Tube cross-reference
3LF4 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 3LF4 power - beam (not sweep). Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 3LF4
The following tubes are recorded as possible replacements for 3LF4. This direction does not establish that 3LF4 can replace them.
Power - Beam Single (NOT sweep) (under 10W)
The database records 3D6 as a possible replacement for3LF4.
- Parallel heater circuits only
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam Single (NOT sweep) (under 10W) |
| Construction | BeamPower | BeamPower |
| Base | 6BB | 6BA |
| Socket | B7G | B8G |
| Base pins | 7 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 2.8 V | 2.8 V |
| Heater current | 0.05 A | 0.11 A |
Power - Pentode (NOT beam)
The database records 3LE4 as a possible replacement for3LF4.
- Not suitable for all circuits
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Pentode (NOT beam) |
| Construction | BeamPower | Pentode |
| Base | 6BB | 6BA |
| Socket | B7G | SUBMINIATURE6 |
| Base pins | 7 | 6 |
| Sections | 1 | 1 |
| Heater voltage | 2.8 V | 1.4 V |
| Heater current | 0.05 A | 0.1 A |
Where 3LF4 can be used as the replacement
In these recorded relationships, 3LF4 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 3LF4.
Power - Beam Single (NOT sweep) (under 10W)
The database records 3LF4 as a possible replacement for3D6.
- Parallel heater circuits only
| Specification | 3LF4 replacement | Original tube |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam Single (NOT sweep) (under 10W) |
| Construction | BeamPower | BeamPower |
| Base | 6BB | 6BA |
| Socket | B7G | B8G |
| Base pins | 7 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 2.8 V | 2.8 V |
| Heater current | 0.05 A | 0.11 A |
Power - Pentode (NOT beam)
The database records 3LF4 as a possible replacement for3LE4.
- Not suitable for all circuits
| Specification | 3LF4 replacement | Original tube |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Pentode (NOT beam) |
| Construction | BeamPower | Pentode |
| Base | 6BB | 6BA |
| Socket | B7G | SUBMINIATURE6 |
| Base pins | 7 | 6 |
| Sections | 1 | 1 |
| Heater voltage | 2.8 V | 1.4 V |
| Heater current | 0.05 A | 0.1 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 3LF4 specifications →