By the way, is it possible to make a crystal radio speaker? If yes, how can I do it?
I would prefer to have a speaker rather than an ear bud, this would allow the entire class to hear it when she presents the radio, rather than 30 kids wrestling over a single earbud...
Thanks
Craig
Crystal sets don't really do speakers, not enough output power. All the power you hear in the crystal set is comming off of the antenna through the rectifier etc. That said, you can take one of those crystal earbuds and with a little bit of work modify it to play through a horn (remember the old victrola?) speaker. It will NOT have room filling volume, but you won't need to wear the earbud. Experiment with a simple paper cone and see if you can get something out.
The earbuds are cheap enough to mess with. If you have a strong local station you can sometimes hear it with the earbud just sitting on a table in a quiet room.
You could also try some cheap computer speakers, as some of these have an amplifier built in. You will have to put something in the circuit to keep from loading down your detector and loosing output (like a transformer). don't know how well that would work. Not really keeping with the crystal radio spirit though.
