[Elecraft] K2, distorted audio signal

[W3FPR]

Wolfgang,

That sounds a lot like the Weird At One Frequency problem (WAOF), and 
occurs at a point where the VFO and BFO frequencies interfere with each 
other.

The best solution is to flush trim RF Board U4 pins and any components 
in the vicinity that might act like an antenna.

If that does not correct it, send an email to support at elecraft.com and 
perhaps W8FGU will provide some additional information.

73,
Don W3FPR

On 7/21/2025 4:21 AM, Wolfgang via Elecraft wrote:
> Hello,
>
> I have had an occasional problem with my K2 for some time now. It is a 
> fully equipped K2 with a low serial number, "006xx."Most of the 
> official modifications have been carried out, including the "K2ATOBKit 
> Rev E."
>
> Regarding the fault description:
>
> Occasionally, the audio signal in CW and SSB sounds distorted when I 
> turn on the K2 (VFO on 40 m).As far as I can tell, the signals sound 
> normal again after switching from 40 m to 20 m and back.I have not 
> been able to determine anything else.
>
>
> Therefore, my question is:Does anyone know this behavior and know 
> where to start troubleshooting?
> Two audio examples can be found here: 
> https://magentacloud.de/s/arZWnmiCcHNCcz5 
> <https://magentacloud.de/s/arZWnmiCcHNCcz5>
>
>