The DE2LF is a dull emitter triode dating from 1925. It was designed for LF amplification and had a lower anode impedance than the DE2HF released at the same time.. The valves from M-OV of this period used carbonized thoriated tungsten filaments. The carbonizing reduced the effects of any residual gasses in poisoning the thoriated filament.![](../pics/aaj0043a.jpg)
The second variant of the BBC logo is present on this valve illustrating the fact that this valve is an original 1920s valve, made between 1924 and 1927, and not a later replacement.The balloon envelope is 32 mm in diameter and, excluding the B4 base pins, is 73 mm tall.References: 4051 & 1003 Type DE2LF was first introduced in 1925. See also 1925 adverts. |
Pin Connections
| 1 | 2 | 3 | 4 | ![](../static/key.gif) a | g1 | f | f |
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Absolute Maximum Operating Conditions¶
| Vh | Ah | Va | Vg | mAa | ![](../static/pdflogo.gif)
| 2.0 | 0.12 | 45 | - | 0.5 |
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PDF scanned from an original document held by the museum |
Updated January 24, 2011.
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