I decided today on a whim to check out my
Alton 3.5KW generator, and see what kind of waveform it was putting out. I had read a few things online that caused me to wonder about the quality of the power it puts out for me... I hooked it up and measured it with my oscilloscope.

As I don't have a 10x probe at my disposal, I had to adjust the image so i could see the top of the waveform. It's not a sine wave, but it does have the general shape and only a few deformations. Much better than most of the UPS signals I have seen...
This is my secondary generator, the one that will run the well pump and pressure pump for the wellhouse in the event of a power outage - so I can have RUNNING WATER... I didn't get a chance to measure the output of the main gen that powers the house. Perhaps I will take a look at that in the near future, just for grins...