250Bd/500 FSK embedded channels, likely Ukr nets

Three 250Bd/500 FSK "embedded" channels, 1000 Hz spaced, spotted on 6775.0 KHz (CF) and originating north of Rivne, Ukraine; probably trials or experimental transmissions.

Fig. 1

 It's to notice that the 105-bit streams share the same 43-bit preamble/sequence:

00111111111111011110001011000110011001101110
00111111111111011110001011000110011001101110
00111111111111011110001011000110011001101110

Fig. 2

My friend cryptomaster informed me that he too listened to a similar signal (3 x 250Bd/500 FSK), but spacing between channels was 500 Hz); his analysis can be read here:
http://www.radioscanner.ru/forum/topic36750-202.html#msg1463633

https://yadi.sk/d/gQhScJMvESFlIg