Well, I'm trying to sort through all of this.
That system is just a mobil auto-tracking satellite dish that sits in the roof of an RV or similar. It's 12VDC powered by the vehicle. I don't understand where a 120 volt to (I assume) 12VDC power supply comes in. Are they saying to power the system with this instead of the vehicle power? I assume also that the vehicle has a 120 volt generator hence your question about a ground prong?
-Hal
