Fox hole radio?

Question

Greetings all. I’m in the process of building “ye olde foxhole radio”. Before I go buying a pre-fab germanium diode, I was going to make my own first, in the spirit of the myth.

Does anyone have a good and working idea of what makes a good point contact diode for this simple radio project?

I have a few different razor blades. Some of which I have let rust and some I have heated to the point of “blueing”. Are thin “shaving” blades better than the thick utility ones?

I have a safety pin on which I have affixed a pencil lead. Even though modern pencil leads are different, will this still work? There is continuity through the graphite and into the pin. I have them tied to each other with copper wire. Do I need any insulation?

I have 100 feet of speaker wire to act as an antenna. Is there a better wire type?

Are there any other tips are tricks to get this working that I might not find on web pages or turn of the century electronic journals???

Thanx.

Answer 1

You are moving in the right direction.  If you can find a peice of crystal, i.e. galena, you could use that safety pin to probe for a hot spot on it that would act as the detector like the original crystal radios.  The type of wire you are using is fine.  In theory anyway, any two dissimlar metals could be used as the diode detectors, but the way you are going should work.  Don't expect miracles, and have patience.  A good ground connection on the side of the tuning circuit awayfrom the antenna connection will help.