Whoops! I originally posted about this in the wrong subforum!
Anyway, I recently built an Australian crystal mystery set and an external LM386 based amp so it could run a speaker. The set has decent performance, given that I live in a smaller apartment and only have a ~1 m long wire clipped to my stove's vent hood as an antenna and a pipe connected to a radiator as my ground. I'm able to pull the local AM stations and a few from further afield. I figure if I had a larger antenna and a better ground my sensitivity would be greatly improved. Has anyone else built one of these?
I came across these experimental variants for the short wave bands that I'm going to experiment with over the next few weeks.