The definition of db is 10 log (powerA/powerB) and has NOTHING TO DO
with human perception. (Where DID that old wive's tale come from...)
The landmark Bell Laboratories study on how well average people
distinguish between varying levels of sound came well after the
measurement unit was defined.
The number was approximately THREE dB, not one. Note that this is a
bell-shaped curve thing, some can tell the difference with less, some
need more. It may be true that there isn't a human being alive that can
distinguish ONE dB under the test conditions.
A corollary to this was the common telco observation that if the
network (who would fuss about 0.2 dB) didn't have tone and a meter on a
circuit, they couldn't tell three db short or long (+/-) if their lives
depended upon it.
--- Mel Farrer <mfarrer@tality.com> wrote:
>
> I would agree, with one added comment. The definition of dB, as I
> remember,
> 1dB is the unit of sound level change that is detectable by the human
> ear.
> So if you are at the noise floor, yes it will make a difference.
>
> -----Original Message-----
> From: Jon Ogden [mailto:jon.ogden@cain-forlaw.com]
> Sent: Thursday, September 06, 2001 11:14 AM
> To: '2'; AMPS; at towertalk
> Subject: RE: [TowerTalk] True Or Not True #2
>
>
>
>
> >
> >
> > On HF/MF skywave, is a 58% increase in power out (2db)
> > noticable at the
> > Rx end?
>
> I would say that it depends. If you are already 20 or 30 over 9 at
> the RX
> end then probably not.
>
> If you are right at the noise floor be it noise generated by any
> factor (bad
> band conditions, atmospheric noise, man made noise, or pileups), then
> I
> would say it sure could be noticeable.
>
> 73,
>
> Jon
> NA9D
>
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>
=====
73 & GL
-----------------
Guy Olinger, K2AV
k2av@contesting.com
Apex, NC, USA
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-----
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