Analogy Oscilloscope

Hi,
I have an old analogy oscilloscope. My question is what is the small knot does sitting on top of the big Volt/div knot. Is it for fine adjustment?

Thanks

On an analog 'scope, that knob is likely for fine adjustment of the vertical sensitivity. The calibrated position would be for the knob fully clockwise. Turning the knob counter-clockwise will reduce the gain (and make the gain uncalibrated, i.e. the vertical scale will not correspond to the large knob reading).

crutschow,

Thanks for the info.