Gentlemen:

How do I test 201A tubes on a "modern" tube tester?

I have antique testers, but at this time I don't want to be restoring a tube tester to test tubes for a radio I am restoring!! Is filament continuity good enough in this case?

Thanks
Lou

:Gentlemen:
:
:How do I test 201A tubes on a "modern" tube tester?
:
:I have antique testers, but at this time I don't want to be restoring a tube tester to test tubes for a radio I am restoring!! Is filament continuity good enough in this case?
:
:Thanks
:Lou
:

Continuity testing is simple enough, and the old tubes' filaments were prone to being burnt open by overvoltage from a misadjusted rheostat, but it won't tell you if the electron emission is adequate. Think that I'd be inclined to bust out one of the antique testers and see what it has to say about one of these tubes.

A 201A is same as 01A. Use that setting if your tester has a 4 pin socket. If you don't have a 4 pin socket need to make an adapter.

Usually 201A's are acceptable if there is filament continuity. Low emission can usually be brought back in these tubes.

Norm

::Gentlemen:
::
::How do I test 201A tubes on a "modern" tube tester?
::
::I have antique testers, but at this time I don't want to be restoring a tube tester to test tubes for a radio I am restoring!! Is filament continuity good enough in this case?
::
::Thanks
::Lou
::
:
:Continuity testing is simple enough, and the old tubes' filaments were prone to being burnt open by overvoltage from a misadjusted rheostat, but it won't tell you if the electron emission is adequate. Think that I'd be inclined to bust out one of the antique testers and see what it has to say about one of these tubes.
:

"Low emission can usually be brought back in these tubes."

This is easily done by running the filaments a few volts above rated, for a few hours. The thoriated cathode will boil off radioactive thorium atoms to the surface of the cathode when it is heated above normal temperature. This increases emission. Recheck emission every few hours, or so, to monitor progress.

A tube tester can be used for this. Best to disconnect any connections to the plate or grid if using a tube tester for rejuvenation. A hay-wired, 4-pin tube base can be used for this.