24 October 2020

two new 50Bd/850 FSK broadcast channels

It seems that the Turkish friends (or "stars and stripes" friends in Turkey) have activated two new 50Bd/850 FSK broadcast channels on 8788.0 and 8792.0 KHz (cf), or likely 8090.0 KHz in ISB mode. Spotted them on 22th October for the first time. 

Fig. 1

Fig. 2

As expected, since the 50Bd/850 waveform, both the channels are KW-46/KIV-7 secured. The "business card" consists of the pseudo-random sequence generated by the polynomial x^31+x^3+1, those bits replace the stop bits and are used by KW-46 cryptographic equipment to provide synchronization (figure 3).

Fig. 3

Tx site (or Tx sites ?) is in Turkey; unfortunately there are no KiwiSDR in the southern Mediterranean, they would have allowed a more accurate DF.

Fig. 4



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