As a first step in the JET ICRF programme, two antenna generator units have been installed at JET and operated up to the d sign specification of 3MW coupled in the Torus for 1 second. After a brief description of the system, the experimental results of wave coupling to the plasma and matching the plasma loaded antenna are discussed. The first heating results are presented concentrating on the analysis of a case where the total power to the plasma increases by a ratio of 2.5. The main results are: a peak power deposition profile generating large internal temperature relaxation (giant sawteeth), a comparison of results using antennae with different wavelength radiation patterns and the low level of impurity effects.