The Tektronix 492 is a high-performance, rugged, microprocessor-controlled portable spectrum analyzer. Designed for laboratory and field applications, it covers a wide frequency range from 50 kHz to 21 GHz (up to 220 GHz with optional waveguide mixers) and features automatic modes with a three-knob operation for simplified frequency span, resolution bandwidth, and reference level adjustments.

Specifications

General

ParameterValue
InterfacesGPIB (Option 08)
DisplayElectrostatic CRT (Digital Storage available via Option 01)
Warm-Up Time2 hours (for specified frequency stability)

Physical

ParameterValue
Power Supply90 to 132 VAC / 180 to 250 VAC, 48 to 440 Hz, 125 W (typical)
Operating Temperature-15 to +55 °C
Dimensions (W×H×D)328 mm × 175 mm × 498 mm
Weight20 kg (44 lbs)

Frequency Specifications

ParameterValue
Frequency Range50 kHz to 21 GHz (up to 220 GHz with optional external waveguide mixers)
Frequency Span Range50 kHz/div to 500 MHz/div in 1-2-5 sequence plus Zero and Max Span (down to 100 Hz/div with Option 03)
Center Frequency Tuning Accuracy+/-(5 MHz + 1% of center frequency)

Resolution & Video Bandwidths

ParameterValue
Resolution Bandwidth (RBW) Range1 kHz to 1 MHz in decade steps
Resolution Bandwidth (RBW) AccuracyWithin 20% of selected bandwidth
Resolution Bandwidth (RBW) Shape Factor15:1 or better (60 dB to 6 dB bandwidth ratio)
Video Bandwidth (VBW) RangeSelectable Wide or Narrow noise filters

Amplitude Specifications

ParameterValue
Maximum Input Power (Continuous Wave)+30 dBm (1 Watt) with minimum 10 dB RF attenuation
Maximum DC Input Voltage0 V (DC coupled RF input)
Dynamic Range80 dB
Reference Level Range-100 dBm to +30 dBm
Reference Level Steps10 dB and 1 dB steps
Input Attenuator Range0 to 60 dB
Input Attenuator Steps10 dB
Display Scale (Log)10 dB/div and 1 dB/div
Display Scale (Linear)Linear scale selectable

Sweep & Triggering

ParameterValue
Sweep Time Range20 us/div to 5 s/div in 1-2-5 sequence
Trigger SourcesFree Run, Internal (Video), Line, External

Inputs, Outputs & Interfaces

ParameterValue
RF Input Connector TypeType N female (50 ohm)
RF Input Impedance50 ohms
RF Input VSWR< 1.3:1 up to 1.8 GHz
Calibrator Output (CAL OUT) Frequency100 MHz
Calibrator Output (CAL OUT) Amplitude-20 dBm

Display & Measurement Features

ParameterValue
CRT Display TypeElectrostatic deflection CRT with internal graticule
Baseline ClipperYes (removes intense baseline trace)
Save Reference MemoryYes (with Option 01 Digital Storage)
Max Hold ModeYes (with Option 01 Digital Storage)
B-Minus-Save-A ModeYes (with Option 01 Digital Storage)

Factory Options & Configurations

ParameterValue
Option 01 (Digital Storage)Adds digital storage and trace manipulation
Option 02 (Internal Preselector)Adds internal preselector for 1.7 GHz to 21 GHz bands
Option 03 (Phase Lock)Adds phase lock and frequency stabilization
Option 08 (GPIB Capability)Adds IEEE-488 (GPIB) remote control interface
External Waveguide Mixer CompatibilitySupports Tektronix WM490 series external mixers up to 220 GHz

Power Specifications

ParameterValue
AC Input Voltage Range90 to 132 VAC / 180 to 250 VAC (rear panel selectable)
AC Input Frequency Range48 to 440 Hz

Physical Characteristics

ParameterValue
Form FactorPortable, ruggedized enclosure
Carrying HandleSide-mounted adjustable carrying handle
Front Panel CoverSnap-on protective front cover with storage space

Environmental & Safety

ParameterValue
Storage Temperature Range-62 °C to +85 °C
Operating AltitudeUp to 4,570 m (15,000 feet)

Frequency

ParameterValue
Frequency BandsBand 1: 50 kHz - 1.8 GHz; Band 2: 1.7 GHz - 5.5 GHz; Band 3: 3.0 GHz - 7.1 GHz; Band 4: 5.4 GHz - 12.0 GHz; Band 5: 12.0 GHz - 18.0 GHz; Band 6: 15.0 GHz - 21.0 GHz
First LO Frequency Range2.072 GHz to 3.872 GHz

Performance

ParameterValue
Residual FM≤ 7 kHz p-p in 10 ms (without Option 03), ≤ 50 Hz p-p in 10 ms (with Option 03)
Residual Responses≤ -90 dBm (50 kHz to 1.8 GHz, 0 dB input attenuation)

Inputs & Outputs

ParameterValue
External Reference Input Frequency100 MHz (Option 03)
Sweep Output Level0.5 V/div (0 to +5 V)
Video Output Level0.5 V/div

Display

ParameterValue
CRT Graticule Size8 x 10 divisions
Digital Storage Horizontal Resolution1000 points (Option 01)
Digital Storage Vertical Resolution8 bits / 256 levels (Option 01)

Environmental

ParameterValue
Environmental ComplianceMIL-T-28800C Type III, Class 3, Style C
EMC ComplianceMIL-STD-461A Part 4

Receiver Characteristics

ParameterValue
1st Intermediate Frequency2072 MHz
2nd Intermediate Frequency829 MHz
3rd Intermediate Frequency10 MHz
Third-Order Intermodulation Distortion≤ -70 dBc for two -30 dBm input signals

Spurious Responses

ParameterValue
LO Emission at RF Input≤ -30 dBm (standard) / ≤ -70 dBm (with Option 02 internal preselector)

Display Performance

ParameterValue
Log Scale Display Accuracy±1.0 dB per 10 dB (maximum ±2.0 dB over 80 dB range) for 10 dB/div; ±0.4 dB over 16 dB range for 2 dB/div

Options

ParameterValue
Option 07 (75 Ohm Input Impedance)Replaces standard 50 Ohm RF input with 75 Ohm input for Band 1 (50 kHz to 1000 MHz)

Technology

Superheterodyne Spectrum Analyzer

Applications

RF and Microwave Signal Analysis