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These documentation source files are not the one true version, just a copy for testing purposes. DO NOT EDIT THESE FILES. To use this on Windows you will need a working asciidoc installation and the path to it must be included in your CMAKE_PREFIX_PATH (probably via a local CMake tool chain file). At the time of writing the official asciidoc package does not work on Windows. The latest development master does however work, it can be downloaded as a snapshot ZIP archive from here: https://github.com/asciidoc/asciidoc/archive/master.zip git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@5316 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
60 lines
2.7 KiB
Plaintext
60 lines
2.7 KiB
Plaintext
// Status=review
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Utility programs *+jt9code+* and *+jt65code+* let you explore the
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conversion of user-level messages into channel symbols or ``tone
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numbers,'' and back again. These programs can be useful to someone
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designing a beacon generator for JT9 or JT65, for understanding the
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permissible structure of transmitted messages, and for studying
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behavior of the error-control codes.
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Channel-symbol values for JT9 run from 0 to 8, with 0 representing the
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sync tone. The total number of symbols in a transmitted message is
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85. To run +jt9code+, enter the program name followed by a JT9
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message enclosed in quotes. In Windows the command and program output
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might look like this:
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C:\WSJTX> jt9code "G0XYZ K1ABC FN42"
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Message: G0XYZ K1ABC FN42
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Channel symbols:
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0 0 7 3 0 3 2 5 4 0 1 7 7 7 8 0 4 8 8 2 2 1 0 1 1 3 5 4 5 6
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8 7 0 6 0 1 8 3 3 7 8 1 1 2 4 5 8 1 5 2 0 0 8 6 0 5 8 5 1 0
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5 8 7 7 2 0 4 6 6 6 7 6 0 1 8 8 5 7 2 5 1 5 0 4 0
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Decoded message: G0XYZ K1ABC FN42
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For the corresponding program *+jt65code+* only the
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information-carrying channel symbols are shown, and the symbol values
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range from 0 to 63. Sync synbols lie two tone intervals below data
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tone 0, and the sequential locations of sync symbols are described in
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the <<JT65PRO,JT65 Protocol>> section of this Guide.
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A typical execution of +jt65code+ is shown below. The program
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displays the packed message of 72 bits, shown here as 12 six-bit
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symbol values, followed by the channel symbols:
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C:\WSJTX> jt65code "G0XYZ K1ABC FN42"
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Message: G0XYZ K1ABC FN42
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Packed message, 6-bit symbols: 61 36 45 30 3 55 3 2 14 5 33 40
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Information-carrying channel symbols:
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56 40 8 40 51 47 50 34 44 53 22 53 28 31 13 60 46 2 14 58 43
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41 58 35 8 35 3 24 1 21 41 43 0 25 54 9 41 54 7 25 21 9
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62 59 7 43 31 21 57 13 59 41 17 49 19 54 21 39 33 42 18 2 60
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Decoded message: G0XYZ K1ABC FN42
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For an illustration of the power of the strong error-control coding in
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JT9 and JT65, try looking at the channel symbols after changing a
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single character in the message. For example, change the grid locator
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from +FN42+ to +FN43+ in the JT65 message:
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C:\Users\joe\wsjt\wsjtx_install>jt65code "G0XYZ K1ABC FN43"
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Message: G0XYZ K1ABC FN43
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Packed message, 6-bit symbols: 61 36 45 30 3 55 3 2 14 5 33 41
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Information-carrying channel symbols:
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25 35 47 8 13 9 61 40 44 9 51 6 8 40 38 34 8 2 21 23 30
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51 32 56 39 35 3 50 48 30 8 5 40 18 54 9 24 30 26 61 23 11
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3 59 7 7 39 1 25 24 4 50 17 49 52 19 34 7 4 34 61 2 61
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Decoded message: G0XYZ K1ABC FN43
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You will discover that every possible JT65 message differs from every
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other possible JT65 message in at least 52 of the 63
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information-carrying channel symbols.
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