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STC 5B/255M (CV391) beam tetrode

Size This valve measures 90x30mm overall and has a loctal base


Heater voltage 6.3V
Heater current 0.9A
Max anode voltage 600V
Max screen voltage 300V
Max anode current 120mA
Max anode dissipation 25W
Max screen dissipation 4.5W
Mutual conductance 6mA/V
Inner amplification factor (Va=300V; Vg2=250V;
Max frequency for above ratings 60MHz
Cag 0.13pF
Cge 12pF
Cae 8.5pF


Pin Function
1 Heater
2 Anode
3 Screen grid
4 Internal shield
5 Control grid
6 Control grid
7 Cathode and beam plates
8 Heater



CV391 stamp