[Elecraft] Testing how loud it is!

[Ron D'Eau Claire]

George, W5YR wrote:

As a new K2 operator, my impression of the AF Gain control is that it
functions unlike the audio gain control of any receiver that I have ever
used before - and that is a fairly large number!   <:}

At times, it seems to progressively increase the signal or noise level
proportionally with knob setting. At other times, it seems to have far
less effect, again in terms of audio signal level increase versus knob
position. I suspect that the actual transfer function of the audio
system is somewhat dependent upon signal level, which while contrary to
the usual objective in linear system design and implementation, may not
be all that bad in the K2 application. My K2 has not had the gain pot
mod.

============================

Have you done the mod to rewire the volume control, George? In the
original design, the volume control simply "shorted out" the balanced
audio inputs to the audio amplifier. That produces an odd transfer
function as well as the oft-reported problems with a 'scratchy pot'
because the pot had to have virtually ZERO ohms across it in the "off"
position. Few pots are really a dead short at minimum, nor do they
maintain a smooth resistance change as tiny movements are made near
minimum. 

Your symptoms do sound very odd! But if you haven't done the
modification to rewire the control, you might like it's action a lot
better and if the other oddities remain they may be easier to run down.

Ron AC7AC
K2 # 1289