The Site Master (Figure 1-1) is a hand held SWR/RL(standing wave ratio/return loss) and Distance-To-Fault measurement instrument that includes a built-in synthesized signal source. It uses a keypad to enter data and a liquid crystal display (LCD) to provide a graphical indication of SWR or RL over the selected frequency range. The Site Master Sill and S331 have a built-in distance-to-fault capability. The Site Master SI 10 and S330* as well as models Sill and S331, allow measurement data to be converted to Fault Location via the companion Soft- ware Tools program. The Site Master is capable of up to two hours of continuous operation from a fully charged internal battery. It can also be operated from a 12.5 dc source (which will also simultaneously charge the battery). Built-in energy conservation features can be used to extend battery life over an eight-hour work day. The Site Master is designed for measuring SWR, return loss, or cable insertion loss and locating faulty RF components in antenna systems. The displayed trace can be scaled and/or enhanced with settable frequency markers and/or a limit line. A menu option provides for an audible “beep” when the limit value is exceeded. To permit use in low-light environments, the LCD can be back lit using a front panel key.