[CQ-Contest] How much is a dB worth ?

[Tim Shoppa]

Certainly, Tom! My antenna is a 130-foot doublet, up 75 feet between trees,
fed by tuners and ladder line.

On 160M the antenna is fed by tying the ladder line together at ground
level and feeding it against ground as a "Marconi T". Essentially the
ladder line becomes a vertical element and the 130-foot top becomes a
tophat.

Some pictures of ladder line relay switching and tuners here:
http://www.trailing-edge.com/tuners.html

I have a couple 160M receive antennas too (a K9AY for NE/SW, and a
west-facing pennant.)

Tim N3QE

On Tue, Mar 1, 2016 at 9:29 AM, Tom Carrubba KA2D <ka2d at arrl.net> wrote:

> Hi Tim
>
> May I ask, what antenna do you use?
>
> Thanks
> Tom KA2D
>
> -----Original Message----- From: Tim Shoppa Sent: Tuesday, March 01, 2016
> 6:40 AM To: cq-contest at contesting.com Subject: Re: [CQ-Contest] How much
> is a dB worth ?
> My interpolation on CW and RTTY using my personal logs, for 24-34 hour
> efforts in 48 hour contests and almost unchanged antenna system, after
> adding two different amps.
>
> Note that my numbers only track transmit power dB, not receive system dB's.
> I have improved my receive system on 160M but not on the other bands in
> this time.
>
> Note that for CW tests I was often in the top 10 box for assisted LP but
> now am not necessarily in the top 10 box for CW now that I enter assisted
> HP. And I actually lump a couple different contests together and apply some
> tweaks based on what I feel to be changes in propagation to keep things
> comparable to my last year on LP.
>
> Going from barefoot to AL-811H (8dB) doubled my QSO's and tripled my
> scores. With this change I usually get S&P on first call and can often hold
> a run frequency for a good time in the biggest CW and RTTY contests.
>
> Going from AL-811H to AL-1500 (another 4dB) added another 30% to my QSO
> numbers and another 50% to my scores. With this change I almost always get
> S&P on first call and only rarely get pushed off a run frequency.
>
> So making a little table, just using ARRL DX CW as an example:
>
> 100W = 1000Q's
> 600W = 2000Q's (8dB more power for 3dB more Q's).
> 1500W = 2400Q's (12dB more power for 3.8dB more Q's)
>
> 100W = 1M points
> 600W = 2.7M points (8dB more power for 4.2dB more points).
> 1500W = 3.5M points (12dB more power for 5.5dB more points).
>
> I would say each dB more power, means 7 to 9% more Q's.
> And each dB more power, means  more points 11 to 12% more points.
>
> There is some "compression" to the score expansion (a dB is worth more
> moving from 100W to 600W, than a dB moving from 600W to 1500W).
>
> I think this compression factor would have been less, or not there at all,
> if I had improved my receive system as well as my transmit power (i.e. I am
> now an alligator, all mouth, no ears).
>
> If I had chosen WPX, the QSO ratios would be similar, but the point ratios
> will be a little larger (WPX mults continue to grow quicker than ARRL DX or
> CQ WW mults.)
>
> Tim N3QE
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