHC

Jeff Liebermann wrote:

A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion. In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner.


Trying to wrap my mind around this...

I wouldn't know how splitting the signal to two receivers would work.
The issue arises at the antenna doesn't it?

Indeed, if a single wire antenna would work for diversity reception,
wouldn't it then follow that you would not have to use diversity
reception? The signal would already be there for you.

Seems like a simple test could answer this one.

- 73 de Mike N3LI -

Michael Coslo wrote:
Jeff Liebermann wrote:

A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion. In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner.


Trying to wrap my mind around this...

I wouldn't know how splitting the signal to two receivers would work.
The issue arises at the antenna doesn't it?

Indeed, if a single wire antenna would work for diversity reception,
wouldn't it then follow that you would not have to use diversity
reception? The signal would already be there for you.

Seems like a simple test could answer this one.

- 73 de Mike N3LI -

Depends on how you define "work".

The only scenario I can think of would be if the received frequency was
changing slightly for some reason and the two receivers were on slightly
different frequencies.


--
Jim Pennino

Remove .spam.sux to reply.

On Apr 28, 1:53*pm, Michael Coslo wrote:
Jeff Liebermann wrote:
A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion. *In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner. *

Trying to wrap my mind around this...

I wouldn't know how splitting the signal to two receivers would work.
The issue arises at the antenna doesn't it?

Indeed, if a single wire antenna would work for diversity reception,
wouldn't it then follow that you would not have to use diversity
reception? The signal would already be there for you.

Seems like a simple test could answer this one.

* * * * - 73 de Mike N3LI -

I think the first place to start is to what the actual antenna pattern
represents in terms of polarity.
For instance, we have two vectors outside the earths boundary thus you
must have two vectors inside the arbitrary boundary. Obviously the
gravity vector will be at right angles to the earths surface. The
other vector representing the rotation of the earth will naturally be
an circular pattern which is the "saucer" pattern portion of the
overall pattern, which is what hams mainly use. Thus we have to make
the first determination as being what each portion of the pattern
represents in terms of polarity, the centre being straight plume field
and the bottom circular field which is a rotational vector. Since they
are in vector form we can see them as a stream of particles where the
two vectors will be additive. It is only then that the problem of
different or the same phase factors can be ascertained. Definitions
applied can be approach later. Personally, I view the gravity vector
as linear with the other providing a wobberly helical vector i.e
circular. but varying angles to the earths surface. Other thinkers
will surely disagree, if only to fight over near field over far field!

On Apr 28, 3:59*pm, Art Unwin wrote:
On Apr 28, 1:53*pm, Michael Coslo wrote:



Jeff Liebermann wrote:
A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion. *In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner. *

Trying to wrap my mind around this...

I wouldn't know how splitting the signal to two receivers would work.
The issue arises at the antenna doesn't it?

Indeed, if a single wire antenna would work for diversity reception,
wouldn't it then follow that you would not have to use diversity
reception? The signal would already be there for you.

Seems like a simple test could answer this one.

* * * * - 73 de Mike N3LI -

I think the first place to start is to what the actual antenna pattern
represents in terms of polarity.
For instance, we have two vectors outside the earths boundary thus you
must have two vectors inside the arbitrary *boundary. Obviously the
gravity vector will be at right angles to the earths surface. The
other vector representing the rotation of the earth will naturally be
an circular pattern which is the "saucer" pattern portion of the
overall pattern, which is what hams mainly use. Thus we have to make
the first determination as being what each portion of the pattern
represents in terms of polarity, the centre being straight plume field
and the bottom circular field which is a rotational vector. Since they
are in vector form we can see them as a stream of particles where the
two vectors will be additive. It is only then that the problem of
different or the same phase factors *can be ascertained. Definitions
applied can be approach later. Personally, I view the gravity vector
as linear with the other providing a wobberly helical vector i.e
circular. but varying angles to the earths surface. Other thinkers
will surely disagree, if only to fight over near field over far field!

I have no doubt that gravity effects radio waves in the same manner
that it has been proven to effect light. The effects are going to be
such that unless your signal is passing by a black hole of no
practical concern.

Have a great day Art.

Jimmie

On Apr 28, 3:42*pm, JIMMIE wrote:
On Apr 28, 3:59*pm, Art Unwin wrote:



On Apr 28, 1:53*pm, Michael Coslo wrote:

Jeff Liebermann wrote:
A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion. *In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner. *

Trying to wrap my mind around this...

I wouldn't know how splitting the signal to two receivers would work.
The issue arises at the antenna doesn't it?

Indeed, if a single wire antenna would work for diversity reception,
wouldn't it then follow that you would not have to use diversity
reception? The signal would already be there for you.

Seems like a simple test could answer this one.

* * * * - 73 de Mike N3LI -

I think the first place to start is to what the actual antenna pattern
represents in terms of polarity.
For instance, we have two vectors outside the earths boundary thus you
must have two vectors inside the arbitrary *boundary. Obviously the
gravity vector will be at right angles to the earths surface. The
other vector representing the rotation of the earth will naturally be
an circular pattern which is the "saucer" pattern portion of the
overall pattern, which is what hams mainly use. Thus we have to make
the first determination as being what each portion of the pattern
represents in terms of polarity, the centre being straight plume field
and the bottom circular field which is a rotational vector. Since they
are in vector form we can see them as a stream of particles where the
two vectors will be additive. It is only then that the problem of
different or the same phase factors *can be ascertained. Definitions
applied can be approach later. Personally, I view the gravity vector
as linear with the other providing a wobberly helical vector i.e
circular. but varying angles to the earths surface. Other thinkers
will surely disagree, if only to fight over near field over far field!

I have no doubt that gravity effects radio waves in the same manner
that it has been proven to effect light. The effects are going to be
such that unless your signal is passing by a black hole of no
practical concern.

Have a great day Art.

Jimmie

Totally wrong!
The vector inside the boundary opposes gravity!
The particle has a straight line trajectory and does not fall back to
earth during that trajectory.The rotary vector supplies spin to the
other vector force
just as the dimples in an golf ball or the rifling of a firearm
barrel. These same vectors are represented
by time varying electrical current (straight line) as well as
displacement current which generates a vortex by its circular motion.
When the current flow is completely outside the surface of the
radiator skin depth disappears as does resistance. So the radiator has
a skin of tightly bonded particles upon which the straight line
trajectory is imposed. Remember, earth gravity has zero effect on
propagation inside a arbitrary boundary otherwise straight line
projection could not exist.

On 4/28/2010 6:48 PM, Art Unwin wrote:
On Apr 28, 3:42 pm, wrote:
On Apr 28, 3:59 pm, Art wrote:



On Apr 28, 1:53 pm, Michael wrote:

Jeff Liebermann wrote:
A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion. In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner.

Trying to wrap my mind around this...

I wouldn't know how splitting the signal to two receivers would work.
The issue arises at the antenna doesn't it?

Indeed, if a single wire antenna would work for diversity reception,
wouldn't it then follow that you would not have to use diversity
reception? The signal would already be there for you.

Seems like a simple test could answer this one.

- 73 de Mike N3LI -

I think the first place to start is to what the actual antenna pattern
represents in terms of polarity.
For instance, we have two vectors outside the earths boundary thus you
must have two vectors inside the arbitrary boundary. Obviously the
gravity vector will be at right angles to the earths surface. The
other vector representing the rotation of the earth will naturally be
an circular pattern which is the "saucer" pattern portion of the
overall pattern, which is what hams mainly use. Thus we have to make
the first determination as being what each portion of the pattern
represents in terms of polarity, the centre being straight plume field
and the bottom circular field which is a rotational vector. Since they
are in vector form we can see them as a stream of particles where the
two vectors will be additive. It is only then that the problem of
different or the same phase factors can be ascertained. Definitions
applied can be approach later. Personally, I view the gravity vector
as linear with the other providing a wobberly helical vector i.e
circular. but varying angles to the earths surface. Other thinkers
will surely disagree, if only to fight over near field over far field!

I have no doubt that gravity effects radio waves in the same manner
that it has been proven to effect light. The effects are going to be
such that unless your signal is passing by a black hole of no
practical concern.

Have a great day Art.

Jimmie

Totally wrong!
The vector inside the boundary opposes gravity!
The particle has a straight line trajectory and does not fall back to
earth during that trajectory.The rotary vector supplies spin to the
other vector force
just as the dimples in an golf ball or the rifling of a firearm
barrel. These same vectors are represented
by time varying electrical current (straight line) as well as
displacement current which generates a vortex by its circular motion.
When the current flow is completely outside the surface of the
radiator skin depth disappears as does resistance. So the radiator has
a skin of tightly bonded particles upon which the straight line
trajectory is imposed. Remember, earth gravity has zero effect on
propagation inside a arbitrary boundary otherwise straight line
projection could not exist.

Welcome back, Art!

And I'm quite serious.

Obviously you are no longer taking your medications or maybe they just
let you out.

Please keep it up. I, for one, have missed your lack of connection to
reality. It is very amusing.

tom
K0TAR

On Apr 28, 9:19*pm, tom wrote:
On 4/28/2010 6:48 PM, Art Unwin wrote:



On Apr 28, 3:42 pm, *wrote:
On Apr 28, 3:59 pm, Art *wrote:

On Apr 28, 1:53 pm, Michael *wrote:

Jeff Liebermann wrote:
A link to the Wikipedia page would probably have been sufficient:
http://en.wikipedia.org/wiki/Diversity_scheme
The problem is that NONE of the diversity schemes mentioned in the
Wikipedia article apply to the single antenna example under
discussion. *In my never humble opinion, there's no way to provide any
form of diversity reception improvement with a single antenna, unless
one also has two feeds, going to two different receivers, and ending
in either a decision switch, or some form of intelligent combiner.

Trying to wrap my mind around this...

I wouldn't know how splitting the signal to two receivers would work..
The issue arises at the antenna doesn't it?

Indeed, if a single wire antenna would work for diversity reception,
wouldn't it then follow that you would not have to use diversity
reception? The signal would already be there for you.

Seems like a simple test could answer this one.

* * * * *- 73 de Mike N3LI -

I think the first place to start is to what the actual antenna pattern
represents in terms of polarity.
For instance, we have two vectors outside the earths boundary thus you
must have two vectors inside the arbitrary *boundary. Obviously the
gravity vector will be at right angles to the earths surface. The
other vector representing the rotation of the earth will naturally be
an circular pattern which is the "saucer" pattern portion of the
overall pattern, which is what hams mainly use. Thus we have to make
the first determination as being what each portion of the pattern
represents in terms of polarity, the centre being straight plume field
and the bottom circular field which is a rotational vector. Since they
are in vector form we can see them as a stream of particles where the
two vectors will be additive. It is only then that the problem of
different or the same phase factors *can be ascertained. Definitions
applied can be approach later. Personally, I view the gravity vector
as linear with the other providing a wobberly helical vector i.e
circular. but varying angles to the earths surface. Other thinkers
will surely disagree, if only to fight over near field over far field!

I have no doubt that gravity effects radio waves in the same manner
that it has been proven to effect light. The effects are going to be
such that unless your signal is passing by a black hole of no
practical concern.

Have a great day Art.

Jimmie

Totally wrong!
The vector inside the boundary opposes gravity!
The particle has a straight line trajectory and does not fall back to
earth during that trajectory.The rotary vector supplies spin to the
other vector force
just as the dimples in an golf ball or the rifling of a firearm
barrel. These same vectors are represented
by time varying electrical current (straight line) as well as
displacement current which generates a vortex by its circular motion.
When the current flow is completely outside the surface of the
radiator skin depth disappears as does resistance. So the radiator has
a skin of tightly bonded particles upon which the straight line
trajectory is imposed. Remember, earth gravity has zero effect on
propagation inside a arbitrary boundary otherwise straight line
projection could not exist.

Welcome back, Art!

And I'm quite serious.

Obviously you are no longer taking your medications or maybe they just
let you out.

Please keep it up. *I, for one, have missed your lack of connection to
reality. *It is very amusing.

tom
K0TAR

Perception is not the same as reality. A mixer in a radio is different
than what is required when seeking diversity. The first is the mixing
of two different frequencies where diversity requires the mixing of
two frequencies of the same except one has a delay. The output of the
latter is three traces where the two separate bone vibration of the
ears can separate the two and where your middle ear can provide the
summation. Your brain supplies the jumper of your choice. Without
discovery you can abide with perception and not with change. With
discoveries you must accept change. If all is known then one doesn't
have to accept change and can exist without a brain by being a
follower and not a leader.

On Wed, 28 Apr 2010 14:53:09 -0400, Michael Coslo
wrote:

I wouldn't know how splitting the signal to two receivers would work.
The issue arises at the antenna doesn't it?

Ah! The nut of the problem.

To my knowledge, diversity forces you to find the signal elsewhere,
not in the same spot because it isn't there anymore, or at least not
in the same polarization. This last diversity (polarization) is but
one of many. It may be solved at the antenna that features multiple
polarization capability - here Tom's ramble throws EZNEC against the
wall to see what sticks, and he introduces new issues that distract.

There is space diversity, time diversity, phase diversity, frequency
diversity (and there are more if we consider more modulations) and all
we get is the all encompassing "diversity" being hung out to dry.

The distractions that I see discussed are problems of combining
signal, not in finding signal. Interesting problem there, but hardly
something noted to being an issue with an antenna. Someone will
correct my misapprehension in this thread if there is one.

73's
Richard Clark, KB7QHC