The EL34 is a much loved audio power valve with an anode dissipation of 25 Watts. The EL34-B from Chinese manufacturer Shuguang is a modern interpretation of the original 1954 design.
The rectangular anode and above the top mica the control grid has substantial heat sinks.
The holes in the sides of the anode show the grids within - this is a true pentode with three wire grids.
The hole in the anode wall reveals the two inner grids. The control grid looks to be wound with copper wire or with copper plated wire. At the top left of the lower hole can be seen part of a suppressor grid turn.
The top mica with collard holding the grid supports. The cathode tube has slightly bowed sides.
The control grid heat-sinks. The support rod is pure copper.
The base cap and glass foot. On a B9D base this valve would have been made as an all glass device.
A view of the close wound screen grid.
The lower mica.
Thanks to Garry Hicks for lending this valve for photographing.
The wide glass tube envelope is 36 mm in diameter and excluding IO base pins the valve is 97 mm high.