Tube cross-reference
1M3 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 1M3 tuning indicator. Compare core specifications and verify every restriction before using a replacement.
Exact variations of 1M3
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.
DM70 Tuning Indicator
- Base
- Subminiature
- Socket
- B9A
- Base pins
- 8
- Sections
- 1
- Heater voltage
- 1.4 V
- Heater current
- 0.025 A
Replacement tubes for 1M3
The following tubes are recorded as possible replacements for 1M3. This direction does not establish that 1M3 can replace them.
Tuning Indicator
The database records DM70 as a possible replacement for1M3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Tuning Indicator | Tuning Indicator |
| Construction | TuningIndicator | TuningIndicator |
| Base | SDN | Subminiature |
| Socket | Not recorded | B9A |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 1.4 V | 1.4 V |
| Heater current | 0.025 A | 0.025 A |
Tuning Indicator
The database records DM71 as a possible replacement for1M3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Tuning Indicator | Tuning Indicator |
| Construction | TuningIndicator | TuningIndicator |
| Base | SDN | Subminiature |
| Socket | Not recorded | Not recorded |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 1.4 V | 1.4 V |
| Heater current | 0.025 A | 0.025 A |
Tuning Indicator
The database records 1N3 as a possible replacement for1M3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Tuning Indicator | Tuning Indicator |
| Construction | TuningIndicator | TuningIndicator |
| Base | SDN | Not recorded |
| Socket | Not recorded | Not recorded |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 1.4 V | 1.4 V |
| Heater current | 0.025 A | 0.025 A |
Where 1M3 can be used as the replacement
In these recorded relationships, 1M3 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 1M3.
Tuning Indicator
The database records 1M3 as a possible replacement forDM70.
No special restrictions are recorded for this substitution.
| Specification | 1M3 replacement | Original tube |
|---|---|---|
| Tube type | Tuning Indicator | Tuning Indicator |
| Construction | TuningIndicator | TuningIndicator |
| Base | SDN | Subminiature |
| Socket | Not recorded | B9A |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 1.4 V | 1.4 V |
| Heater current | 0.025 A | 0.025 A |
Tuning Indicator
The database records 1M3 as a possible replacement for1N3.
No special restrictions are recorded for this substitution.
| Specification | 1M3 replacement | Original tube |
|---|---|---|
| Tube type | Tuning Indicator | Tuning Indicator |
| Construction | TuningIndicator | TuningIndicator |
| Base | SDN | Not recorded |
| Socket | Not recorded | Not recorded |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 1.4 V | 1.4 V |
| Heater current | 0.025 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 1M3 specifications →