Mostly the germanium is housed in a small glass housing with wire leads coming off each end. The diode is a "germanium" type diode and not a "silicon" based diode. Mostly any germanium diode will work. Some not as well as others. The most common diode used is a 1N34A germanium diode for crystal radios. These are virtually impossible to reproduce or "homebrew", so we will move on to another kind of detector.

In the old original crystal radios they used what was called a "catswisker" type detector.  As these can be much easier to build this is what we will use or build.

There are as many way to build a "catswisker" detector as there are people trying to build them. We will start with the most simple and work our way up to the more sophisticated detectors.

All of the different type of catswisker detectors use one thing in common, the mineral or crystal. There are many different type of minerals or "rocks" that can be used as the crystal. Here is a listing of different types of minerals that can be used.

Click Here >     ../minerals/index.shtml

The best one to use is Galena. It is very reactive and much easier to use than most of the others, so we will use  galena as our crystal.

A trip to the local "rock shop" or sometimes to a flea market, or even on ebay you will find this mineral for sale. It is not very expensive and very abundant.