Complex sentence: Since the ground waves used in this band require vertical polarization, vertical antennas are used for transmission, usually mast radiators, either insulated from the ground and fed at the bottom, or occasionally fed through guy-wires.
Split into simpler sentences: Since the ground waves used in this band require vertical polarization, vertical antennas are used for transmission. Mast radiators are most common, either insulated from the ground and fed at the bottom, or occasionally fed through guy-wires.