In message <[email protected]>, Mike Dennison
<[email protected]> writes
Dick, PA0SE wrote:
I have tested "pseudo-stereophonic" reception of CW by feeding the halves
of a stereo headphone via series tuned circuits resonating at 1002 and
842Hz (922 ± 80Hz) respectively. At first the result was pleasant; it
sounded like being in a room with the wanted 922Hz signal in the centre.
But it did not take me long to find out that it contributed absolutely
nothing to the readibility of signals under difficult conditions.
It proved again that our sophisticated ear/brain system cannot be helped
by such primitive contraptions.
Yes, I'm aware of this but am keeping an open mind. I have already
done some interesting tests that combine some of the advantages
of both analogue and digital techniques. One crude test last
weekend produced significantly better readability of a weak station
in heavy static than was available either direct from my radio, or via
a DSP unit.
What sparked off this idea was the number of people who agreed
that listening to a pair of headphones on the bench gave them
better reception than when the phones were on the head. Therefore
there appears to be at least one uninvestigated way of enhancing
reception which at present relies on chance and acoustics.
I agree that all theoretical work tends to ignore the colossal
advantage of using the brain, but I am not a theorist and would like
to find ways of helping the brain along a bit.
Thanks very much to all those who replied re time delays.
As soon as I have reached some conclusions I will report my
results - or that Dick is indeed right and the brain can't be helped at
all!
Don't forget the old trick of fixing a loudspeaker to the end of a pipe
and using the organ pipe resonance frequency. Quite common in the 40s
and 50s. I wonder if two could be used, tuned to different frequencies
and placed at opposite ends of the room?
73
Mike
--
M.J.Powell
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