AEA E20/20 Avionics [6021-5054] Time Domain Reflectometer (TDR). The E20/20 TDR Avionics Kit is designed specifically for testing and fault locating on aircraft wiring. The Step TDR is ideal for troubleshooting all types of coax, twisted pairs, single-wires in a harness, and aircraft power cables. Use “Step TDR” technology’s amazingly accurate display and locating ability to save time and money. The kit includes connection adapters for mating with aircraft wiring harness style connectors making testing fast and convenient. Additionally, the TDR, manuals, PC software and accessories are all in a rugged anti-FOD carrying case designed for flight line and aircraft use. ETDR PC Vision™ software can upload, save, and print test results, and customize the TDR’s cable list for specific aircraft as desired.