On 10/31/2010 5:48 PM, John Rippey wrote:
Dr.. Johnson, many thanks for the information responding to my question
about DNR variations. It covers exactly what I was looking for.
I own a Carver preamp that is 25 years old and contains Bob Carver's
"autocorrelation" circuitry, which does a very good job
of reducing noise from LPs, etc. I was wondering if Carver could do it 25
years ago for vinyl discs, why can't today's transceivers excel in that
department? You've answered the question.
Part of it is that music is much more coherent than voice or even CW and
part of it is that noise reduction from vinyl may have removed some of
the characteristics of some musical instruments that tend to produce
noise like signals, like percussion and quiet wind instruments, not to
neglect double basses bowing noises and reed instrument linkage rattles.
My interest is principally atmospheric noise, but since I'm in a city, those
other noise generators come into play as well. The "holy grail" is certainly
what I was seeking. Again, thanks for the education.
Actually city noises are likely much stronger than atmospheric noises.
Some data says "atmospheric" noise levels are rising but I believe that
to be more true in European urban areas than out here near the Boondocks.
73,
John, W3ULS
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73, Jerry, K0CQ
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