Ok, I took it apart today. Not that there is much to take apart, I only removed it from the enclosure. Initially I thought that it has to be done from the front (there are 4 screws). But aparently not, two screws in the back keeps enclosure on, you can pull it out when unscrewed.
I can not comment actual electronic design of the scope.
Here you can take a look at the schematic in case you want to dig in / comment. Specs are also available there (in Russian).
I played with it shortly. Did not figure it out completely. It works, everything is logical. The thing is I was not able to view signal with harmonics above 10kHz even thou specs claim 250kHz being the bandwidth. I was able to see sinusoidal signal up to 300+ kHz, but with significantly reduced amplitude. Need to play more.
Interestinlgy, I think the way you worked with it as instrument was first you calibrated it against internal test/control signal and then applied signal under the test in order to see it and evaluate. I would not call it measurement, too crude
Scope is definitely not calibrated in the sense we understand it now.
It has been opened once before me, to change power cord. I did not see any other signs of intrusion. Fuse is dated 1968, device itself 1965. It is possible it was not used for first few years. It has been on at least 4 inventory lists according to different stickers. Last use was in Riga Technical University, I got it from the guy who works there who got it when those were going for utilisation. I did not ask for the year, but he's young guy.
I did add few more pics to the
gallery.
Now about my motivation to search for exactly this scope. My own connection to this model is from mid 70ties. My parents worked in one of the insitutes of university nowadays known as University of Latvia. I myself graduated from there in 1996, but that's another story. When I was a kid ~5-6 years old my parents got rid of me by sitting me in front of this scope, turning it on, (I guess) giving me test signal and letting me catch it, loose it, catch it again and play with it
Which I did for significant amounts of time. Repeatedly. I had no clue what I was doing, just turning knobs, but it totally fascinated me. This is the reason why now I was able to remember the model, it is "burned into my retinas"
I browsed through Soviet scopes and this is unmistakeably the one.
Some sources (e.g.
this) claim this is the first soviet scope design from 1948. The one I got says the year of production is 1965, serial #7716. But this is renamed model, so this is not one of the first 10k scopes in USSR. Still, I know people who learned scopes in 80ties and even 90ties in school using this scope. Quite long life, I'd say