Sensibly equivalent¶ to:
The CV380 is the commercial EF54 produced to a UK government procurement specification that applied a small modification to the design.
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. A feature of the CV380 is aligned grids that provide conditions to reduce partition noise.
The all glass construction is covered with an aluminium screening can in the same fashion as the EF50 et al with a metal base cover that houses the evacuation tube within the locating spigot.
The top of the envelope. The GPO was the General Post Office of the UK. A government body and both regulator and controller of both the postal service and the telephone system.
The wide glass tube envelope is 33 mm in diameter and, excluding the B9G base pins, is 59 mm tall.
References: Data-sheet & 1043. Type CV380 was first introduced in 1947.
Absolute Maximum Operating Conditions¶
Updated December03, 2014. shape:wide.glass.tube construction:all.glass type:pentode age:1940.1950 base:b9g heater:6.3v pins:9 pin:1.h pin:2.a pin:3.g2 pin:4.k pin:5.k pin:6.g1 pin:7.k pin:8.k pin:9.h