Unidentified - 8783kHz data burst - US military?
This thing goes berserk after the 1 minute mark.
I've heard PSK, RTTY, SSTV, weather fax and the rest before, but I can't work out what this one is.
However... With some scrounging, it seems it may possibly be military traffic. It sounds very similar to this sample of US military scrambling:
http://det.bi.ehu.es/~jtpjatae/sound/...
Original site with more samples:
http://det.bi.ehu.es/~jtpjatae/sound....