"blknomad"......You need to provide more information as to what is not working. The first time you fire up a new antenna with a DirecTv receiver box, you have to go into the receiver menu and set up the antenna configuration. Hopefully, you didn't grab an HD box from home and try to run it with this new antenna. You're new portable is not HD, but SD, requiring a different receiver.
So.....we need more info, like where did you get the box from, home, or is it specifically for the RV. If the receiver is specifically for the RV, you need to walk through the the sat dish setup. DirecTV can do this for you.