JT4
From Signal Identification Wiki
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|---|---|
| Mode | USB |
| Modulation | MFSK |
| ACF | — |
| Emission Designator | — |
| Bandwidth | 17.5 Hz,30.6 Hz,56.9 Hz,123 Hz,241 Hz,477 Hz,949 Hz |
| Location | Worldwide |
| Short Description | JT4 is a 4-FSK extreme weak-signal mode which is designed especially for Earth-Moon-Earth communications. It is part of the WSJT-X software. |
| I/Q Raw Recording | — |
| Audio Sample | |
JT4 is an extreme weak signal communication mode which is designed especially for Earth-Moon-Earth (EME) communications, also called moonbounce. It uses 4-FSKFrequency-Shift Keying modulation and 1-minute transmit/receive time slots. One transmission lasts about 47 seconds and the remaining 13 seconds is reserved for timing inaccuracies and decoding.
| Submode | Tone spacing | Bandwidth | Minimum SNR for decoding |
|---|---|---|---|
| JT4A | 4.38 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | 17.5 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | -23 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. |
| JT4B | 8.75 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | 30.6 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | -22 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. |
| JT4C | 17.5 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | 56.9 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | -21 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. |
| JT4D | 39.4 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | 123 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | -20 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. |
| JT4E | 78.8 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | 241 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | -19 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. |
| JT4F | 158 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | 477 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | -18 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. |
| JT4G | 315 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | 949 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). | -17 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. |
Samples[edit]
Showcase sample is JT4A. These samples were recorded directly from the WSJT-X software. If you encounter an actual JT4 transmission, please add a sample here!| JT4A | JT4B | JT4C |
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| JT4D | JT4E | JT4F |
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| JT4G |
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Frequencies[edit]
JT4 is designed for EME communications so it is most likely found on common EME frequencies. However, it can be used for weak signal HFHigh Frequency (3-30 MHz) communications and other purposes as well.
