The 1503B is designed to quickly and Easily locate opens, shorts, crimps and Other defects in metallic cables up to 15,000 Meters (50,000 ft) in length Through a process similar to radar, the 1503B transmits electrical pulses down the cable under test. Impedance changes in the cable reflect some of the pulse energy back to the 1503B. The reflections are displayed on the LCD display. The characteristics of the display trace allow the user to determine the nature of the cable fault. The 1503B has 2, 10, 100 and 1000 Nanosecond pulse width. When using The 2 ns pulse width on 50 ?? cable With a Vp of 0.66, Multiple faults as close As 10 feet can be detected. Cable Impedances of 50, 75, 93 and 125 ohms are selectable for testing different types of cable.