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