9 July 2018

CIS-12 & CIS Selcall FSK 150Bd/200 ("Vishnya")


Interesting and quite rare CIS-12 & CIS Selcall FSK 150Bd/200 - aka "Vishnya" - picked up by my friend AngazU using northern Europe KiwiSDRs in the 5 MHz band. Also thanks to friends cryptomaster and KarapuZ for pointing  out the name of the FSK signal and some interesting links: actually I met only single CIS "Vishnya" selcalls some months ago (November 2017) but I forgot it
http://i56578-swl.blogspot.com/2017/11/cis-selcall-vishnya-fsk-150bd200.html
CIS selcall is mentioned here in radioscanner:
http://signals.radioscanner.ru/base/signal106/
http://signals.radioscanner.ru/base/signal251/

It's notice that:
a) before the moment of transfer of CIS-12 signal, the equipment correctly stops transmission and also correctly restarts it after transferring the selcall;
b) since CIS-12 has a pilot tone at 3300Hz, the FSK insertions are centered on the suppressed carrier (zero offset from the nominal frequency);
c) after demodulation, CIS selcall exhibits a 45-bit period.

Fig. 1
Fig. 2
Fig. 3
UTE listeners frequently refer to a waveform using the name of the source equipment: in this case the nickname "Vishnya" comes from R-016V "Вишня" equipment, or R-016V "Vishnya" using the latin alphabet, which stands for the English "Cherry"  (Fig. 4).

Fig. 4 - R-016V "Вишня"