[Elecraft] K2 #2548 - Low S-meter sensitivity

[John Buck]

What problem?
If you can hear a slight increase in noise when you connect the antenna 
then you have enough gain.

According to my very quick calculations based on the numbers you gave 
and assuming that S9 is correctly about 50 uV, then your meter should 
saturate on the 20 mW signal.  Your data indicates to me that your rig 
is working just about right.

The real problem is that people have become accustomed to receivers with 
excess noise and too much front end gain.

Hearing a lot of noise is just a sign that the gain is higher then 
needed in the front end of the receiver.

The S meter in my K2 is calibrated per the book and verified with a good 
signal generator/attenuator.  And it works about as you describe 
assuming you can hear antenna noise without the preamp on 40.

People have gotten used to very large s meter swings for small signals.
This is not an advantage.

Aloha,
John KH7T