The article is about "AM radio", which I think is commonly understood to be medium wave (also known as "AM band") transmissions. https://www.fcc.gov/general/am

The article is about "AM radio", which I think is commonly understood to be medium wave (also known as "AM band") transmissions. https://www.fcc.gov/general/am-radio https://www.fcc.gov/general/am-radio