'\" t
.\"     Title: jt65code
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 02/20/2018
.\"    Manual: WSJT-X Manual
.\"    Source: AsciiDoc
.\"  Language: English
.\"
.TH "JT65CODE" "1" "02/20/2018" "AsciiDoc" "WSJT\-X Manual"
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.SH "NAME"
jt65code, jt9code, jt4code \- Weak signal communications encoding support utility\&.
.SH "SYNOPSIS"
.sp
\fBjt65code\fR "\fIMESSAGE\fR"
.sp
\fBjt65code\fR [\fIOPTIONS\fR]
.sp
\fBjt9code\fR "\fIMESSAGE\fR"
.sp
\fBjt9code\fR [\fIOPTIONS\fR]
.sp
\fBjt4code\fR "\fIMESSAGE\fR"
.sp
\fBjt4code\fR [\fIOPTIONS\fR]
.SH "OPTIONS"
.PP
\fB\-t\fR
.RS 4
Prints a selection of messages alongside their corresponding decoded form and types\&.
.RE
.SH "DESCRIPTION"
.sp
\fBjt65code\fR, \fBjt9code\fR and \fBjt4code\fR are utility programs that let you explore the conversion of user\-level messages into channel symbols or \(lqtone numbers\&.\(rq These programs can be useful to someone designing a beacon generator for JT9 or JT65, or for studying behavior of the error\-control codes for each of the protocols\&.
.sp
Channel\-symbol values for JT9 run from 0 to 8, with 0 representing the sync tone\&. The total number of symbols in a transmitted message is 85\&. To run jt9code, enter the program name followed by a JT9 message enclosed in quotes\&. In Windows the command and program output might look like this:
.sp
.if n \{\
.RS 4
.\}
.nf
$ jt9code "G0XYZ K1ABC FN42"
Message:   G0XYZ K1ABC FN42
Channel symbols:
 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
 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
 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
Decoded message: G0XYZ K1ABC FN42
.fi
.if n \{\
.RE
.\}
.sp
For the corresponding program jt65code only the information\-carrying channel symbols are shown, and the symbol values range from 0 to 63\&. Sync synbols lie two tone intervals below data tone 0, and the sequential locations of sync symbols are described in the JT65 Protocol section of this Guide\&.
.sp
A typical execution of jt65code is shown below\&. The program displays the packed message of 72 bits, shown here as 12 six\-bit symbol values, followed by the channel symbols:
.sp
.if n \{\
.RS 4
.\}
.nf
$ jt65code "G0XYZ K1ABC FN42"
Message:   G0XYZ K1ABC FN42
Packed message, 6\-bit symbols:  61 36 45 30  3 55  3  2 14  5 33 40
Information\-carrying channel symbols:
   56 40  8 40 51 47 50 34 44 53 22 53 28 31 13 60 46  2 14 58 43
   41 58 35  8 35  3 24  1 21 41 43  0 25 54  9 41 54  7 25 21  9
   62 59  7 43 31 21 57 13 59 41 17 49 19 54 21 39 33 42 18  2 60
Decoded message: G0XYZ K1ABC FN42
.fi
.if n \{\
.RE
.\}
.sp
For an illustration of the power of the strong error\-control coding in JT9, JT65 and JT4, try looking at the channel symbols after changing a single character in the message\&. For example, change the grid locater from FN42 to FN43 in the JT65 message:
.sp
.if n \{\
.RS 4
.\}
.nf
$ jt65code "G0XYZ K1ABC FN43"
Message:   G0XYZ K1ABC FN43
Packed message, 6\-bit symbols:  61 36 45 30  3 55  3  2 14  5 33 41
Information\-carrying channel symbols:
   25 35 47  8 13  9 61 40 44  9 51  6  8 40 38 34  8  2 21 23 30
   51 32 56 39 35  3 50 48 30  8  5 40 18 54  9 24 30 26 61 23 11
    3 59  7  7 39  1 25 24  4 50 17 49 52 19 34  7  4 34 61  2 61
Decoded message: G0XYZ K1ABC FN43
.fi
.if n \{\
.RE
.\}
.sp
You will discover that every possible JT65 message differs from every other possible JT65 message in at least 52 of the 63 information\-carrying channel symbols\&.
.PP
WSJT\-X home page
.RS 4
http://www\&.physics\&.princeton\&.edu/pulsar/K1JT/wsjtx\&.html
.RE
.PP
WSJT\-X User\(cqs Guide
.RS 4
.RE
.SH "AUTHOR"
.sp
Joe Taylor, K1JT\&.
.SH "COPYING"
.sp
\fBjt65code\fR, \fBjt9code\fR and \fBjt4code\fR are Copyright \(co 2001 \- 2015 by Joseph H\&. Taylor, Jr\&., K1JT, with contributions from additional authors\&. WSJT\-X is Open Source software, licensed under the GNU General Public License (GPLv3)\&.
.sp
These programs are distributed in the hope that they will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE\&. See the GNU General Public License for more details\&.