"Bill Renfro" wrote in message
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| I have seen tube brightners for this. They install between the flyback
| winding and the tube heaters.

Or install a separate 60 Hz transformer with taps.

| If you had one you could use a CRT rejuvinator on the tube.
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From $5 up on eBay, but you need to be able to judge how to configure it to
this tube.

NM