The US Army VT-144 (commercial 813) is an RCA design high voltage, low current power beam tetrode with an anode dissipation of 125 Watts. This exhibit was made by National Union.
The valve base would be mounted on spacers so that a blower could be fitted under the chassis and a stream of forced air cooling would pass over the envelope.
The National Union name on the base cap. The ceramic insulators are present because of the high anode voltages.
The graphite anode, beam plates extending above and below the anode and locating pip on the side as this fits a bayonet base.
Locating pin and SC-545-A.
A closer view of the top insulator with filament tension springs above.
The top ceramic insulator with ribbon connections for the anode to the top cap. The thickness of the graphite anode can be seen here.
The National Union logo, Made in USE and the commercial Type designation of 813 on the envelope.
A closer view of the National Union Logo.
The classic envelope is 63 mm in diameter, and excluding the UX7 base pins is 170 mm tall.
