The GU-43B tetrode is used for wideband power amplification at frequencies up to 100 MHz in RF equipment. The GU-43B has similar characteristics to the 4CX1000 tube.
Cathode: indirectly heated, oxide-coated.
Cooling: forced air.
Height: at most 125 mm.
Diameter: at most 100 mm.
Mass: at most 1.5 kg.