This is a radio experimental device, the non-commodity. By sharing a part of the design, experimental costs, you can get the device involved in the common test. The participants should have a certain expertise, and an obligation to the honest feedback, sharing test information. This device may not affect the test BUG. This device is a 50 ohm impedance test system can be tested (usually the application of a short-wave antenna) complex impedance Z, resistance R, reactance X, and the standing wave the SWR. Upon completion of each test, the curve, and in the analysis of the playback mode, the switching curve display, point by point inspection.