Sensibly equivalent¶ to:
The GL446A from GE is what the Americans call a lighthouse tube because of its appearance. The 2C40 was the successor.
The cathode with its flat top is placed in close proximity to the wire mesh grid, that connects to the middle ring. The anode protrudes down the top glass cylinder and almost touches the grid. This follows the pattern of most high frequency planar triodes. So called because the operating area is all in the one plane and the electrodes have a very small physical separation.
Most of the European devices had co-axial connections unlike the conventional base used by General Electric. The 1951 data book has this listed but later editions do not.
The GL446A used as a microwave mixer at a wavelength of about 10 cm. Image courtesy of E G Bowen from A Textbook of Radar chapter XII published 1954.
The metal skirt of the envelope is 25 mm in diameter and, excluding the IO base pins, is 49 mm tall.
Absolute Maximum Operating Conditions¶
Updated January 06, 2022.