Rogers Digital is all encrypted, which is why you need one of their tuner boxes for every display.

I get the impression you're asking if you can split the OUTPUT of the Rogers box to multiple displays, and the answer to that is... no, probably not how you'd like. In fact, now that I think more on it, that free box also isn't going to work for your projector, as it outputs its signal on RF channel 3 - which still requires an NTSC tuner to receive. There's no RCA-style outputs.

So, I guess finding an old VCR or something with a good quality analog tuner might be a reasonable way to go for now, since those are practically free at this point. You MIGHT be able to talk Rogers into at least 1 free basic cable box (one up on the actual free box) since that would have an RCA output you could almost certainly hook directly up to your projector.