Alexanderson alternator
E75687
continuous-wave transmitter
electromechanical oscillator
high-frequency alternator
radio transmitter
The Alexanderson alternator is an early high-frequency radio transmitter that generated continuous-wave signals using a rotating machine, playing a key role in long-distance wireless communication before vacuum-tube oscillators.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Alexanderson alternator canonical | 5 |
How this entity was disambiguated
This entity first appeared as the object of triple T603960 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Alexanderson alternator Context triple: [Ernst Alexanderson, developed, Alexanderson alternator]
-
A.
Fleming valve
The Fleming valve is an early thermionic vacuum tube diode invented by John Ambrose Fleming that enabled the rectification and detection of radio signals, laying groundwork for modern electronics.
-
B.
Edison
Edison is a large, diverse township in central New Jersey known for its suburban communities, major transportation links, and historical association with inventor Thomas Edison.
-
C.
George Westinghouse
George Westinghouse was an American inventor and industrialist best known for pioneering railway air brakes and promoting alternating current (AC) power systems.
-
D.
Volta Laboratory
Volta Laboratory was an experimental research facility established in the late 19th century that became a key center for innovation in sound recording, telephony, and related communication technologies.
-
E.
Charles Proteus Steinmetz
Charles Proteus Steinmetz was a pioneering German-American electrical engineer and mathematician whose work on alternating current (AC) systems and electrical theory greatly advanced modern power engineering.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Alexanderson alternator Target entity description: The Alexanderson alternator is an early high-frequency radio transmitter that generated continuous-wave signals using a rotating machine, playing a key role in long-distance wireless communication before vacuum-tube oscillators.
-
A.
Fleming valve
The Fleming valve is an early thermionic vacuum tube diode invented by John Ambrose Fleming that enabled the rectification and detection of radio signals, laying groundwork for modern electronics.
-
B.
Edison
Edison is a large, diverse township in central New Jersey known for its suburban communities, major transportation links, and historical association with inventor Thomas Edison.
-
C.
George Westinghouse
George Westinghouse was an American inventor and industrialist best known for pioneering railway air brakes and promoting alternating current (AC) power systems.
-
D.
Volta Laboratory
Volta Laboratory was an experimental research facility established in the late 19th century that became a key center for innovation in sound recording, telephony, and related communication technologies.
-
E.
Charles Proteus Steinmetz
Charles Proteus Steinmetz was a pioneering German-American electrical engineer and mathematician whose work on alternating current (AC) systems and electrical theory greatly advanced modern power engineering.
- F. None of above. chosen
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
continuous-wave transmitter
ⓘ
electromechanical oscillator ⓘ high-frequency alternator ⓘ radio transmitter ⓘ |
| application |
naval communications
ⓘ
point-to-point telegraphy ⓘ |
| developedBy | General Electric ⓘ |
| enabled | reliable transatlantic radio links ⓘ |
| era | early 20th century ⓘ |
| firstUseYear | circa 1906 ⓘ |
| frequencyRange | up to about 100 kHz ⓘ |
| heritageStatus | associated with UNESCO World Heritage Site Grimeton Radio Station ⓘ |
| historicalSignificance |
bridged transition from spark transmitters to vacuum-tube transmitters
ⓘ
first practical source of high-power continuous-wave radio signals ⓘ |
| inventor | Ernst Alexanderson ⓘ |
| keyComponent |
field windings
ⓘ
high-speed rotor ⓘ slip rings ⓘ stator with many poles ⓘ |
| limitation |
large size
ⓘ
limited maximum frequency compared to vacuum tubes ⓘ mechanical complexity ⓘ |
| modulationMethod | on-off keying for Morse code ⓘ |
| namedAfter | Ernst Alexanderson ⓘ |
| notableFrequency | 17.2 kHz ⓘ |
| operatingPrinciple | rotating electrical machine generates radio-frequency alternating current ⓘ |
| powerSource | mechanical rotation ⓘ |
| precededBy | spark-gap transmitter ⓘ |
| preservedAt | Grimeton Radio Station ⓘ |
| replaced | spark-gap transmitter ⓘ |
| requires |
high rotational speed
ⓘ
precise mechanical engineering ⓘ |
| signalGenerationMethod | mechanical alternation of magnetic fields ⓘ |
| status | obsolete for regular communication service ⓘ |
| supersededBy |
vacuum-tube oscillator
ⓘ
vacuum-tube transmitter ⓘ |
| transmissionType | continuous wave ⓘ |
| usedAt | VLF station SAQ Grimeton ⓘ |
| usedBy |
RCA
ⓘ
United States Navy ⓘ early commercial radio stations ⓘ |
| usedFor |
continuous-wave radio transmission
ⓘ
long-distance wireless communication ⓘ transoceanic radio communication ⓘ |
| usedIn |
low frequency radio
ⓘ
very low frequency radio ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Alexanderson alternator Description of subject: The Alexanderson alternator is an early high-frequency radio transmitter that generated continuous-wave signals using a rotating machine, playing a key role in long-distance wireless communication before vacuum-tube oscillators.
Referenced by (5)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
Ernst Alexanderson