Assertion: wave's wavelength | /r/HasProperty | allocated to amateur
Facets:
value: in 1923—forced amateurs
type: TEMPORAL
value: by the second national radio conference
type: OTHER
Source sentences:
text: Extreme interference at the upper edge of the 150-200 meter band—the official wavelengths allocated to amateurs by the Second National Radio Conference in 1923—forced amateurs to shift to shorter and shorter wavelengths; however, amateurs were limited by regulation to wavelengths longer than 150 meters (2 MHz).