Cox cable states, "You should check your television's manual to determine if it includes a QAM tuner or check for the DCR (Digital Cable Ready) label on your TV set. If you are unable to determine if your TV includes a built-in QAM tuner, then you should check with the manufacturer." Mauel states, "ATSC/NTSC system. " Does this mean I don't have QAM and will need a receiver?