The R4131 covers a band-width as wide as 10 kHz to 3500 kHz and is controlled by a microcomputer. This analyzer features easy confirmation of all measuring conditions, since its frequency span is 4 GHz to 50 kHz, resolution is 1 MHz to 1 kHz, level data resolution by a marker is 0.05 dB, tube surface dynamic range is 80 dB, and the setting conditions of the its major functions are shown on its CRT display. The panel of this equipment enables its three major functions (center frequency, frequency span, and reference level) to be independent of each other, and its layout makes for excellent operability. In addition, the resolution band, sweep time and input attenuator values are set automatically by its AUTO feature.