Agilent/Keysight 3581A

The Agilent/Keysight 3581A is a spectrum analyzer engineered for detailed signal analysis in audio and baseband frequency ranges. It delivers critical measurement capabilities for signal monitoring, distortion evaluation, and frequency response characterization. This benchtop instrument combines selectable resolution and video bandwidth controls with dynamic measurement flexibility, making it suitable for telecommunications infrastructure testing, audio equipment characterization, and general RF signal analysis.

Technical Specifications

• Frequency Range: 10 Hz to 1.5 MHz


• Resolution Bandwidth: 10 Hz to 300 Hz (1-2-3 sequence) or 5 kHz fixed


• Video Bandwidth: 0.1 Hz to 300 Hz (1-3-10 sequence)


• Frequency Span: 20 Hz to 1.5 MHz continuously adjustable


• Input Impedance: 1 MΩ || 25 pF nominal


• Input Attenuation: 0 dB to 70 dB in 10 dB steps


• Maximum Input Level: +20 dBm (0 dB attenuation); +30 dBm with external 10:1 probe


• Dynamic Range: 70 dB typical without preamplifier


• Display: Cathode Ray Tube with analog sweep


• Amplitude Measurement: Absolute power, relative power, dB/division selection, reference level adjustment


• Sweep Time: Automatic or manual control


• Power Requirements: 115 V or 230 V AC, 50/60 Hz


• Power Consumption: Approximately 75 VA

Key Features

• Harmonic and intermodulation distortion measurements


• Frequency response plotting capability


• Continuously variable span and dB/division settings


• External trigger and amplitude modulation inputs


• Type N RF input connector with calibration output

Typical Applications

• Telecommunications infrastructure testing


• Audio amplifier performance verification


• Noise floor analysis


• Filter characterization


• Signal integrity troubleshooting


• Electronic component evaluation

Compatibility & Integration RF Input: Type N connector. External inputs via BNC connectors for trigger, amplitude modulation, and calibration output. Benchtop laboratory operation.