[en] The NSCL K1200 cyclotron operates with partially overlapping turns at the extraction septum and beam loss of about 50 % at extraction. We have improved the deflector's power dissipation and mechanical accuracy in pursuit of higher intensity for deflector-limited beams. The radial and vertical dimensions of the deflector are unusually compact to fit within the superconducting magnet. Improvements include adding water cooling to all segments (deflector is hinged), indirect cathode cooling via beryllium oxide support insulators, septum support and alignment and use of a leading edge notch to increase the radiating area. Experiments with a pyrolytic graphite septum show better power dissipation performance than with a tungsten septum, but with the maximum voltage somewhat reduced. (authors)