Mullard ET51 / CV5277 trochotron
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This valve measures 85x43mm overall and has a 26 pin B26A base |
| Heater voltage | 6.3V |
| Heater current | 300mA |
| Target supply voltage | 200V |
| Target resistor | 18k ohms |
| Output voltage across target resistor | 100V |
| Spade supply voltage | 100V |
| Spade resistor | 100k ohms |
| Grid bias voltage | +30V |
| Grid circuit resistance | <10k ohms |
| -ve grid input pulse amplitude | 75V |
| Voltage on all spades to clear tube | 0V |
| Spade 0 voltage to reset tube | 0V |
| Max input frequency | 1MHz |
| Pin | Function | Pin | Function |
| 1 | Spade 0 | 14 | Spade 2 |
| 2 | Target 9 | 15 | Target 1 |
| 3 | Target 8 | 16 | Even switching grids |
| 4 | Odd switching grids | 17 | Target 0 |
| 5 | Target 7 | 19 | Spade 9 |
| 6 | Spade 7 | 20 | Spade 8 |
| 7 | Target 6 | 21 | Heater |
| 8 | Target 5 | 22 | Spade 6 |
| 9 | Spade 5 | 23 | Spade 4 |
| 10 | Target 4 | 24 | Spade 3 |
| 11 | Do not connect | 25 | Heater |
| 12 | Target 3 | 26 | Spade 1 |
| 13 | Target 2 | 27 | Cathode |
Above: ET51; below: ET51 which also has CV5277 stamped on the body
