| I don't think you're going to find it. Hopefully I'm wrong. But, I can only semi-remember once seeing a piece of electrical test equipment with a pot (center knob) and a concentric rotary switch. My guess is for one good reason is that you'd have to have some pretty good ergonomics in the knob design in order to have a concentric switch ring-knob that could be gripped with enough force to overcome the click resistance, without accidentally disturbing the pot position.
__________________ "Art without engineering is dreaming; engineering without art is calculating." --SKR | 
