Editing of new FST4/FST4W text in the User Guide.

doc/user_guide/en/introduction.adoc

@@ -17,25 +17,27 @@ encoding.  JT65 and QRA64 were designed for EME ("`moonbounce`") on
 the VHF/UHF bands and have also proven very effective for worldwide
 QRP communication on the HF bands.  QRA64 has some advantages over
 JT65, including better performance for EME on the higher microwave
-bands.  JT9 was originally designed for the HF and lower 
+bands.  JT9 was originally designed for the HF and lower bands.  Its
-bands.  Its submode JT9A is nearly 2 dB more sensitive than JT65 while using
+submode JT9A is 1 dB more sensitive than JT65 while using less than
-less than 10% of the bandwidth.  JT4 offers a wide variety of tone
+10% of the bandwidth.  JT4 offers a wide variety of tone spacings and
-spacings and has proven highly effective for EME on microwave bands up
+has proven highly effective for EME on microwave bands up to 24 GHz.
-to 24 GHz.  These four "`slow`" modes use one-minute timed sequences
+These four "`slow`" modes use one-minute timed sequences of
-of alternating transmission and reception, so a minimal QSO takes four
+alternating transmission and reception, so a minimal QSO takes four to
-to six minutes — two or three transmissions by each station, one
+six minutes — two or three transmissions by each station, one sending
-sending in odd UTC minutes and the other even.  FT8 is operationally
+in odd UTC minutes and the other even.  FT8 is operationally similar
-similar but four times faster (15-second T/R sequences) and less
+but four times faster (15-second T/R sequences) and less sensitive by
-sensitive by a few dB.  FT4 is faster still (7.5 s T/R sequences) and
+a few dB.  FT4 is faster still (7.5 s T/R sequences) and especially
-especially well-suited for radio contesting.  FST4 was added to
+well-suited for radio contesting.  FST4 was added to _WSJT-X_ in
-_WSJT-X_ in version 2.3.0.  It is intended especially for use on the
+version 2.3.0.  It is intended especially for use on the LF and MF
-LF and MF bands; further details can be found in the following
+bands, and already during its first few months of testing
-section, <<NEW_FEATURES,New Features in Version 2.3.0>>.
+intercontinental paths have been spanned many times on the 2200 and
-On the HF bands, world-wide QSOs are possible with any of these modes
+630 m bands.  Further details can be found in the following section,
-using power levels of a few watts (or even milliwatts) and compromise
+<<NEW_FEATURES,New Features in Version 2.3.0>>.  On the HF bands,
-antennas.  On VHF bands and higher, QSOs are possible (by EME and
+world-wide QSOs are possible with any of these modes using power
-other propagation types) at signal levels 10 to 15 dB below those
+levels of a few watts (or even milliwatts) and compromise antennas.
-required for CW.
+On VHF bands and higher, QSOs are possible (by EME and other
+propagation types) at signal levels 10 to 15 dB below those required
+for CW.
 
 *ISCAT*, *MSK144*, and optionally submodes *JT9E-H* are "`fast`"
 protocols designed to take advantage of brief signal enhancements from
@@ -63,10 +65,11 @@ sequences they can be decoded at signal-to-noise ratios as low
 as -31 dB in a 2500 Hz bandwidth. *FST4W* is designed for
 similar purposes, but especially for use on LF and MF bands.
 It includes optional sequence lengths as long as 30 minutes and
-reaches sensitivity tresholds as low as -45 dB.  WSPR and FST4W users
+reaches sensitivity tresholds as low as -45 dB.  Users
-with internet access can automatically upload reception reports to a
+with internet access can automatically upload WSPR and FST4W
-central database called {wsprnet} that provides a mapping facility,
+reception reports to a central database called {wsprnet} that
-archival storage, and many other features.
+provides a mapping facility, archival storage, and many other
+features.
 
 *Echo* mode allows you to detect and measure your own station's echoes
 from the moon, even if they are far below the audible threshold.

doc/user_guide/en/new_features.adoc

@@ -2,13 +2,16 @@
 === New in Version {VERSION}
 
 _WSJT-X 2.3.0_ introduces *FST4* and *FST4W*, new digital protocols
-designed particularly for the LF and MF bands.  On these bands their
+designed particularly for the LF and MF bands.  Decoders for these
-fundamental sensitivities are better than other _WSJT-X_ modes with the
+modes can take advantage of the very small Doppler spreads present at
-same sequence lengths, approaching the theoretical limits for their
+these frequencies, even over intercontinental distances.  As a
-rates of information throughput.  FST4 is optimized for two-way QSOs,
+consequence, fundamental sensitivities of FST4 and FST4W are better
-while FST4W is for quasi-beacon transmissions of WSPR-style messages.
+than other _WSJT-X_ modes with the same sequence lengths, approaching
-FST4 and FST4W do not require the strict, independent time
+the theoretical limits for their rates of information throughput.  The
-synchronization and phase locking of modes like EbNaut.
+FST4 protocol is optimized for two-way QSOs, while FST4W is for
+quasi-beacon transmissions of WSPR-style messages.  FST4 and FST4W do
+not require the strict, independent phase locking and time
+synchronization of modes like EbNaut.
 
 The new modes use 4-GFSK modulation and share common software for
 encoding and decoding messages.  FST4 offers T/R sequence lengths of

doc/user_guide/en/protocols.adoc

@@ -14,11 +14,11 @@ Special cases allow other information such as add-on callsign prefixes
 aim is to compress the most common messages used for minimally valid
 QSOs into a fixed 72-bit length.
 
-The information payloads for FST4, FT4, FT8, and MSK144 contain 77 bits.
+Information payloads for FST4, FT4, FT8, and MSK144 contain 77 bits.
-The 5 new bits added to the original 72 are used to flag special
+The 5 additional bits are used to flag special message types used for
-message types signifying special message types used for FT8 DXpedition
+nonstandard callsigns, contest exchanges, FT8 DXpedition Mode, and a
-Mode, contesting, nonstandard callsigns, and a few other
+few other possibilities.  Full details have been published in QEX, see
-possibilities.
+{ft4_ft8_protocols}.
 
 A standard amateur callsign consists of a one- or two-character
 prefix, at least one of which must be a letter, followed by a digit
@@ -54,11 +54,6 @@ were the callsigns `E9AA` through `E9ZZ`.  Upon reception they are
 converted back to the form `CQ AA` through `CQ ZZ`, for display to the
 user.
 
-The FST4, FT4, FT8, and MSK144 protocols use different lossless compression
-algorithms with features that generate and recognize special messages
-used for contesting and other special purposes.  Full details have
-been published in QEX, see {ft4_ft8_protocols}.
-
 To be useful on channels with low signal-to-noise ratio, this kind of
 lossless message compression requires use of a strong forward error
 correcting (FEC) code.  Different codes are used for each mode.
@@ -76,16 +71,15 @@ _WSJT-X_ modes have continuous phase and constant envelope.
 
 FST4 offers T/R sequence lengths of 15, 30, 60, 120, 300, 900, and
 1800 seconds.  Submodes are given names like FST4-60, FST4-120, etc.,
-the appended numbers indicating sequence length in seconds.  Message
+the appended numbers indicating sequence length in seconds.  A 24-bit
-payloads contain 77 bits, and a 24-bit cyclic redundancy check (CRC)
+cyclic redundancy check (CRC) is appended to the 77-bit message
-appended to create a 101-bit message-plus-CRC word.  Forward error
+payload to create a 101-bit message-plus-CRC word.  Forward error
 correction is accomplished using a (240,101) LDPC code.  Transmissions
 consist of 160 symbols: 120 information-carrying symbols of two bits
 each, interspersed with five groups of eight predefined
 synchronization symbols.  Modulation uses 4-tone frequency-shift
 keying (4-GFSK) with Gaussian smoothing of frequency transitions.
 
-
 [[FT4PRO]]
 ==== FT4
 

doc/user_guide/en/tutorial-example5.adoc

@@ -1,24 +1,23 @@
-FST4 is is designed for making 2-way QSOs on the LF and MF bands.  Do
+Do not confuse FST4 with FT4, which has a very different purpose!
-not confuse it with FT4, which has a very different purpose!  Most
+FST4 is is designed for making 2-way QSOs on the LF and MF bands.
-on-screen controls, auto-sequencing, and other features behave in FST4
+Operation with FST4 is similar to that with other _WSJT-X_ modes: most
-as in other modes.  However, operating conventions on the 2200 and 630
+on-screen controls, auto-sequencing, and other features behave in
-m bands make it desirable to have additional user controls that set
+familiar ways.  However, operating conventions on the 2200 and 630 m
-the active frequency range for decoding.  Spin boxes labeled *F Low*
+bands have made some additional user controls desirable.  Spin boxes
-and *F High* set lower and upper frequency limits for the FST4
+labeled *F Low* and *F High* set lower and upper frequency limits used
-decoder.  
+by the FST4 decoder, and these limits are marked by dark green
-
+angle-bracket symbols *< >* on the Wide Graph frequency scale:
-image::FST4_center.png[align="center"]
-
-Decoding limits are marked by dark green angle-bracket symbols *< >* on
-the Wide Graph frequency scale:
 
 image::FST4_Decoding_Limits.png[align="center"]
 
-In general the specified range should be no larger than you need, since
+{empty} +
-detected transmissions in modes other than the selected FST4 sequence
-length will be undecodable and will slow down the decoding process.
 
-If *Single decode* on the the *File | Settings | General* tab is
+image::FST4_center.png[align="center"]
-checked, the decoding range is further limited to the *F Tol* range
+
-around *Rx Freq*.
+It's best to keep the decoding range fairly small, since QRM and
+transmissions in other modes or sequence lengths will slow down the
+decoding process (and of course will be undecodable).  By checking 
+*Single decode* on the the *File | Settings | General* tab, you can
+further limit the decoding range to the setting of *F Tol* on
+either side of *Rx Freq*.
 

doc/user_guide/en/tutorial-example6.adoc

@@ -1,16 +1,18 @@
-FST4W has significant advantages over WSPR for use on the 2200 and 630
+FST4W is used in the same way as WSPR, but FST4W has significant
-m bands.  As for WSPR, the default Rx Freq is 1500 Hz and F Tol is
+advantages for use on the 2200 and 630 m bands.  By default the
-100 Hz, so the active decoding range 1400 to 1600 Hz.  However, for added
+central *Rx Freq* is 1500 Hz and *F Tol* is 100 Hz, so the active
-flexibility you can select different center frequencies and F Tol values.
+decoding range is 1400 to 1600 Hz.  However, for added flexibility you
-We expect that usage conventions will soon be established for FST4 activity on 2200 and 630 m.
+can select different center frequencies and *F Tol* values.  We expect
+that usage conventions will soon be established for FST4W activity on
+2200 and 630 m.
 
-A new drop-down control below F Tol offers a round-robin mode for
+A new drop-down control below *F Tol* offers a round-robin mode for
 scheduling FST4W transmissions:
 
 image::FST4W_RoundRobin.png[align="center"]
 
-If three operators agree in advance to select the options 1/3, 2/3,
+If three operators agree in advance to select the options *1/3*,
-and 3/3, for example, their FST4W transmissions will occur in a fixed
+*2/3*, and *3/3*, for example, their FST4W transmissions will occur in
-sequence with no two stations transmitting simultaneously.  Sequence 1
+a fixed sequence with no two stations transmitting simultaneously.
-is the first sequence after 00:00 UTC.  For WSPR-like scheduling
+Sequence 1 is the first sequence after 00:00 UTC.  For WSPR-like
-behavior, you should select Random with this control.
+scheduling behavior, you should select *Random* with this control.