I'm not sure if this helps, but I ran up on an odd installation during a service call.
The problem was both TV2's getting the same signal, though the customer thought the remotes were addressed identically.
Installing Tech used existing cable for all the TV's. 3 were upstairs, one down. Inside the house box were 5 cables, 2 diplexers, and a splitter. 2 from the dish, one to the 522, one to the 322 (both of those diplexed). The TV out on each diplexer ran to the "outs" on the splitter. The 5th line ran from the "in" on the splitter into the attic, where it connected to the "in" on anther splitter. From there, 2 other lines went to the TV2's.
The other tech had the 522 out on 60, and the 322 out on 73. When I arrived, both TV's were on 60 (which is how I normally install--less for the customer to have to remember). I ended up resolving the problem by placing the proper TV on cable mode, channel 73, although I suppose I could have just put it on channel 22 or whatever.
That is why I do not like going behind other techs. It took an hour to chase down all the wire, when, had I known exactly how it was installed, I could have been out of there in 10 minutes or less.
By changing the signal type and channel number, the customer had switched from the 322 to the 522, probably accidentally. You can definately run your house off of TV2. I don't know what this node is that you speak of, though. Also, I have no idea how an OA antenna would impact any of this.