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So who invented the radio: Guglielmo Marconi or Alexander Popov?

Popov, perhaps, was the first - but he did not patent his inventions and did not try to commercialize them



In 1895, Russian physicist Alexander Popov used his tool for studying thunderstorms to demonstrate the transmission of radio waves.

Who invented the radio? Your answer will probably depend on where you come from.

On May 7, 1945, the Bolshoi Theater in Moscow was crammed with scientists and statesmen from the Communist Party of the Soviet Union, celebrating the 50th anniversary of the first radio demonstration held by Alexander Popov . It was an opportunity to honor the domestic inventor and try to divert historical records away from the achievements of Guglielmo Marconi , who in many countries of the world is recognized as the inventor of radio. May 7th was announced in the USSR as Radio Day , which is still celebrated in Russia.

The statement on the priority of Popov as the inventor of radio is based on the lecture he gave on May 7, 1895, “On the relation of metal powders to electric vibrations” at St. Petersburg University.

Alexander Popov developed the first radio capable of transmitting Morse code


Popov’s device was a simple coherer [“Branly tube”] - a glass flask, inside of which there are metal filings, and two electrodes, several centimeters apart, come out. The device was based on the work of the French physicist Eduard Branly , who described a similar scheme in 1890, and on the work of the English physicist Oliver Lodge , who improved the device in 1893. Initially, the resistance of the electrodes is large, but if an electric pulse is applied to them, a path will appear for the current to pass with a small resistance. The current will go, but then the metal filings will begin to clump and the resistance will increase. The coherer needs to be shaken or tapped on it every time to re-scatter the sawdust.

According to the Central Museum of Communications named after A.S. Popov in St. Petersburg, Popov’s device was the first radio receiver capable of recognizing signals by their duration. He used the Lodge coherer indicator and added a polarized telegraph relay that worked as a DC amplifier. The relay allowed Popov to connect the output of the receiver with an electric bell, recording device or telegraph, and receive electromechanical feedback. A photo of such a device with a call from the museum collection is given at the beginning of the article. Feedback automatically returned the coherer to its original state. When the bell rang, the coherer automatically shook.

March 24, 1896 Popov held another revolutionary public demonstration of the device - this time already transmitting information in Morse code via wireless telegraph. And again, being at St. Petersburg University, at a meeting of the Russian Physicochemical Society, Popov sent signals between two buildings 243 meters apart. The professor was standing at the blackboard in the second building, writing down the letters Morse code accepted. The result was the words: Heinrich Hertz .

Such as those of Popov, coherer-based circuits became the basis for first-generation radio equipment. They continued to be used until 1907, when they were replaced by receivers with crystal detectors.

Popov and Marconi had a completely different attitude to radio


Popov was a contemporary of Marconi, but they developed their equipment independently, not knowing about each other. It is difficult to determine primacy precisely due to inadequate documentation of events, controversial definitions of what to consider radio, and national pride.

One of the reasons why in some countries the championship is given to Marconi is that he was more aware of the intricacies of intellectual property. One of the best ways to preserve a place in history is to register patents and publish their discoveries in time. Popov did not do this. He did not file a patent application for his lightning detector, and there is no official record of his demonstration on March 24, 1896. In the end, he abandoned the development of the radio and took up the recently discovered x-rays.

Marconi filed a patent application in Britain on June 2, 1896, and it became the first application from the field of wireless telegraphy. He quickly collected the investments necessary to commercialize his system, created a large industrial enterprise, and therefore in many countries outside of Russia he is considered the inventor of radio.

Although Popov did not attempt to commercialize the radio for the purpose of transmitting messages, he saw its potential in using it to record atmospheric disturbances - as a lightning detector. In July 1895, he installed the first lightning detector at the Forest Institute meteorological observatory in St. Petersburg. He was able to detect thunderstorms reaching a distance of up to 50 km. The following year, he installed the second detector at the All-Russian Manufacturing Exhibition, which was held in Nizhny Novgorod, 400 km from Moscow.

A few years later, the Hoser Victor watch company in Budapest began manufacturing lightning detectors based on Popov’s developments.

Popov's device got to South Africa


One of his cars even reached South Africa, having traveled a distance of 13,000 km. Today it is on display at the Museum of the South African Institute of Electrical Engineers (SAIEE) in Johannesburg.

Museums are not always sure about the details of the history of their own exhibits. The origin of obsolete equipment is particularly difficult to track. Museum records are incomplete, staff often changes, and as a result, information about an object and its historical importance may disappear from the organization’s memory.

This could have happened with the Popov Detector in South Africa, if not for the sharp eye of Dirk Vermülen, an electrical engineer and longtime member of the history buff group at SAIEE. For many years, Vermeulen believed that this exhibit is an old ammeter with the ability to record readings, used to measure current strength. However, one day he decided to study the exhibit better. To his delight, he discovered that this was possibly the oldest exhibit in the SAIEE collection, and the only surviving instrument of the Johannesburg Meteorological Station.


Popov's lightning detector from the Johannesburg Meteorological Station, exhibited at the Museum of the South African Institute of Electrical Engineers.

In 1903, the colonial government ordered the Popov detector, among other equipment necessary for the newly opened station, located on a hill on the eastern border of the city. The circuitry of this detector is the same as Popov’s original design, except that the trembler, which shook the sawdust, also rejected the recording pen. The recording canvas was wrapped around an aluminum drum, making a revolution once an hour. With each rotation of the drum, a separate screw shifted the canvas by 2 mm, as a result of which the equipment could record events for several days in a row.

Vermülen described his findfor the December 2000 issue of Proceedings of the IEEE. Unfortunately, he left us last year, but his colleague Max Clark was able to send us a photograph of the South African detector. Vermülen actively campaigned for the creation of the museum's collection of artifacts stored in SAIEE, and achieved his goal in 2014. It seems fair in an article devoted to pioneers of radio communications, to note the merits of Vermülen, and to recall the radio wave detector he found.

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