Thanks for your reply but you must be thinking of another model. I have a TS570-S. The knob comes off with a set screw. The metal post that the knob fastens to goes thru the faceplate into what is likely a variable capacitor. That thing is loose. The knob still turns fine. No problem there. It's just that the capacitor and it's post are not secured.
A metal spring like device on the faceplate side may be the problem/solution however I have not figured out how it works yet. No word yet back from Kenwood either. I must have called the wrong number.
I know exactly what I am talking about. There is an encoder on the other end of the shaft. The setup looks like a pot and the nut that mounts it to the front panel is loose.