The output signal right out of the inverter is square before and after the mod, the mod only changed the freq. but when using a LC circuit on the ouput we can get a sine wave just like I did.
I used a series LC circuit. the LC combo was tuned for 650 Hz, and you can see that the wave is better at that frea, then when I run it at 420hz, the wave is distorted. I didn't have big enouph caps to tune it for the 420hz.