10-13-2010, 11:11 PM
I don't know if a 199 will fit, I seem to remember that they had a smaller base then either a 30 or a WD11. One tube that can be made to work is something like a 1A5 or 1Q5 wired up as a triode, with adapter, if you get an earlier version they even have a similar envelope to a WD11.
Best Regards
Arran
Best Regards
Arran