A system dedicated to dissipating heat produced by amplifier tubes of a spacecraft comprises a radiating panel installed substantially parallel to the amplifier tubes and thermally coupled to them to radiate to the outside a portion of the heat that they produce, a radiating receptacle whose walls define a housing adapted to receive the collectors of the amplifier tubes, and preferably a heat distributor that is preferably interleaved between the collectors and one wall of the receptacle to distribute the heat that the collectors produce between the collectors and the wall.