The 4CX1500A is a high-performance ceramic/metal, forced air-cooled, power tetrode designed for use in Class AB1 or Class C RF amplifier service. It may also be used for audio frequency modulator, pulse modulator and DC power regulator service. The 4CX1500A filament is precision fabricated in a cylindrical mesh configuration for exceptional mechanical stability and long life. The 4CX1500A is designed to be a direct replacement for the 4CX1500A manufactured in the United States.