[bonyt]

When I look at that crystal radio kit, my fingers hurt. I had a kit like that as a kid in the 90s - not sure if it was a radio or more generic electronics - with the springs to hold wires together. At some point, made a short circuit and burned my fingers. Immediately upon seeing that, the memory comes back. I guess it's burned into my memory.

[knotimpressed]

Surely it wasn’t a crystal radio you were building, since they have no power source?

For any powered circuit though, a few AAs can dump a surprising amount of current and heat into naive fingers.

[MisterTea]

I loved those spring electronics kits, Radio Shack always sold a bunch. And yeah, the D batteries could get the springs glowing and wires smoking. A lot of my early electronics projects were smoke machines.