Tube cross-reference
EF37 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the EF37 voltage pentode. Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for EF37
The following tubes are recorded as possible replacements for EF37. This direction does not establish that EF37 can replace them.
Voltage Radio Detector Converter
The database records 6J7GT as a possible replacement forEF37.
- Parallel heater circuits only
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode | Voltage Radio Detector Converter |
| Construction | Pentode | Pentode |
| Base | Not recorded | 7R |
| Socket | IO | IO |
| Base pins | 8 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.2 A | 0.3 A |
Where EF37 can be used as the replacement
In these recorded relationships, EF37 is the replacement tube. The listed original tubes are not automatically suitable as replacements for EF37.
Voltage Radio Detector Converter
The database records EF37 as a possible replacement for6J7.
- Parallel heater circuits only
| Specification | EF37 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode | Voltage Radio Detector Converter |
| Construction | Pentode | Pentode |
| Base | Not recorded | 7R |
| Socket | IO | UX7 |
| Base pins | 8 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.2 A | 0.3 A |
Voltage Radio Detector Converter
The database records EF37 as a possible replacement for6J7GT.
- Parallel heater circuits only
| Specification | EF37 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode | Voltage Radio Detector Converter |
| Construction | Pentode | Pentode |
| Base | Not recorded | 7R |
| Socket | IO | IO |
| Base pins | 8 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.2 A | 0.3 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 EF37 specifications →