HP Agilent 8566B Microwave Spectrum Analyzer 100Hz-22GHz w/ 85660B Display Unit

HP Agilent 8566B Microwave Spectrum Analyzer 100Hz-22GHz w/ 85660B Display Unit

The HP 8566B is a two-unit swept-tuned microwave spectrum analyzer covering 100 Hz to 22 GHz, paired here with the HP 85660B Spectrum Analyzer Display unit. The 8566B serves as the sweep/control chassis while the 85660B provides the dedicated CRT display, marker readout, trace storage, and front-panel measurement controls. Both units interconnect via the cable visible on the rear panel. This system was designed for bench and rackmount use in microwave frequency measurement applications.

Specifications & What's Included

• Make: Hewlett-Packard (HP / Agilent)
• Model: 8566B (sweep/control unit)
• Option / Display Unit: 85660B (Spectrum Analyzer Display)
• Frequency range: 100 Hz to 22 GHz (DC-coupled input)
• External mixer coverage: 26.5–75 GHz (preselected); up to 325 GHz with other external mixers
• Display: Green phosphor CRT with active trace (confirmed powered up — see photo set)
• IF Output: 21.4 MHz (Out, Video, Input — BNC connectors)
• Display Outputs: Y, Z, Blank (BNC)
• Recorder Outputs: Video, Penlift, Sweep (BNC)
• External Trigger Input: 5V Max (BNC)
• Computer interface: GPIB (HP-IB) — visible on rear panel
• User RAM: 16 KB (for trace data, instrument states, and downloadable programs / DLPs)
• Front-panel sections (85660B): Trace A/B, A–B, Max Hold, Reference Line, Display Line, Threshold, Sweep (Cont/Single), Trigger (Free Run/Line/Ext/Video), Scale (Log/Lin), Key Function, Level
• Front-panel sections (8566B): Coupled Function, Marker (Entry, Mode, Zoom, Marker Track), Instrument State, numeric keypad (Center Frequency, Frequency Span, Start/Stop Freq, Reference Level)
• Output: 100 MHz reference output connector on 8566B front panel
• Form factor: Two-unit benchtop/rackmount system
• Rack-mount ears / handles: NOT included with this listing

Applications

The HP 8566B is a second-generation synthesized microwave spectrum analyzer from Hewlett-Packard's 856x series, introduced in the early 1980s and widely used through the 1990s in RF/microwave engineering, telecommunications, aerospace, and defense test environments. The synthesized local oscillator architecture gives the 8566B excellent frequency accuracy and low residual FM compared to earlier non-synthesized analyzers, making it suitable for phase noise spot-checks, spurious and harmonic measurements, and EMI pre-compliance work across the microwave frequency range. The 22 GHz upper limit — extensible to 325 GHz with external waveguide mixers — made the 8566B one of the most versatile single-sweep analyzers of its era. Today these instruments continue to be used in legacy calibration labs, university research, and surplus test benches where GPIB-controlled microwave measurement capability is needed at a fraction of the cost of a modern analyzer. The 85660B display option separates the display function from the sweep chassis, allowing the instrument to be operated either as a standalone benchtop unit or integrated into automated test systems via HP-IB.