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CV820 / 3S4 power amplifier pentode

Size This valve measures 51x17mm overall and has a B7G base.

See also CV484 which also carries the 3S4 marking.

Filament voltage 1.4/2.8V
Filament current 100/50mA
Max anode voltage 100V
Max screen voltage 75V
Mutual conductance * 1.5mA/V
Anode impedance * 100k ohms
Anode current * 7.4mA
Screen current * 1.4mA
Max cathode current 13mA

*: At Va=90, Vg2=67.5, Vg1=-7.

Pin Function
1 Filament -ve **
2 Anode
3 Control grid
4 Screen grid
5 Filament -ve, Suppressor grid **
6 Anode
7 Filament +ve **

**: Pin1 is filament -ve for 2.8V operation; pin 5 is -ve for 1.4V where pins 1 and 7 are filament +ve.

CV820