For the next clock I needed another kind of tube, a tube to separate hour and minutes.
I found the IV25 tube, a dot matrix tube with 7 dots. I ordered the tubes in ukraine. Some days later I got 6 of them. Nice.
If you order this tubes in ukraine too, don’t wonder, that you will get two types. One is labeled with IV25, the other one is labeled with IVLM 1-1/7. They are equal.
The Filament voltage is between 2.04 and 2.76 V. The Filament current is 30 .. 40 mA.
The segment (dot) voltage should be between 10 and 20V. The segment current is 10 mA.
Difficult is to describe the location of the Filament pins. This are pin 1 and 6.
This is pin 1. And now, count clockwise. I mark pin 6 with an connector.