I just bought it. And I'm actually gonna build that sucker. Using a piece of
floor board, brass screws and cup washers, germanium trannies, just like I
remembered, and relive my youth.
I remember building my first AM radio receiver, similarly. I went out and found
someone who was willing to give me some bits of galena crystals (I got a tiny
handful), bought myself a 5lb block of lead (for swimming pool supplies), melted
the lead and placed the galena into it and let it cool, wound my own coils with
a sliding tap from bent metal, made capacitors from sheet glass and aluminum
foil, and hand built my earpiece, too, from magnet wire, cylindrical magnet
segments, and bits of very thin steel sheet. (The cup washer and brass screws
thing I seem to recall doing as part of a microphone, once, using granulated
carbon between them.) I could pick up at least the three stronger stations in
my area at the time. No purchased semiconductors of any kind.
You can also purchase a kit that Bell Labs produced some time ago (1960's, but I
found someone still selling the kit a year ago) where you built your own oven
capable of 1800F allowing you to build your own semiconductors, and it included
the ingredients to make a solar cell (I think.) If you are really into this,
you might look for that, too. I think it's about US$30, when I looked last
year. Might be fun to see about making a transistor!
A few years ago, I also built up a small water-cooled quartz chamber (nickel
plated reflectors) where I could reach lamp-heated temperatures over 1200C using
a standard AC closed-loop power controller and tungsten lamp heating (16 of the
puppies.) Used dry nitrogen back-fill to keep oxygen out of the chamber for
testing purposes (things caught fire real fast, otherwise!) (I used sapphire
light pipes inserted into the chamber for temp monitoring of the target.) Never
did play with the gases involved in making semiconductors with this one, though
-- way too dangerous (yes, I can actually personally buy the gases in the US for
some crazy reason.)
Jon
