Choose a country or area to see content specific to your location
Confirm your country to access relevant pricing, special offers, events, and contact information.
PRODUCTS AND SERVICES
- Spectrum Analyzers (Signal Analyzers)
- Network Analyzers
- Logic Analyzers
- Protocol Analyzers and Exercisers
- Bit Error Ratio Testers
- Noise Figure Analyzers and Noise Sources
- High-Speed Digitizers and Multichannel DAQ Solutions
- AC Power Analyzers
- DC Power Analyzers
- Materials Test Equipment
- Device Current Waveform Analyzers
- Parameter / Device Analyzers and Curve Tracers
- Generators, Sources, and Power Supplies
- Modular Instruments
- Network Test and Security
- Network Visibility
- Additional Products
- All Products, Software, Services
Explore by Use Case
Explore by Industry
- All Solutions
What are you looking for?
no image available
4291U Upgrade Kit for the 4291A
- Overview and Features
- Post-Purchase Upgrades
This product was manufactured by Keysight or one of its predecessors many years ago. We provide this page to assist you in using or replacing your product.
If this product's status is "Discontinued": This product is no longer sold by Keysight, but is still fully supported. You can receive free enhanced self-support via the Keysight website or by calling or emailing the Keysight Contact Center. Repair and calibration agreements and per-incident services are available from Keysight Service Centers. Use the “Contact an Expert” link at the top of this page to learn more about your calibration & repair services or replacement options.
If this product's status is "Obsolete": You can receive free self-support via the Keysight website only. Use the “Contact an Expert” link at the top of this page to learn more about your calibration & repair services or replacement options.
- © Keysight Technologies 2000–2023
- Trademark Acknowledgements