"It’s happened to me even with 2 vfo knobs. Grab the wrong knob and gone... " Easily solved on the TS-590 by saving rig state to QuickMem. It's the first thing I do when I have the DX tuned. One or 2 button pushes and (almost) everything is back to when you saved it. I would hope the K3/K4 have a similar feature. 73, Andy, k3wyc