JT4
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|---|---|
| Mode | USB |
| Modulation | MFSK |
| ACF | — |
| Emission Designator | — |
| Bandwidth | 17.5 Hz,35 Hz,70 Hz,158 Hz,315 Hz,630 Hz,1.26 kHz |
| Location | Worldwide |
| Short Description | JT4 is an 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. JT4 should be decodable with signal-to-noise ratio down to about -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..
JT4 has seven submodes, JT4A to JT4G, each with wider tone spacing. The wider submodes are designed for operation in the higher microwave bands at least up to 24 GHzGigaHertz (GHz) 10^9 Hz.
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.
