The Tektronix 1503 is a Long Range TDR Cable Tester. Portable and rugged, the Tektronix 1503 Long Range TDR Cable Tester is a field maintenance tool that is simple to operate and will test long runs of coax or twisted pair cables in telephone and other communications applications. For easy carrying and operating in tight spaces, the Tektronix 1503 is lightweight and small and will operate at least 5 hours on the internal, rechargeable batteries. Range of the Tektronix 1503, dependent upon cable type, is up to 50,000 feet. Resolution capability provides for resolving faults as close together as three feet on short cables. Impedance levels of 50, 75, 93, and 125-ohms.