Detector for a crystal radio

[KC2UGV]

check out the Midnight science web site.
If you have any "Razor Blades" single sided carpenters knife blade will work o k if you don't have any of the old double edge stainless blades (non blue coating)
heat it up till the steel starts turning different shades of blue and use a safety pin for the contact.

Check your old non working parts donors. if it has a clear glass diode inside it's some form of germanium, May/not be a 1n34 but it will suffice.

take a section from an old BIC pen and fill it full of copper oxide (heat a piece of copper and scrape) shove a wire into both ends and plug with wax (bees wax , paraffin, ear, whatever you have handy.

on another note
old sauce pots can be turned into variable capacitors in a pinch

need a capacitor across the earphone?

nothing like taking a piece of wax paper and a couple sheets of aluminum foil.............

Thanks for the advice there. As for the cap: