http://www.arrl.org/?artid=7958

All I caught was the initial ping, not the pong. However, it was fun
to
at least hear HAARP in action. Note that the pulses should have a
constant amplitude. In reality, that wasn't the case.

http://www.lazygranch.com/temp/satur...30pm_noagc.ogg
http://www.lazygranch.com/temp/satur...30pm_noagc.ogg

(To play ogg, use winamp, irfanview, or VLC player)
http://www.videolan.org/
http://www.irfanview.com/
http://www.winamp.com/

To view and play the waveform, try Audacity
http://audacity.sourceforge.net/