This tube is very hard to find. It’s compact size and it’s connection socket, similar to the car brake light bulb makes it the stangest tube I’ve ever seen.

MS-13

There is very few information about it and it’s usage… it’s from the M-series of professional tubes so I could guess it was used in some kind of portable precision survey equipment.

MS-13 light bulb type base

It’s base looks very similar if not equal (I must try) as a car light bulb.

The tube and it’s datasheet

I don’t know russian so I just know how to recognize the most important parameters to make working the tube. I’ll appreciate more info’s about this tube, feel free to contact me at “l.i.papadopol at gmail.com”

-Working voltage 720-780V
-Plateau lenght 200V
-Plateau slope 0.15%
-Load resistance 8-15MOhm
-Working temperature -40° +50°
-Lenght 100mm diameter 21.5mm