Dumb question - what is the best way to measure the voltage and quality of AC voltage (120) with an oscilloscope? With a sweepe function generator or high voltage probes 0r what?

 

If your "120" means 120Vrms, then just use the probe that came with the scope. If "120" means something else, then please provide additional data.

 

You can measure 120V with standard scope probes but they need to be x10 probes. I'm not sure what you mean by measuring the "quality". It could be ripple if you're talking about D.C. or perhaps the purity of the sine wave if you're talking about A.C. You can do the former easily with a scope, but the latter is more difficult.

Brian