🚀 go-pugleaf

A long, long time ago, I would guess it was the late 60's, the
Scientific American "Amateur Scientist" section was all about making
your own transistors at home.  They were FETs, created by oxidizing
organometallic compounds on a hotplate.  The connections to the
semiconductor were with made by hand with small pieces of osmium.
Most of this is based on very stale rememberances; take it with a
large grain of salt!

I have some personal experience with crystal radios.  Originally they
used a point contact with a piece of galena, which is naturally
occuring lead sulfide. I tried it using a chunk of galena from a rock
collection; I wrapped the rock with bare copper wire and then made the
point contact with a breadboard mounted safety pin.  It seemed to work
about as well as a commercial germanium diode.  Up until the late '50s
or early '60s you could buy a ready made galena detector from
electronic suppliers like Allied and Lafayette.