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Osram B21
ST shape double triode
Osram B21
Near equivalent to the PM2B more PM2B data. The only data
I have for this valve comes from the AVO Valve Data Manual, 15th.
1962 edition. The filament voltage is 2.0V. At Va=150 Vg1= -3,
anode current is 5 mA and gm is 1.5 ma/V (mS). This valve was used
for QPP (quiescent push-pull) output. It has a B7 base.