The 5894 is a European pattern double beam tetrode for use as transmitter power amplifiers, frequency multipliers etc. For General Electric it is styled the GL-5894.
Type 5894 can also be used as a Class B audio modulator for AM transmitters.
The heater is centre tapped so it can be used in mains based designs and/or directly with 12 Volt vehicle batteries as the heater supply.
Each anode is held by the glass at the top of the envelope. The shape places a flat surface towards the electron flow and angled sides for greater radiation efficiency.
The bright structure in the centre is the common beam plate. Within that the screen grid is double sided and the control grids are one per side.
A much closer view of the white cathode with the two wire grids. The control grid looks to be gold plated.
The wide glass tube envelope is 43 mm in diameter, and excluding the B7A base pins is 104 mm tall.
References: Data-sheet, 1040 & 1043. Type 5894 was first introduced in 1955. See also1955 adverts.
