It should be simple enough...?
Hello SGiard.
I now this thread is old but maybe you're still tuned in?
I just signed up at this forum, to try and help you out on your problem. I too have become more and more interested in this particular area of HV electronics, and today I broke off the rear electron-gun-tube from an old colour TV. I was really astonished by the simplicity of this device, and yet, the huge potential it holds!
Regarding the workings of a monochrome electron-gun, there would have to be;
1. Primary operation [3 pins] 5-10kV
1st Anode supply (+) 2nd Anode supply (+) and a Cathode supply (-)
2. Filament voltage [2 pins] 5V @ 10-15A
Like in a light bulb. A wire is heated creating an electron cloud
3. Horizontal rectification [2 pins] ?
For aligning the beam horizontally
4. Vertical rectification [2 pins] ?
For aligning the beam vertically
As you do not have 9 pins on your gun, I would suspect the H/V rectification has been abandoned for some reason, and perhaps constructed around the big vacuum tube instead. The ANODE is situated at the middle (center in your picture w. the thick wire connected to it), and the rest of the silvercasing is the CATHODE + WENDEHLT PLATE.
I hope this could help you out a little.
Best regards,
Jesper, DK