Sensibly equivalent¶ to:
The EC55 is a physically small disc seal triode valve, with co-axial connections. This type of planar valve evolved during WWII as an improved replacement for the CV90.
The heater and cathode are connected via the lower co-axial connector the emitting surface is a flat topped thimble. The grid has a circular connection to the flat internal metal mesh. The anode is copper and has a flat surface facing the grid and positioned very close to it.
A grounded grid configuration would allow for a two cavity mechanical design.
This valve is rated at 600 MHz but its extended maximum frequency of 4 GHz made it a natural choice for microwave designs.
See also CV273 for a view of the grid wires as these two valves have almost identical grid construction.
The anode end, showing the very small gap between anode tip and grid mesh.
The planar envelope is 16 mm in diameter and, overall is 68 mm tall.
References: Data-sheet & 1040. Type EC55 was first introduced in 1947.
Absolute Maximum Operating Conditions¶
Updated August 12, 2021.