[Elecraft] K3 CAT noise

[bill4570 at comcast.net]

While operating in the PSK-31 data mode, my K3 produces a noisy waterfall any time CAT control is enabled.  This shows up as horizontal lines on the waterfall about 1 mm apart.  As soon as I disable CAT, the lines dissappear.

I can copy right through the noise, so it's not an operating issue, but it's distracting.

Has anyone else come across this?  What was the resolution?

Bill,  W7QQ