Jim,
All very good points, and I'll accept those statistics re. % SS score per
each dB improvement during a 24 hour stretch.
But in a DX pileup over a narrow time window, propagation variations can
easily swamp a dB or two. When I worked Dima at E30FB, after his 9th call
to me, my signal upfaded just enough for him to copy my full callsign. That
upfade itself could have been 3 to 6 dB, just enough to bring my signal
above all the other callers who refused to standby while he was trying to
work "N6S?".
And finally, I agree I'm not much of a contester, but I do love CW SS, and
won the Pacific Division for LP single op in 2018. So I have been known to
make the effort...!
73,
Steve
N6SJ
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Jim Brown
Sent: Friday, May 1, 2020 12:35 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 1dB more RF Power?
On 4/30/2020 5:40 PM, Bob Shohet, KQ2M wrote:
> Every DB matters - wherever you can find it.
Absolutely. When the signal is close to the noise, small differences in the
level of the signal become VERY important. And those half and single dB add
up. 1 dB from bigger coax or hard line, more/longer radials for a vertical,
raise a 40M dipole by 5 ft, or an 80M dipole by 10 ft, or turn an inverted
vee into flat dipole at the same height. Three of those 1 dB changes combine
for 3 dB (equivalent to doubling the TX power.
Another observation. My friend N6SJ is a DXer, but not much of a contester.
KQ2M and I are both contesters. Contesters, especially those trying to pull
a multiplier over a difficult path, have experienced the value of a dB,
often several times in a weekend. N6ZFO, anther contester who's a retired
statistician/scientist, says that 1 dB is good for a 2.6% increase in an
ARRL Sweepstakes score; three of those is good for 8%. Casual operators
won't notice the difference, but the other guy trying pull you out of static
WILL.
On SSB, we can increase our loudness on the other end with EQ and amplitude
compression. Rolling off everything below 500 Hz adds 3 dB; amplitude
compression set for 10 dB on voice peaks adds that 10 dB. That
13 dB is equivalent to multiplying TX power by 200!
73, Jim K9YC
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