STC CV28 / 3J/121E air cooled triode
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This valve measures 340x90mm overall (50mm across the copper anode), not including the connection straps. |
The data for this valve says that a CV28 with no cooling fins is a CV1994. However, this valve is labelled as faulty and it is likely that the fins were never fitted due to this.
| Filament voltage (1) | 15.6V |
| 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 |
| Capacitances | |
| 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.
