CIS Navy FSK 50Bd/250 (T-600)

50Bd/250 FSK is another waveform used by CIS Navy for their fleet broadcast. Unlike the same waveform but with 136-bit framing (T-600 136), this one shows all the characteristics of the (perhaps more) well known 50Bd /200 broadcast, ie:

* 44 initial 42 bit initial sequence (usually  "100001010010111110000101001101011010101101")
* 70-bit Initialization Vector (ten 7-bit words, repeated twice)
* payload arranged in the 4:3 ratio
* 7-bit words "000100" as EOM

 

https://disk.yandex.com/d/zr9Mj7M7jII2xQ

CIS FSK 50Bd/250 136 bit (T-600-136)

Interesting signal from my friend KarapuZ: it's the quite uncommon 50Bd/250 136 Bit by some Cis networks, most likely CIS Navy. The waveform is similar to the well known T600 (50Bd 200/250Hz) but in this case the full period is 544 bits lenght, ie 4 x 136 bit frames.

Fig. 1

Fig. 2

https://yadi.sk/d/eESTZ-hN3HFu3R