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Tubes Asylum Questions about tubes and gear that glows. FAQ |
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In Reply to: Weak XF1s, with lots of flashing posted by Bob S on March 14, 2002 at 13:02:30:
You might try letting the tubes sit with only the filament on for 50 hours or so - sometimes the oxide-coated emitter surface has to reform after a period of storage. Option # 2 (desperation only) - raise the filament maybe 20 % for awhile and retest - repeat until the emission (cathode current or Gm) increases. This will NOT work "for long" and used "treasure" and is not meant to get junk "good enough to sell", but if the tubes are essentially new, then the results can be long-lasting.
As to getter flashing, if the tube vacuum is hard and stays hard (proper off-gassing of the metal parts pre-manufacture, etc), the getter can stay shiny even if the cathode is ready for the graveyard.
Likewise, a strong tube with a marginal vacumm, or that offgases in operatio, will consume the getter even thought the cathode still has plenty of life remaining.TUBOS
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Follow Ups
- Re: Weak XF1s, with lots of flashing - TUBOS 03/14/0217:57:07 03/14/02 (0)