Spectrum analysis (analyzing a signal in terms of amplitude vs. frequency) is still widely used by RF Engineers today. You can measure signal power, harmonics, occupied bandwidth and channel power. And if you know what you’re looking for, you can pick out input related spurious signals, measure amplifier compression points, and characterize third order inner modulation products. This video covers the basics of spectrum analysis using SignalVu-PC software from Tek.
Dauer 5m 35s