Measuring the input signal

O.K. now we that the CRO has been connected to the circuit we can actually adjust the view of the signal on the display to allow us to make an accurate reading This is done by following the instructions listed belowSelect the input channel that we wish to view using the Mode Selector.i.e. if Channel A is required the Mode Selector would be in the CH A position, Channel B the CH B position and to see both of the input signals the Mode Selector would be in the DUAL position.
After selecting the input we wish to the AC GND DC Selector is moved from the GND position to the D.C. position.NOTE It may seem that if an A.C. signal is being measured, the AC GND DC Selector should be set in the A.C. position. This is not neccessary unless there is a large D.C. offset in the A.C. input. So please avoid the temptation to use the A.C. selection.At this point the Vertical Gain must be adjusted. This is adjusted to allow the signal to be viewed on a scale that is convienient. Show me examples of how the Vertical Gain Controls Work..