I built several crystal radios when I was young. I fell asleep many nights listening to the strongest local news station, WPEN. I thought it was great that it didn’t require batteries. I wound the coils myself around an empty toilet paper roll and would use 28 to 30 gauge wire. It only required a germanium diode (germanium because its forward voltage is only .25 volts compared to a silicon diode’s .65 volts), a capacitor (I used a "tuning gang"), and an earphone. By 4th grade (early to mid 1960’s), I was already building amplifiers with state of the art transistors (vacuum tubes were still the norm in radios and televisions at that time), so I’d connect my crystal set to the input of the amplifier I built to allow my brothers and I to listen to WPEN at night.
Though analog radio is still with us, if or when they go “all digital”, it will make crystal radio sets obsolete. I find that a sad thought.