The De Forest DL series first appeared in 1926. The L references the change to the UX4 base.The DL-4 was designed as an RF amplifier as is denoted on the packing can.
The transit can for the DL-4.Thanks to Joe Gruber for sending the images.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 | 0.25 | 90 | -4.5 | 5.3 | 7,800 | 1.15 | 9.0 |
|
Updated September 22, 2020.
|
|
