Many large (>500 MW) hydrogen-cooled generators built during the 1960s and 1970s have experienced chronic problems - especially loosening of their stator endwinding support system. The resulting increase in vibration often causes damage to stator bar insulation. During an outage at its Boardman Power Plant last year, Portland General Electric replaced the rotating exciter of its Westinghouse generator with a slip ring shaft and brushes, rewound the rotor and repaired cracking at the tooth tops, retightened the stator core, and installed a new and improved endwinding support system. Who says you can't teach an old dog new tricks?