Having a scope in a home lab used to be a real luxury, but these days, its fairly common for the home gamer to have a sophisticated storage scope (or two) hanging around. Dedicated spectrum analyzers are a bit less common, but they have also dropped in price while growing in capabilities. Want to buy your very own spectrum analyzer? [Kiss Analog] has a buyer’s guide for what to consider.
If you’ve already got a scope, it may have a Fast Fourier Transform (FFT) function, and he talks about how it could be used in place of a spectrum analyzer or vice versa. But it really depends on what you’re planning on using it for. If you’re doing compliance testing for emissions, an analyzer is invaluable. If you like building transmitters or even just oscillators for other purposes, viewing the output on a spectrum analyzer can show you how well or poorly your design is performing. Any application where you need to visualize large swaths of the RF spectrum is a candidate for a spectrum analyzer.
Towards the end of the video, you’ll get to see some actual uses on a Uni-T UTS3021B. While those are at the higher end of the hobby price spectrum (no pun intended), it has many features that would have required an instrument ten times that price in years gone by.
There are also some very inexpensive options out there. While it is true, to a degree, that you get what you pay for, it is also true that even these cheap options would be amazing to an engineer from the 1990s. Yes, of course. You could do it with a 555.