They are known as Foxhole Radios, and you can find more information by
using a web search engine.
-Lawrence LeMay
Bryan Pope <bpope(a)wordstock.com> wrote:
Hi
I built several crystal sets. One I built using a razor
blade and a piece of graphite from a pencil. It doesn't
work with stainless blades. You need one of the older
style "Blue Blades".
Most rock shops have some galena. With some lead and
sulfur, you can make your own galena.
Dwight
A razor blade and pencil lead!?! Wow.. that is very cool! I am old
enough (errrgh... I never thought I would say that!) to know about using
germanium diodes (ala Crystal Radio Kits from that once wonderful store Radio
Shack), but a razor blade and pencil lead... How do you put it together?
Hi
I put the razor blade down with a thumb tack on a piece
of wood. I wrapped a few loops of 20 gauge copper wire
around the lead. The pencil lead is the cats whisker.
The blades do need to be the tempered steel,
not the stainless. That area with the thin colored
oxide is the best place to look for good rectification.
It was graphite lead out of a standard #2 wood pencil.
I never did determine the direction of the diode but
for the purposes of a crystal detector, it doesn't make
much difference. You did need to look for the best spot,
just like a galena crystal.
Dwight