[Elecraft] Noisy AF gain pot on K2

[Ron D'Eau Claire]

John, I assume you mean the modification that was posted a year or so ago
for K2 that were pre-S/N 3000 like yours. 

One of the advantages of that mod is that it *does* reduce the audio output
to zero. I can say that mine (S/N 1289) goes to zero after the mod. 

In the earlier circuit, such as you have if you've not modified your K2, the
pot is simple shunt resistor across the audio line. It can reduce the audio
to zero only if the pot truly has zero ohms resistance at minimum. Few pots
do, and it's common for a pot to get "noisy" at the lower settings.

The revised circuit uses the pot in a more common arrangement that does not
depend upon zero ohms at minimum to kill the audio. 

You'll also find that the action of the pot is better. That is the change in
volume per degree of rotation of the pot is more logarithmic like other
audio gain controls. 

Ron AC7AC

-----Original Message-----
A month or two ago there were a few messages posted concerning the well
documented cure for a noisy AF gain pot on the K2. The consensus was that
the mod helped but did not reduce the gain to zero on full anti-clockwise
rotation. No-one disputed this on the reflector. With DSP fitted I find that
I have too much audio at minimum setting.  (I'm 74 & a bit deaf!!)  Has
anyone done the mod and
achieved near silence at the minimum position??   Thanks in anticipation. 
John  GW3JXN    K2 2649