I confess to having generated those files, although it was several years
ago that I put them on my web site. They just get referenced here or
there about once a year when a similar topic surfaces.
http://www.ab7e.com/weak_signal/mdd.html
One dB was about all I could claim was distiguishable, but a difference
two dB was surprisingly so.
73,
Dave AB7E
On 4/30/2020 5:40 PM, Bob Shohet, KQ2M wrote:
I remember last year someone (perhaps AB7E?) posted audio files of DB
differences, 1 DB at a time.... 1DB, 2DB, 3DB, as well as under
varying sending conditions. I always thought that 1 DB could be heard
but until those audio files I never realized just how much it could
matter.
Whether we are calling cq or calling a station it is unlikely that we
will ever know when that extra 1 DB mattered; but now add in
differences in pitch, keyer speed, sending style, propagation effects
(flutter, aurora, echo, etc) and all of a sudden that 1 DB extra
signal strength might really stand out, especially if a band is noisy
and and/or propagation is marginal, not to mention when there is a
good op on the other end listening for the slightest signal
differences in a pileup.
Every DB matters - wherever you can find it.
73
Bob, KQ2M
*From:* n6sj@earthlink.net
*Sent:* Thursday, April 30, 2020 8:15 PM
*To:* 'David Gilbert' ; towertalk@contesting.com
*Subject:* Re: [TowerTalk] 1dB more RF Power?
OK Dave, point well taken!
But the only time I've worked anyone right at the noise level was when
Dima RA9USU sucked my CW signal out of the noise when he was at
E30FB. Took him 10 tries to finally get my call. I admit 1 dB might
have made a difference for that Q!
73,
Steve
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of David
Gilbert
Sent: Thursday, April 30, 2020 4:58 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 1dB more RF Power?
True ... although noise doesn't care when or where you put your
signal, and 1 dB can sometimes make a valuable difference if you
happen to be right at the level of the mud.
And, of course, there is always the possibility that the folks you're
competing against are just as adroit in signal placement as you are.
If there are enough of them 1 dB could matter then as well.
73,
Dave AB7E
On 4/30/2020 12:12 PM, n6sj@earthlink.net wrote:
> Great discussion!
>
> But personally, I think on CW your timing (call early, call late),
> keying speed (call faster, call slower), and placement of your signal
> in the receiver's passband (call high, call low) will all have a much
> bigger effect on being noticed and answered than a 1dB increase in
RF signal power.
>
> On SSB your timing, mic equalization, enunciation, and inherent voice
> timbre will similarly swamp a 1dB power increase.
>
> 73,
> Steve
> N6SJ
>
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