How Radios Were Invented

By: Alya Khalid

Break Studios Contributing Writer

The credit of how radios were invented can not be allotted to one era or person. Radios were invented when a connection between electromagnetic current and light was established. The main contributors in the invention of radio were Heinrich Hertz, Guglielmo Marconi, James Clerk Maxwell and Mahlon Loomis.

Radio started as wireless telegraph. The first ones to adopt this system were the navy. Titanic’s disaster was a contribution of the weak faulty telegraph system. When Titanic was sending out panic location signals, the interference caused a delay in reception. Help could not reach on time and she sank without a trace.This was the time when radio as an appliance was not invented.

Radio was invented in a step wise series of discoveries and experimentation. Lee De Forest after the disaster started working on a stronger receiver which he called a responder. In the year 1890 Thomas Edison was developing light bulb and he discovered during his work, that electromagnetic waves were transferable in vacuum. John Embrose Fleming in 1904 discovered the change of alternating current into direct current after passing through vacuum. He added two electrodes to the setting and called it a diode.

James Clerk Maxwell discovered a relation between electric charge and magnetism. This phenomenon he named, electromagnetism. In 1864 he proved that there was a third factor, light involved in spreading the electromagnetic effect. This led to a cycle of the electric current and magnetic field. Electric current produced a magnetic field that in turn generated electric current.

James Clerk Maxwell proposed that a wave could be present between the two if another phenomenon, alternating current was introduced to the process. A changing electric charge will produce a changing magnetic field and vice versa. A wave should form in this alternation. This wave or radio wave later was utilized to transfer sound and pictures to receivers.

In the 1880's Heinrich Hertz got interseted in Maxwell's theory. While working on it he found that a current jumping to and fro from a wire to another could be the cause of such waves. He proved this theory by performing an experiment with two rods, acting as signal receivers. He proved in his experiment that these were electromagnetic waves.

Fleming became aware of the technology and was convinced it would prove fruitful in the field of radio transmission. He added a thin wire grid connecting the two diodes. This apparatus was capable of picking up electromagnetic signals and then their amplification so they became audible. Radio was invented with the help of this triode called transmission through vacuum tube. This same technology led to the invention of television later.

In 1896 Guglielmo Marconi sent the first coded signals on air, and called it wireless telegraph. Radio was invented in that time as a contraption. He was the first to send a public radio broadcast in 1898. After opening a radio broadcast company, he established connections with Britain, France and USA. In 1909 he received a Nobel prize for this achievement. Voice signals were sent for the first time in 1921. Marconi is known as the inventor of a functional machine, called radio.

In 1915 Nikola Tesla filed a case against Marconi, revealing that he had given the idea of radio four years before, Marconi had started his work on radio waves. Tesla won the case and is known as the inventor of theoretical radio. Although Marconi still takes credit for creating one.

References:

Radio History

Electromagnetic Waves

Posted on: May. 13, 2010