This control is used to adjust the calibration of the SWR meter while in SWR CAL mode. Turning this control fully CCW (Counter Clock Wise) until it clicks and dims the display backlighting

• 当你选用驻波表模式时这个旋钮用来校整驻波比,反时针调谐旋钮直到发出"嘀"的一声,显示屏背光会变暗