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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