The CF Step function sets the step size of the 
center frequency when using the arrow keys or 
scroll wheel.  
 
When the scroll wheel or arrow keys or are 
used to alter the center frequency, each 
turn/press will move the center frequency by 
the step size specified by the CF Step function. 
 
In auto mode, the center frequency step size is 
equal to 10% (1 division) of the span. 
> CF Step[F4] and set the CF Step to 
Auto or Man. 
2.  If Man was selected, set the frequency and unit 
of the center frequency step size.