My First Differential Probe Question - HP/Agilent 1141A and 1142A

[NY2KW]

Just learning to play with my first differential probe, the HP 1141A and power control unit 1142A.   I went thru the basics and adjusted Offset null and DC Gain reject.  Tried it on some signal generator signals and looks good. 

Can someone explain when and how the coarse and fine Variable Offset is used?

thanks in advance

Jerry

[aliarifat794]

The coarse and fine variable offset controls on your HP 1141A differential probe allow you to adjust the DC offset of the measured signal. This can be helpful in situations where you need to centre the waveform within the oscilloscope's display or align it with a specific reference level.

If the waveform is shifted too high or too low on the oscilloscope screen and you need to bring it back to the centre or align it with a particular reference level, you will need to use the coarse variable offset control.

If the waveform is nearly centred but slightly off, or if you need to align it very precisely with a reference level, you would use the fine variable offset control.

[NY2KW]

Thanks, that's what I thought but the coarse and fine controls on my 1142A do not seem to have any effect.  I will need to open it up and check the pots.