866A

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866A
866 mercury rectifier 1.jpeg
Westinghouse 866A mercury vapor half-wave rectifier tube.
Classification Diode
Cathode
Cathode type Directly heated
Heater voltage 2.5
Heater current 5 A
Anode
Max voltage 5000
Max current 250 mA
References
RCA Transmitting Tube Manual TT-3, 1940

The 866 is a mercury vapor half-wave rectifier intended for high-voltage applications. The voltage drop is approximately 15 volts up to 150 Hz. To avoid unwanted shorts the tube must be operated in a vertical position and the filament preheated for at least 30 seconds before applying the plate voltage.

Construction[edit]

Structurally, it consists of a linear electrode arrangement; a cup shaped anode with top cap and a cylindrical cathode. The socket is a medium 4 pin bayonet UX-4 and the glass envelope is ST-19. The 2.5 volt/ 5 Amp filament is connected to pins 1 and 4.

Operation[edit]

Under normal operating conditions the tube glows blue and mercury droplets are visible.

Pictures in working conditions[edit]

Westinghouse 866A mercury vapor half-wave rectifier tube. Glowing with 5mA 
Westinghouse 866A mercury vapor half-wave rectifier tube. Glowing with 5mA in the dark (long exposure) 
Westinghouse 866A mercury vapor half-wave rectifier tube. Glowing with 180mA in the dark. 

References[edit]

  • RCA Transmitting Tube Manual TT-3. Radio Corporation of America. 1940. pp. 64–65. 

External links[edit]