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
https://store.scitoys.com/radio-kits-... (their variable capacitor is for if your coil has a ferrite core and is smaller than the one in this video)

You can find the circuit diagram shown in this video on this page:
http://rimstar.org/equip/crystal_radi...

See also:

How a Crystal Radio Works
   • How a Crystal Radio Works  

Crystal Radio Troubleshooting and Tips
   • Crystal Radio Troubleshooting and Tips  

Make Crystal Earphone/Earpiece for Crystal Radio
   • Make Crystal Earphone/Earpiece for Cr...  

Use Earbuds/Earphones with Crystal Radio
   • Use Earbuds/Earphones with Crystal Radio  

Make a Crystal Radio Coil with Taps
   • Make a Crystal Radio Coil with Taps  

Make Razor Blade Diode for Crystal Radio/Foxhole Radio
   • Make Razor Blade Diode for Crystal Ra...  

How to Make Crystal Radio Amplifier for Speaker
   • How to Make Crystal Radio Amplifier f...  

How to Make Amplifier for Crystal Radio Earphone
   • How to Make Amplifier for Crystal Rad...  

Steps for How to Make Amplifier for Crystal Earpiece
   • Steps for How to Make Amplifier for C...  

How to Make an AM Radio Transmitter (so you can transmit to your crystal radio)
   • How to Make AM Radio Transmitter  

Amplitude Modulation with Simple AM Radio Transmitter
   • Amplitude Modulation with Simple AM R...  

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