diff --git a/v1.7_Features.txt b/v1.7_Features.txt index deb09e8eb..cb0debdf7 100644 --- a/v1.7_Features.txt +++ b/v1.7_Features.txt @@ -1,13 +1,90 @@ - New Features in WSJT-X Version 1.7 - ---------------------------------- + Alpha Release: WSJT-X Version 1.7 + --------------------------------- -1. New modes: ISCAT, JTMSK, MSK144, QRA64 -2. Newly implemented submodes: JT65B-C, JT9B-H (wide and fast) +Short list of new features +-------------------------- +1. New modes: ISCAT, JTMSK, MSK144, QRA64. +2. Newly implemented submodes: JT65B-C, JT9B-H (wide and fast). 3. FT decoder replaces KV decoder for JT65; KVASD is no longer used. 4. Improvements to JT4, JT9, and JT65 decoders. -5. Multi-pass decoding for JT9, JT65 and WSPR. +5. Multi-pass decoding for JT65 and WSPR. 6. Many improvements to Rig Control. 7. Improved convenience features for EME Doppler tracking. 8. Multiple configurations can be saved and restored. 9. Sample-file download facility. 10. Optional auto-sequencing for "fast" modes. + +New Modes +--------- +1. MSK144 is intended for meteor scatter at 50 MHz and higher. +Designed and tested by K9AN and K1JT, it uses a low-density parity +check code (LDPC) -- one of the latest-and-greatest areas of active +research in comminucation theory. + +MSK144 is a direct descendant of JTMSK with a number of improvements +for better performance on weak and short meteor pings. The effective +character transmission rate is about 250 cps, compared with 147 cps +for FSK441. Like JT4, JT9, JT65, and JTMSK, MSK144 uses strong +forward error correction, so message decoding is essentially "all or +nothing". You will see little or no "garbage" on your screen. + +Standard MSK144 message frames are 72 ms long, compared to 117 ms for +JTMSK. The MSK144 waveform allows coherent demodulation for up to 3 +dB better sensitivity. After QSO partners have exchanged callsigns, +MSK144 user can use even shorter messages, only 20 ms long. As in all +the fast modes in WSJT-X, the 20 ms or 72 ms messages are repeated +without gaps for the duration of a transmission cycle. For most +purposes we recommend a T/R cycle duration of 15 s, but 5 s and 10 s +sequences are also supported. + +An MSK144 signal occupies the full bandwidth of a typical SSB +transmitter, so transmissions are always centered at an offset of +1500Hz. For best results, selectable/adjustable Rx and Tx filters +should be set to provide the flattest possible response over at least +300 - 2700 Hz. The maximum permissible frequency offset between you +and your QSO partner is ± 200 Hz, and less is better. + +2. QRA64 is a designed for EME and other weak-signal use. Its +internal code was designed by Nico Palermo, IV3NWV. It uses a "Q-ary +Repeat Accumulate" code, another one of the latest research areas in +communication theory. The QRA64 code is inherently better than the +Reed Solomon (63,12) code used in JT65, yielding already a 1.3 dB +advantage. QRA64 uses a new synchronizing scheme based on a 7 x 7 +Costas array, so you will not see a bright sync tone at the lowest +tone frequency. This change yields another 1.9 dB advantage. + +In most respects our implementation of QRA64 is operationally similar +to JT65. QRA64 does not use two-tone shorthand messages, and it makes +no use of a callsign database. Rather, additional sensitivity is +gained by making use of "already known" information as a QSO +progresses -- for example, when reports are being exchanged and you +have already decoded both callsigns in a previous transmission. QRA64 +presently offers no message averaging capability, though that may be +added. In our early tests, many EME QSOs have already been made using +submodes QRA64A-E on bands from 144 MHz to 10 GHz. + +3. ISCAT is essentially the same as in recent versions of program WSJT. +For details consult the WSJT User Guide: +http://physics.princeton.edu/pulsar/K1JT/doc/wsjt/ + + +Program Setup +------------- + +Some of the new program capabilities are enabled when you check +"Enable VHF/UHF/Microwave features" on the Settings | General tab. +For MSK144 mode, we suggest setting "T/R 15 s" and "F Tol 100 Hz"; +check "Sh" to enable the use of short messages and "Auto Seq" for +auto-sequencing. For QRA64 mode, set Tx and Rx frequencies to 1000 +Hz. We encourage you to check "Save all" when making tests, and to +save any of the resulting .wav files that might help us to improve +program performance or behavior, or to illustrate a problem that you +identify. + + +Final Comments +-------------- + +We will be grateful for any and all reports from test users that may +help us to further improve WSJT-X. Send your reports to +wsjtgroup@yahoogroups.com.