The AV-10 Ramp Tester is used to test avionics equipment on aircraft. It can test VOR, ILS, ADF, DME, transponder, and marker beacon systems. It generates low power RF signals to check the functionality and accuracy of aircraft receivers. The document provides details on the specifications, components, operation, battery replacement, and testing procedures for each avionics system that can be checked using the AV-10 Ramp Tester.