Virtual Valve Museum

Virtual Valve Museum

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STC CV1994 / 3Q/121E air cooled triode

SIze This valve measures 340x85mm overall, not including the connection straps.

This valve is a CV28 supplied without the air cooling fins. Cooling fins 10AR/2436 need to be fitted before the valve is used.

Filament voltage (1) 16.5V
Filament current 22A
Max anode voltage 10kV
Max anode dissipation (2) 800W
Mutual conductance (3) 3.1mA/V
Anode impedance (3) 12.5k ohms
Amplification factor (3) 40
Max total emission:
Less than 30MHz 10kV/400mA
up to 30MHz 5kV/400mA
up to 60MHz 4kV/400mA
Cin nom 23.2pF
Cout nom 1.6pF
Ca, g1 nom 15.9pF

(1) Valves are marked with the filament voltage which may differ from valve to valve

(2) With forced air cooling this figure can be 1.1kW

(3) At Va=5kV, Ia=200mA

Connections: The longer strap leads are the filament.


Bottom quarter view Top quarter view

Glass part Grid