Tube cross-reference
31A3 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 31A3 rectifier - half wave. Compare core specifications and verify every restriction before using a replacement.
Exact variations of 31A3
These designations belong to the same electrical variation group. Their names may differ because of international standards, manufacturing tolerances, or materials, but they are recorded as electrically equivalent—not merely substitutes.
UY41 Rectifier - Half Wave
- Base
- Not recorded
- Socket
- B8A
- Base pins
- Not recorded
- Sections
- 1
- Heater voltage
- 31 V
- Heater current
- 0.1 A
Replacement tubes for 31A3
The following tubes are recorded as possible replacements for 31A3. This direction does not establish that 31A3 can replace them.
Rectifier - Half Wave
The database records U404 as a possible replacement for31A3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Rectifier - Half Wave | Rectifier - Half Wave |
| Construction | Rectifier | Rectifier |
| Base | 8HB | Not recorded |
| Socket | Not recorded | Not recorded |
| Base pins | Not recorded | Not recorded |
| Sections | 1 | 1 |
| Heater voltage | 31 V | 40 V |
| Heater current | 0.1 A | 0.1 A |
Rectifier - Half Wave
The database records UY41 as a possible replacement for31A3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Rectifier - Half Wave | Rectifier - Half Wave |
| Construction | Rectifier | Rectifier |
| Base | 8HB | Not recorded |
| Socket | Not recorded | B8A |
| Base pins | Not recorded | Not recorded |
| Sections | 1 | 1 |
| Heater voltage | 31 V | 31 V |
| Heater current | 0.1 A | 0.1 A |
Rectifier - Half Wave
The database records UY42 as a possible replacement for31A3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Rectifier - Half Wave | Rectifier - Half Wave |
| Construction | Rectifier | Rectifier |
| Base | 8HB | Not recorded |
| Socket | Not recorded | B8A |
| Base pins | Not recorded | 8 |
| Sections | 1 | 1 |
| Heater voltage | 31 V | 31 V |
| Heater current | 0.1 A | 0.1 A |
Voltage - Triode (single)
The database records V312 as a possible replacement for31A3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Rectifier - Half Wave | Voltage - Triode (single) |
| Construction | Rectifier | Triode |
| Base | 8HB | Not recorded |
| Socket | Not recorded | Not recorded |
| Base pins | Not recorded | Not recorded |
| Sections | 1 | 1 |
| Heater voltage | 31 V | 4 V |
| Heater current | 0.1 A | 0.65 A |
Where 31A3 can be used as the replacement
In these recorded relationships, 31A3 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 31A3.
Rectifier - Half Wave
The database records 31A3 as a possible replacement forUY41.
No special restrictions are recorded for this substitution.
| Specification | 31A3 replacement | Original tube |
|---|---|---|
| Tube type | Rectifier - Half Wave | Rectifier - Half Wave |
| Construction | Rectifier | Rectifier |
| Base | 8HB | Not recorded |
| Socket | Not recorded | B8A |
| Base pins | Not recorded | Not recorded |
| Sections | 1 | 1 |
| Heater voltage | 31 V | 31 V |
| Heater current | 0.1 A | 0.1 A |
Rectifier - Half Wave
The database records 31A3 as a possible replacement forUY42.
No special restrictions are recorded for this substitution.
| Specification | 31A3 replacement | Original tube |
|---|---|---|
| Tube type | Rectifier - Half Wave | Rectifier - Half Wave |
| Construction | Rectifier | Rectifier |
| Base | 8HB | Not recorded |
| Socket | Not recorded | B8A |
| Base pins | Not recorded | 8 |
| Sections | 1 | 1 |
| Heater voltage | 31 V | 31 V |
| Heater current | 0.1 A | 0.1 A |
Voltage - Triode (single)
The database records 31A3 as a possible replacement forV312.
No special restrictions are recorded for this substitution.
| Specification | 31A3 replacement | Original tube |
|---|---|---|
| Tube type | Rectifier - Half Wave | Voltage - Triode (single) |
| Construction | Rectifier | Triode |
| Base | 8HB | Not recorded |
| Socket | Not recorded | Not recorded |
| Base pins | Not recorded | Not recorded |
| Sections | 1 | 1 |
| Heater voltage | 31 V | 4 V |
| Heater current | 0.1 A | 0.65 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 31A3 specifications →