This De Forest CF185 was made for use in WWI. The image shows the valve with the base fitted into a socket adapter to candelabra. As the candelabra base is only for the filament the anode and grid connections are by flying leads with spade connectors fitted. The adapter is 30 mm overall.
The base cap could be either the four pin UV or the three pin 'Navy Base'.
Close up showing the glass former that the grid is wound on. The anode is double sided and the filament is a single inverted V.
Thanks to Joe Gruber for sending the images.
The wide glass envelope is 29 mm in diameter and, including the base pins, is 103 mm tall.
Reference: Joe Gruber. Type CF185 was first introduced in 1915. See also 1915 adverts.
Absolute Maximum Operating Conditions¶
Updated September 22, 2020.