The 8505A is a high performance RF network analyzer that includes a leveled source, frequency counter, two measurement channels, dual-trace CRT with both cartesian and polar displays, digital readout of the measured value, and an electronic line stretcher. Together with appropriate signal routing accessories, the 8505A is a fully integrated stimulus/response test system that measures magnitude, phase, and delay characteristics of linear networks by comparing the incident signal with the signal transmitted through the device or reflected from its input.