RV Setup

I have searched the forum but no luck on my question.

I just bought a new (for me) RV.  I was living in a smaller RV and had direct TV vie a 18in dish that was outside. The new RV has a TracVision LF/SF antenna that is located inside a dome on the roof.

The dome does look for Sat (I can hear it) but I never get a picture.  I get a constant 771 error.  

What to do?