Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!apple!ems
From: ems@Apple.COM (Mike Smith)
Newsgroups: sci.electronics
Subject: Crystal radios - wasn't it a 'galena' crystal?
Keywords: galena PbS radio crystals
Message-ID: <5386@internal.Apple.COM>
Date: 23 Nov 89 01:06:54 GMT
Organization: Apple Computer Inc., Cupertino, CA
Lines: 20

Wasn't the detector in old crystal radios made of 'galena'?
Someone posted that the crystal was a germanium lump, but I
seem to remember 'galena' as the stuff...  If so, it
raises an interesting point.

Galena is PbS (Lead Sulfide).  Taking a look at the periodic
chart it looks like Pb and S are in about the right places to 
make a semiconductor (like Indium Phospide, Gallium arsenide, etc.)
Is PbS a semiconductor (if properly doped)?  If so, what are it's
properties?  I seem to remember some 'old timers' saying that a
good crystal was far better than those new fangled diode things...

-- 

E. Michael Smith  ems@apple.COM

'If you can dream it, you can do it'  Walt Disney

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