Popov may have been the first - but he did not patent his inventions and did not try to commercialize them.
In 1895, Russian physicist Alexander Popov used his thunderstorm instrument to demonstrate the transmission of radio waves.
Who invented the radio? Your answer will probably depend on where you are from.
On May 7, 1945, the Bolshoi Theater in Moscow was packed with scientists and statesmen from the Communist Party of the Soviet Union, celebrating the 50th anniversary of the first radio demonstration held by . It was an opportunity to pay homage to a domestic inventor and try to steer historical records away from achievements , who in many countries of the world is recognized as the inventor of the radio. May 7 was announced in the USSR , which is celebrated to this day in Russia.
The claim of Popov's priority as the inventor of the radio is based on a lecture he delivered on May 7, 1895 "On the relation of metal powders to electrical vibrations" at St. Petersburg University.
Alexander Popov developed the first radio capable of transmitting Morse code
Popov's device was simple ["Branly tube"] - a glass bulb, inside which are metal filings, and two electrodes come out, located a few centimeters from each other. The device was based on the work of a French physicist , who described a similar scheme in 1890, and in the works of the English physicist , who improved the device in 1893. Initially, the resistance of the electrodes is high, but if an electrical impulse is applied to them, a path for the passage of current with a small resistance will appear. 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 each time to re-scatter the sawdust.
Petersburg, Popov's device was the first radio receiver capable of recognizing signals by their duration. He used Lodge's coherer indicator and added a polarized working as a DC amplifier. The relay allowed Popov to connect the receiver's output to an electrical bell, recorder, or telegraph, and receive electromechanical feedback. A photo of such a device with a bell from the museum's 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.
On March 24, 1896, Popov held another revolutionary public demonstration of the device - this time already transmitting information in Morse code over a wireless telegraph. And again, while at St. Petersburg University, at a meeting of the Russian Physical and Chemical Society, Popov sent signals between two buildings located 243 meters from each other. The professor stood at the blackboard in the second building, writing down the letters accepted by Morse code. The result is the words: .
Coherer-based circuits such as Popov's became the basis for the first generation of radio equipment. They continued to be used until 1907, when they were replaced by crystal detector receivers.
Popov and Marconi treated the radio completely differently
Popov was a contemporary of Marconi, but they developed their equipment independently, not knowing about each other. Precisely determining primacy is difficult due to inadequate documentation of events, controversial definitions of what counts as radio, and national pride.
One of the reasons Marconi is given the upper hand in some countries is that he was more aware of the intricacies of intellectual property. One of the best ways to keep your place in history is to file patents and publish your discoveries on time. Popov did not. He did not apply for a patent for his lightning detector, and there is no official record of his demonstration on March 24, 1896. As a result, he abandoned the development of radio and turned to the recently discovered X-rays.
Marconi applied for a patent in Britain on June 2, 1896, and it became the first application from the field of radiotelegraphy. He quickly raised the investments necessary to commercialize his system, created a large industrial enterprise, and is therefore considered the inventor of radio in many countries outside of Russia.
Although Popov did not try to commercialize radio for the purpose of transmitting messages, he saw its potential in using it to record atmospheric disturbances - like a lightning detector. In July 1895, he installed the first lightning detector at the meteorological observatory of the Forestry Institute in St. Petersburg. He was able to detect thunderstorms coming at a distance of up to 50 km. The next year he installed the second detector at the All-Russian Manufactory Exhibition, 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 designs.
Popov's device ended up in South Africa
One of his cars even made it to South Africa, covering 13 km. Today it is exhibited in the museum. (SAIEEE) in Johannesburg.
Museums do not always know exactly the details of the history of their own exhibits. The origin of obsolete equipment is particularly difficult to trace. Museum records are incomplete, staff changes frequently, and as a result, information about an object and its historical importance may disappear from the memory of an organization.
This could have happened to Popov's detector in South Africa, if it weren't for the keen eye of Dirk Vermeulen, an electrical engineer and longtime member of the SAIEE history buff. For many years, Vermeulen believed that this exhibit was an old recordable ammeter used to measure current. However, one day he decided to study the exhibit better. To his delight, he discovered that it was possibly the oldest item in the SAIEE collection, and the only surviving instrument from the Johannesburg Meteorological Station.
Popov's lightning detector from the Johannesburg meteorological station, on display at the South African Institute of Electrical Engineers museum.
In 1903, the colonial government ordered a Popov detector, among other equipment needed for a newly opened station located on a hill on the eastern border of the city. The layout of this detector is identical to Popov's original design, except that the trembler that shook the sawdust also deflected the writing pen. The recording sheet was wrapped around an aluminum drum that rotated once an hour. With each revolution of the drum, a single screw shifted the web by 2 mm, as a result of which the equipment could record events for several days in a row.
Vermeulen for the December 2000 issue of Proceedings of the IEEE. He unfortunately left us last year, but his colleague Max Clark was able to send us a photo of the South African detector. Vermeulen actively campaigned for the creation of a museum of the collection of artifacts stored in SAIEE, and achieved his goal in 2014. It seems fair in an article dedicated to the pioneers of radio communication to note the merits of Vermeulen, and recall the radio wave detector he found.
Source: habr.com