Russian military 20bd 7kHz FSK
 | |
|---|---|
| Frequencies | 7.041 MHz,7.0625 MHz,7.0425 MHz,7.061 MHz,6.941 MHz,6.9425 MHz,6.961 MHz,6.9625 MHz |
| Frequency Range | 6.941 MHz - 7.0625 MHz |
| Mode | USB |
| Modulation | FSK |
| ACF | — |
| Emission Designator | — |
| Bandwidth | 7 kHz |
| Location | Russia |
| Short Description | Slow 20-baud FSK signal with very large 7 kHz frequency shift. Used by Russian military. |
| I/Q Raw Recording | — |
| Audio Sample | |
This is a slow 20-baudBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. FSKFrequency-Shift Keying mode used by Russian military, with unusual 7 kHzKiloHertz (kHz) 10^3 Hz frequency shift. Due to such a large frequency shift, it may be confused as being two CW transmissions on nearby frequencies. Tranmissions have been heard on the 40-meter amateur radio band, usually but not always, on two frequencies simultaneously.
At least one source of the signal has been traced to Crimea, close to Sevastopol, where the Russian Black Sea Fleet base is located.
Samples[edit]
| Another sample with some faint ham radio talk between the two frequencies |
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Frequencies[edit]
Transmissions usually happen on two frequencies simultaneously, and two such frequency pairs have been identified. "Pair 1" seems to be more commonly used.
| USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) tuning freq | Lower tone | Upper tone | Center freq |
|---|---|---|---|
| 7041 | 7041.5 | 7048.5 | 7045 |
| 7062.5 | 7063 | 7070 | 7066.5 |
| USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) tuning freq | Lower tone | Upper tone | Center freq |
|---|---|---|---|
| 7042.5 | 7043 | 7050 | 7046.5 |
| 7061 | 7061.5 | 7068.5 | 7065 |
As of May 2026, new frequency pairs have been observed. The frequencies may have been changed to reduce interference from amateur radio transmissions.
| USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) tuning freq | Lower tone | Upper tone | Center freq |
|---|---|---|---|
| 6941 | 6941.5 | 6948.5 | 6945 |
| 6962.5 | 6963 | 6970 | 6966.5 |
| USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) tuning freq | Lower tone | Upper tone | Center freq |
|---|---|---|---|
| 6942.5 | 6943 | 6950 | 6946.5 |
| 6961 | 6961.5 | 6968.5 | 6965 |
Other frequencies may also be used but this has not been confirmed.
Decoding Software[edit]
Video Examples[edit]
- Signal Phantom: Russian Navy Intruder Wide FSK Signals Re-Appear on 40m Band
- Signal Phantom: Russian Navy Wide FSK Intruder Reappears On 40m Band | Signal Phantom
Additional Links[edit]
- "Some weird CW found on 40m" on SOTA Reflector
- "RTTY with 7kHz shift on 7.045 and 7.066?" on r/signalidentification
Additional Images[edit]
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