what you are using to record with, combo VCR DVDR would be getting the signal from the built in anolouge tuner. If no anolouge signal available, you would need to take the output from your TV and feed that into the input of your recorder, which would record whatever signal it produced. Problem with this, you could only record the channel that the TV was showing and TV needs to be on.
Better solution buy a DVD HDD recorder with built in set top box, allowing timer recording of whatever channel you want.