Does your dvd recorder have a digital tuner, or is it just analogue?
If it has a digital tuner, it should pick up the digital channels without problem - exactly with your old set up.
If it has only an analogue tuner, you can record but it is more complicated. You will have find the AV or EXT channel it is using, set it to record the appropriate one, turn your tv on at the correct channel and leave it on. If you change channel your recording will also change; if you turn the tv off it will record nothing