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More work on User Guide for v2.2.0.
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@ -82,7 +82,7 @@ fully automated QSOs.
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[[CONTEST_MSGS]]
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=== Contest Messages
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The new FT4, FT8, and MSK144 protocols support special messages optimized
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The FT4, FT8, and MSK144 protocols support special messages optimized
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for *NA VHF* and *EU VHF* contests. FT8 also supports messages for
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*ARRL Field Day* and the *ARRL RTTY Roundup*. The decoders recognize
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and decode these messages at any time. Configure the program to
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@ -3,31 +3,32 @@
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*Improvements to decoders*
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*FT4:* Corrected bugs that prevented AP (_a priori_) decoding and/or
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multi-pass decoding in some circumstances. Improved the algorithm for
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AP decoding.
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multi-pass decoding in some circumstances. Improved and extended the
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algorithm for AP decoding.
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*FT8:* Decoding is now spread over three intervals. The first starts
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11.8 s into an Rx sequence and typically yields around 85% of the
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possible decodes, so you see all of these decodes much earlier than
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before. A second processing step starts at 13.5 s, and the final one
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at 14.7 s. Overall decoding yield on the most crowded bands is
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improved by 10% or more. Systems with receive latency greater than
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0.2 s will see smaller improvements, but will still see many decodes
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earlier than before. In FT8 DXpedition Mode, AP decoding is now
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implemented for Hounds when the Fox has a compound callsign.
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possible decodes, so you see most decodes much earlier than before. A
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second processing step starts at 13.5 s, and the final one at 14.7 s.
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Overall decoding yield on crowded bands is improved by 10% or more.
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Systems with receive latency greater than 0.2 s will see smaller
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improvements, but will still see many decodes earlier than before.
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SNR estimates no longer saturate at +20 dB, and large signals in the
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passband no longer cause the SNR of weaker signals to be biased low.
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Times written to cumulative journal file ALL.TXT are now correct even
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when the decode occurs after the T/R sequence boundary.
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when the decode occurs after the T/R sequence boundary. In FT8
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DXpedition Mode, AP decoding is now implemented for Hounds when the
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Fox has a compound callsign.
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*JT4:* Formatting and display of averaged and Deep Search decodes has
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been cleaned up and made consistent with other modes used for EME and
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extreme weak-signal work at VHF and above.
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extreme weak-signal work on microwave bands.
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*JT65:* Many improvements have been made for averaged and Deep Search
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decodes and their display to the user. For details see <<VHF_JT65,JT65>>
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in the <<VHF_AND_UP,VHF+ Features>> section.
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decodes, and their display to the user. For details see <<VHF_JT65,JT65>>
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in the <<VHF_AND_UP,VHF+ Features>> section of this guide.
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*WSPR:* Significant improvements have been made to the WSPR decoder's
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sensitivity, its ability to cope with many signals in a crowded
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@ -36,37 +37,24 @@ three decoding passes. Passes 1 and 2 use noncoherent demodulation of
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single symbols and allow for frequency drifts up to ±4 Hz in a
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transmission. Pass 3 assumes no drift and does coherent block
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detection of up to three symbols. It also applies bit-by-bit
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normalization of the single-symbol bit metrics, which has proven
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helpful for signals corrupted by artifacts of the subtraction of
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stronger signals and also for LF/MF signals heavily contaminated by
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lightning transients. With these improvements the number of decodes in a
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crowded WSPR sub-band typically increases by 10 to 15%.
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normalization of the single-symbol bit metrics, a technique that has
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proven helpful for signals corrupted by artifacts of the subtraction
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of stronger signals and also for LF/MF signals heavily contaminated by
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lightning transients. With these improvements the number of decodes
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in a crowded WSPR sub-band typically increases by 10 to 15%.
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*New message format:* When *EU VHF Contest* is selected, the Tx2 and
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Tx3 messages -- those conveying signal report, serial number, and
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6-character locator -- now use hashcodes for both callsigns . This
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change is not backward compatible with earlier versions of _WSJT-X_.
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See <<CONTEST_MSGS,Contest Messages>> for details.
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*New modes FT4W and FT4S* are now available for use with extremely
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weak signals on the LF and MF bands.
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*FT4W* behaves like WSPR but uses different schemes for coding and
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modulation. On the AWGN (Additive White Gaussian Noise) channel and
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with 2-minute T/R sequences, FT4W is about 1.5 dB more sensitive than
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WSPR, even with the enhanced decoder outlined above. With 5-minute
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T/R sequences FT4W reaches a threshold sensitivity close to -37 dB.
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*FT4S* is desighned for 2-way QSOs on the 620 amd 2200 m bands. It
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uses the same message formats as FT4, FT8, and MSK144, but different
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coding and modulation and much slower T/R sequences lasting 2 minutes.
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We intend FT4S to be a replacement for JT9 on the LF and MF bands.
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change is *not* backward compatible with earlier versions of _WSJT-X_, so
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all users of *EU VHF Contest* messages should be sure to upgrade to
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versiion 2.2.0. See <<CONTEST_MSGS,Contest Messages>> for details.
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*Minor enhancements and bug fixes*
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- *Save None* now writes no .wav files to disk, even temporarily.
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- An explicit entry *WW Digi Contest* has been added to *Special
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- An explicit entry for *WW Digi Contest* has been added to *Special
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operating activities* on the *Settings | Advanced* tab.
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- The contest mode FT4 now always uses RR73 for the Tx4 message.
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@ -77,6 +65,10 @@ We intend FT4S to be a replacement for JT9 on the LF and MF bands.
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- The *Status bar* now displays the number of decodes found in the
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most recent Rx sequence.
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- As an aid for partial color-blindness, the "`inverted goal posts`"
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marking Rx frequency on the Wide Graph's frequency scale are now in a
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darker shade of green.
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=== Documentation Conventions
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In this manual the following icons call attention to particular types
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