Assertion: radio's receiver | /r/ObjectUse | used until late 1920s
Facets:
value: very widely
type: DEGREE
value: by hobbyists
type: OTHER
Source sentences:
text: The regenerative receiver, invented by Edwin Armstrong in 1913 when he was a 23-year-old college student, was used very widely until the late 1920s particularly by hobbyists who could only afford a single-tube radio.