Today, we try to make a radio. The University of
Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
created them.
How I grooved on stories and
daydreams when I was nine years old! And radio
provided them. Radio gave us the words, our minds
drew the pictures, and that was a powerful
combination.
It was rare to have more than one radio in a house
in the 30s, and you listened to it when your
parents said you could. But listening always ended
too soon. You were always called away -- to school,
to supper, to chores, and to bed.
There was a way around the problem, but it wasn't
easy. You could build your own crystal set. That
was a simple primitive radio whose heart was a
polycrystalline lump of galena, set in lead. The
crystal worked as a rectifier -- in place of a
radio tube. You pecked away at its surface with a
fine wire probe called a cat's-whisker. Sooner or
later you hit just the right facet of the crystal
-- one that responded to the station you'd set on a
home-made coil.
The signal was weak. There was no amplifier. You
listened to it with earphones. But with your own
crystal set, you'd be able to pull the covers over
your head and listen to your heart's content --
after your mother'd said good night. You'd be able
to listen to music, or I Love a Mystery, and no one
would know.
Mechanics Illustrated or any of a
hundred how-to-do-it books all explained, in
formidable detail, how to make a crystal set from
hardware-store parts. But you were nine years old,
and something always went wrong -- a loose wire, a
badly wound coil. So you never quite figured out
how to make your own radio to play under the
bed-covers. In the end you were left reading comic
books with a flashlight.
The radio permeated American life with amazing
speed after its invention at the end of the
nineteenth century. Here's an old Boy Scout manual,
published just a few years later -- in 1910. It
tells you how to earn a merit badge in Radio. You
had to draw the complete circuit diagram for a
receiver set -- from memory. You also had to build
your own set, using a tube -- not a crystal. Then
you had to pick up a signal 25 miles from a
transmitter. Of course, all that was for
14-year-olds.
But you were only nine, and making a radio was far
easier to dream about than to do. So you dreamt and
wished. Of course, that wish actually came true.
Today you can let Dvorak and Britten wash you into
slumber. But I still wish I could have made one of
those temperamental crystals sing me to sleep.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
