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53 lines
2.9 KiB
Plaintext
53 lines
2.9 KiB
Plaintext
// Status=review
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_WSJT-X_ is a computer program designed to facilitate basic amateur
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radio communication using very weak signals. The first four letters in
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the program name stand for “Weak Signal communication by K1JT,” while
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the suffix “-X” indicates that _WSJT-X_ started as an extended (and
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experimental) branch of the program _WSJT_.
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_WSJT-X_ Version 1.6 offers four protocols or “modes”: JT4, JT9, JT65
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and WSPR. The first three are designed for making reliable
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QSOs under extreme weak-signal conditions. They use nearly identical
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message structure and source encoding. JT65 was designed for EME
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(“moonbounce”) on the VHF/UHF bands and has also proven very effective
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for worldwide QRP communication on the HF bands. JT9 is optimized for
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the LF, MF, and lower HF bands. It is about 2 dB more sensitive than
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JT65 while using less than 10% of the bandwidth. JT4 offers a wide
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variety of tone spacings and has proved very effective for EME on
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microwave bands up to 24 GHz. All three of these modes use one-minute
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timed sequences of alternating transmission and reception, so a
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minimal QSO takes four to six minutes — two or three transmissions by
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each station, one sending in odd UTC minutes and the other even. On
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the HF bands, world-wide QSOs are possible using power levels of a few
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watts and compromise antennas. On VHF bands and higher, QSOs are
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possible (by EME and other propagation types) at signal levels 10 to
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15 dB below those required for CW.
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WSPR (pronounced “whisper”) stands for Weak Signal Propagation
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Reporter. The WSPR protocol was designed for probing potential
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propagation paths using low-power transmissions. WSPR messages
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normally carry the transmitting station’s callsign, grid locator, and
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transmitter power in dBm, and they can be decoded at signal-to-noise
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ratios as low as -28 dB in a 2500 Hz bandwidth. WSPR users with
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internet access can automatically upload their reception reports to a
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central database called {wsprnet} that provides a mapping facility,
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archival storage, and many other features.
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_WSJT-X_ provides spectral displays for passbands up to 5 kHz,
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flexible rig control for nearly all modern radios used by amateurs,
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and a wide variety of special aids such as automatic Doppler control
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for EME QSOs. The program runs equally well on Windows, Macintosh,
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and Linux systems, and installation packages are available for all
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three platforms.
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_WSJT-X_ is an open-source project released under the {gnu_gpl}
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(GPL). If you have programming or documentation skills or would like
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to contribute to the project in other ways, please make your interests
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known to the development team. The project’s source-code repository
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can be found at {devsvn}, and most communication among the developers
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takes place on the email reflector {devmail}. User-level questions
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and answers, and general communication among users is found on the
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{wsjt_yahoo_group} email reflector.
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