HP / Agilent 8472A Point Contact Crystal Detector

The HP/Agilent 8472A is a point contact crystal detector that converts RF power into proportional DC voltage output across a wide frequency spectrum. Engineered for precision RF power measurements, signal tracing, and low-level signal detection, this compact probe delivers reliable performance in coaxial measurement systems and laboratory test setups. The detector operates from 10 MHz to 18 GHz with exceptional sensitivity and minimal noise, making it suitable for applications ranging from power monitoring to envelope demodulation for oscilloscope observation.

Technical Specifications

• Frequency Range: 10 MHz to 18 GHz


• Detector Type: Point Contact Crystal Detector


• Input Impedance: 50 Ω (nominal)


• Output Impedance: 15 kΩ maximum, shunted by 10 pF


• Maximum Input Power: 100 mW (peak or average)


• Sensitivity (High Level): 0.4 mV DC/µW CW


• Output Noise: <200 µV p-p with CW power at 100 mV output


• Output Polarity: Negative (standard); positive output available with Option 003


• Temperature Coefficient: Typically 0.015 dB/°C (0°C to 55°C)


• VSWR Performance: 10 MHz to 4.5 GHz: <1.2 SWR | 4.5–7 GHz: <1.35 SWR | 7–12.4 GHz: <1.5 SWR | 12.4–18 GHz: <1.7 SWR


• Tracking (Matched Pairs): ±0.2 dB per octave (10 MHz–8 GHz) | ±0.3 dB (8–12.4 GHz) | ±0.6 dB (12.4–18 GHz)

Key Features

• Compact form factor: 9/16 in. diameter × 1-1/2 in. long


• Male OSM-type input connector (female BNC or OSSM output options)


• Handles peak and average power up to 100 mW


• Low-noise detection with sub-millivolt noise floor


• Wide dynamic range suitable for relative power measurements to 100 mW

Typical Applications

• RF power measurement and monitoring


• Signal tracing in RF circuits


• Power leveling and control


• Low-level signal detection and analysis


• Envelope demodulation for scope-based waveform capture


• Coaxial measurement systems

Compatibility & Integration The 8472A integrates directly into coaxial test setups via standard 50 Ω male OSM input. Output options accommodate different measurement instruments: standard 8472A provides female BNC; H01-8472A variant offers female OSSM connector. Static discharge precautions required during handling - maintain proper grounding and avoid contact with exposed leads.