Certified Radio-Trician's Course(REG. U. S. PAT. OFF.)
NATIONAL RADIO INSTITUTE
WASHINGTON, D. C.
Fundamental Principles of Radio
WHAT IS ELECTRICITY?
In our study of Radio, we will be dealing with electricity a
large part of the time. Naturally we will have to know something
about electricity even before we begin to talk about Radio.
You are most likely very familiar with the use of electricity.
You know it will light a room or run a trolley car, but do you
know anything else about it? You have never seen an electric
current--you know it travels through wires, you know that in
Radio not even connecting wires are necessary between reeiver
and broadcaster, but just what is this “current” which is so
powerful that it is doing a larger part of the world's work?
Now we are going right to the bottom of the matter and in
this very chapter you will get a clearer insight into the nature
of electricity than many electricians have. In fact, as a trained
Radio Expert you will know considerable about electricity--
while the electrician is not so fortunate. His training and
experience have not taught him very much about Radio.
For many years, even long after electricty was harnessed
and made to run motors, scientists were unable to decide just
what electricity really was. Even today there are some points
in connection with it that are not entirely clear, but enough has
been learned about it to give us a fairly clear idea of what goes
on in an electric circuit, and how it is that a voice can be carried
from one end of the country to the other in much less than a
second of time, with and even without the use of connecting
wires.
Years ago it was discovered that everything in nature was
made up of “atoms”--the earth, the food you eat, the water you
drink, the air you breathe. Now you will want to know what
we mean by an atom. Let's take something very small and try
to find out what it's made of.
Suppose we take a grain of salt--we could use a grain of
sand, or anything else--and break it up. You can easily imagine
a grain of salt ground up into a fine powder. Now we seperate
