[NLRS] 222 and up

Mon Sep 26 21:00:10 EDT 2016

Gary - I cannot speak for the committee, but I provided them with some analysis that I did to see what made sense as far as QSO points, since the QSO points in the first release of the rules seemed out of whack to me. The QSO points are similar to, but not identical to the results of the analysis I did. There is nothing magical about what I did, and the conclusions could be different based on the same input. 

The short answer to your question is that there is relatively high activity on 2.3GHz and 10GHz, less activity on 3456MHz and 5760MHz. 

I wanted to see if the QSO points could be derived objectively. They can be, sort of. My assumption was that QSO points should be based on three things, 1) the SNR ratio decreases as the frequency increases for similarly equipped stations on the same band, and as scoring is distance based, the band QSO points should reflect this, 2) the contest should encourage activity on bands on which there is little activity and the QSO points should also reflect this, 3) the QSO points should reflect the difficultly of getting on the band and operating on the band. 

I can go into the gory details, but essentially I normalized everything to 1 at 432. I calculated SNR ratios based on a simple troposcatter model. For input I assumed that the equipment was the same on all bands, 60W to a 17 ft Yagi (or equivalent) and sky noise (as much as possible) limited receive performance. Keeping the antenna the same size allows the capture area to increase with frequency, negating in part the decrease in SNR as frequency increases. This was the first adjustment I made. Yes I know that 60W on 10GHz is expensive, but it is available. More on that later.  

Activity levels were determined by normalizing last years results by band. This is one of the large reasons that the QSO points for 2304MHz and 10GHz are down from the 3446MHz and 5760MHz. There is a surprising, at least to me, large amount of activity on 10GHz which drops the QSO points calculated for this band. 

The difficulty of getting on the band is, of course, subjective, but I tried to approximate it objectively by comparing the cost of getting on each band. For that I considered the cost of a DEMI transverter (if available, on 1296MHz I used one of the SG labs transverter), Directive Systems antenna, and a preamp if necessary. This was not exact, there were some small variations in antenna gain and linear amplifier power, but it is possible to put together a plug and play 60W station with long Yagis and preamps if necessary from commercial sources, except on 2304GHz where no commercial amp is available, but one can be assembled with a little work with the PyroJoe boards. That surprised me a bit. In short, the cost of getting on bands from 222MHz to 1.2G are about the same, there is a step there, and another 

I then generated QSO points based on a multiplier that consisted of factor 1), and half of 2) and 3). 

Doing this provides set of QSO points similar to, but not identical to, what is in the rules. I assume that the committee underwent a similar analysis. You can combine these in various ways and I am not sure that any one way is better than the others.

I posted this analysis on the VHFContesting Archive in May, when comments on the proposed rules were requested. That post is here:

< http://lists.contesting.com/archives//html/VHFcontesting/2016-05/msg00073.html >

It is not an exact calculation, I doubt that is possible and depends a lot on what one considers important for input. There is nothing sacred about my calculations and I they are certainly open to other conclusions. I just wanted to see if one could take a stab at calculating these if not objectively, at least from a well defined starting point and realistic numbers. 

There are still some holes there, but you will get the general idea. I hope that the committee will look at the results of the suggested QSO points at the end of each contest and adjust them accordingly.

Like I said, I cannot comment for the committee, but I did do an analysis myself and the QSO points the committee proposes make sense to me, even if they do not agree exactly with my numbers. I know that the nonmonotinicity and discontinuous nature of the points as a function of frequency bothers many people. I understand that, but there is no real reason that the QSO points should increase smoothly with frequency and good reasons, at least to me, for it not to. - Duffey KK6MC

On Sep 26, 2016, at 6:04 PM, Gary Mohrlant <w0ghz at arrl.net> wrote:

> 
> 
> Can someone tell me why 2.3ghz and 10ghz only have a band factor of 6.
> 
> 
> Gary W0GHZ
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--
KK6MC
James Duffey
Cedar Crest NM