I rejuvenated a tube for the first time today

[jpdylon]

THe rejuve function puts a couple thousand volts between grids and cathode. The arcing strips away the contaminants that build up over time

--however it also strips away the nickel plating on the cathode, so it should be a last resort only. On occasion, rejuvenation can destroy the cathode rendering the tube useless.

The reason why I bought my beltron tester is that its rejuvenation method does not use high voltage discharge but rather a combination of lower voltage at a higher current with a gradual increase in heater voltage during the process. This way the cathode risk doesn't get damaged, much greater results are achieved, and the tube lasts considerably longer than with standard rejuvenation methods.

If you can get a hold of a beltron, do so. They are great machines and are almost a must if you have lots of rare CRTs.