Virtual Valve Museum

Virtual Valve Museum

HomeFull List

This is an archive website. It will not receive any updates, additions or corrections.

BT89 xenon thyratron (CV2109)

BT89 size The thyratron measures 120x37mm overall and has a 4-pin base.

The serial number L15696 is printed on the glass.

Filament voltage 2.5V
Filament current 5A
Max positive anode voltage 1000V
Max negative anode voltage 1500V
Max peak anode current 2A
Max mean anode current 0.5A
Max negative grid voltage 100V


Pin Function
1 n/c
2 Grid
3 Filament
4 Filament
TC Anode

The cathode connection for the anode and grid supply voltages should be made either to the centre tap of the secondary of the filament transformer or to pin 3; but not to pin 4.


BT89 inside view