My KATO provides the least distortion I have ever seen in a generator. A good voltage regulator like a Delco H9000 suppresses field feedback ringing and KATO's secondary exciter winding includes a fourth phase. The secondary stator has about 150% of the laminations and double the wire. Even with all the chargers going, and then field collapse when switching off (500 amperes), THD is less than I measured with Southern California Edison 300 ampere 480 volt three phase service. Their generators are great but transmission and distribution transformers coupled with other user's line noise degraded the signal. But then again I am fussy.
