Hitachi TM3030 Plus Instruction Manual page 244

Spacer is used to adjust the image brightness.
Cartridge
filament
Figure 5.1-16 Replacing the Cartridge Filament Spacer
Fasten the Wehnelt onto the cartridge filament clockwise. Incorporate it into the electron gun
after verifying there is not play. Align the guard ring pin with the holder groove of the cartridge
filament, and insert it vertically.
Holder groove
Figure 5.1-17 Wehnelt and Cartridge
Filament
Figure 5.1-19 Inserting the Cartridge Filament
If broken:
Guard ring
Figure 5.1-18 Cartridge Filament
5 - 7
Reuse (Wehnelt)
Discard
(Cartridge filament, spacer)
Pin
Insertion Part