In that case, the best experience in my opinion is to DIY one of the simplest radio receiver, that is, a super-regenerative or similar one that could be built off a single transistor/jfet and a high impedance headphone. Or, to make things cleaner, a couple transistors where 1st one acts as antenna preamplifier (and -very important- to prevent the other transistor oscillations to be radiated by the antenna).
It's a very simple project that can be built on a breadboard in an afternoon, encourages experimenting and teaches a lot in the process.
Just 1 or 2 transistors you say? Link to a circuit diagram (or even an ASCII art reply) greatly appreciated - sounds like a fun way to spend an afternoon or an evening.
Plenty of examples to choose from, just search for images of "super-regenerative transistor receiver schematic" (with no quotes) on your favorite search engine. This also works well when looking for examples or data about circuits or parts, for example "audio compressor schematic" or "LM13700 data sheet" (again, no quotes). Swapping "data sheet" with "pdf" is often more effective to find the actual document.
