[Elecraft] K2 scratchy noise on RX CW signals

[Andrew Moore]

Hi Elecrafters -

Today I took delivery of K2 #892 and very happy to have it in the shack
after selling my #4958, I think it was, years ago... if anyone has it I'd
like it back please). This #892 has a "static sounding" scratchy/raspy
noise on top of CW signals. It sounds similar to what you'd hear from an
oxidized audio frequency pot. The strength and presence of the noise is
proportional to the incoming CW signal strength.

The rig is running from a clean, large high current capacity battery so I'm
sure the supply power is good. The noise occurs across multiple bands. I
get the sense it's something in the audio chain. The installed KDSP2
digital audio filter has already been put in bypass mode and the scratchies
persist.

Before I continue debugging I wanted to see if anyone had suggestions about
what components to target.

Thanks,
-Andrew / NV1B
..