[CQ-Contest] arrl correction factor
Martin , LU5DX
lu5dx at lucg.com.ar
Fri Jul 1 05:43:29 PDT 2011
Excellent analysis Tom and I understand the situation in the US.
On a world wide basis it's pretty different in most cases. Taking the ARRL
DX test as an example. Consider a station here in LU, entering M2 with heck
of a big amount of engineering, tons of aluminum up on the towers and a
station in the Caribbean with probably a quarter of the aerials. We'll end
up working 8500+ Qs and the Caribbean will work 12000 + Qs. That really
don't have to do with better engineering, better antennas or better ops,
it's about distance.
DX Contesting in most cases has been reduced to finding a good spot in zones
33/35 for CQ WW tests and zones 7/8/9/10 for ARRL DX tests.
The amount of effort spent in building a competitive station and the effort
it takes to complete a DX QSO based on the distance no longer is a key
But you are right, Caribean or Zone 33 stations at some point may say, hey
guys, you enjoy and advantage on 28 Mhz when SFI is under 90. In that case
it's up to the contest organizers how much they want to analyze these
What I would like to say though is that we have statistical data to analyze
the conditions along a given path from almost anywhere in the world to
anywhere in the world.
Thing is I made some calculations and the resulting data set (1.8 Mhz not
included) will have over 300 million rows. Not even close to what we
consider a really big data set nowadays at all, but a pretty important one
300 millions possibilities result from taking into account DX Location (DX
Countries and Call Area districts in large countries like the USA, Canada,
Russia, VK, and others), SFI (from 30 to 200 in steps of 5), K index (from
1 to 10 in steps of 1) and date ( to consider seasonal conditions).
That data set will allow to assign a figure of merit for each QSO based on
SNR numbers over a given path. Calculations should be done using average
power say about 500 W and average antennas at average height.
Whether stations use more or less power and better antennas is not part of
what we need to generate the data set.
I don't think anybody would want to go that route, but in fact it is
possible to establish such scoring system.
Just like you I'm in favor of analyzing all the possibilities I don't want
to just vent my opinion because I'm impacted. But at least let's all come to
an agreement where statements like:
"..I've never complained and I'm in the black hole..", "..things are okay
the way they are..." "...move to Canary Islands..." or things like that are
not part of a serious discussion.
I'm talking about generating a data set with the results of propagation
analysis software to have those figures of merit beforehand, otherwise,
contest organizers will have to include the algorithm in their log checking
software and run the calculations on the fly...
On Thu, Jun 30, 2011 at 7:01 PM, Tom W8JI <w8ji at w8ji.com> wrote:
> Disclaimer, this is not what I usually work with so I am open to
> corrections by those more experienced.
> Kind of a selfish point of view.
>> We down here do not complain about having a small time window to work USA
>> 160M , most probably just a couple of hours right before our sunrise
>> of the time.
> Distance, without things like path problems, is by the inverse of the
> square of distance. Doubling distance results in a power density reduction
> of four times.
> Twice the distance is four times power density reduction or 6 dB, absent
> other attenuation.
> 3800 miles for the NE coast of USA compared to 4700 miles for this area is
> 1.8 dB.
> The difference from K3LR to me into middle Europe is about 4150 to 4700
> miles, worth about 1 dB.
> If we look to middle Europe from Minnesota attenuation due to distance
> alone should put Minnesota at a 1.3 dB advantage to me because they are
> closer to Europe, but they have a clear disadvantage. That disadvantage is
> in both multipliers and contacts because with normal ionosphere it might be
> 10-20 dB or more.
> The real problem we have in the USA is not distance, but the variability of
> the path. Anything near the north magnetic pole is unreliable and
> unpredictable, and suffers much higher attenuation.
> Europe, the center of large contact numbers, is at about 45 degrees. A
> longitudal location change results in less distance change than we often
> expect. Latitude is even more important because of the magnetic pole when
> the path gets close. This is because most of the problems are with
> propagation path, not distance.
> The effect of distance scoring would be to penalize NE USA stations in
> respect to almost everyone. An inadvertent drawback is it puts the SE at
> advantage to everyone, including people with much worse propagation who
> unfortunately have shorter distance to Europe.
> If the goal is to allow all of the USA more excitement, we need to not
> shoot from the hip based on only the top ten and the seriously flawed idea
> we have some purely distance disadvantage. After we have a level headed
> non-emotional understanding of the problem, there might be some correction
> that at least tends to level (it will never actually be level) the USA.
> Any change should not be by which of us makes the most noise or loudest
> protest, but rather what makes the most sense if a change to really make
> everything better is even possible. It should be agreeable to groups from
> all areas of the country.
> This turned into a strong campaign in both directions long before anyone
> took the time to think through it. Now we have hard feelings over something
> that never should have even been pushed without understanding how any change
> affects everyone.
> I do not believe this affects you, unless the plan is to correct the entire
> world by distance. If that is true, it might be better to just start a brand
> new contest based on distance alone and not try to fix an existing one by
> correcting what really is not the problem.
> 73 Tom
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