Another thread here made me think of asking this

We see lots of folks talking about crank radios, or solar radios, but around here at least, most NEWS on the radio is on the AM band, usually on a strong signal station

Why not a crystal radio? No, not a cat whisker (yeah, those will work), but one made from a variable cap, and a diode, with a high Z earphone. No power needed at all

Thoughts? Anyone make one commercally?