[Elecraft] mods to K2

[Jim Brown]

On 9/27/2013 12:37 PM, Vic K2VCO wrote:
> This argument will never die.

As long as some of those doing the talking are ignorant of the facts, 
yes. :)

> I maintain that even ONE dB matters in this situation. 

And you are correct.  Here are the FACTS. The 6dB and 10 dB "rules of 
thumb" are based on the FACT that a 6-10 dB change in the loudness of a 
sound that is well above the background noise level will be perceived by 
the human ear/brain as "twice as loud," or half as loud. The key words 
here are "well above the background noise level."  This fact is quite 
well known from the study of psychoacoustics (that is, how humans hear), 
and is related to the fact that human hearing and  sight are logarithmic 
in their response to loudness and brightness.

The FACTS are very different if the desired "signal" is close to the 
noise level, or to the level of other sounds. In that situation, a 
change as little as 1-2 dB can be VERY perceptible, and make the 
difference between hearing and not hearing it.  One of the things I did 
professionally was mix sound for live jazz performances. It wasn't long 
before I learned that changes of only 2-2 dB in the balance between 
instruments was often the difference between just right and not hearing 
one of them.

Most serious contesters and DXers fight for every dB in their stations. 
Consider that the gain of the BEST 2-el beam over a dipole at the same 
height is no more than 3-4 dB, and that adding another element typically 
adds 1 - 1.5 dB. And that assumes that these are well designed, 
efficient antennas.  Those with traps are 1-3 dB less than that. Note 
that these are MEASURED numbers, not advertising numbers, and are taken 
from documentation of an excellent series of tests of a dozen or so 
tri-banders by N0AX and K7LXC about 15 years ago.  Ward and Steve 
actually measured two big antennas with negative gain as compared to a 
dipole. :)

73, Jim K9YC