If you want an antenna analyzer for $40 (or less, if you have a good stock of parts) this looks like a worthwhile project.

However, their spectrum analysis abilities are lacking. While these scopes do have a Fast Fourier Transform (FFT) function, it’s limited and nearly useless for RF.

RF signal observation has evolved from yesteryear’s spectrum analyzer to today’s RF recorder. Swept spectrum analyzers, FFT analyzers, and real-time signal analyzers all had limitations. Today ...

Although a spectrum analyzer exhibits better dynamic range and less distortion, the digital oscilloscope FFT provides a cost-effective, space-saving alternative.

The Compact Spectrum Analyzer (CSA) from MPB srl of Italy is a compact real-time FFT handheld spectrum analyzer.

GAO Instruments’ USB PC-based digital storage oscilloscope,the Model A0120006, features a 5-in-1 design that integrates a digital scope,logic analyzer, FFT spectrum analyzer, electronic counter, and ...