Thanks for the feedback, people. I had originally figured that those were just 75ohm cables - glad to know that is still the case.
2x6, I don't think Dad will appreciate those expensive wires (he spends alot of time just watching Fox news during his visits).
And the TV is not under warranty, but it doesn't matter - I just ran the DVD to it via the s-video hook-up, and the vcr/cable box via plain old coax cable. Moved the Dreamcast to another bedroom w/ a TV.