3

The Mobile Unit

It may be that a lot of what follows in this chapter will be familiar information to some readers. Explanations are necessary, however, to be sure that everyone gets off on the same foot. So, if this is old stuff to you, please bear with those to whom it may be a bit strange.

Before there is any discussion of the ways in which the human voice can be transmitted from one place to another by wire or by radio, we should understand the basic principle of how the common wireline telephone works. What happens when you speak into the mouthpiece of the instrument?

Look at a telephone handset the next time you use it. It used to be that only one style of telephone was available, made by one manufacturer and, like the old Model T Ford, ...

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