The Ion Cyclotron Heating system for ITER is foreseen to include automatic tuning systems utilising fast capacitive stubs the design of which is the subject of an additional repon prepared by ERMJKMS . The system proposed by ERM/KMS would be similar to that presently used on the TEXTOR machine with the additional requirement that it must operate under steady state conditions over a prolonged period of time. The TEXTOR capacitors are driven by a servo electric motor and ball screw combination.