ORIGINAL: OliverJacob
http://www.survivalistboards.com/showthread.php?t=74036
if you own a scope, you can find out yourself when running under different loads....you'd be surprised how your wave will look.
Some electronics are 'forgiving' and handle these impuritys, some don't.
Yes I own an oscilliscope, I checked my 220V backup generator when I bought it a few years ago, the sine wave is quite good. I live in a neighborhood that has old utility systems in it, power outages are frequent, I am comfortable running any electronics I own off of it, (I plug it right into the main box when the need arises via a transfer switch). My little generator, (HF 800w) I haven't checked the wave but it is rock solid at 60HZ, about all I use it for is running a 25 amp DC power supply and some outdoor work lighting sometimes.