11LO9I-CRO tube

[mihai.n]

I'm an electronical enthusiast and I have an URSS oscilloscope that it's broken.
the main problem it's in the high voltage power supply,
another problem it's my lack of knowledge about CRT and how they work.
I found the data sheet for this CRT valve but I can't understand what it's the pin no. 2 on and what this is doing.
first I try to repair the original power supply which is made with an iron powder transformer and self-oscilation circuit but this doesn't work properly and I couldn't make this supply to work properly.
now i try to make another type of power supply that it's based on push-pull topology and another core ( ETD34 ) at 30kHz. unfortunately I didn't had time to experimented with this new supply.
Now I want to understand what does every plate in this tube and I want to check all the supply voltages without the tube connected to be sure that everything it's fine.

I know that on:
pin 1 and 14 it's the heater lamp (also this it's checked and it seems to be ok )
pin 2 it's a mistery (this pin it's connected via an potentiometer between -12V and +100Vcc), maybe with this pot can I adjust some geometrical issues?
pin 3 it's the cathode
pin 4 it's the gride
pin 5 it's the 4th anode
pin 6,9,11 not used
pin 7,8 X (time base ) plates
pin 10 astigmatism
pin 12 focus
pin 13 2nd anode accelerating
D1,D2 Y plates

http://lampes-et-tubes.info/cr/11LO9I.pdf

11LO9I (11ЛО9И) Oscilloscope CRT

lampes-et-tubes.info

For more photos I leave below links:

 

[Sablon Audio]

You’re probably best off posting this on diyaudio or tubeasylum as it is very specific/ technical