CIS W-MFSK-17

CIS W-MFSK-17

Frequencies	5.071 MHz,6.778 MHz,8.158 MHz,13.373 MHz,13.361 MHz
Frequency Range	5.071 MHz - 13.373 MHz
Mode	USB
Modulation	MFSK
ACF	—
Emission Designator	—
Bandwidth	37.5 kHz
Location	Russia
Short Description	Presumably Russian MFSK signal with wide bandwidth and 17 tones
I/Q Raw Recording	Download file
Audio Sample

CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 or CISCommonwealth of Independent States (CIS), the former Soviet Republic Wide-MFSKMultiple Frequency Shift-Keying-17, was first spotted on November 20, 2018. Second observation was made on September 30, 2024. Third observation was made on February 04, 2026.

The signal has 17 tones with 2.3 kHzKiloHertz (kHz) 10^3 Hz spacing in between them and width about 37.5 kHzKiloHertz (kHz) 10^3 Hz. The source of the signal supposedly located in Moscow (or at least nearby) based on good reception on RTL-SDR V4 located in Moscow and absence of the signal on WebSDR University of Twente (http://websdr.ewi.utwente.nl:8901/) on the same frequencies during transmission (except for 13.373 MHzMegaHertz (MHz) 10^6 Hz, which was faint), the purpose of the signal is unknown. CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 looks similar to Russian MFSKMultiple Frequency Shift-Keying signals such as XPB or XPA, but has a much higher bandwidth. Like other Russian MFSKMultiple Frequency Shift-Keying signals, CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 was observed to transmit on several frequencies, one after another. Unlike XPA that also has 17 tones, CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 seems to not have any preamble.

Frequencies

November 20, 2018, 11:46 (UTC): CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 was observed on 13.386 MHzMegaHertz (MHz) 10^6 Hz (USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)) with center frequency around 13.397 kHzKiloHertz (kHz) 10^3 Hz.

September 30, 2024: CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 was observed around 13.361 MHzMegaHertz (MHz) 10^6 Hz (USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)) with center frequency at 13.380 MHzMegaHertz (MHz) 10^6 Hz.

Frequencies (USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)), start and end times of CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 transmissions observed on February 04, 2026.:

Frequency	Start time (UTC)	End time (UTC)
5.071 MHzMegaHertz (MHz) 10^6 Hz	9:24 (unconfirmed)	???
6.778 MHzMegaHertz (MHz) 10^6 Hz	9:28 (unconfirmed)	9:32
8.158 MHzMegaHertz (MHz) 10^6 Hz	9:32	9:37
13.373 MHzMegaHertz (MHz) 10^6 Hz	9:44 (unconfirmed)	9:46

The "(unconfirmed)" sign next to start time means that the signal was found at this time when it was already trasnmitting for unknown amount of time.

Samples

The showcase audio sample is USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) with 20 kHzKiloHertz (kHz) 10^3 Hz bandwidth, covering the lowest 9 tones. The showcase IQQuadrature signals form the basis of complex RF signal modulation and demodulation, both in hardware and in software, as well as in complex signal analysis. sample is 192 kHzKiloHertz (kHz) 10^3 Hz wide, about 10 seconds long and contains this signal as well as others.

USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) sample with narrow (3 kHzKiloHertz (kHz) 10^3 Hz) bandwidth, covers only two tones:

NFMNarrowband Frequency Modulation sample, covers the entire signal:


Raw IQQuadrature signals form the basis of complex RF signal modulation and demodulation, both in hardware and in software, as well as in complex signal analysis. sample, complete transmission with some interfering signals, 48 kHzKiloHertz (kHz) 10^3 Hz wide:
File:Unknown MFSK-17 or FHSS raw 2.zip

Possible Variant

A possible variant of CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 had been seen in 2026. Unlike previously observed transmissions, the variant transmission is short, possibly 10 seconds long. The transmission begins with 13 tone MFSKMultiple Frequency Shift-Keying with bandwith about 33 kHzKiloHertz (kHz) 10^3 Hz, then swithes to 17 tone MFSKMultiple Frequency Shift-Keying with bandwith about 30 kHzKiloHertz (kHz) 10^3 Hz. In both parts the tone spacing is irregular, there is larger spacing in between 7th and 8th tones in the first part and 9th and 10th tones in the second. The larger spacing may indicate that not all of the available tones are used. One of the tones in the first part of the transmission was observed to be keying (turning on and off) very fast with equal timing while other tones were keying with irregular timing as can be seen in many of other MFSKMultiple Frequency Shift-Keying signals. The regular-keying tone is not always the same.

This variant may be related to CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 due to similar very wide bandwith and 17 tones in the second part, but it may also be a different signal.

Possible variant of W-MFSKMultiple Frequency Shift-Keying-17 next to an AMAmplitude Modulation broadcast Possible W-MFSKMultiple Frequency Shift-Keying-17 variant, another sample

Video Examples

https://drive.google.com/file/d/1lR_tdfV76vfF1gp_ahEl7y-GThakEsoO/view?usp=sharing - CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 on 6.778 MHzMegaHertz (MHz) 10^6 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables), February 4
https://drive.google.com/file/d/1lAKUnGHSev0RIIyMUMegBxRBRVZmE8Yx/view?usp=sharing - CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 on 8.158 MHzMegaHertz (MHz) 10^6 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables), February 4
https://drive.google.com/file/d/1E_m_cRop2GKZSV6sreKl2MUVFBAYrN0g/view?usp=sharing - CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 on 13.373 MHzMegaHertz (MHz) 10^6 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables), February 4

Additional Links

First observation of the CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 (second signal in the post):
http://i56578-swl.blogspot.com/2018/11/two-interesting-mfsk-catches.html

Additional Images

CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 observed on November 20, 2018 (Picture was taken from i56578-swl) CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 observed on September 30, 2024. CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 observed on September 30, 2024. Close-up of the signal showing the 17 tones. CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 observed on Febraurary 4, 2026. 5.071 MHzMegaHertz (MHz) 10^6 Hz. CISCommonwealth of Independent States (CIS), the former Soviet Republic W-MFSKMultiple Frequency Shift-Keying-17 observed on Febraurary 4, 2026. 6.778 MHzMegaHertz (MHz) 10^6 Hz.