The Keysight (formerly Agilent / HP) 8561E is a portable RF spectrum analyzer delivering benchtop-level measurement capability in a highly ruggedized package. Operating continuously from 30 Hz to 6.5 GHz, it combines outstanding phase noise, wide dynamic range, and synthesized tuning. Standard features include fast digital resolution bandwidths down to 1 Hz, a precision timebase, and built-in measurement personalities for adjacent-channel power, occupied bandwidth, and time-gated measurements. Compliant with MIL-T-28800 ruggedness standards, it is engineered to withstand harsh environmental conditions in both field and manufacturing applications.

Specifications

General

ParameterValue
InterfacesGPIB (IEEE-488)
DisplayMonochrome CRT

Physical

ParameterValue
Operating Temperature-10 to +55
Dimensions (W×H×D)337 × 187 × 461
Weight20 kg

Frequency Specifications

ParameterValue
Frequency Range30 Hz to 6.5 GHz (Continuous)
Frequency Band BreakdownBand 0: 30 Hz to 2.9 GHz; Band 1: 2.75 GHz to 6.5 GHz
Resolution Bandwidth (RBW) Range1 Hz to 2 MHz (1, 3, 10 sequence)
Fast Digital Resolution Bandwidths1, 3, 10, 30, 100 Hz
Video Bandwidth (VBW) Range1 Hz to 3 MHz (1, 3, 10 sequence)
Phase Noise (SSB) at 10 kHz Offset≤ -113 dBc/Hz (at 1 GHz)

Amplitude Specifications

ParameterValue
Maximum Safe Input Level (Average Power)+30 dBm (1 W) continuous
Maximum Safe DC Voltage0 V (DC coupled), 50 V (AC coupled)
Input Attenuator Range0 to 70 dB
Input Attenuator Step Size10 dB
Reference Level Range-119.9 dBm to +30.0 dBm
Log Scale Fidelity±0.85 dB (0 to -90 dB from reference level)
Linear Scale Fidelity±3% of reference level
Calibration Output Signal300 MHz, -10 dBm ±0.3 dB

Sweep and Triggering

ParameterValue
Sweep Time (Span > 0 Hz)50 ms to 100 s
Sweep Time (Zero Span)50 µs to 100 s

Trace and Display

ParameterValue
Trace DetectorsNormal, Peak, Sample, Negative Peak
Standard Measurement PersonalitiesAdjacent channel power (ACP), channel power, carrier power, occupied bandwidth (OBW) percentage, time-gated measurements

Inputs, Outputs, and Interfaces

ParameterValue
RF Input Connector TypeType-N (female)
RF Input Impedance50 Ω
10 MHz Reference Input ConnectorBNC (female)
10 MHz Reference Output ConnectorBNC (female)
External Trigger Input ConnectorBNC (female)
Video Output ConnectorBNC (female)

Environmental and Compliance

ParameterValue
Storage Temperature-51 °C to +71 °C
Shock and Vibration ToleranceMIL-T-28800 Class 3

Sweep Specifications

ParameterValue
Sweep Points per Trace601
Sweep Time Accuracy (Span > 0 Hz)±10%
Sweep Time Accuracy (Zero Span)±1%

Demodulation

ParameterValue
Audio DemodulationAM and FM

Tracking Generator (Option 002)

ParameterValue
Tracking Generator Frequency Range300 kHz to 2.9 GHz (Option 002 only)
Tracking Generator Output Power-80 dBm to -10 dBm (Option 002 only)

Front Panel Connections

ParameterValue
Probe Power Output+15 VDC, -12.6 VDC (150 mA max)

Frequency

ParameterValue
Frequency Span Range0 Hz, 100 Hz to 6.5 GHz
Resolution Bandwidth Selectivity (60 dB / 3 dB)< 15:1 (300 Hz to 2 MHz), < 5:1 (10 Hz to 100 Hz)

Amplitude

ParameterValue
Measurement RangeDisplayed Average Noise Level (DANL) to +30 dBm
Amplitude Display Range1, 2, 5, 10 dB/div (10 divisions) log; 10 divisions linear
LO Emission (at RF Input)≤ -80 dBm (with 10 dB attenuation)

Technology

Superheterodyne RF Spectrum Analysis

Applications

RF Component Testing, Digital Radio Measurements, Phase Noise Analysis, Field Maintenance