Not sure of the actual question, but as the manual shows, you can tune in several different ways. A few include turning the knob using the mouse (I assume the method you are referring to), hovering over the knob and using the wheel on your mouse, hovering over a digit in the frequency readout and using your mouse scroll wheel, or double clicking on the waterfall to jump to that frequency. I am sure there are others, but these are the main ones I tend to use.