21 November 2018

two interesting MFSK catches

1) MFSK-66 (33+33) 40Bd/40 (presumed)
Transmission heard on 9122.0 KHz/usb on 20 November, 0832z. It looks like they use 2-tones x symbol and a manipulation speed of 40 Bd (Fig. 1). Dividing the spectrum into two equal parts gives a grid of 33 tones, 40Hz spaced, with the expected symbol rate of 40Bd (Fig. 2): this is why I defined the signal as MFSK 33+33 40Bd/40Hz, but I could be wrong. Likely Russian users.

Fig. 1
Fig. 2
Fig. 3

2) 19KHz wide MFSK-17 33.3Bd/1200Hz
Transmission heard on 13386.0 KHz/usb (centered on ~ 13397 KHz) on 20 November, 1156z. Never meet a such wide band MFSK waveform.

Fig. 4
Fig. 5


1 comment:

  1. I noticed these transmissions last week. First time for me. 73 and good luck. PY1VHF.