how to build a crystal radio

[andris]

I've built the radio with all the procuedures and I still cannot get it to work,no sounds.Is there any specific procedures (steps) to follow other than what is already given so I can have the radio woking? How do we connect the insulators? How do we connect them and what is it suppose to do? Is the microameter necessary to use so this radio can function? Please answer ASAP. Thanks.

[kgudger]

Hello and welcome to the forum:

I've looked over the experiment details, but have not built this radio before. It looks like the experiment is explained pretty thoroughly, so I will try and answer your specific questions.
The insulators insulate the antenna from "ground", so they are very important. I believe the diagram in the experiment shows how to connect them properly, so if you are having trouble with the diagram, please tell me specifically what the problem is.
The experiment says:

Multimeter or microammeter and voltmeter (optional)

so you don't have to use the meter to get the radio to function.

Please note that this radio only works with AM radio stations. In many parts of the world there are not many of these stations left, so you may have trouble finding a broadcasting station to listen to.

Keith

[deleted-71588]

Please DO NOT POST an address to protect your identity and conform to the Science Buddies website rules; however,
please let us know what Country,State/Province, County/Parish you are you located in (or a large major city you are within 100 miles of). With that information, we can look up what AM broadcast stations, their power ratings, their operating hours and where they are located.

The long-wire antenea may need to be stretched in a direction perpendicular to the direction where the AM broadcast station antennea is located in order to pick up enough signal strength.

What crystal diode did you use (e.g. 1Nxxxxx part number)?
What material did you use for the base to assemble your radio on?
What size oatmeal or other cardboard container (diameter and height) did you use?
What size wire and insulation type did you use to wind the coil?
Have you tested your ceramic earphone with another audio source? You are using a high impedance ceramic earphone and not some low impedance ear buds for an iPod/iPhone like device aren't you?

The obvious kinds of mistakes would be open circuits (connections between parts are not being made, broken wires) and short circuits (things touching that shouldn't or built on base that has absorbed moisture or is otherwise conductive).

[andris]

thanks for your replies guys , they really helped me. i got it to work, though! i got a 92% on my science fair. i owe it all to you! thans alot.