This valve is a Marconi DE3 triode from 1924.The filament is rated at 2.8 Volts at 0.06 Amps, this suggests two dry cells in series as the filament supply, but in fact a 4.5 Volt 'bell' battery would be used with a series rheostat. The filament could thus be maintained at the 'correct' voltage. The valve can be used at LF or HF or as a detector according to the label.The DE3 was designed for use as a detector or AF amplifier.The construction is a vertical anode 18 mm long and 5 mm diameter, into which the grid and filament fit coaxially. The filament is a single strand, and the grid is a fine wire helix supported on a side rod through the whole length of the anode.The wide glass tube envelope is 25 mm in diameter and, excluding the B4 base pins, is 91 mm tall.References: 4051 & 1003 Type DE3 was first introduced in 1924. See also 1924 adverts. |
Pin Connections
| 1 | 2 | 3 | 4 |  a | g1 | f | f |
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Absolute Maximum Operating Conditions¶
| Vh | Ah | Va | Vg | mAa | ra | gm | μ | 
| 2.8 | 0.06 | 20-80 | -4.5 | - | 22,000 | 0.32 | 7.0 |
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PDF scanned from an original document held by the museum |
Updated August 10, 2015.
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