Assertion: radio wave's frequency | /r/HasProperty | produced into the radio range
Facets:
value: by operating the arc
type: MANNER
Source sentences:
text: In 1902 Danish physicists Valdemar Poulsen and P. O. Pederson were able to increase the frequency produced into the radio range by operating the arc in a hydrogen atmosphere with a magnetic field, inventing the Poulsen arc radio transmitter, the first continuous wave radio transmitter, which was used through the 1920s.