Learn to use GNU Radio Companion without a physical radio in this 24-minute tutorial video. Explore the basics of software-defined radio (SDR) by creating an FFT display of a fixed signal source or soundcard input. Gain insights into data types, GUI layout, and essential concepts such as sample rates, complex numbers, frequency synchronization, and variable handling. Discover various wave types and receive helpful GUI hints. By the end of this introductory session, you'll be prepared to delve into actual SDR builds in the upcoming part 2.