Development of Radio Transmissions

From 1746 to 1945

Electricity
Without the discovery and usage of electricity we would probably still use carriers and letters to communicate. Through the knowledge and the control of electricity we were able to find new ways to communicate via long distances. The development of electricity started in the 18th century. For quite some time the research of electrical phenomenons was only in the interest of some Physicists without any practical use. This changed dramatically after the discovery that electricity and magnetism were connected. Finally through the electrodynamics, the connection of mechanics and electricity, triggered the second industrial revolution.

Telegraphy
Telegraphy began in 1833 with the first transmission of a message by Gauss and Weber. As early as 1850, the first telegraph networks were established for telecommunications. With new companies such as Siemens, a new industrial field was created with this technology. In 1865 the first global institution for the standardization of telecommunications, the ITU, was established.

Telephony
A completely new field of telecommunications opened up in 1860 with the development of the telephone. Alexander Graham Bell created a company that still operates today, the Bell Telephone Company, which later became AT&T. Telephone networks emerged worldwide by the end of the century, first manually switched, followed by automatic dialing.

Electromagnetic Radiation
A new era of telecommunications began 1886. The electromagnetic waves, postulated by Maxwell were verified by Heinrich Hertz. The development of wireless telegraphy started soon after that. New elements for detection and reception of electromagnetic waves were developed with the coherer and the crystal detector. Guglielmo Marconi achieved his first commercial successes by introducing a radio-driven telegraph system. This was patented for the shipping industry in 1896.

Modulated Electromagnetic Waves
The age of electronics began in 1906 with the invention of the triode. This made possible to send and modulate continuous electromagnetic waves with the help of triodes. Speech and music could be transmitted wirelessly. 1918 special receiver electronics were invented , which made it possible to separate different transmission channels from each other.

Triumph of Radio
In the 1920s, radio receivers became very popular. For the first time, frequency bands were divided into channels in order to allow programs to be operated in parallel. Radiotelephony developed relatively late in the form of walkie-talkies and became an important instrument at the beginning of World War II.