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 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

On Apr 28, 6:45*pm, Michael Coslo wrote:
Richard Clark wrote:
On Wed, 28 Apr 2010 10:11:51 -0700 (PDT), Bill wrote:

how useful is the discussion to the average reader of r.r.a.a.?

Hi Bill,

Well, diversity antenna work is quite useful to the average reader - I
suppose (they haven't actually clamored for the discussion or
embroiled themselves in the topic, but you did couch this in terms of
"readers").

Sure, at least in a practical sense. I make use of diversity receivers
in wireless microphone work.

While these are used at UHF frequencies rather than HF, our problems are
more multipath, maybe picket fencing a bit.

So while I know better than to get into the definitions of diversity
antennas, given my meager abilities, *my guess is that if one antenna
worked better than two - or merely worked at all, we'd be using just one.

Tom's pseudo stereo looks suspiciously like a wetware version of my
wireless systems,only that they vote, whereas his signal levels are too
low for that, so he does it in his head.

Unfortunately, if we divorced the two authors who fail to offer what
Diversity means, apart from what is already accepted in convention,
then we remove the entertainment value and "readership" would likely
decline.

That is for certain.

A paradox.

One of my favorite words.

if the pseudo stereo is derived from 2 different antennas then you
have diversity reception where the separate antennas provide different
signals that may fade at different times due to polarization changes
or incident angle changes... that is what tom was driving at as a
useful diversity system, albeit at the expense of more complex
receiver hardware.

when you take a single rf signal and split it through different
receive processors to shift the phase, or do different sidebands, or
just run through different high/low pass audio filters, you don't
really have diversity, you have some kind of a processing system that
makes it easier for your brain or some other decoder to sort out the
signal from the noise. I played with some simple ones years ago and
they can provide interesting effects that can make sorting out signals
in pileups easier, or maybe pulling signals out of the noise a bit
easier, but none of them will really prevent the multipath, arrival
angle, or polarization fading. that is where tom was trying to point
out that any way you combine the rf from two antennas into one you
lose the advantages of the diversity of the antennas.

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 Wed, 28 Apr 2010 15:51:35 -0700 (PDT), K1TTT
wrote:

that any way you combine the rf from two antennas into one you
lose the advantages of the diversity of the antennas.

I saw that bold statement as well, and then it was treated to a fog of
support.

At some point, the RF from two antennas must combine by the time it
hits our ears. That, or diversity reception means two people
listening to two sources and then matching notes - which means the RF
from the two antennas combine on the final page draft.

So, let me put this forward.
Two antennas
feeding two separate RF chain amplifiers
both chains mixed from a single LO
two separate mixers into IF chain amplifiers
--- somewhere they have to combine ----
two IFs into two detectors
two detectors into two separate audio chain amps
each audio chain driving a speaker element.

I have (gasp!) interpolated, interpreted, simply guessed, guessed
wrong, guessed right, about this single LO. Maybe it was in the
detector at the end of the IF chain. Whatever.

So, with this duality extending from antenna(s) to speaker(s), is the
prohibition against combining the RF from two antennas merely a
syllogism?

OK, backing up that chain to the concept of two separate RF chain
amplifiers. Lets just call it one RF chain amplifier or no RF
amplifiers and straight to a mixer. Is the prohibition at the
combining of RF from two antennas located at the mixer input? No
parallel connection?

This is getting ugly because it is not about diversity, and it is not
about antennas.

73's
Richard Clark, KB7QHC

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 4/28/2010 12:11 PM, Bill wrote:
On Apr 27, 7:22 pm, Art wrote:
Tom Rauch W8JI has added to his home page a discussion about diversity
antennas
As a known authority on antennas he presents interesting insights
regarding my
diversity antenna where I show computer results of different polarity
gains.
His knowledge of antennas is much greater than mine, so if any have
shown an interest in my antenna design it would be worth while to read
Tom's aproach as to what exactly is happening and why
Regards
Art Unwin KB9MZ

Sly old Art Unwin alludes to his antenna design and initiates a long
technical thread which talks about anything but an Unwin antenna. And
how useful is the discussion to the average reader of r.r.a.a.?

It's the amusing part. Totally useless technically, but often comprises
nearly 100% of the traffic on this group for days or weeks.

tom
K0TAR

On Apr 28, 5:51*pm, K1TTT wrote:
On Apr 28, 6:45*pm, Michael Coslo wrote:



Richard Clark wrote:
On Wed, 28 Apr 2010 10:11:51 -0700 (PDT), Bill wrote:

how useful is the discussion to the average reader of r.r.a.a.?

Hi Bill,

Well, diversity antenna work is quite useful to the average reader - I
suppose (they haven't actually clamored for the discussion or
embroiled themselves in the topic, but you did couch this in terms of
"readers").

Sure, at least in a practical sense. I make use of diversity receivers
in wireless microphone work.

While these are used at UHF frequencies rather than HF, our problems are
more multipath, maybe picket fencing a bit.

So while I know better than to get into the definitions of diversity
antennas, given my meager abilities, *my guess is that if one antenna
worked better than two - or merely worked at all, we'd be using just one.

Tom's pseudo stereo looks suspiciously like a wetware version of my
wireless systems,only that they vote, whereas his signal levels are too
low for that, so he does it in his head.

Unfortunately, if we divorced the two authors who fail to offer what
Diversity means, apart from what is already accepted in convention,
then we remove the entertainment value and "readership" would likely
decline.

That is for certain.

A paradox.

One of my favorite words.

if the pseudo stereo is derived from 2 different antennas then you
have diversity reception where the separate antennas provide different
signals that may fade at different times due to polarization changes
or incident angle changes... that is what tom was driving at as a
useful diversity system, albeit at the expense of more complex
receiver hardware.

when you take a single rf signal and split it through different
receive processors to shift the phase, or do different sidebands, or
just run through different high/low pass audio filters, you don't
really have diversity, you have some kind of a processing system that
makes it easier for your brain or some other decoder to sort out the
signal from the noise. *I played with some simple ones years ago and
they can provide interesting effects that can make sorting out signals
in pileups easier, or maybe pulling signals out of the noise a bit
easier, but none of them will really prevent the multipath, arrival
angle, or polarization fading. *that is where tom was trying to point
out that any way you combine the rf from two antennas into one you
lose the advantages of the diversity of the antennas.

Tom
From my viewpoint which may well be unconventional,
may I point out that both elements as well as the array as a whole is
resonant and in equilibrium.
Thus in reality, you have two separate antennas that are additive and
go to the same receiver.
The receiver uses the addition of the two current flows or two
separate flows thus picking up both linear and non linear signals. So
I would suggest that the antenna is therefore sensitive to both .
phases( ie in phase and out of phase fields).
Ww8ji is of the opinion that the program is in error by virtue of the
statement it makes since it is unable to print the truth but doesn't
provide evidence of same.I believe he is looking at an array that is
not in equilibrium to arrive at his viewpoint.
Both elements pick up the same message with one having a delay in
time due to phase change regardles of what created it, deflection or
other wise. This is no different to viewing both elements as
mechanically vibrating and because the array as a whole is in
equilibrium both will vibrate in unison
Regards
Art