So, I got the 2nd one from Amazon today.
Hooked it all up and connected the Oscilloscope to it.
EXACT same results.
I tested this one with a load. 499watts for 10 minutes no problem.
520watts for 1 minute, no problem.
I've contacted Bestek for information regarding the unusual Sine wave.
Meanwhile, I'm going to keep the 2nd one and take my chances.
I could not even get a definitive answer at forums that specialize in electronics. So maybe it's some kind of electronic wizardry to get the "improved" sine wave from it. I would not call it a 'Pure Sine wave" inverter. But perhaps "a good bit better than a Modified Sine Wave" inverter.
Time will tell.
This one goes in the car and is used when traveling for various things so it won't see full time or heavy duty.
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