The 4CW25000a, a water cooled power tetrode, was primarily designed for RF linear power amplifier service and/or for television linear amplifier service. Additionally it wass rated for industrial heating operations and as a switch tube for pulsed applications.
The filament/cathode is of thoriated tungsten. The valve weighs 6.1 kg.
The type designation can be seen written on the label.
connections are made to special rings on the side and base of the valve.
Cooling is by high volume water flow. The water would be allowed to be raised in temperature by about 10 degrees Celsius, and would be de-ionised for high purity and low conductivity. The pipework would contain a plastic section for isolation, and a choke for RF isolation.
The wide metal tube envelope is 121 mm in diameter and, is 322 mm tall including the pipes. The body is 245 mm tall.