Crystal Radio

Author	Views	Views Today	Rank	Comments
	54,900	43		48

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)

Related Circuits

Comments

Add A Comment

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?

alex Crystal Radio Saturday, January 31, 2009 3:23:15 PM

Crystal radio's require NO power source. they are able to use the energy from the radio waves interacting with the antenna coil. The germanium diode with it's low forward bias voltage is the ideal device for use in this circuit.

pranab Crystal Radio Saturday, January 31, 2009 3:27:43 AM

its not working properly

sumit Crystal Radio Friday, July 25, 2008 8:18:57 AM

where's the supply voltage?

mrudula Crystal Radio Wednesday, June 04, 2008 10:50:21 AM

please help me out with the shematics. i dont get for what is there a extention from c1.is it a coil or has the wira to be completad in a loop?

cody Williams Crystal Radio Saturday, March 29, 2008 12:52:36 PM

I just got done w/ mine.

The last 10 comments are currently shown. Show All Comments. Add A Comment

If you would like to leave a comment, you can do so using the form below. Comments can be things like suggestions, successes or failures, improvements, similar circuits, error reports, an answer to a previous commenter's question, or anything in between. However if you would like to ask a question it is suggested that you use the forum instead. The forum provides a more robust environment for discussion.

Important: If you post a technical question here, there is no guarantee it will be answered. All technical questions should be posted to the forum. The owner of this site generally does not answer questions in comments.

All comments are subject to approval before they are displayed here, so your comment will not appear immediately. This is done mainly to prevent spam and other abuse. If you wish to remain anonymous, simply enter "anonymous" for your name and/or email.

Name:
Email:
Subject:
Comments:
Anti Spam Code:	Please enter the exact text shown in the image above into the box below. Browser cookies must be enabled to comment on circuits.

Privacy Policy

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?
alex	Crystal Radio	Saturday, January 31, 2009 3:23:15 PM
Crystal radio's require NO power source. they are able to use the energy from the radio waves interacting with the antenna coil. The germanium diode with it's low forward bias voltage is the ideal device for use in this circuit.
pranab	Crystal Radio	Saturday, January 31, 2009 3:27:43 AM
its not working properly
sumit	Crystal Radio	Friday, July 25, 2008 8:18:57 AM
where's the supply voltage?
mrudula	Crystal Radio	Wednesday, June 04, 2008 10:50:21 AM
please help me out with the shematics. i dont get for what is there a extention from c1.is it a coil or has the wira to be completad in a loop?
cody Williams	Crystal Radio	Saturday, March 29, 2008 12:52:36 PM
I just got done w/ mine.