[TowerTalk] perspective

[Rajiv Dewan, N2RD]

I have often read that the ear cannot distinguish between two signals that
differ only in amplitude by a fraction of a db.  I often wonder exactly how
this test is done.  Consider two setups:

1.  You hear one signal and then another and are asked to judge which is
stronger.
2.  You hear two signals simultaneously, perhaps even on the same or close
by frequency (parameter of the test ), and they encode different calls in
CW.  Is a call in signal that is a fractional db stronger copied more
readily than the other?  What is impact of fractional db difference in
signal strength on percentage of copy?

Anecdotally, I would think that in the second setting, fractional dbs do
matter.  It would be easy to test using two CW sources and a mixer.

Regards,
Rajiv, N2RD

----- Original Message -----
From: "Tom Rauch" <w8ji@contesting.com>
To: <towertalk@contesting.com>; "Mel Martin" <mel@interlink.net>
Sent: Wednesday, July 19, 2000 11:23 AM
Subject: Re: [TowerTalk] perspective


>
> > Contrary to the common perception, the reason for using monobanders is
NOT
> > higher gain. Much more important aspect of monobanders are.
> >
> > Higher reliability due to simpler construction, less electrical joints
to
> > fail and much lower wind drag.
> >
> > They don't detune as badly with ice or snow loads.
> >
> > Easier to design.
> >
> > The few extra db's are certainly a bonus, but reliability is the big
> > attraction for me.
>
> I've been racking my brain trying to think of a way to test the theory
> that a few dB of signal makes a big difference in a contest, but I
> can't think of a way to prove or disprove it.
>
> Can anyone?
>
>
> 73, Tom W8JI
> w8ji@contesting.com
>
> --
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