Hi, I was really surprised that you've never heard about Tesla. In the USSR times, each socialistic region had one manufacturer that did basically everything F.e. in Yugoslavia, there was Iskra, in Czechoslovakia, there was Tesla.
They made everything from TVs, radios, audio reproduction systems (stuff for whole TV and radio broadcast - like TV cameras, amps, transmitters), small components, discrete parts, logic & analog IOs, oscilloscopes (I have one that goes up to 120MHz right on my bench), precise measurement stuff, even their own computers (some things were often copied or build around some western part that was hard to make here). A lot of stuff they made was (and still is) legendary here, like f.e. tantalum caps (even after 30 years, still better than some new ones) and those cermet trimmers you've got.
TESLA as company didn't make it after the velvet revolution, IMHO mainly because it was company that could work like it did only under communism - it was kind of utopia based system
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In which they basically designed without feedback. They produced huge number of devices and components that didn't have ANY economical potential (far too expensive, low demand or better equivalent already present on the market), often used old technologies and therefore had high expenses (f.e. they had to measure each part if it meets the spec as >10% didn't). Some accurate things were hard to make, so they made it just stable (temp.,time) and measured it with very precision tools - You could've buy "precision" resistor that had 10.5317xxx ohms (but you wouldn't be able to find another one with that value), two perfectly matched transistors, or zener diodes marked as f.e. 5.8563V. Best thing I saw was one zener diode and one normal diode together in series matched so they have almost 0 temp. drift. (sold as one part). And yes, they did that with a bunch of people who measured and selected those devices whole day long, by hand - after all, in communism, everybody had (and have to had) a job and people had to work somewhere and do something...
Btw. that marking on the MHB8255 at 22:18 is two crossed swords. Those parts were designated for army as they were measured as better than spec. standard. And since TESLA (as every other communistic company) was owned by state, army took those parts right away from the process.
A lot of former TESLA property was sold to big companies that make electronics, big part was taken over by ON-Semi (they make sil. wafers and design devices for switching apps and automotive stuff), and Honey Well (they make electronics for industrial boilers and other stuff).