The 3E29 is closely related to the 829B American pattern VHF double tetrode and has the same pin connections. However, the 3E29 is specifically designed for pulse modulator service rather than for use as a VHF PA.
The National Union logo and country of origin.
The Type designation. Note the ceramic insulation beads.
The working face of one section.
The two towers seen end on.
The wide glass tube envelope is 51 mm in diameter and, excluding the B7A base pins, is 92 mm tall.