Fejkblad, Pinkus,
Thank you for your help.
It was maybe not polite from me not to mention that I really searched the internet before posting.
Who would believe me anyway.
Of course, before posting here, I did it on romanian forums, and on elektroda.pl. I find there 2 threads dealing with repair/restoration of this oscilloscope Gizmon and Milik. There was some info but didn't help much, as mine has different symptoms and the guys there had schematics at hand. So, I opened a thread on elektroda.pl asking for docs. No answer yet. I also wrote an mail to Radiotechnika asking for docs. I also find their flyer mentioning the KR-7401. Well after waiting for more than a week, I decided to also ask here, seeing some of you guys are from Poland. I now have a thread on Robotrontechnik forum that mostly deals with ex DDR stuff, in search of data for the CRT the RFT's B13S13 which is a storage CRT.
During the cold war, no western country would buy from eastern ones, technology, only dumping consumer goods.
So, again, no chance that we could discover the KR-7401 under other name in the western world
Well, opening the machine, I determined by eye the pins of the CRT and I supplied the filament with 6.3V. Measured a small current between cathode and control grid I=40uA after running for about 3 minutes. Not much life in it I would say, but I still have the option of trying to regenerate the cathode for about other 500 hours of working which for my needs as radio amateur is really ok. I need a scope not so often and it is the provocation of repairing it instead of making a postal box of it
Thanks again, Gelu, YO5TC