1JT65CODE(1)                      WSJT-X Manual                     JT65CODE(1)
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NAME

6       jt65code, jt9code, jt4code - Weak signal communications encoding
7       support utility.
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SYNOPSIS

10       jt65code "MESSAGE"
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12       jt65code [OPTIONS]
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14       jt9code "MESSAGE"
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16       jt9code [OPTIONS]
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18       jt4code "MESSAGE"
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20       jt4code [OPTIONS]
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OPTIONS

23       -t
24           Prints a selection of messages alongside their corresponding
25           decoded form and types.
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DESCRIPTION

28       jt65code, jt9code and jt4code are utility programs that let you explore
29       the conversion of user-level messages into channel symbols or “tone
30       numbers.” These programs can be useful to someone designing a beacon
31       generator for JT9 or JT65, or for studying behavior of the
32       error-control codes for each of the protocols.
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34       Channel-symbol values for JT9 run from 0 to 8, with 0 representing the
35       sync tone. The total number of symbols in a transmitted message is 85.
36       To run jt9code, enter the program name followed by a JT9 message
37       enclosed in quotes. In Windows the command and program output might
38       look like this:
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40           $ jt9code "G0XYZ K1ABC FN42"
41           Message:   G0XYZ K1ABC FN42
42           Channel symbols:
43            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
44            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
45            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
46           Decoded message: G0XYZ K1ABC FN42
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48       For the corresponding program jt65code only the information-carrying
49       channel symbols are shown, and the symbol values range from 0 to 63.
50       Sync synbols lie two tone intervals below data tone 0, and the
51       sequential locations of sync symbols are described in the JT65 Protocol
52       section of this Guide.
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54       A typical execution of jt65code is shown below. The program displays
55       the packed message of 72 bits, shown here as 12 six-bit symbol values,
56       followed by the channel symbols:
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58           $ jt65code "G0XYZ K1ABC FN42"
59           Message:   G0XYZ K1ABC FN42
60           Packed message, 6-bit symbols:  61 36 45 30  3 55  3  2 14  5 33 40
61           Information-carrying channel symbols:
62              56 40  8 40 51 47 50 34 44 53 22 53 28 31 13 60 46  2 14 58 43
63              41 58 35  8 35  3 24  1 21 41 43  0 25 54  9 41 54  7 25 21  9
64              62 59  7 43 31 21 57 13 59 41 17 49 19 54 21 39 33 42 18  2 60
65           Decoded message: G0XYZ K1ABC FN42
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67       For an illustration of the power of the strong error-control coding in
68       JT9, JT65 and JT4, try looking at the channel symbols after changing a
69       single character in the message. For example, change the grid locater
70       from FN42 to FN43 in the JT65 message:
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72           $ jt65code "G0XYZ K1ABC FN43"
73           Message:   G0XYZ K1ABC FN43
74           Packed message, 6-bit symbols:  61 36 45 30  3 55  3  2 14  5 33 41
75           Information-carrying channel symbols:
76              25 35 47  8 13  9 61 40 44  9 51  6  8 40 38 34  8  2 21 23 30
77              51 32 56 39 35  3 50 48 30  8  5 40 18 54  9 24 30 26 61 23 11
78               3 59  7  7 39  1 25 24  4 50 17 49 52 19 34  7  4 34 61  2 61
79           Decoded message: G0XYZ K1ABC FN43
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81       You will discover that every possible JT65 message differs from every
82       other possible JT65 message in at least 52 of the 63
83       information-carrying channel symbols.
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85       WSJT-X home page
86           http://www.physics.princeton.edu/pulsar/K1JT/wsjtx.html
87
88       WSJT-X User’s Guide
89           http://www.physics.princeton.edu/pulsar/K1JT/wsjtx-doc/wsjtx-main-2.0.1.html
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AUTHOR

92       Joe Taylor, K1JT.
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COPYING

95       jt65code, jt9code and jt4code are Copyright © 2001 - 2015 by Joseph H.
96       Taylor, Jr., K1JT, with contributions from additional authors. WSJT-X
97       is Open Source software, licensed under the GNU General Public License
98       (GPLv3).
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100       These programs are distributed in the hope that they will be useful,
101       but WITHOUT ANY WARRANTY; without even the implied warranty of
102       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
103       General Public License for more details.
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107AsciiDoc 2.0.1                    02/25/2019                       JT65CODE(1)
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