long wave 
noun
1A radio wave of a wavelength above one kilometre (and a frequency below 300 kHz): [as modifier]: long-wave radio...
- The station operates on a long-wave transmitter which is the only one in Ireland capable of serving the entire island, the association claims.
- Independently of Kondratiev, De Wolfe proposed a theory involving the idea of a long-wave cycle in 1924.
- The deflationary spiral under the long-wave Kondratiev cycle is far from over, in spite of appearances.
1.1 [mass noun] Broadcasting using radio waves of 1 to 10 km wavelength: listening to BBC Radio 4 on long wave...
- Those who like to listen to long wave on the radio will have to do without, as only AM and FM are provided.
- The radio seems to be a two-band affair only, so if you are a long-wave addict, you must seek an upgrade.