The EL35 is a larger more powerful audio pentode than the small receiver type EL33 and was intended for use in class AB. The EL37 25 Watt pentode was the replacement for the EL35.
The EL35 was used for audio amplifiers and modulators for small Amplitude Modulated transmitters. As a single ended audio stage the valve would deliver 6 Watts and in push pull a pair would form an amplifier capable of generating 21 Watts in class AB. The design dates to the early 1940's.
Through the envelope coating the mesh anode can be seen.
The top mica: note the heat sink on the control grid and the reduced width of the cathode tube as it passes through the mica. The wire grids can be seen and at first glance this looks like a hexode but no power hexode was made - no need. The outer supports are for the mesh anode whilst the supports between the anode and suppressor grid are present to hold the side micas in place against the top of the envelope.
At this angle the grid windings can be seen more easily.
The classic envelope is 44 mm in diameter, and excluding the IO base pins is 109 mm tall.
References: Data-sheet, 1040 & 1043. Type EL35 was first introduced in 1945. See also1945 adverts.
