yes, using diplexers and splitters. if you wanted to get technical with it, you could set up all tvs to be able to view any tuner you want on different channels.
a note though, i believe if you back feed the tv1 of the 622 to the tv1 of the 222 you wont be looking at a hi-def picture cause you'll be using coax for the feed.
you can split the line (with splitters) at any point on the uhf/vhf line, but never the line in between the diplexers, if that makes sense. if you use a splitter backwards and run the ufh/vhf from both tuners into a splitter, you have then combined the backfeeds, and both will show on different channels, as long as your receivers are modulated to output on different channels. for instance if your setup is already diplexed, you can either split from the uhf/vhf line behind the receiver or at the other diplexer location for that feed (i.e. basement) wehichever is more convenient to run cable from. mirroring the tv 1 feed will get a little more complicated, and you'll be viewing in standard def most likely.
also if you are adding mirror tvs, you have to make sure the tv's you are hooking up are set to receive signal on the proper channel. if your 222 tv 2 is on chan 60, then all tv's copied from that have to be on ch 60 air to receive that picture. you can set you 622 to 50 air or whatever and and watch that tuner on 50 air on the same tvs, if you have combined the backfeeds.
um...hope that makes sense.
