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Re: [CQ-Contest] Impressive demonstration of one dB of signal strength i

To: CQ Contest <cq-contest@contesting.com>
Subject: Re: [CQ-Contest] Impressive demonstration of one dB of signal strength improvement
From: Barry <w2up@comcast.net>
Date: Thu, 22 Aug 2019 15:55:25 -0600
List-post: <mailto:cq-contest@contesting.com>
Regardless of speed, it always seems the fade/QRN is synchronized with the callsign and you miss the same letters each time  :-)

Barry W2UP

On 8/22/2019 8:27 AM, rjairam@gmail.com wrote:
I always thought speed was dependent on the length of fades and type of
burst noise.

Faster would attempt to catch short fades whereas slower would catch longer
fades but weak S/N?

On topband my strategy is around 20wpm and sometimes slower repeats. On
higher bands I would go as fast as I can (which isn’t very fast) and then
slow down for weak signals or ops who have trouble.

Ria
N2RJ

On Wed, Aug 21, 2019 at 7:38 PM Bernie McClenny, W3UR <bernie@dailydx.com>
wrote:

For me, and I suspect for many other Topband ops, when QRN/QRM is involved
slower is better than faster! 18-20 WPM is about the right speed.

Bernie McClenny, W3UR

Editor of: The Daily DX (1997-2019)
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On Aug 21, 2019, at 4:26 PM, Bob Shohet, KQ2M <kq2m@kq2m.com> wrote:

I have never had the opportunity before to hear differences in signal
strength by 1 db increments.  +1 db is clearly an advantage and a +2 db
difference nearly obliterates the weaker signal.  Remarkable.  I wish I had
heard this 20 years ago!    ;-)
The differences in copy between different CW speeds is very interesting
too.  I suspect that most contest ops will generally do better with the
higher speeds unless they are exhausted to the point of mental impairment,
in which case the slower speeds might work better.
Thanks for posting this Frank and a special thanks to AB7E for creating
these audio recordings with explanations!
73


Bob, KQ2M



From: donovanf@starpower.net
Sent: Wednesday, August 21, 2019 11:15 AM
To: cq-contest@contesting.com
Subject: [CQ-Contest] Impressive demonstration of one dB of signal
strength improvement
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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