SUPPLEMENTARY TEXT:
Radio
Radio is a miracle of ages. Aladdin’s lamp, the Magic Carpet seems insignificant compared to the radio.
By radio the human voice may be transmitted around the earth in less time than it takes to say the word “radio”.
Radio is playing an ever increasing part in human life on land, on sea and in the air. It makes possible much more than simply communicating news, music, etc. and it also plays a very important part in navigation.
The radio beacon and radio compass help to locate positions in air and on sea in fog and storms. Without radio, to travel by air would not be one of the safest methods of transportation, although quite recently it seemed almost incredible.
The pictures of our daily newspapers are transmitted by wireless. Even the geophysicists use radio instruments.
There are a few fundamental principles which are the basis of all the electrical means of communication. To know those fundamentals is to understand the systems of communication which at first seem as having nothing in common.
Whether the transmission system is wire or wireless, whether the signals which carry the information can be heard or seen, there is something in common to all the means of communication.
However, different their aims may seem, all of them are simply means to perform certain typical operations, each of them playing an important part in radio communication.
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