The Agilent HP 8591A used Spectrum Analyzer has over 100 functions and are controlled either from the front panel or over the optional HP-IB interface.Advanced marker functions measure: the 99% power bandwidth of a signal; the 3 dB points of a signal; frequency; amplitude; amplitude and frequency differences on a signal; and highest peaks on a signal. The Next Peak button moves the marker to the next highest signal, simplifying harmonic measurements. Other measurement functions on the 8591A include: percentage AM; signal-to-noise ratio; and the FFT. Store/recall up to nine complete front-panel states in battery-backed RAM.

Option Description:
001: 75-ohm Input Impedance
004: Precision Frequency Reference
010: Tracking Generator 50-ohms
011: Tracking Generator 75-ohms
021: HP-IB Interface
023: RS-232 Interface
040: Front Cover
042: Soft Carrying Case
101: Fast Time Domain Sweep
102: AM/FM Demodulator & TV Synch Trigger
103: Quasi-Peak Detection
105: Time