One of the best ways to learn about radios is to build your own, even in the age of cheap SDR dongles. [Aniss Oulhaci] demonstrates this with a simple HF SDR receiver built on a breadboard.

(Embedded below.) The video covers LimeSDR, HackRF, and the Pluto SDR, although the amplifiers should work with any transmitter. The SPF5189Z module is quite cheap and covers 50 MHz to 4 GHz ...