The guy who has it also has the remote!
We still get broadcast TV in Canada without buying one of those boxes. I'm watching TVO with bunny ears right now. I'm not sure that's what you mean but I have enough A/V junk around that I can get all three to work. Even if it's just so I can play Mario Bros. and Sonic the Hedgehog on the same television at once while watching Gag Factor.
I'll see about getting some pictures of it, it picks up radio as well and I can't remember which bands.
I'm under the impression that this style of TV was made for bars/social places so multiple football (for instance) games could be used at once.
There is hardly any information that I can find on the Tri-Screen but here is a link to the forum I stole the images from.
I think you have to register to see pictures.
AudioKarma "TV with 3 CRT's" thread