[TowerTalk] perspective

[wa4dou@juno.com]

Hi Gang,
  I would be inclined to agree with Gerald in principle if it were not
for the fact that you can't take the difference in scores between high
power and low power categorys and simply divide the difference in power
levels down and quantify the totals on a per db basis.. Oh sure, this
does give you another way of trying to understand the differences but
those differences are a result of a much higher power level change
between the two, not minuite changes. For instance, if a high power
category allows 1,000 and a low power category allows 100 watts(an
obvious 10 db difference) and the differences in scores between categorys
is 100 %, then you cannot say that each of those db is worth 10 % greater
scores. The value of a db is logrithmic. The first one is virtually
meaningless, the second one isn't worth much more, so on and so forth
until finally the power change has become so great that the difference
has finally begun to create statistically meaningful results. 10 db is a
big change, it means a whole new level of performance. 5 db is a
meaningful change, statistically meaningful results can be achieved at
this level. 1-2 db is meaningless, you're straining the remains for the
fingerprints of something meaningful here. I'm talking ionspheric
communications here. 1 db is the least power change that any human being
can discern. In fact, just barely discern. Barely means hardly. Discern
means perceive. Hardly perceive!  This is science, not voodoo! Hardly
perceive does not change an unreadable signal into a readable signal. Its
a much bigger change than a db that does it. Yes, it takes all those
little db acting in concert to make the difference. 73 Roy WA4DOU
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On Wed, 19 Jul 2000 21:13:50 EDT TexasRF@aol.com writes:
> 
> We can estimate the worth of a system db by comparing the top 
> contest scores 
> between the high power and low power categories. I have not done 
> this for hf 
> contests but I would bet the points per db would be pretty well 
> defined. This 
> comparison would basically tell the story as related to how well the 
> station 
> is heard as receive capability between high and low power categories 
> would be 
> similar.
> 
> Several years ago I did a study of moonbounce contest scores and 
> stations to 
> determine what kind of antenna system would be needed to give a top 
> score on 
> 2 meters. I found that in that contest 1 db would be worth 
> approximately 25 
> qsos (2 meters only). The formula is still close but varies somewhat 
> from 
> year to year depending on activity level and quality of propagation 
> conditions. 
> 
> The challenges of contesting on 160, 80 and 40 meters are similar to 
> 
> moonbounce contesting: You are dealing with quite a few marginal 
> strength 
> signals compared to the higher bands. It would seem that the dbs 
> would be 
> more important on these bands than the higher bands.
> 
> 73 de k5gw
> 
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