In 1954, a team at the Machine and Electrotechnics Institute in Sofia (today called the Technical University of Sofia) started experimental television broadcasting with two antennas (one for sound and one for image) on the roof of a building near the Vasil Levski monument in the city, after having previously conducted successful cable test transmissions. These experimental broadcasts aroused the interest of the Ministry of Communications, which decided to build a broadcasting tower in Sofia, with a state-controlled channel to air from it. The new channel started with an unofficial broadcast on 1 November 1959, and made its first official broadcast several days later with the live coverage of the 7 November , commemorating the Russian Revolution of 1917. The experimental channel of the MEI did not air anything but a test chart on that day, although it did show a greeting to the new Sofia Television Station three times after 19:05. The MEI channel continued to operate until late 1960, when the team started working on the future introduction of color television.