I tend to agree with Brian.
However, in my world, "true diversity" is attained from 2 identical
receivers, each having a separate antenna in two different locations.
The source signal is a single transmitter. The output of each receiver
is fed to a circuit that determined the best signal-to-noise ratio and a
couple of other qualitative factors. Then the "best" signal of the two
was switched to the single output. That determination and switching,
all done electronically, could occur several hundred times per second.
The result is the output signal appeared totally seamless to the
listener. There were no A+B or A-B configured signals. That's
another methodology.
I would suppose with two receivers, each feeding output to a single ear,
one could use "brain power" to focus on one or the other of the two
signals. I think most would all agree, even today, the "brain filter"
is still one of the best available. However, if the receivers aren't
identical, then the result can seemingly be totally random. This would
appear to present a condition where excessive listening fatigue might occur.
A similar method I employed some 25+ years ago was indeed using two
antennas, one being a HF vertical and one being a HF horizontal. These
were configured with a switching network feeding one receiver. This was
done during the earlier days of Packet, AMTOR and such modes. I devised
a circuit that counted the error correction requests. After a value of
N, the system during a receive cycle, switched antennas. It was
interesting to watch as signals would fade on one antenna was observed
to likely rise on the other. The system greatly enhanced "through put"
of the data transmissions. Later I added a transmit power control to
the system such that the transmitter reduced power in steps until the
error rates increased. Again this relied on the error correction
request from the controller. The system then stepped the power up in
steps to a reliable power value. The objective was to operate at
minimum power based on propagation etc. Ahhhh, the days of "rolling
your own" equipment and methods.
73 Bob, K4TAX
On 8/3/2015 1:32 PM, brain wrote:
I really wonder about ab ab audio in diversity. That is both rx
audio in both ears. The "diversity" comes from the antenna. What does
the brain do worse in "diversity" with this ab ab mode of receiving?
Since you can't do it with the current K3 software, where is the A/B
testing shows the superiority of listening to separate signals in each
ear. I suppose there are papers out there on this.
Unlike many, in split mode I listen to both RX in both ears. No
problem. Adjustment of audio gain optimizes this situation on a per
station basis.
73 de Brian/K3KO
On 8/3/2015 18:00 PM, Guy Olinger K2AV wrote:
Respectfully,
This is not an issue of definition. I'm sure everyone agrees that
on-purpose listening to A-A is not diversity. What they are talking
about
is a situational coping mechanism when using diversity as the main
listening mode in a contest.
This occurs in diversity mode when one ear has a very weak desired
signal
and the other a very loud undesired signal. My current coping
mechanism for
this is to push one headphone bell forward off my ear. It would be
better
to temporarily switch to both ears on desired signal, but this is *very*
clumsy using the front panel.
A discussion on how to deal with it would be helpful. Using diversity in
contesting is a newly emerging skill that is only really emerging with
common usage of two receiver K3's.
There needs to be a non-dismissive serious response to these
concerns. If
there are hard technical reasons why this should be done external to
the K3
it would be good to known these and move on to an external solution. It
does seem though like the straightforward treatment is somewhere
inside the
K3 digital number soup.
73, Guy K2AV
On Monday, August 3, 2015, Don Wilhelm <[email protected]> wrote:
Arie,
The K3 may be in diversity, but you will only hear in diversity mode
when
the audio is A-b.
The diversity effect is 'in your head' as your ears naturally pick
up the
differences between the two receivers and your brain figures out
which is
the best to hear.
When you have the audio set to A-A or b-b, you are hearing the audio
from
only one receiver, and by definition, that is not diversity reception.
73,
Don W3FPR
On 8/3/2015 10:30 AM, Arie Kleingeld PA3A wrote:
Don,
to set things up, I use a macro programmed in the F12-key in N1MM
to copy
the freq/mode/BW From A to B, switch on the SubRx, set audio to A-b
listening and Link the VFO's. Switching of the audio is done in
F9-F10-11
to A-b, A-A, or b-b respectively.
Of course I would like that I could switch the audio when the K3 is in
diversity mode, but That cannot be done in current Firmware. In
diversity
the audio is fixed to A-b.
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