CV1673 / HL2 triode
 |
This valve measures 86x25mm overall and has a 4-pin base |
| Filament voltage | 2V |
| Filament current | 100mA |
| Max anode voltage | 150V |
| Amplification factor * | 27 |
| Anode impedance * | 18k ohms |
| Mutual conductance * | 1.5mA/V |
*: At Va=100, Vg=0.
| Pin | Function |
| 1 | Anode |
| 2 | Grid |
| 3 | Filament -ve |
| 4 | Filament +ve |
NB the CV specification indicates that pin 3 is also connected to internal metallising.
Two more examples, this time in larger metallised envelopes. The left hand one measures 100x42mm. The right hand one is marked both CV1673 and HL2 and measures 106x42mm.