CRT TUBE TESLA (czechoslovakia) A50-120W
These tubes were good functioning only if they're runned in time to time; if they stay unused too much time they tend to go duffy and slow emission.
TESLA (from "TEchnika SLAboproudá" - which means "Low voltage technology") was a large, state-owned electrotechnical conglomerate in the former Czechoslovakia.
The company was established as Elektra on 18 January 1921 and renamed TESLA on 7 March 1946. TESLA had a state-sponsored monopoly on electronics production in communist Czechoslovakia, and produced nearly all electronic products in the country until 1989. Many subsidiaries were created, including those at Liptovský Hrádok, Hradec Králové, Pardubice, Žďár nad Sázavou, Bratislava, and Nižná. Later, some of them were transformed into independent state-owned companies.
While the company's wide range of production was impressive, quantity usually did not meet the needs of industrial customers. Many products gradually became obsolete simply because they were not updated; e.g. one particular type of diode was manufactured for over 30 years without modifications.
Other products, e.g. some kinds of SCRs or Power-Transistors were competitive with the world market and so TESLA was the supplier for all eastern Europe Countries. Some high quality products were even exported to western countries for example turntables NC 470 or NC 500 under mark Lenco.
TESLA had to contend with both foreign and new domestic competition after the fall of communism in Czechoslovakia, and had difficulty competing effectively, which resulted in dramatic downsizing and privatization of the majority of its stores and production facilities. TESLA's logo is a rare sight in the present-day Czech Republic and Slovakia, as only a few of its subsidiaries have survived. One of its former subsidiaries, JJ Electronic is known for its manufacture of vacuum tubes and TESLA Litovel is known for its manufacture of high end turntables known as Pro-Ject.