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Spider Radio One.

I built this radio for a friend of the Family.  A great guy who gave me an incredible amount of parts and material for Kite building.  I used my own design for a spider coil and wound about 65 turns of 24 gauge magnet wire.  This gave me about 330 uH of inductance to work with.  I used a simpler capacitor that can be bought here as opposed to a variable air capacitor.  Shorting the two ends this capacitor will give you over 240 pF, enough to tune the whole AM band.  There is a 47k resistor in parallel with the ear piece and a standard 1N34 Germanium diode.  For the actual form and front piece I used a small sheet of Lexan; it's durable and virtually indestructible.  This set has a high Q value and has great selectability.  This is due to the loose wound theory.  If the wire is not close wound there is less capacitance built up, thus greater selectivity.  If anyone is interested in the exact measurements or is interested in making a similar radio, feel free to email me.  

Disclaimer:  I know crystal sets have been around for a loooong time.  I'm sure similar radios have been built and I do not claim that this is an *original*.