When you're shopping among oscilloscopes signal spectrum analyzers, the central question is whether a used professional instrument can deliver the capability you need without turning into a money pit. The Agilent N9320B RF Spectrum Analyzer addresses that directly: it offers a 9 kHz to 3 GHz frequency span, a -130 dBm displayed average noise level, and resolution and video bandwidth ranges from 10 Hz to 1 MHz. At USD 1,200.00, though, the unit is out of calibration and sold as-is, so the real decision is whether those features justify the extra work you will take on.
Quick verdict
For a buyer who wants a functioning RF analyzer for hands-on RF testing, education, or troubleshooting, the Agilent N9320B can be a solid choice. The unit powers on and functions properly, and its frequency range plus the noise floor make it useful for many lab and field measurements. But because it is sold as-is and without accessories, you should expect additional effort before it becomes a dependable bench tool.
Who it suits
This analyzer fits someone who already knows RF measurement and can work around an instrument that is out of calibration. It suits laboratory teaching, signal verification, and RF troubleshooting where you need a reliable sweep and adjustable resolution bandwidth. It is less suited to a buyer who wants a calibrated, ready-to-run instrument or reliable absolute readings without extra steps.
What stands out
The N9320B's 9 kHz to 3 GHz range covers a broad slice of RF work, from low-frequency radio to common wireless bands around 2.4 GHz. The -130 dBm displayed average noise level gives a reasonably low noise floor for spotting weak signals. With resolution and video bandwidth ranges of 10 Hz to 1 MHz, you can shift between narrow, detailed sweeps and wider scans depending on the measurement.
Meaningful trade-offs
The biggest trade-off is calibration. The unit is out of calibration, so absolute amplitude accuracy needs a recalibration, and that adds time and cost. The as-is condition also means no power cable is included, so you'll need to supply that and any connectors you plan to use. These are predictable issues, but they should be part of your decision.
Agilent N9320B 9 kHz - 3 GHz RF Spectrum Analyzer
The reason to choose this unit is the combination of frequency coverage and sensitivity at a $1,200 price point. The limitation is that it is sold as-is without a power cable, so you'll need to handle cabling and calibration before relying on it.
Bottom line
The Agilent N9320B is a sensible buy if you are comfortable with an as-is instrument and ready to handle the calibration and setup. It gives you real spectrum analysis capability with a useful frequency range and a low noise floor. If you need a calibrated tool that works immediately after unpacking, this one will require more effort to get running.
