[TowerTalk] perspective

[Tom Rauch]

Hi Dave,

> ...question I have is how does my radio know whether the two stations I am
> working have a 3db difference if my AGC is on and working?  I don't think
> I'll see the difference on the "S" meter and I sure won't hear the
> difference on the speaker.  So how does those few db make or break the
> path, the contact, or the contest?

On my IC-751A, one S unit is about 1.5 dB at the low end of the 
scale. Same on my FT-1000D. The MP also behaves the same 
way. Up over S-9, everything is pretty good.

That's OK, because when signals are really weak or in a bunch of 
noise or QRM, one dB can be an extreme difference in the copy. 

The question is, how often are 1500 watt stations in that situation 
in contests?

Another thing often forgotten is gain is not important at all for 
receiving at HF. The only thing that matters on receiving is 
directivity, and maintaining a big null in undesired directions. Some 
of the best transmitting antennas fall down in receiving, so what will 
that do for you?  

> SO, I think the test is not whether the traps are perfect conductors or
> heat sinks but rather do you hear and work the stations and are you
> satisfied with your results.  I see plenty of guys with satisfactory
> results who are using beams that have pretty poor performance results
> under comparison test provided  by the db sheriffs.  From all the hoopla
> about a single db one would think those results are bogus...but they

When I look at the various reports, and if I assume the reports 
could possibly be accurate to a dB, there isn't much difference at 
all in the antennas available to use. Where all this "stuff" about 
dummy loads, 1 dB loss per trap, and no-gain tribanders comes 
from is beyond me! 

This is especially true when you consider the real delta in 
measurements like this. It never fails to amaze me how often 
tolerances are dismissed, and measurements are considered 
absolute.


73, Tom W8JI
w8ji@contesting.com

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