FST4W
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| Frequencies | 136 kHz,474.2 kHz,1.839 MHz |
| Frequency Range | 136 kHz - 1.839 MHz |
| Mode | USB |
| Modulation | GFSK |
| ACF | — |
| Emission Designator | — |
| Bandwidth | 0.36 Hz,0.72 Hz,2.2 Hz,5.9 Hz |
| Location | Worldwide |
| Short Description | FST4W is an amateur radio digital protocol designed particularly for the LF and MF bands, for quasi-beacon transmissions of WSPR-style messages. FST4W uses 4-GFSK modulation and offers T/R sequence lengths of 120, 300, 900, and 1800 seconds. |
| I/Q Raw Recording | — |
| Audio Sample | |
FST4W is an amateur radio digital protocol designed particularly for the LF and MF bands, for quasi-beacon transmissions of WSPR-style messages. FST4W uses 4-GFSKGaussian Frequency-Shift Keying modulation and offers transmit/receive sequence lengths of 120, 300, 900, and 1800 seconds. FST4W is derived from FST4 which is used for two-way contacts (QSOs).
FST4W do not require the strict, independent time synchronization and phase locking of modes like EbNaut. FST4W-120 SNR threshold is about 1.8 dBThe decibel (dB) is a logarithmic unit used to express the ratio of two values of a physical quantity, here the strength of a received signal. lower than WSPR.
| T/R period (s) | Symbol length (s) | Tone spacing (HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).) | Bandwidth (HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).) | Minimum SNR for decoding (dBThe decibel (dB) is a logarithmic unit used to express the ratio of two values of a physical quantity, here the strength of a received signal.) |
|---|---|---|---|---|
| 120 | 0.68 | 1.46 | 5.9 | -32.8 |
| 300 | 1.79 | 0.56 | 2.2 | -36.8 |
| 900 | 5.56 | 0.18 | 0.72 | -41.7 |
| 1800 | 11.2 | 0.089 | 0.36 | -44.8 |
Frequencies[edit]
- 136 kHzKiloHertz (kHz) 10^3 Hz
- 474.2 kHzKiloHertz (kHz) 10^3 Hz
- 1.8366 MHzMegaHertz (MHz) 10^6 Hz
Samples[edit]
The showcase sample is FST4W-120. These samples were recorded directly from WSJT-X. If you have samples of actual FST4W transmissions, please add them here!
| FST4W-120 | FST4W-300 |
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