What is the purpose of a spectrum analyzer in RF troubleshooting?

• A. To monitor user traffic on a network.
• B. To calibrate measurement devices.
• C. To visualize the amplitude of signals as a function of frequency and identify unwanted spurs, noise, or interference.
• D. To measure DC voltage levels.

Answer: (C)

A spectrum analyzer visualizes signal power as a function of frequency, which lets you see all the energy present across the spectrum. In RF troubleshooting this is crucial because you can spot spurs, noise, and interference by looking for discrete lines, unexpected peaks, or a raised noise floor at certain frequencies. This tool lets you inspect the carrier, its bandwidth, harmonics, intermodulation products, and any nearby signals that could be disturbing your operation. By comparing what you see to what is expected, you can diagnose leakage, check filtering and shielding effectiveness, and ensure emissions comply with limits.

Monitoring user traffic on a network is not what a spectrum analyzer does; that’s the realm of network or protocol analyzers. Calibrating measurement devices is a related task but uses different procedures and tools focused on calibration certificates and standards, not just spectrum capture. Measuring DC voltage levels is the job of a voltmeter or multimeter, not a spectrum analyzer.