I certainly do not know what your operating preferences are Dave but by
your comments I would assume (very bad choice of words to a lawyer, I
know) that casual operating predominates.
I am talking from the experiences of an in-the-trenches DXer and
contester, HF and VHF where 2dB makes the difference at times.
Here is an example of a possible situation. I am in a DX pileup on CW and
my signal is only 1dB above the din which means I am just part of the
noise at the other end. If I increase my signal 2dB I will now have a 3dB
advantage and it should predominate. Theroetical...YES; works all the
time....NO. There are way too many other factors involved including
operator skills, antenna angles QSB, etc, etc.
Also 3dB is readily detectable by anyone with normal hearing; tests have
proven that as low as 1.5dB can be detected by a few and 2 dB by a
sizeable number. Find out for yourself the next time you get your hearing
checked.
For those who sit on 75 or 20M SSB and chat with S9 ++ signals all the
time even 10dB probably goes unnoticed unless they are constantly
watching an S meter.
For the chap operating weak signal VHF a signal 2dB out of the noise is
all it takes. The human ear is a wonderful device for detecting a
coherent signal out of white noise.
For the DX Contester, a 2 dB advantage (power, antenna or whatever) can
win or lose a contest. Take a look at the KM1H contest scores from
1987-95 if you doubt that. Getting the band edge first on 20M on SSB into
EU as the band openst is an absolute key strategy. On either mode it
means you can get the jump on the competition and keep moving up first to
the next highest band as it opens.
I realize this is an AMP reflector but I sense a very wide diversity
here. I enjoy amps but put most of my $$$ into antennas. 10 thru 20M have
4 high stacks and a 4/4 on 40M. I can pick up many, many more dB by
switching stack phasing than going from 1200W to 10KW into a single
antenna.
Detecting a 1dB change requires very expensive equipment; I had to pay
$25 for my Simpson 260 at a flea market. For the sake of discussion let
us assume that the signal amplification in Brand X receiver is perfectly
linear.
Thats my 33 1/2 cents worth for today on THAT subject.
73...Carl KM1H
On Tue, 1 Apr 1997 18:50:25 -0800 (PST) "David B. Ritchie"
<dbr@alumni.caltech.edu> writes:
>
>3db is barely detectable by the human ear
>1-2 db can be measured by expensive instruments
>2db hardly seems useful on any band (of course, the first 160db may be
>
>VERY useful)
>Dave N7UE
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