[Amps] testing 572-B tubes

[Roy Koeppe]

Asked,

"... So I am wondering if the TUBES might be a little soft... (etc.)"

I've used 572-Bs many years. Other than a few uncommon displays of
gassyness (glowing between elements) and gas sometimes adhering to the
inside surface of glass envelope and glowing there (harmless) and one
case of a new Cetron lighting up an extremely bright filament, most
simply began losing power output gradually until they could no longer be
driven to useful levels.

73,    Roy    K6XK