That’s Interesting Bernie. For me it is dependent on how well I can hear them.
If they are strong enough for me to hear them reasonably well, then when I am
dealing with heavy qrn with brief short bursts of relative quiet, (I think of
it similar to meteor scatter) – you have maybe 2 seconds to get the call –
faster is better; at higher speed you might get the whole call in one shot
vs.with slower sending, fighting to get one letter or two repeatedly over
perhaps a full minute or longer, or losing the station in qsb. However, if
they are weak and there is heavy qsb and/or qrn, then I agree with you that
slower is usually better – more time to hear each individual character.
Sometimes if I am calling a DX station in high qrn cndx and they are reasonably
loud, I will alternate the speeds in my calling for that reason, especially if
I know the opr can copy cw at higher speeds. I don’t know what the qrn sounds
like on the other side but if there are brief windows in time between static
crashes and they can hear a KQ2 calling, then at 35 wpm they likely already
have my call; at 18 wpm they likely won’t.
73
Bob KQ2M
From: Bernie McClenny, W3UR
Sent: Wednesday, August 21, 2019 6:11 PM
To: KQ2M Bob Shohet
Cc: W3LPL Frank Donovan ; CQ Contest
Subject: Re: [CQ-Contest] Impressive demonstration of one dB of signal strength
improvement
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)
The Weekly DX (2001-2019)
How's DX? (1999-2019)
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http://www.dailydx.com/free-trial-request/
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410-489-6518
> 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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