These recordings are an impressive demonstration of the benefit of
one dB of signal strength improvement in a weak signal situation.
Click on the links on this website:
www.ab7e.com/weak_signal/mdd.html
73
Frank
W3LPL
----- Original Message -----
From: "David Gilbert" <xdavid@cis-broadband.com>
To: elecraft@mailman.qth.net
Sent: Wednesday, August 21, 2019 7:02:21 AM
Subject: Re: [Elecraft] KPA500 Coax size requirements
That's not a universally true statement.
Several years ago I was trying to decide which antenna to buy, and my
choice came down to two antennas that were 2 db apart. I created some
audio files by recording typical band noise and then overlaying them
with recorded CW messages at various strengths. The difference between
1 dB above the noise level and 2 dB above the noise level can make the
difference between no copy and copy. The files and testing methodology
can be found here:
http://www.ab7e.com/weak_signal/mdd.html
If you're ragchewing it doesn't matter, but if you're trying to make a
contact and your signal is at the level of the mud it does.
73,
Dave AB7E
On 8/20/2019 9:18 PM, Jim Danehy wrote:
> ONE DB loss is the LEAST DETECTABLE amount a human can detect. Hardly if not
> impossible to notice.
>
> Jim
> W9VNE/VA3VNE
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