GT1C / CV1128 / NGT2 / VGT128 / 10E/15 triode thyratron, and GT1CSS solid-state replacement
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This valve measures 114x45mm overall and has a 5-pin base. |
This thyratron found many uses as a timebase for radars, and in particular many were used in the Colossus computer which was used at Bletchley Park to crack the codes of the German Lorenz cipher machines. See http://www.codesandciphers.org.uk/lorenz/index.htm, http://www.codesandciphers.org.uk/lectures/ieee.txt and http://www.codesandciphers.org.uk/virtualbp/vcolossus/colossus.htm for further information.
| Heater voltage | 4V |
| Heater current | 1.4A |
| Max anode voltage | 500V |
| Max peak anode current | 1A |
| Max mean anode current | 300mA |
| Grid control ratio | 28 |
| Max anode-cathode voltage drop | 16V |
| Pin | Function |
| 1 | Anode |
| 2 | Grid |
| 3 | Heater |
| 4 | Heater |
| 5 | Cathode |
Left: GT1C; centre: NGT2; right: CV1128; bottom: NGT2 GT1C label, a similar label is carried on the VGT128
