[en] The trend towards longer pulses at higher power levels and frequencies shown in the recent years in the ICRH field has imposed new challenges to electron tube manufacturers. This paper presents answers to meet the requirements of machines such as JET and TORE SUPPRA. The design of the new tubes has been completely reworked. The new tubes have been tested both in the Thomson-CSF special test amplifier and in the JET amplifiers. The latest results obtained from these tests and during operation of the JET machine are detailed. The associated circuits are also essential for the good operation of the tubes. The power x frequency product encountered often leads to the use of coaxial cavities. The main parameters of these cavities are presented