Unknown 20p973 data burst with intro tone
 | |
|---|---|
| Frequencies | 20.943 MHz |
| Frequency Range | 20.943 MHz - 20.943 MHz |
| Mode | USB |
| Modulation | Unknown |
| ACF | — |
| Bandwidth | 2.9 kHz |
| Location | Worldwide |
| Short Description | Unidentified data burst with intro tone. Resembles some previously seen data modes. |
| I/Q Raw Recording | Download file |
| Audio Sample | |
This data mode was encountered in Sep 30, 2024. It resembles another unidentified HF data mode but the preamble tone is at the center of the signal, not at the edge. Possible identification might be High Frequency Data and Voice Link (HFDVL.
Another, less likely candidate is Iranian Navy QPSK modem, but the bursts were not transmitted in a continuous manner. HFDL is also similar but a bit narrower, and the transmission frequency 20943 kHzKiloHertz (kHz) 10^3 Hz is not on any aviation band.
Bandwidth of the signal was about 2.9 kHzKiloHertz (kHz) 10^3 Hz. The showcase sample was recorded in USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) mode, tuned to 20943.2 kHzKiloHertz (kHz) 10^3 Hz.
Samples[edit]
Frequencies[edit]
20943 kHzKiloHertz (kHz) 10^3 Hz
Weaker and possibly slightly narrower transmission was spotted on 20973 kHzKiloHertz (kHz) 10^3 Hz.
