Build a 'Jesus' Radio.

This is a schematic for a one-station radio using an LM386 amplifier and a LED. You might not get the station that gives the radio its name (I get World Harvest Radio [ a shortwave Christian station on many frequencies] on it), but you will almost certainly get something, as its selectivity is horrid.

MISTAKE: I forgot to put a DC blocking capacitor in the schematic. It goes between the headphones and pin 5 of the LM386.

What you will need: 1.An LM386 amplifier chip (sold at Radio Shack now that they have parts again) 2. A red LED for the dectector. 3. Any headphones from a cd player/tape player. 4. Four AA batteries and a holder. 5. A 40NPO capacitor (i don't know what the value is, it's only there to make the selectivity better, you might not need it). 5-5. A 1 to 220 microfarad capacitor between the headphones and output of the LM386 chip to block the DC. 6. A wooden pencil 7. Plenty of wire.

How to get it to work. The pins on the LM386 go counter clockwise starting at the upper left corner. The top of the chip is located where there is a dot or a 'u' shaped indentation on it. The red (positive) wire from the battery holder goes on pin 6, black (negative) end goes on pin 4, the LED goes on pin 3, a long wire for an antenna goes on to the free end of the LED while the capacitor  and the inductor goes between pin 4 and the part of the antenna just before the LED.. Pin 5 of the LM386 goes to the tip the headphone plug, and pin 4 goes to the sleeve/ring of the headphone plug. I used alligator clips and put the tip one halfway down so it connected both ears. To Make The Inductor: Wind about 65-80 turns of 18 gauge solid insulated wire around a wooden (non-conducting) pencil and use alligator clips to connect it to the circuit. If you leave out the inductor, you will get a painful buzzing noise in the headphones as it picks up the much stronger 'radio station' of your power company broadcasting at 60 hertz (in the US) or 50 hertz (many other countries). Other Inductors and capacitors:If you wind 60 turns or so of 30 gauge enamel-coated magnet wire around a film canister, and replace the 40NP0 capacitor with a variable tuning capacitor, you will get some of the AM broadcast band.

For better reception: Take the antenna and tape/clip it onto the faucet in a nearby bathroom or kitchen. At least it works for me because I have well water. I'm assuming the plumbing has a floating voltage determined by the radio waves, and the battery is the ground. If you don't hear anything, leave the antenna just connected to nothing, and connect the negative terminal of the battery (and pin 4 of the LM386,  ring of headphones...etc) to the faucet. If you still don't hear anything, try different value capacitors and different numbers of turns on the inductor. If you still hear silence:Take your finger and touch pin 3 of the LM386 chip. If you hear a 50 or 60 hertz buzzing sound, the problem is not with the hookup to the LM386 chip. For those who don't mind making a mess:Take a long (20 feet or so) length of enamel coated magnet wire, wind it around a pencil loosely, then compress and expand the "coil" until you hear something. You have just made a semi-variable inductor that way.

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