Your tailgater looks similar to my Winegard Carryout. I have only been able to get it to work with 2 televisions so far. I have 3 tv's in my trailer.
To get it to work with 2 tv's you require 2 satellite receivers.
To get it to operate more Tv's you would have to split the Hdmi signal out of the receiver and run a Hdmi cable to each location and then you would only be able to watch the same channel on each of the TV's.
I believe the Automatic type satellite like the Winegard Traveller' can operate more tv's at the same time but at a way higher cost $1500 or so. This is the one that I am starting to consider as it seems like the easiest way to get all my tv's working.
Hope that helps,
312QBUD Owners Thread
2015 Wildwood Heritage Glen 312QBUD
2000 Chev 2500 Extended Cab 6 Liter
1400lbs Equal-i-zer Hitch