|
DF91Sensibly equivalent¶ to:See also:
|
|
|
The DF91 is a is a miniature screened pentode for dry battery operation. It was designed for broadcast radio reception and is a variable μ RF device.This exhibit has a plan screen whereas DF91 has a perforated outer screen.See also 1T4.
The bright anode obscures the inner detail but at the top can be seen the filament tension spring and the single strand coated filament wire.The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 46 mm tall.References: Data-sheet & 1040. Type DF91 was first introduced in 1947. See also 1947 adverts. |
Pin Connections
| 1 | 2 | 3 | 4 | 5 | 6 | 7 |  f- | a | g2 | ic | f- | g1 | f+ |
|
|
Absolute Maximum Operating Conditions¶
| Vh | Ah | Va | Vs | Vg | mAa | mAs | ra | gm | 
| 1.4 | 0.05 | 90 | 67.5 | 0 | 3.5 | 1.5 | 0.5M | 0.9 |
|
Updated February 17, 2022.
|
|
