The De Forest DL series first appeared in 1926. The L references the change to the UX4 base.The DL-7 was designed as an audio output valve. This Type was made with the standard tubular envelope and also with a larger diameter bulb.Thanks to Joe Gruber for sending the image.The envelope is 32 mm in diameter and, excluding the UX4 base pins, is mm tall.Reference: Bill Condon & Joe Gruber. |
Absolute Maximum Operating Conditions¶
| Vh | Ah | Va | Vg | mAa | ra | gm | μ | 
| 5.0 | 0.5 | 135 | -9.0 | 6.0 | 6,500 | 1.1 | 7.0 |
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Updated September 22, 2020.
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