Hams on CW multiple frequencies & pile-up 7005.0kHz AM.wav
Made using the online remote shortwave receiver of University of twente in Enschede Holland: <a href="http://websdr.ewi.utwente.nl:8901/" rel="nofollow">http://websdr.ewi.utwente.nl:8901/</a>
CW (Morse) transmissions across a wide band, filter in AM mode on the widest setting, multiple stations heterodyning with each other and a dead carrier somewhere, a couple bursts of high activity are when several stations are calling a dx station all at once across a range of frequencies, this is called a pile-up.