Are there any particular advantages to germanium power diodes? I came across a small bench power supply from the seventies that is good for 1 or 2 Amps continuous duty. The zener failed, however, so I am re-working it. The center tap rectifier is a pair of diodes with no markings on them at all except for a bullet shape which points the polarity. I think they are germanium because they both show a .4-volt forward drop on the diode test feature of my meter rather than the usual .6 to .7 volt drop. The leads on these diodes are very stout, about 14 gauge wire. Martin McCormick WB5AGZ Stillwater, OK OSU Information Technology Division Network Operations Group -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist