I have a 2008 Dolphin that looks much like yours. If you haven't learned yet, the box on top of the unit is a temporary junction box that is removed when you install a satellite dish. Inside the box you should find two coaxial leads and a control wire. One of the coaxial leads goes to the rear TV and the other two leads are routed through a PVC tube to the front of the RV behind the TV. I installed a Winguard Trav'lr HD unit for Direct TV. Unfortunately the control wire is not the correct one for my Winguard and I also needed two coaxial feeds for my DirecTV DVR but since everything was in a PVC tube removing and adding the correct wires was a snap. My coach has a Haier HD 32" TV installed and the combination works great. One button and the satellite reciever finds the target and comes on line. Turn on the DirecTV reciever, let in boot up and your watching TV.
Installation of the Winguard on the roof was pretty routine once the junction box was removed and proper wires installed. One caution is to be sure the Winguard Dish is positioned so your batwing antenna clears it. I screwed up and missed it slightly so my attenna hits the dish in some cases. Not a big thing as most off air digital TV signals don't require antenna aiming, as a matter of fact much of the time I don't even raise the antenna.
