[Elecraft] Re: Elecraft Digest, Vol 14, Issue 19 --- S-meter & S-units

[Wa6bfh at aol.com]

One very important consideration of the use of “S-meters”, and “S-units” is 
 remembering that signals are heard as a “Square Law Function” Every time 
you  double or lengthen the communications path by twice the distance, the 
signal has  fallen to one-fourth, or a 6 dB change!
 
It is good to know how many dB per S-unit your receiver‘s meter indicates.  
This will probably not be a linear consideration -- and don’t believe the old  
wives tale about 6 dB’s per S-unit. It is the rare radio indeed where that is  
true!
 
Even better than using “S-units”, give other stations reports in (ACCURATE)  
dBm! You will need the use of a calibrated signal generator to assess your  
receiver.