I was looking in to my old 800W 120VAC DC to AC supply, to see just how bad the square wave is.
The test in my view was not complete. I did not load test the supply. To see how the wave forms was effected. Due to missing Nut assembly for the Positive lead. I felt it would be unsafe due to insecure connection that could heat up due to possible arcing issues.
With the unit unloaded I proceeded to do a preliminary look at it with the 87 V, a digital meter. The 87, read that it was 120.2VAC and 61.12Hz.
With that I was curious what was going on with the waveform.
I hooked up the Scopemeter in to the mix. AC Neutral to Ground reference for the probe. The probe hooked in to the AC Hot on the line Splitter.
with that, I set the A input channel to 10:1 and took a look.
with that we see that it is going from +120V to 0 then -120V in reference to Neutral.