Tube cross-reference
1F1 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 1F1 specialized - ballast. Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 1F1
The following tubes are recorded as possible replacements for 1F1. This direction does not establish that 1F1 can replace them.
Voltage Pentode or Tetrode (under 100V)
The database records 1AJ4 as a possible replacement for1F1.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Specialized - Ballast | Voltage Pentode or Tetrode (under 100V) |
| Construction | Ballast | Pentode |
| Base | Not recorded | 6AR |
| Socket | UX4 | B7G |
| Base pins | Not recorded | 7 |
| Sections | 1 | 1 |
| Heater voltage | Not recorded | 1.4 V |
| Heater current | 0.72 A | 0.025 A |
Where 1F1 can be used as the replacement
In these recorded relationships, 1F1 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 1F1.
Voltage Pentode - Sharp Cutoff (single)
The database records 1F1 as a possible replacement for1AF4.
No special restrictions are recorded for this substitution.
| Specification | 1F1 replacement | Original tube |
|---|---|---|
| Tube type | Specialized - Ballast | Voltage Pentode - Sharp Cutoff (single) |
| Construction | Ballast | Pentode |
| Base | Not recorded | 6AR |
| Socket | UX4 | B7G |
| Base pins | Not recorded | 7 |
| Sections | 1 | 1 |
| Heater voltage | Not recorded | 1.4 V |
| Heater current | 0.72 A | 0.025 A |
Voltage Pentode or Tetrode (under 100V)
The database records 1F1 as a possible replacement for1AJ4.
No special restrictions are recorded for this substitution.
| Specification | 1F1 replacement | Original tube |
|---|---|---|
| Tube type | Specialized - Ballast | Voltage Pentode or Tetrode (under 100V) |
| Construction | Ballast | Pentode |
| Base | Not recorded | 6AR |
| Socket | UX4 | B7G |
| Base pins | Not recorded | 7 |
| Sections | 1 | 1 |
| Heater voltage | Not recorded | 1.4 V |
| Heater current | 0.72 A | 0.025 A |
Verify before substituting
Matching a base or heater voltage is not enough to prove that two tubes are interchangeable. Check pin connections, heater current, maximum ratings, bias requirements, warm-up behavior, and the equipment manufacturer’s service documentation before making a substitution.
View the complete 1F1 specifications →