My hickok 600a does not have this tube listed.does anybody know what settings I would use? thank you. 201a 301a etc.

Hi Greg

Does your tube tester have #26 listed? An 01A is about the same as a 26 but has a 5 volt filament. Set up the tester for 26 and increase filament voltage to 5. 201A, 301A tests the same as 01A. Tubes with prefix UX201A are globe shaped tubes with RCA name.

Norm

:My hickok 600a does not have this tube listed.does anybody know what settings I would use? thank you. 201a 301a etc.

:Yes it does. Thank you very much.:
: Does your tube tester have #26 listed? An 01A is about the same as a 26 but has a 5 volt filament. Set up the tester for 26 and increase filament voltage to 5. 201A, 301A tests the same as 01A. Tubes with prefix UX201A are globe shaped tubes with RCA name.
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:Norm
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::My hickok 600a does not have this tube listed.does anybody know what settings I would use? thank you. 201a 301a etc.

If you have an '01A tube that's weak, try rejuvenating it. If it's really bad, turn the filament switch up to 7.5 volts for a very brief moment (like 5 to 10 seconds). Then run the filament at 6.3 volts for 15 minutes or so (you can start with 5 or 10 minutes to see the effect). Test at regular filament voltage. 01A tubes use thoriated tungsten cathodes. You can't easily rejuvenate oxide coated cathodes this way. Matter-of-fact, running the filament voltage really high can semi-permanently poison the cathode by driving bad items to the surface (I forgot all of them, but there are a few, including silicon, which is used in some metal processes).

T.

Rejuvenation seems to work better in globe type O-1A's rather than ST's - I guess filament composition changed over the years. There were some factory-built rejuvenators that I've occasionally seen at swap meets (and I have a set of plans for a new construction) - but you can use your tube tester justb as well. Know that you will burn out a few filaments for every tube you save - so use this procedure for tubes you are willing to sacrifice to the 'dud' box. But even then, you can transistorize the dud for a few bucks (details available if interested)...