Tube cross-reference
7B8 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 7B8 voltage radio detector converter. Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 7B8
The following tubes are recorded as possible replacements for 7B8. This direction does not establish that 7B8 can replace them.
Voltage Radio Detector Converter
The database records 7A8 as a possible replacement for7B8.
- Parallel heater circuits only
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Radio Detector Converter | Voltage Radio Detector Converter |
| Construction | Heptode | Octode |
| Base | 8X | 8U |
| Socket | B8G | B8G |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 7 V | 6.3 V |
| Heater current | 0.32 A | 0.32 A |
Voltage Radio Detector Converter
The database records 7B8LM as a possible replacement for7B8.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Radio Detector Converter | Voltage Radio Detector Converter |
| Construction | Heptode | Heptode |
| Base | 8X | Not recorded |
| Socket | B8G | B8G |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 7 V | 6.3 V |
| Heater current | 0.32 A | 0.3 A |
Where 7B8 can be used as the replacement
In these recorded relationships, 7B8 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 7B8.
Voltage Radio Detector Converter
The database records 7B8 as a possible replacement for7A8.
- Parallel heater circuits only
| Specification | 7B8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Radio Detector Converter | Voltage Radio Detector Converter |
| Construction | Heptode | Octode |
| Base | 8X | 8U |
| Socket | B8G | B8G |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 7 V | 6.3 V |
| Heater current | 0.32 A | 0.32 A |
Voltage Radio Detector Converter
The database records 7B8 as a possible replacement for7B8LM.
No special restrictions are recorded for this substitution.
| Specification | 7B8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Radio Detector Converter | Voltage Radio Detector Converter |
| Construction | Heptode | Heptode |
| Base | 8X | Not recorded |
| Socket | B8G | B8G |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 7 V | 6.3 V |
| Heater current | 0.32 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 7B8 specifications →