[Manekinen] built a very responsive spectrum analyzer. The components at the party are what you’d expect, an ATmega8 does the hard work interpreting data from the LM324 op-amp. This build stands ...

Luckily, I was able to scrounge up a decrepit Windows laptop and get a compiled ... but if your only need for a spectrum analyzer is to design the occasional filter or check signal quality ...

For example, whereas an oscilloscope would show total noise level, a spectrum analyzer would show the noise as related to frequency. Available in both analog and digital models, digital analyzers ...