The Legnaro ECR ion source is installed on high voltage platform, capable of operating up to 350 kV and to be powered by an externally located insulation transformer. The test of the prototype of the high voltage cable termination is described, together with design of the full size cable termination. Tests of other high voltage parts are described. In the extraction beamline from the platform a triplet was added after the acceleration column, so that injection in the following U-bend is simplified. Using empirical fitting formula for prediction of einzel lens cardinal data and perturbative expansion for triplets, understanding of beam lines was considerably improved and optimization for arbitrary ions were possible. A comparison of the performance of the several plasma chambers that were used in this ECR ion source is given, discussing also the effect of a low voltage sputter probe. A comprehensive software program, centralizing remote control of most platform and source regulation, was successfully tested. ©1999 American Institute of Physics.