[Elecraft] Distortion

[Don Wilhelm]

Hans,

That sounds like the old WAOF (Weird At One Frequency) problem. That is 
the region where the PLL oscillator and VFO frequencies "cross paths" 
near 7185 kHz.  See http://www.elecraft.com/Apps/Alert11_WAOF.html.  
Note that this alert refers to older version A K2s, you will not find 
C70 on your board.

If this is your problem, the audio signals will sound rather like they 
are 'under water'  If you have something different, then ask again.

With a new K2 layout, that seldom happens, so check to be certain D16 is 
mounted flush with the board.
In addition, the components mounted on the bottom of U4 (C88, RFC15 and 
C91) should have leads as short as possible - make certain they are 
connected to the correct pins.
You may need to trim all leads in the vicinity of U4 so there is nothing 
that would act as an 'antenna'.

73,
Don W3FPR

On 3/26/2014 1:44 PM, Hans Elfelt Bonnesen wrote:
> K2 Audio Distortion.
>
> My otherwise flawless K2 # 7359  is found to have
> serious audio distortion problems on received and transmitted signals on 40 meter.
> The problem appears as soon as I go above 7171 kHz. On 7182 the problem makes SSB contacts impossible
> Lower frequencies do not suffer. Why ?
> I still haven’t checked the problem on other bands.
>
>