| JT65CODE(1) | WSJT-X Manual | JT65CODE(1) |
jt65code, jt9code, jt4code, qra64code, ft8code, msk144code - Weak signal communications encoding support utilities.
jt65code "MESSAGE"
jt65code [OPTIONS]
jt9code "MESSAGE"
jt9code [OPTIONS]
jt4code "MESSAGE"
jt4code [OPTIONS]
qra64code "MESSAGE"
qra64code [OPTIONS]
ft8code "MESSAGE"
ft8code [OPTIONS]
-t
-T
jt65code, jt9code, jt4code, and ft8code are utility programs that let you explore the conversion of user-level messages into channel symbols or “tone numbers.” 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.
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:
$ 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
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.
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:
$ 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
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:
$ 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
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.
$ qra64code "G0XYZ K1ABC FN43"
Message Decoded Err? Type --------------------------------------------------------------------------
1 G0XYZ K1ABC FN43 G0XYZ K1ABC FN43 1: Std Msg Packed message, 6-bit symbols 61 36 45 30 3 55 3 2 14 5 33 41 Information-carrying channel symbols
61 36 45 30 3 55 3 2 14 5 33 41 14 28 2 7 58 45 9 43 20 48 29 55 43 24 3 13 18 21
40 3 17 28 59 62 2 50 26 24 2 1 2 61 10 9 16 40 1 18 28 30 33 39 60 45 16 21 60 11
9 40 14 Channel symbols including sync
20 50 60 0 40 10 30 61 36 45 30 3 55 3 2 14 5 33 41 14 28 2 7 58 45 9 43 20 48 29
55 43 24 3 13 18 21 40 3 20 50 60 0 40 10 30 17 28 59 62 2 50 26 24 2 1 2 61 10 9
16 40 1 18 28 30 33 39 60 45 16 21 60 11 9 40 14 20 50 60 0 40 10 30
$ msk144code "G0XYZ K1ABC FN43"
Message Decoded Err i3.n3 ----------------------------------------------------------------------------------------------------
1. G0XYZ K1ABC FN43 G0XYZ K1ABC FN43 1. Standard msg Channel symbols 110000110100110001010010011100110010010110000011011001001100001101111010 110010110111111100001101001111000111101011111011100001110000011101110110
$ ft8code "G0XYZ K1ABC FN43"
Message Decoded Err i3.n3 ----------------------------------------------------------------------------------------------------
1. G0XYZ K1ABC FN43 G0XYZ K1ABC FN43 1. Standard msg Source-encoded message, 77 bits: 00001000111111010001110111010000010011011110111100011010100010100001100111001 14-bit CRC: 00110001001011 83 Parity bits: 10000110000001010101100000100110100110100000111000101110000110001001110000000110011 Channel symbols (79 tones):
Sync Data Sync Data Sync 3140652 03174526450547670460602143205 3140652 64040136505454507064041140042 3140652
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Joe Taylor, K1JT.
jt65code, jt9code, jt4code, and ft8code are Copyright © 2001 - 2020 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).
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.
| 02/09/2021 | AsciiDoc 2.3.0 |