Second , Lets hope Ernie does not seem this thread resurrected like this otherwise he would have a heart attack, lol.
A couple of corrections , Mr Edd... , first the range is in the Mhz , like from 5 to 900 Mhz , but unfortunaelly both services free OTA and Analog or Digital Cable use the same range (although different channel numbers) therefore your solution with the reverse splitter does not work , on the contrary it makes it worst and could even bring problems for your neighborg cable TV system.
second, as far as TV services is concern , in the 900 to 2500 Mhz range, there is only the IF signals from an LNB from a Satellite TV system which was not the case on this thread and for that the typical splitter does not work. If by high end splitter you mean a satellite splitter then you have to make sure it is at least power pass on 1 port. Best solution is to use a couple of Diplexers to combine and separate.
Welcome again , and please , check first if the thread is too old when replying. You can start a new one with questions if you like.