The Thor HD-SDI to 8VSB series encoder modulator chassis are designed for corporations or video professionals that need to modulate HD video onto RF carriers compatible with North American ATSC tuners. Over the air television systems in this region use a unique modulation protocol known as 8 level vestigial side band (8VSB) modulation. While most tuners and television sets sold in North America support demodulation of QAM-256 under ITU-T J.83B in addition to ATSC’s 8VSB signal, most can only tune to one type of signal at a time. This creates a problem for system integrators who want to inject their own programing into broadband lineups containing channels from a master antenna system. Thor offers 8VSB modulators for use in any application where ATSC signals must be combined with locally modulated content.