SA GRN Site - Williamstown Location - Telstra site 6 km NE of Williamstown TRIAL HILL Lat/Long -34 39 22 / +138 57 07 Data Channel 413.2875 Voice Channels 415.2875 415.7875 416.2875 416.7875 417.2875 417.7875 412.775 (New) 413.025 (New)