01-30-2013, 11:22 PM
The 33 is wrong, it's an 2 volt output tube for a battery radio, very likely it was supposed to have a 47 or a 2A5. Somebody probably grabbed a random tube with the same base just to fill an empty socket, or wasn't aware that a 2 volt battery tube was very different from a 2.5 volt AC tube.
Regards
Arran
Regards
Arran