[Amps] New Tubes - Question

[Harold Mandel]

{snip}
The getter of the tube is intended to work during the air evacuation
from the tube during the manufacture, not during any burn in.
{snip}

As long as the getter material is silver and not chalk white
as seen through the glass, stray oxygen molecules in the 
envelope will attach themselves like magnets during
burn-in.

When the getter material turns chalky white, the
tube is probably too gassy anyway.

Hal 
W4HBM