Crystal Radio

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I have received a number of emails regarding schematics for crystal radios. After about the third email, I figured that I may as well put one on my page. So here it is. The circuit is very simple with only 5 parts, but performs very nicely when used with the right size antenna.

Schematic

Parts

Part	Total Qty.	Description	Substitutions
C1	1	Tuning Capacitor (See Notes)
D1	1	1N34 Germanium Diode
L1	1	Loopstick Antenna (See Notes)
SPKR1	1	Crystal Earphone
MISC	1	Wire, Board, Wire For Antenna, Knob For C1

Notes

C1 and L1 can be bought, or salvaged from an old AM radio (which is where I got mine). You may need to experiment with the connections on L1 in order to get the best (or any) signal.

You may or may not need the ground connection. I never use it and the radio usually works fine without it.

The bigger the antenna, the more stations you pick up and the louder you hear them. On my radio, I get about 10 stations, 3 of which are very loud in the earphone. Of course, not everyone has room for a 60' antenna...

A 47K resistor in parallel with the earphone will help properly load the detector (This suggestion from Kb8tej1@aol.com)

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Comments

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anonymous Crystal Radio Friday, August 31, 2012 5:39:44 PM

WHERE IS THE POSITIVE CONNECTION?

Tony B (old timer) Crystal Radio Thursday, September 30, 2010 4:08:11 AM

If you live in a city, you probably dont need the earth connection, as you will get a strong signal friom local stations, but in the countryside the earth becomes essential to receive anything in some locations. It only needs to be a metal rod, preferably copper, about 1-2 metres long, buried in the ground.A lead water supply pipe will do nicely.

anonymous Crystal Radio Friday, March 26, 2010 6:15:56 PM

I built this radio exactly as shown in 1969 and was AMAZED it worked...I was only 8 yrs old. I substitued the diode with a transistor, using only two of its three leads and wound the coil on an oatmeal tube carton with a copper strip as my 'tuner'..lol. the cap was from an old radio. BTW, I hate oatmeal.

razorradio Crystal Radio Friday, November 06, 2009 2:37:33 PM

This is a great hobby. One of my first xtal radios was this same circuit!. I even had a radio that was just a diode and an earpiece! If you live close to a radio station and have a good antenna and ground you will either get one station or several at once. My main crysatal radio when I was a kid was a variable loopstick + a 1N60 diode (similar to a 1N34) and a crystal earpiece. I also biult a couple radios that had a razorblade touched by a pencil lead as a detector instead of the diode. I recently just got my first DX on an AM crystal set. The circuit is similar to yours, but with a tapped coil on PVC pipe instead of a ferrite loopstick. NOTE TO NEWCOMERS: A regular earphone will not work. You need a crystal earphone (also called piezo electric).

arun Crystal Radio Thursday, October 15, 2009 6:04:48 AM

Is there any kind of inductor or rheostat is needed.......Loop stick anteena has only one terminal ..How to connect both +ve and ground ...Plzzzz reply soon

anonymous Crystal Radio Wednesday, September 02, 2009 9:16:41 AM

There is NO FM radios on that page.

anonymous Crystal Radio Wednesday, September 02, 2009 9:13:52 AM

Can a loudspeaker be used for the circuit instead of the crystal earphone????????

anonymous Crystal Radio Tuesday, July 21, 2009 4:59:35 AM

can we use this device to make light flickers by changing the speaker to LED

anonymous Crystal Radio Friday, May 08, 2009 8:20:19 PM

If this radio is able to use the energy from the radio waves interacting with the antenna coil for power, is there a way to use this as a free energy device too? Turn this into a small charger for example
(Editor's notes: We're only talking a few microamps here.)

Sanjeet Crystal Radio Sunday, February 15, 2009 3:56:23 AM

Where is the battery or power or it is of without battery?

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anonymous	Crystal Radio	Friday, August 31, 2012 5:39:44 PM
WHERE IS THE POSITIVE CONNECTION?
Tony B (old timer)	Crystal Radio	Thursday, September 30, 2010 4:08:11 AM
If you live in a city, you probably dont need the earth connection, as you will get a strong signal friom local stations, but in the countryside the earth becomes essential to receive anything in some locations. It only needs to be a metal rod, preferably copper, about 1-2 metres long, buried in the ground.A lead water supply pipe will do nicely.
anonymous	Crystal Radio	Friday, March 26, 2010 6:15:56 PM
I built this radio exactly as shown in 1969 and was AMAZED it worked...I was only 8 yrs old. I substitued the diode with a transistor, using only two of its three leads and wound the coil on an oatmeal tube carton with a copper strip as my 'tuner'..lol. the cap was from an old radio. BTW, I hate oatmeal.
razorradio	Crystal Radio	Friday, November 06, 2009 2:37:33 PM
This is a great hobby. One of my first xtal radios was this same circuit!. I even had a radio that was just a diode and an earpiece! If you live close to a radio station and have a good antenna and ground you will either get one station or several at once. My main crysatal radio when I was a kid was a variable loopstick + a 1N60 diode (similar to a 1N34) and a crystal earpiece. I also biult a couple radios that had a razorblade touched by a pencil lead as a detector instead of the diode. I recently just got my first DX on an AM crystal set. The circuit is similar to yours, but with a tapped coil on PVC pipe instead of a ferrite loopstick. NOTE TO NEWCOMERS: A regular earphone will not work. You need a crystal earphone (also called piezo electric).
arun	Crystal Radio	Thursday, October 15, 2009 6:04:48 AM
Is there any kind of inductor or rheostat is needed.......Loop stick anteena has only one terminal ..How to connect both +ve and ground ...Plzzzz reply soon
anonymous	Crystal Radio	Wednesday, September 02, 2009 9:16:41 AM
There is NO FM radios on that page.
anonymous	Crystal Radio	Wednesday, September 02, 2009 9:13:52 AM
Can a loudspeaker be used for the circuit instead of the crystal earphone????????
anonymous	Crystal Radio	Tuesday, July 21, 2009 4:59:35 AM
can we use this device to make light flickers by changing the speaker to LED
anonymous	Crystal Radio	Friday, May 08, 2009 8:20:19 PM
If this radio is able to use the energy from the radio waves interacting with the antenna coil for power, is there a way to use this as a free energy device too? Turn this into a small charger for example (Editor's notes: We're only talking a few microamps here.)
Sanjeet	Crystal Radio	Sunday, February 15, 2009 3:56:23 AM
Where is the battery or power or it is of without battery?