Alexander Stepanovich Popov (1859-1906) is the Great Russian physicist and electrical engineer, inventor of electric communication without wires. The well-known device of Popov has resulted from educational demonstration of experiences of Hertz where the device for reception of electromagnetic fluctuations of Hertz served as the transmitter. Then the scientist improved mechanism of reception-transfer of electromagnetic waves on distance, applied in the receiver as an element sensitive to waves known as coherer. Having found out that the receiver reacts to lightning discharges on considerable distances, Popov created storm indicator which was also the first-ever reception radio station. During further tests on Baltiyskoe and Black seas has been revealed possibility to accept signals not only on telegraph, but also on hearing. So telephone receiver with a tube came to life. A.S. Popov's merits were awarded by Russian technical society in 1898 with money bonus, and also with honorable diploma and gold medal on 4th World electrotechnical congress in Paris in 1900.
Souvenir sheet represents A.S. Popov's portrait, telephone receiver, for which inventor was awarded with a gold medal in Paris, and also its scheme. Illustrative material is given by the St.-Petersburg state electrotechnical university "LETI" and the Russian scientific and technical society of radio engineering, electronics and communication n.a. A.S. Popov.
| № |
Face value |
Size |
Description |
Price, mint |
Price, used |
Edition |
| 1305 |
20.00 |
33×33 |
A.S. Popov's portrait
multicolor |
20.00 |
11.80 |
120000 |