There's a book that you might find interesting: "Build Your Own Transistor Radios: A Hobbyist's Guide to High-Performance and Low-Powered Radio Circuits" [1].

I've not read it, but I've heard good things about it.

[1] https://www.amazon.com/Build-Your-Transistor-Radios-High-Per...

I recall WWII PoW stories of 'foxhole' radios[1] made from rusting razors and paper clips, I always thought replicating that would be quite fun.

[1] https://en.m.wikipedia.org/wiki/Foxhole_radio

Yea man, crystal radios are great. Many books, vids and material on the subject. Think I built my fist set in primary school, winding and mounting the coils are delightfully steampunk-esqueish, building a sweet box for the thing from aromatic hardwood is a trip in itself.

Hell yes, make you some crystal radio magic, highly recommended.