Mineral sound machine

1. There are zinc iron ore, galena, pyrite and other ores can be detected, but it is not very stable, the probability of successful proction is not very large. It's better to buy detector diodes, such as 1N60, 1n34, 2ap9 detector tubes, which can be bought on Taobao, and they are very cheap.

2. 1N60 detector diode
mobile phone headset
5V / 220V transformer
0.3mm enameled wire
a long antenna
ground wire - ground.

3. In the early stage of ore radio, we used a needle tip to detect ore (later, we had a germanium diode for better effect) + cobweb antenna + high resistance earphone (high resistance loudspeaker is also OK). When we use a loudspeaker, we can hear it in a small room. There are not many radio stations. The key is that we don't need electricity.

4. 5.1 is two main channels, two surround channels, plus a middle channel and a subwoofer, which can create a ready-made all-round sound, while 2.1 is two main channels and a subwoofer,

5. How do you remember to make a mineral radio again
I'll give you a website to have a look at, and you'll get something:
http://www.cnham.net/Index.html

6. If you don't have a variable capacitor or a 2000pf capacitor, if you don't have a variable capacitor, you can remove one from the old radio. If you don't have a 2000pf capacitor, you don't need to use it. For the antenna, you can just set up a 10-20m long wire. You can go to the ore radio forum http://www.crystalradio.cn/bbs/ There are many schematic diagrams and antenna installation drawings, wish you success!!