[RTTY] Re: Noise with MMTTY

Bill Turner wrt at dslextreme.com
Tue Mar 23 09:07:51 EST 2004

On Tue, 23 Mar 2004 10:29:59 -0600, Charles Morrison wrote:

>I can't speak to this issue directly.  However, on the human factors side
>people doing signal detection research stumbled across something that is
>counter intuitive.  Is it easier to copy a weak CW signal on a quiet or
>noisy band?
>Many people will say it is easiest to copy CW on a quiet band.  However,
>under controlled testing people did a better job of copying a weak CW signal
>in noise than when there was no noise.  A demonstration of this on NPR
>nearly blew me away.  The played 10 seconds of what to the human ear sounded
>like silence but actually contained a very low level CW signal.  When noise
>was added in the CW signal was very obvious.  Of course too much noise mask
>the signal entirely.
>I doubt electronic circuits/software work the same as the human brain.  But,
>the next time you operate the original digital mode don't cuss any noise for
>it might be help your brain detect a signal that it otherwise might not


I've noticed a similar effect on CW myself.  Often I can copy CW better
with a wide filter instead of a narrow one, even though the apparent
noise is more.  Strange.

Bill, W6WRT
QSLs via LoTW

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