Unidentified digital burst signal around 31.475 MHz (possible military/industrial data link)
 | |
|---|---|
| Frequencies | 31.475 MHz |
| Frequency Range | 31.475 MHz - 31.475 MHz |
| Mode | NFM |
| Modulation | Likely multi-carrier FSK or PSK (possibly STANAG or MIL-STD-188 variant) |
| ACF | — |
| Bandwidth | 6.25 kHz |
| Location | Czech Republic |
| Short Description |
Unidentified wideband digital signal captured around 31.475 MHz. The signal consists of short periodic bursts separated by silence, each showing a rectangular multi-tone structure on the waterfall. Likely some kind of professional or military data modem, not matching common AFSK, PSK or MFSK profiles. |
| I/Q Raw Recording | — |
| Audio Sample | |
This is AFSK1200 SCADA Arclamp (talk)
Captured around 31.475 MHzMegaHertz (MHz) 10^6 Hz in the 30–50 MHzMegaHertz (MHz) 10^6 Hz VHFVery High Frequency (30-300 MHz) low band using Airspy Mini and SDR#. Signal appears as short, repeating digital bursts with strong synchronization structure and a bandwidth of approximately 10 kHzKiloHertz (kHz) 10^3 Hz. Waterfall shows clear block-like framing typical of burst transmission. Not consistent with AFSK1200, MFSKMultiple Frequency Shift-Keying, PSKPhase-Shift Keying, or standard amateur/professional modes. Possible candidates include MIL-STD-188-110A/B, STANAGNATO Standardization Agreement (STANAG), defines processes, procedures, terms, and conditions for common military or technical procedures or equipment between the member countries of the North Atlantic Treaty Organization (NATO). 4285, or an industrial telemetry/data link. Further analysis is required to confirm protocol type. Audio and waterfall images attached.
