[Elecraft] K2 Static

[Don Wilhelm]

Art,

That sounds suspiciously like a capacitor that is breaking down 
somewhere between the product detector output and the 
speaker/headphones.  As such it is going to be difficult to locate.  Of 
course, my guess could be wrong, and it could be coming from somewhere 
ahead of the Product Detector.

Is there any 'static' at all when there is no signal?  If there is, then 
does it depend on the setting of the RF Gain control?  If the level 
changes with the AF gain control then it is between the AF gain and the 
Product Detector - if there is no change when the AF Gain is reduced, 
then the problem is associated with the AF amplifier stage.  Does it go 
away if you short the /MUTE signal (Control Board U6 pin 17 to ground?  
If so, then the components on the Control Board are OK - replace RF 
Board C177.

Do you have either the KAF2 or KDSP2 installed?  If you do, remove them 
and add the jumpers.  If the noise is gone, the removed option is the 
source of the problem.

I would suggest that you equip yourself with replacements for C177, on 
the RF board, C23, C25, C26, C27, C30, C28, and C29 on the Control 
Board, then either replace them wholesale or one at a time seeing if the 
problem goes away after each one.

The other problem is that my definition of 'static' can be quite 
different from your perception.  To me, staic is a sharp impulse type 
noise such as you would hear with nearby thunderstorms.  Perhaps you can 
be more descriptive and it would help with the analysis.

73,
Don W3FPR
 

Arthur Lewis wrote:
> I have an annoying static that rides on the receive signal of my K2/100. It is in the audio and it comes in on CW and SSB regardless of which filter I am using. Filters seem set ok. Both phone & CW receive audio sound fine, but the static rides on the audio. The stronger the signal, the more the static. The unit is an older K2/100. Serial is 642.
>
> Anyone ever have this problem.
>
> Art WA8VSJ 
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