Setting up third receiver

I have 2 current receivers and RG6 ran though out the house.  I had the children's room set up on a splitter with the tv cable ran to the antanea cable.  I attached the new third receiver to the tv and tried both RG6 plugs.  I am getting 'A satellite signal could not be detected.' error.  I am not sure what else to try.  I have validated the satellite type, shape, etc from the other receivers.  I have a satellite with a dual.  I asked before I bought the third receiver and the person on DirecTV help said that I woul dnot have a problem.  I am wondering if I have the cables configured wrong.  Also, I do not have a land line phone. I have one receiver with no phone connection and the other receiver with a wireless conenction.  I have the possibility  of connecting this receiver to the network hub (but I am not sure if or how that would help).  Please let me know if I would be better to call tech help or if this is enough info to help me.

Thanks
Debi