Tube cross-reference
1M1 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 1M1 tuning indicator. Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 1M1
The following tubes are recorded as possible replacements for 1M1. This direction does not establish that 1M1 can replace them.
1N3
American To ForeignTuning Indicator
The database records 1N3 as a possible replacement for1M1.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Tuning Indicator | Tuning Indicator |
| Construction | TuningIndicator | TuningIndicator |
| Base | Not recorded | Not recorded |
| Socket | Not recorded | Not recorded |
| Base pins | Not recorded | 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 1M1 specifications →