The 710A radar power co-axial triode with external anode was designed by Western Electric for 600 MHz (50 cm) operation in pulse mode. This exhibit carries both the Western Electric name and lower down it says made in USA by National Union.
The 710A is directly heated and the filament runs at 7 Amps at 8.25 Volts. The anode dissipation is 100 Watts with forced air cooling. The peak anode voltage during pulse operation is 9 kV.
The VT90 was the original 'micropup' from M-OV that made airborne Radar a practical proposition and this exhibit carries both Type designations.
The VT90 was developed from the DET12 first as a co-axial version of the original valve with a Type designation of E1029 and later as the E1046 it produced pulses with a 5 kW peak power.
The filament is on the right with the control grid on the left. The flat cylinder on the anode is the clamping point and anode connection.
The grid cylinder connected to the support. The grid may be a wire cage but it is not possible to see.
The filament end. The wires look to be unused. The Number is 693. The serial number has been hand written and reads 7866.
The thin glass tube envelope is 17 mm in diameter and, including the base, is 127 mm long.