My Dish system uses satellites 72 and 61.5 eastern arc. We have a portable dish just like the one on top of our house with two LNBs and one coax running to the receiver, a Dish VIP211Z. The AS is a 2003 Safari from the factory wired only for cable and broadcast roof-top-antenna. The shore cable connection is RG59. (same 75 ohm impedance as RG6 from dish) It was decoupled from the Winegard RV-7032 wall plate and connected to a barrel connector that I mounted in the same wall plate. It is the blue one in the photograph. Mounting the barrel there required enlarging the hole in the wall. Enough wall material was left to add the two screws to the left and right of the barrel connector. No measurable loss of signal was indicated on the satellite receivers signal level display.
Roof top antenna is still operational. The bedroom TV outlet gets signal only from the roof-top antenna with the modification. The shore cable connection can still be used for commercial cable but not at the same time as the satellite. With the modification it can't serve the bedroom outlet which we never use anyway.
I made no effort the try using the shore cable connection as factory wired because the wall plate contains a splitter that I believe would interfere with passing DC from the satellite receiver to the LNBs or at least load it down. Further signal reduction from the satellite would occur as it passed through the splitter.
Winegard makes the RV-7542 wall plate where they replace the 12 volt
power connector with a barrel connector. I chose not to use the RV-7542 because we use the 12 volt