The reason that particular log relationship was chosen was because it gives
a tidy fit to differential thresholds for human auditory perception as first
outlined by Weber and Fechner ca. 1830.
For more see any reasonably advanced text on eperimental psychology, or E.G.
Boring "History of Experimental Psychology".
Cheers
end
Barry Kirkwood PhD ZL1DD
Signal Hill Homestay
66 Cory Road
Palm Beach
Waiheke Island 1240
NEW ZEALAND
www.waiheke.co.nz/signal.htm
----- Original Message -----
From: <n4kg@juno.com>
To: <bjk@ihug.co.nz>
Sent: Friday, 07 September, 2001 9:33 AM
Subject: Re: [TowerTalk] Re: [AMPS] True Or Not True #2
> Is that a DEFINITION or an OBSERVATION?
>
> I always thought the DEFINITION was the logarithmic relationship
> dB = 10 log P2 / P1.
>
> Tom N4KG
>
> On Fri, 7 Sep 2001 "Barry Kirkwood" <bjk@ihug.co.nz> writes:
> >
> > By definition, from psychophysics, 1dB is the increase or decrease
> > in signal
> > strength that can be discerned by an average observer on 50% of
> > occasions.
> > A 2dB increase should be discernible by an average observer at any
> > signal
> > level.
> > cheers
> >
> > end
> > Barry Kirkwood PhD ZL1DD
> > Signal Hill Homestay
> > 66 Cory Road
> > Palm Beach
> > Waiheke Island 1240
> > NEW ZEALAND
> > www.waiheke.co.nz/signal.htm
> > ----- Original Message -----
> > From: Colin Lamb <k7fm@teleport.com>
> > To: 2 <2@vc.net>; AMPS <amps@contesting.com>; at towertalk
> > <towertalk@contesting.com>
> > Sent: Friday, 07 September, 2001 7:19 AM
> > Subject: Re: [AMPS] True Or Not True #2
> >
> >
> > >
> > > Rich asked "On HF/MF skywave, is a 58% increase in power out (2db)
> > noticable
> > > at the
> > > Rx end?"
> > >
> > > That all depends upon how you define noticeable. If your s-meter
> > is
> > sitting
> > > at S-9, and assuming that 6 db per s-unit is the standard, that
> > would mean
> > > the s-meter would change from 54 db to 56 db - or 2 db over S-9.
> > If the
> > > variation in signal strength is greater than that due to
> > reflection, then
> > it
> > > would be difficult to detect a 2 db change and not noticeable.
> > >
> > > However, if the signal was at or near the noise level, then 2 db
> > increase
> > > could make the signal more easily read. A 2db increase is like
> > Christmas
> > to
> > > someone using a single yagi for moonbounce.
> > >
> > > 73, Colin K7FM
> > >
> > >
> > >
> > > --
> > > FAQ on WWW: http://www.contesting.com/FAQ/amps
> > > Submissions: amps@contesting.com
> > > Administrative requests: amps-REQUEST@contesting.com
> > > Problems: owner-amps@contesting.com
> > >
> > >
> >
> >
> >
> > List Sponsored by AN Wireless: AN Wireless handles Rohn tower
> > systems,
> > Trylon Titan towers, coax, hardline and more. Also check out our
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> > supporting towers up to 96 feet for under $1500!!
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> >
> > -----
> > FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> > Submissions: towertalk@contesting.com
> > Administrative requests: towertalk-REQUEST@contesting.com
> > Problems: owner-towertalk@contesting.com
> >
>
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-----
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