... blank keys around the LCD, 6 at the bottom and 6 at the right. If the SW_TC880 is powered on, the function of the keys will correspond ... , LINE, press RANG as Fig. 1.3 shows, then the right part of the LCD will display 250M, 500M, 1KM, 2KM, 4KM and 8KM ... . Press 500M as Fig. 1.4 shows, then the test range ...