[Elecraft] K2 Noise Solved

[DDWEBB at aol.com]

A few weeks back I wrote that I was experiencing  a most unusual noise 
problem. I had hoped that someone else might have had  the same problem and would 
have the answer. This didn't happen.
The  noise was noticeable when the volume control and RF Gain were at minimum 
and  even the antenna disconnected.   
I want to thank Gary,   KI4GGX, who was of great encouragement to me is the 
solving of this problem. He  even suggested I record the noise.  I did and sent 
it to him to hear.
I  finally decided to use the bruit force approach and used a 1000 UF 
capacitor  with one side grounded.
Starting at U9 the audio amp, shorting leads to  ground through the 
capacitor, I discovered the noise was coming in via the  CW side tone path. I traced 
the noise to the input to U 10B pin 5.
Under a  high intensity light and a magnifying glass, all solder pads looked 
clean and  shiny.
Not knowing where else to go, I resoldered all the pins of U10 plus  C36. I 
suspect C36 may have been my problem but all that noise has now gone  away.
Don Webb...KA7L  




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