Assertion: crystal receiver | /r/ObjectUse | used for transoceanic communication
Facets:
value: during that period
type: TEMPORAL
Source sentences:
text: Even so, they are usually only able to receive stations within distances of about 25 miles for AM broadcast stations, although the radiotelegraphy signals used during the wireless telegraphy era could be received at hundreds of miles, and crystal receivers were even used for transoceanic communication during that period.