15 September 2018

"Winnie pooh" HF test transmissions

odd wideband signals spotted recently on 9110 KHz (center frequency) and likely related to Russian tests or exercises. Transmissions (Figure 1) consist of a 3xFSK 250bd/500 waveform which occurs as stand-alone transmission or as preceding a wideband PSK waveform, the latter also heard as stand-alone. The FSK signals are 1500 Hz spaced, carry encrypted streams and occupy a 4KHz bandwidth. PSK signals exhibit a clear component in the fourth power (Figure 2) that leads to think to a QAM waveform either 5000Bd/5KHz bandwidth and 10000Bd/10KHz bandwidth. Further analysis of the IQ samples, or just further recordings, are needed to shed some light on the modulation.

Fig. 1
Fig. 2
Besides the two (new?) waveforms, the most surprising thing was hearing a short track of the Russian version of "Winnie Pooh" cartoon transmitted in DSB mode in between FSK and PSK (Figure 3): strange but true, check by yourself
- Russian cartoon track https://t.co/il9bFkhOyQ  
(at first I had mistaken its waterfall pattern as a sort of vocoder, my friend KarapuZ immediately identified it as a Winnie Pooh cartoon track).

Fig. 3
A topic was opened by KarapuZ on radioscanner ("ansanto" is my nickname there):

No comments:

Post a Comment