Terrific presentation, Doug. Wish I'd seen something like this when I got
serious about contesting 20 years ago!
A few comments:
- 6% per dB is a lot! That would compensate for my UBN losses in most contests.
In the big DX contests with close scores, 1dB or 2dB could make the difference
between winning and coming in second or third.
- One of the most compelling slides for me was "Feedline Improvements". I've
worked on that in my station over the years, but have never seen a treatment of
just how much bang for the buck it can offer.
- I think it's implied in a couple of slides, but ther are also cost/dB
equations related to tower height/capacity, namely how much bang for the buck
you get by increasing antenna height and/or installing stacks, both of which
require taller and/or beefier towers (lots of $$$$, not to mention the cost of
longer low-loss feedlines, stack-switching gear, ring rotors, cables, etc.).
Yet another item that adds to cost is getting (or fighting for) zoning
permission to build more/higher towers. It's tough to quantify these
improvements because more effective signal angles don't translate directly to
an overall increase in dB.
- There are other improvements that are hard to quantify with a cost/dB
formula, particularly improvements on receive. For example, a 4-square on 40
will be many dB below even a modest, low short-forty on transmit, but will have
superior F/B that enables better copy of weak stations. Then there's the
hard-to-quantify advantage of being able to switch to a vertical array on
receive when snowstorm static is wiping out receive on the beam. And with the
right transceiver (at more cost) there's the advantage of being able to use
antennas with different polarization for diversity reception. That one has
definitely boosted my QSO totals on 40. And the cost of improvements like these
isn't always in dollars. A 4-quare on 40 is relatively inexpensive to build,
but a major amount of work if you install a full-size ground radial system.
- Finally, I'd add one more item to "There is no secret!": Increase your time
in the chair. For most of us, more time in the chair translates directly to
higher contest scores and there's no dollar cost. While improvement may include
getting/staying healthier, eating right, regulating caffeine, getting enough
rest before the contest, plotting an off-time strategy, and so on, my own
experience is that hours in the chair increase with enthusiasm, grit and
determination. Also, I suspect a study might show that the more on-the-air
practice you get between major contests, and the more time you spend preparing
for a given contest, the more hours you're likely to put in.
73, Dick WC1M
-----Original Message-----
From: Doug Grant <dougk1dg@gmail.com>
Sent: Thursday, August 22, 2019 1:03 PM
To: cq-contest@contesting.com
Subject: Re: [CQ-Contest] CQ-Contest] Impressive demonstration of one dB of
signal strength improvement
On Thu, Aug 22, 2019 at 4:00 PM W3LPL wrote:
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
>
>
Many years ago, Clarke Greene, K1JX, casually mentioned that he had determined
adding 1dB to your signal strength would result in a 6% increase in your
contest score (mostly applied to DX contests). I filed that away for future
reference.
Test cases are hard to find, but I found one in 2014 when N1UR switched from
Low Power to High Power in the CQWW. Same op, same QTH, same antennas, and very
comparable propagation near the top of the cycle.
My conclusion: the K1JX "6% per dB" rule was about right.
The exercise for the reader is to figure out how to add dB at the best "dB per
dollar" ratio. Not all dB cost the same!
You can find some hints in a presentation I did a while back at CTU:
https://www.contestuniversity.com/wp-content/uploads/2017/06/K1DG_CTU_2015_Ten_Ways_to_Improve_your_Contest_Score.pptx
Slides 5-22 cover this topic.
73,
Doug K1DG
.
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