— David Wagner 2008/02/13 21:32

The 1N34A germanium diode is, by far, the most popular crystal radio detector and some can perform very well. However, the devices sold as 1N34A diodes may be one of at least three different kinds.

Fairly recent (but obsolete and no longer manufactured) 1N34A diodes are usually housed in the typical DO-7 glass package with a black or smoky cathode end, though this can vary.

Modern diodes sold as germanium 1N34A often have a brightly-colored band around their glass DO-7 package marking the cathode. The cathode band on modern 1N34A diodes usually does not extend to the end of the glass capsule.

They typically have a fairly high series resistance.

Modern silicon Schottky rectifiers sold as 1N34A diodes are typically housed in a DO-35 package.