i have comcast cable, and am not sure if using a dvd recorder without a tuner and connecting it to the cable box will allow me to record tv shows from the cable channels, or if a recorder with a built-in tuner is the way to go. one man who bought a magnavox dvd recorder from walmart, this one had a tuner built in but he couldn't record any channels past basic cable, such channels looked scrambled. i dont want to have these issues. i dont even have premium movie channels or anything like that, just expanded basic cable is what i have, like up to channel 120. which dvd recorder should I buy?