Creating Electromagnetic Waves with an Electromagnet: Fact or Fiction?

[relativelyslow]

is the crystal a germanium diode?

 

[chroot]

Yes, they generally sell these kits at Radio Shack. They're a great place to begin tinkering with electronics.

The radios are still called "crystal radios," even though they no longer contain a crystal. In the old days, they were built with a small crystal of lead sulfide and a bit of metal, used to allow current to pass in one direction but not in another. In a modern crystal radio, the germanium diode performs the same function, but better.

- Warren

 

[relativelyslow]

cool. ill definitely check out radio shack tomorrow

 

[relativelyslow]

does the radio create the radio waves? if it did, wouldn't that be a perpetual motion device?

 

[chroot]

No... a crystal radio receives radio waves from a transmitter tower operated by the radio station. It's definitely not a perpetual motion machine!

- Warren

 

[relativelyslow]

what inductance (current range) works best for radios? should i post building a radio in the engineering section?

 

[chroot]

I don't know what you mean by "current range," but the inductor used in a crystal radio is selected, along with the capacitor, to provide resonances at the appropriate transmission frequencies. More complex radios are, well, more complex.

- Warren

 

[relativelyslow]

at wilcocorp.com/catalog, you can get free inductors but it asks for an inductance range or current range.

 

[Goalie_Ca]

Current range is probably the current limit. Don't forget, if you pass too high of a current through a wire it will burn like a fuse or a burnt out lightbulb.

 

[relativelyslow]

what would be the ideal limit for a radio or practical for experimenting?