The KGEI 50kW transmitter, like many early transmitters, cooled its final tubes in water jackets. It required a massive water pumping system. Part of the system included a large copper tank under the transmitter where from where the water was drawn, after passing through a radiator in another part of the building. Most modern transmitters now use the vapor cooling method which only requires a radiator to recover steam as water and return it to the transmitter. Photo courtesy of FEBC.