FU959F is a metal ceramic structure of the oxide cathode,forced air-cooled,high amplification factor of transistor.rated anode dissipation power is 1500W,the GRID power dissipation rating is 25W,the maximum operating frequency is 250MHz,mainly used in the cathode incentive AB2 and Class B amplifier, and cathode excitation anode modulated class C amplifier,with the U.S.Eimac production of the 3CX1500A7 type tube used interchangeably.