MFSK: CROWD-36 (SERDOLIK)

CROWD-36(SERDOLIK)

MFSK-34, Br-40, Sh-40, Ch-34

Author: SergUA6 

Band Width ~1400 Hz

Baud Rate 40 Hz

Count of Carriers 34 manipulation frequency

Step between carriers 40 Hz

RX mode SSB

An excellent example of CROWD36 (SERDOLIK) MFSK. Send by Ware.

Sonograms:

pic.1 General view at the different spectrum resolution.

pic.2 Manipulation speed

Diagrams:

pic.3 Allocation and quantity of the frequencies

pic.4 demodulation in SA

CROWD-36(SERDOLIK) MFSK From the different sources, it is used by various diplomatic services of the CIS countries, Russia is defined in general easily enough. Spacing is 40, speed 40, frequencies 34.Alghough it is necessary to manage to count the frequencies, because to do it on the spectrum it not so that easy. ;) The number "36" in the name of the signal is the mystery for me. I haven't ever seen 36 frequencies, so I may suppose that 36 frequencies are very seldom used or quantity of frequencies does not play a role in the name of the signal. 
Speed of manipulation in chat-mode makes 10 hertz.  Mazielka 2 tone and it is possible Mazielka 6 tones are Very closely connected with Crowd-36.

MFSK: WinMor

WinMor, mode 2*MFSK-4

Amateur's mode. Br - 46.875

Here is the record of the signal. Send by JenyaT.

Author: SergUA6

Band Width ~500 Hz

Baud Rate 46.875 Hz

Count of Carriers 4 in one group and 4 in second group

Step between carriers 46.875 in group, 93.75 between groups Hz

RX mode SSB

Sonograms:

pic.1 General view

pic.2 Detaltization. Two groups of MFSK-4

pic.3 Detalization of the groups. Space between the groups.

Diagrams:

pic. 4 Start

pic.5 Start detalization

Pictures:

pic.6 Graphic spectrum of the signal

WinMor, mode 2*MFSK-4 - it is the new amateure mode (atleast it is announced in 2010 year), which had been created by radio amateurs. The protocol has a lot of transmission formats. In the current example of the signal, two MFSK-4 channeles are used. The signal is bright enough, so there shouldn't be problems with it's identification.

MFSK: NEXEDGE

NEXEDGE

NXDN - 4800, 2400. C4FM, BW ~ 10000 Hz, 5000 Hz

1. an example of NXDN with manipulation speed 4800, sendby Rulez Reloaded

2. an example of NXDN with manipulation speed 2400, send by Rulez Reloaded

Author: SergUA6

Band Width ~10000 or 5000 Hz

Baud Rate 4800 or 2400 Hz

n-Ary (PSK/MPSK) C4FM

Count of Carriers 4

ACF ~ 80, ~ 40 ms

RX mode Source IF record

Sonograms:

pic.1 General veiw NXDN with speed 4800

pic.2 Generalview NXDN with speed 2400

Diagrams:

pic.3 Manipulation speed 4800

pic.4 Manipulation speed 2400

Pictures:

pic.5 Sub-optimum demodulation 4800

pic.6 Sub-optimum demodulation 2400

pic.7 ACF NXDN in 2400 mode, only 80 ms

NEXEDGE - is the communication system using NXDN protocol. NXDN is the joint development Kenwood and ICOM companies. The protocol is declared as opened one, modulation which is used on VHF, is the classical C4FM. The Same type of modulation is also used in the other

known communication system APCO-25 on the basis of standard P-25.

On it similarity comes to an end, P-25 and NXDN are incompatible.

As a whole, the signal is easily identified, especially in SA last versions: there are special possibilities, for confident enough identification C4FM. Two variants of the signal are prepresented on the records: broadband, under the standard channel by a strip/band 12.5 kHz, and narrow-band under the channel 6.25 Khz. The maximum technical speed accordingly in a broadband mode 9600 bps, in narrow-band 4800 bps. Thus clock frequency of manipulation for C4FM turns out twice less, 4800 Hz and 2400 Hz.

MFSK: Rosmodem

Rosmodem

Amateur mode, Br~15.5 or 1, Sh~15.5, Freqs~144 or more

Here is the sample of this signal, recieved from the real air. Send by Zmej.

Here is an example of work of the new ROS protocol.

(Author): SergUA6

Band Width ~2250-2300 Hz

Low Range ~400 Hz, shift is possible

Baud Rate ~15.5, and very slow mode 1 Hz

Count of Carriers not less than 144

Step between carriers ~15.5 Hz

Pilot tone(s) Start tone ~1481 Hz, with duration ~ 4200 ms,shift is possible

ACF ~18662 ms

RX mode SSB

Sonograms:

pic.1 General view

pic.2 Manipulation speed

Diagrams:

pic.3 Allocation of frequencies and their quantity

pic.4 the signal's ACF and view in VMW

ROSMODEM - the new radio amateur protocol created by Spanish developer Alberto Nieto Ros, the technology of the extension of a spectrum is put in a basis. In this signal if to trust the description, base MFSK-16 extends by the pseudo-casual law at least to MFSK-144. High enough characteristics of this protocol are declared. ACF most likely connected with the period of pseudo-casual sequences of randomization, but this is only supposition. The real transfer speed is essentially lower then speed of manipulation, that can indirectly speak not only about the spectrum extension, but also about usage of serious noise-resistant coding. The mode with speed of manipulation 1 Hz is supported, here are used formerstep between frequencies and principle of creation former.