Thomas, thanks very much for your excellent responses. And I second the good wishes extended by the others.
Regarding:
I say that based on the ratings indicated in this datasheet for the original version of the Elrog tube, as well as on the ratings specified in this 1939 datasheet for the original Western Electric tube. Although this 1950 datasheet does indicate 400 volts as a "maximum rating, design center value" for the Western Electric tube.
Regards,
-- Al
Regarding:
450V/90mA would already be slightly over the limit and thus is not recommended.I would add that neither number is in itself over the limit. It is the combination of the two that would result in the tube's maximum power dissipation rating being slightly exceeded.
I say that based on the ratings indicated in this datasheet for the original version of the Elrog tube, as well as on the ratings specified in this 1939 datasheet for the original Western Electric tube. Although this 1950 datasheet does indicate 400 volts as a "maximum rating, design center value" for the Western Electric tube.
Regards,
-- Al