Assertion: radio wave's frequency | /r/CapableOf | drop below 10 mhz
Facets:
value: regularly
type: TEMPORAL
value: during the winter months
type: TEMPORAL
value: in darkness
type: LOCATION
Source sentences:
text: The maximum usable frequency regularly drops below 10 MHz in darkness during the winter months, while in summer during daylight it can easily surpass 30 MHz.