I figured it wouldn't be a bad idea to have a pure sine wave inverter onboard for the AV stuff and for computers. I added a 400 watt unit and it solved the TV hum problem. While I was at it I wired in a power strip that can be used by other "sensitive" electronics.
Here is what nice clean utility power looks like on the oscilloscope. Isn't it pretty.
Here is what ugly AC power looks like from the Xantrax (modified sine wave) inverter
|Here is what the signal looks like from a pure sine wave inverter.