The CV945 (commercially the 28D7) is a double beam tetrode designed to work as a class A audio amplifier. When both sections are used in push-pull the output is 175 mW. The anode and heater circuits are rated at 28 Volts. This is the voltage one would expect to find in a lorry or truck when the engine was running. The /W variant was made to resist shock and vibration in aircraft control applications.
The twin sections side by side.
One anode face view. At the top the grid supports are copper with heat radiating fins above.
The dome carries the original 28D7 Type designation within an octagon - typical of American manufacture.
The wide glass tube envelope is 28 mm in diameter, and excluding the B8B base pins is 66 mm tall.
References: Data-sheet & 3002. Type CV945 was first introduced in 1943. See also1943 adverts.
