The Russians (prob INTEL) are back into DIGIMODE experiments on last days..
That waveform has been spotted on (at least) 5 frequencies in 2 days, 30 & 31 october 2015
short description of the waveform : 5x mFSK-16 (br:20Bd sh:20Hz) w/ short 250Bd BPSK breaks every 10 secs (carrier changes from 2250Hz to 1000Hz, randomely?) + 1750/1500 tone sequence as EOT
PS: the EOT tone sequence is the same heard on other Russian digimode experiments
That modem trials were already active in 2013 and I’ve made a video of it in the past: