How to Make/Build a Crystal Radio

Step-by-step instructions for making a tunable crystal radio. This is a radio that gets its power from the radio waves. I made it almost entirely from junk except for the diode (1N34 germanium diode) and the earpiece (though you can use a speaker from a phone instead.) The capacitor is made from aluminum foil and a paper towel roll. The coil is rolled on a toilet paper roll. The wire is enameled magnet wire. For the antenna I use a 15 foot wire laid out on the floor. For the earth ground I connect a wire to the ground in the household wiring. I originally got this circuit from the book "Radio Receiver Projects You Can Build" by Homer L. Davidson. For this circuit, the diode must be germanium. The following is a partial list of germanium diodes that should work: 1N34A, 1N60, 1N91, 1N119, 1N270, 1N277, 1N283 The following are not germanium diodes and may need a long antenna or a powerful radio station nearby to work: 1N4148 (silicon, found on a lot of circuit boards), B16 (zener diode), 1N5060 (avalanche diode) The crystal earpiece (piezoelectric earphone) and/or 1N34 germanium diode and/or air core variable capacitors can be ordered from most of these sources: http://www.midnightscience.com http://www.scitoyscatalog.com/category/R.html (their variable capacitor is for if your coil has a ferrite core and is smaller than the one in this video) http://www.maplin.co.uk/p/mono-crystal-earpiece-with-35mm-jack-plug-r62gk You can find the circuit diagram shown in this video on this page: http://rimstar.org/equip/crystal_radios.htm See also: How a Crystal Radio Works http://youtu.be/0-PParSmwtE Crystal Radio Troubleshooting and Tips http://youtu.be/HZZmKZJrIW0 Make Crystal Earphone/Earpiece for Crystal Radio http://youtu.be/OVapqz4yBCY Use Earbuds/Earphones with Crystal Radio http://youtu.be/GCh2LVHUavQ Make a Crystal Radio Coil with Taps http://youtu.be/Gi9EmhrcfIg Make Razor Blade Diode for Crystal Radio/Foxhole Radio http://youtu.be/eIdHsjfbckw How to Make Crystal Radio Amplifier for Speaker http://youtu.be/JtPwxbOgBHw How to Make Amplifier for Crystal Radio Earphone http://youtu.be/cQ-LxMDrD_o Steps for How to Make Amplifier for Crystal Earpiece http://youtu.be/V0dKdSNv_dY How to Make an AM Radio Transmitter (so you can transmit to your crystal radio) http://youtu.be/_4-Sx-T6VBc Amplitude Modulation with Simple AM Radio Transmitter http://youtu.be/R04yEKqgGPc Follow me on Twitter: https://twitter.com/#!/RimStarz - http://rimstar.org