Q: I cannot set amplitude below 1 V on model 4003A, 4010A, 4011A, 4012A, 4017A, or 4040A. Is something wrong?
A: No, there is nothing wrong with the unit. Lower range of amplitude can only be set when you enabled the "-20dB" button from the front panel. To enable, push the button so that it is in the pushed-in position.