This set of images is of an all glass valve with gold pins. It is smaller than an EL84 and does not have cooling fins attached to the control grid. But what is it?
Thanks to Jonathan Edwards for sending these pictures.
The number of grids visible suggest a pentode or beam tetrode.
The image of the base connections is not quite sharp enough to give good detail.
The envelope is ?? mm in diameter, and excluding the base pins is &??nbsp;mm tall.
Updated March 01, 2013.