The VR136 is the pre-CV UK service designation for the commercial EF54. The valve is a VHF high-slope pentode and has a sharp cut-off. The cathode is brought out to several pins to provide a low inductance path, part way to a ring connection as found in co-axial valves. The VR136 has aligned grids to reduce partition noise and was developed from the EF50 during WWII. The VR136 was capable of operation up to 200 MHz.
The all glass construction is covered with an aluminium screening can in the same fashion as the EF50 et al.
The B9G base was one of the first used for all glass construction.
The plain reverse of the screening can. Damp storage has allowed some corrosion to take hold.
The all glass valve has the metal base cover added and then the aluminium screening can is placed over and the edge rolled over to seal.
The wide glass tube envelope is 33 mm in diameter and, excluding the B9G base pins, is 60 mm tall.
