The CV82 UHF triode from the 1930s uses disc seal construction but does not then make use of a mesh grid to divide the filament from the anode. The so called lighthouse layered valves came later. The copper grid disc is 48 mm in diameter.
The CV82 specification was based on the S27A.
The finned anode at the top with grid winding below and through the grid can be seen the flat white area of the cathode.
The control grid has had one side of the wires shaved off. There are clamps top and bottom holding the grid supports firm - an early frame grid construction.
Looking up from the base.
The underside of the flat rectangular cathode is uncoated. Note the heater wires on the right.
The wide glass tube envelope is 29 mm in diameter and, excluding the base wires, is 70 mm tall.
