| General RF troubleshooting | Frequency coverage from at least 9 kHz to 3 GHz; choose a higher upper limit if your work includes newer wireless bands or microwave signals. | Coverage must include the signals, harmonics, and spurious emissions you expect to inspect. | Confirm the full frequency range is included and operates correctly; check for frequency gaps or options that are not installed. |
| Cellular and wireless-device testing | Typically 6 GHz or higher for broad sub-6 GHz work; assess the exact bands and channel bandwidths used by your devices. | Some systems operate above 3 GHz, and wide channels may require suitable analysis bandwidth or dedicated analysis functions. | Verify supported analysis bandwidth, demodulation features, and measurement options against your test requirements. |
| Microwave measurements | Set the upper frequency limit to cover the highest signal and relevant harmonics; common instrument ranges extend to 18 GHz, 26.5 GHz, or higher. | Operating near the analyzer’s maximum frequency can affect sensitivity and may require suitable cables, adapters, and calibration. | Inspect the input connector, check for wear or damage, and confirm specified performance at the frequencies you need. |
| Resolving closely spaced signals | Resolution bandwidth (RBW) should reach 1 kHz or below for many general tasks; narrower RBW may be needed for closely spaced carriers or low-level spurs. | Narrower RBW can separate nearby signals and reduce displayed noise, but usually increases sweep time. | Test several RBW settings and confirm the analyzer completes a sweep without errors or abnormal traces. |
| Finding weak signals | Compare displayed average noise level (DANL) at the frequencies and RBW settings you will use. A lower DANL indicates better ability to see weak signals. | Noise floor varies with frequency, attenuation, preamplifier use, and RBW, so one headline value may not describe real performance. | Check noise-floor plots or perform a terminated-input measurement; verify any preamplifier option is present and functional. |
| Accurate signal-level measurements | Look for stated absolute amplitude accuracy appropriate to the work; around ±1 dB is a useful target for many general-purpose measurements. | Amplitude accuracy affects comparisons, compliance checks, and power estimates. | Review the calibration status and uncertainty information. If possible, compare readings at multiple levels with a calibrated source or power sensor. |
| Close-in noise and oscillator testing | Check phase-noise performance at the offset frequencies relevant to the device under test; do not rely on a single offset figure. | Phase noise can mask nearby low-level signals and limit oscillator or transmitter measurements. | Confirm the required phase-noise measurement function or option is installed, and review performance across relevant offsets. |
| Filter, amplifier, and cable testing | A tracking generator covering the required frequency range is useful; verify its output range and level-control capability. | A tracking generator enables swept-response measurements when used with suitable connections and calibration. | Confirm the generator is included, check its output across the intended range, and budget for any required adapters or test accessories. |
| EMC pre-compliance investigations | Choose frequency coverage for the applicable test range and check for quasi-peak, average, or other required detector functions. | A general spectrum analyzer may help locate emissions, but it may not provide all detectors, bandwidths, or procedures required for formal compliance testing. | Match the instrument’s detector functions, input protection, and measurement bandwidths to the relevant test method; confirm whether external preselection is needed. |
| Used-instrument condition and support | Prefer a unit with traceable calibration records, documented self-test results, and available service information. | Age, storage, heavy use, and missing options can affect performance and total ownership cost. | Check startup and self-test, display, keys, connectors, fan noise, included accessories, calibration date, return terms, and the cost of recalibration. |