mirror of
				https://github.com/saitohirga/WSJT-X.git
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	First cut at adding FST4, FST4W to the User Guide.
This commit is contained in:
		
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				@ -30,8 +30,7 @@ set (UG_SRCS
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  install-mac.adoc
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  install-windows.adoc
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  introduction.adoc
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		||||
  measurement_tools.adoc
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		||||
  protocols.adoc
 | 
			
		||||
  intro_subsections.adoc
 | 
			
		||||
  logging.adoc
 | 
			
		||||
  make-qso.adoc
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		||||
  measurement_tools.adoc
 | 
			
		||||
@ -53,6 +52,8 @@ set (UG_SRCS
 | 
			
		||||
  tutorial-example2.adoc
 | 
			
		||||
  tutorial-example3.adoc
 | 
			
		||||
  tutorial-example4.adoc
 | 
			
		||||
  tutorial-example5.adoc
 | 
			
		||||
  tutorial-example6.adoc
 | 
			
		||||
  tutorial-main-window.adoc
 | 
			
		||||
  tutorial-wide-graph-settings.adoc
 | 
			
		||||
  utilities.adoc
 | 
			
		||||
@ -82,6 +83,9 @@ set (UG_IMGS
 | 
			
		||||
  images/FreqCal_Graph.png
 | 
			
		||||
  images/FreqCal_Results.png
 | 
			
		||||
  images/freemsg.png
 | 
			
		||||
  images/FST4_center.png
 | 
			
		||||
  images/FST4_Decoding_Limits.png
 | 
			
		||||
  images/FST4W_RoundRobin.png
 | 
			
		||||
  images/ft4_decodes.png
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  images/ft4_waterfall.png
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  images/ft8_decodes.png
 | 
			
		||||
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		||||
							
								
								
									
										
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								doc/user_guide/en/intro_subsections.adoc
									
									
									
									
									
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								doc/user_guide/en/intro_subsections.adoc
									
									
									
									
									
										Normal file
									
								
							@ -0,0 +1,40 @@
 | 
			
		||||
=== Documentation Conventions
 | 
			
		||||
 | 
			
		||||
In this manual the following icons call attention to particular types
 | 
			
		||||
of information:
 | 
			
		||||
 | 
			
		||||
NOTE: *Notes* containing information that may be of interest to
 | 
			
		||||
particular classes of users.
 | 
			
		||||
 | 
			
		||||
TIP: *Tips* on program features or capabilities that might otherwise be
 | 
			
		||||
overlooked.
 | 
			
		||||
 | 
			
		||||
IMPORTANT: *Warnings* about usage that could lead to undesired
 | 
			
		||||
consequences.
 | 
			
		||||
 | 
			
		||||
=== User Interface in Other Languages
 | 
			
		||||
 | 
			
		||||
The _WSJT-X_ user interface is now available in many languages.  When
 | 
			
		||||
a translated user interface is available for the computer's default
 | 
			
		||||
System Language, it will appear automatically on program startup.
 | 
			
		||||
 | 
			
		||||
=== How You Can Contribute
 | 
			
		||||
 | 
			
		||||
_WSJT-X_ is part of an open-source project released under the
 | 
			
		||||
{gnu_gpl} (GPLv3). If you have programming or documentation skills or
 | 
			
		||||
would like to contribute to the project in other ways, please make
 | 
			
		||||
your interests known to the development team.  We especially encourage
 | 
			
		||||
those with translation skills to volunteer their help, either for
 | 
			
		||||
this _User Guide_ or for the program's user interface.
 | 
			
		||||
 | 
			
		||||
The project's source-code repository can be found at {devrepo}, and
 | 
			
		||||
communication among the developers takes place on the email reflector
 | 
			
		||||
{devmail}.  Bug reports and suggestions for new features, improvements
 | 
			
		||||
to the _WSJT-X_ User Guide, etc., may be sent there as well.  You must
 | 
			
		||||
join the group before posting to the email list.
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
=== License
 | 
			
		||||
 | 
			
		||||
Before using _WSJT-X_, please read our licensing terms
 | 
			
		||||
<<LICENSE,here>>.
 | 
			
		||||
@ -3,42 +3,39 @@
 | 
			
		||||
_WSJT-X_ is a computer program designed to facilitate basic amateur
 | 
			
		||||
radio communication using very weak signals. The first four letters in
 | 
			
		||||
the program name stand for "`**W**eak **S**ignal communication by
 | 
			
		||||
K1**JT**,`" while the suffix "`-X`" indicates that _WSJT-X_ started as
 | 
			
		||||
an extended and experimental branch of the program _WSJT_,
 | 
			
		||||
first released in 2001.  Bill Somerville, G4WJS, and Steve Franke,
 | 
			
		||||
K9AN, have been major contributors to program development since 2013
 | 
			
		||||
and 2015, respectively.
 | 
			
		||||
K1**JT**,`" while the suffix "`*-X*`" indicates that _WSJT-X_ started
 | 
			
		||||
as an extended branch of an earlier program, _WSJT_, first released in
 | 
			
		||||
2001.  Bill Somerville, G4WJS, and Steve Franke, K9AN, have been major
 | 
			
		||||
contributors to development of _WSJT-X_ since 2013 and 2015, respectively.
 | 
			
		||||
 | 
			
		||||
_WSJT-X_ Version {VERSION_MAJOR}.{VERSION_MINOR} offers ten different
 | 
			
		||||
protocols or modes: *FT4*, *FT8*, *JT4*, *JT9*, *JT65*, *QRA64*,
 | 
			
		||||
*ISCAT*, *MSK144*, *WSPR*, and *Echo*.  The first six are designed for
 | 
			
		||||
making reliable QSOs under weak-signal conditions. They use nearly
 | 
			
		||||
identical message structure and source 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 LF, MF, and lower HF bands.  Its submode JT9A is 2 dB more
 | 
			
		||||
sensitive than JT65 while using less than 10% of the bandwidth.  JT4
 | 
			
		||||
offers a wide variety of tone spacings and has proven highly effective
 | 
			
		||||
for EME on microwave bands up to 24 GHz.  These four "`slow`" modes
 | 
			
		||||
use one-minute timed sequences of alternating transmission and
 | 
			
		||||
reception, so a minimal QSO takes four to six minutes — two or three
 | 
			
		||||
transmissions by each station, one sending in odd UTC minutes and the
 | 
			
		||||
other even.  FT8 is operationally similar but four times faster
 | 
			
		||||
(15-second T/R sequences) and less sensitive by a few dB.  FT4 is
 | 
			
		||||
faster still (7.5 s T/R sequences) and especially well-suited for
 | 
			
		||||
radio contesting.  On the HF bands, world-wide QSOs are possible with
 | 
			
		||||
any of these modes using power levels of a few watts (or even
 | 
			
		||||
milliwatts) and compromise antennas.  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.
 | 
			
		||||
 | 
			
		||||
Note that even though their T/R sequences are short, FT4 and FT8 are
 | 
			
		||||
classified as slow modes because their message frames are sent only
 | 
			
		||||
once per transmission.  All fast modes in _WSJT-X_ send their message
 | 
			
		||||
frames repeatedly, as many times as will fit into the Tx sequence
 | 
			
		||||
length.
 | 
			
		||||
_WSJT-X_ Version {VERSION_MAJOR}.{VERSION_MINOR} offers twelve
 | 
			
		||||
different protocols or modes: *FST4*, *FT4*, *FT8*, *JT4*, *JT9*,
 | 
			
		||||
*JT65*, *QRA64*, *ISCAT*, *MSK144*, *WSPR*, *FST4W*, and *Echo*.  The
 | 
			
		||||
first seven are designed for making reliable QSOs under weak-signal
 | 
			
		||||
conditions. They use nearly identical message structure and source
 | 
			
		||||
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.  Its submode JT9A is nearly 2 dB more sensitive than JT65 while using
 | 
			
		||||
less than 10% of the bandwidth.  JT4 offers a wide variety of tone
 | 
			
		||||
spacings and has proven highly effective for EME on microwave bands up
 | 
			
		||||
to 24 GHz.  These four "`slow`" modes use one-minute timed sequences
 | 
			
		||||
of alternating transmission and reception, so a minimal QSO takes four
 | 
			
		||||
to six minutes — two or three transmissions by each station, one
 | 
			
		||||
sending in odd UTC minutes and the other even.  FT8 is operationally
 | 
			
		||||
similar but four times faster (15-second T/R sequences) and less
 | 
			
		||||
sensitive by a few dB.  FT4 is faster still (7.5 s T/R sequences) and
 | 
			
		||||
especially well-suited for radio contesting.  FST4 was added to
 | 
			
		||||
_WSJT-X_ in version 2.3.0.  It is intended especially for use on the
 | 
			
		||||
LF and MF bands; further details can be found in the following
 | 
			
		||||
section, <<NEW_FEATURES,New Features in Version 2.3.0>>.
 | 
			
		||||
On the HF bands, world-wide QSOs are possible with any of these modes
 | 
			
		||||
using power levels of a few watts (or even milliwatts) and compromise
 | 
			
		||||
antennas.  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
 | 
			
		||||
@ -51,15 +48,25 @@ messages up to 28 characters long, while MSK144 uses the same
 | 
			
		||||
structured messages as the slow modes and optionally an abbreviated
 | 
			
		||||
format with hashed callsigns.  
 | 
			
		||||
 | 
			
		||||
Note that some of the modes classified as slow can have T/R sequence
 | 
			
		||||
lengths as short the fast modes.  "`Slow`" in this sense implies
 | 
			
		||||
message frames being sent only once per transmission.  The fast modes
 | 
			
		||||
in _WSJT-X_ send their message frames repeatedly, as many times as
 | 
			
		||||
will fit into the Tx sequence length.
 | 
			
		||||
 | 
			
		||||
*WSPR* (pronounced "`whisper`") stands for **W**eak **S**ignal
 | 
			
		||||
**P**ropagation **R**eporter.  The WSPR protocol was designed for probing
 | 
			
		||||
potential propagation paths using low-power transmissions. WSPR
 | 
			
		||||
messages normally carry the transmitting station’s callsign, grid
 | 
			
		||||
locator, and transmitter power in dBm, and they can be decoded at
 | 
			
		||||
signal-to-noise ratios as low as -31 dB in a 2500 Hz bandwidth.  WSPR
 | 
			
		||||
users with internet access can automatically upload reception
 | 
			
		||||
reports to a central database called {wsprnet} that provides a mapping
 | 
			
		||||
facility, archival storage, and many other features.
 | 
			
		||||
**P**ropagation **R**eporter.  The WSPR protocol was designed for
 | 
			
		||||
probing potential propagation paths using low-power transmissions.
 | 
			
		||||
WSPR messages normally carry the transmitting station’s callsign,
 | 
			
		||||
grid locator, and transmitter power in dBm, and with two-minute
 | 
			
		||||
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
 | 
			
		||||
with internet access can automatically upload reception reports to a
 | 
			
		||||
central database called {wsprnet} that 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.
 | 
			
		||||
 | 
			
		||||
@ -1,107 +1,31 @@
 | 
			
		||||
[[NEW_FEATURES]]
 | 
			
		||||
=== New in Version {VERSION}
 | 
			
		||||
 | 
			
		||||
*Improvements to decoders*
 | 
			
		||||
_WSJT-X 2.3.0_ introduces *FST4* and *FST4W*, new digital protocols
 | 
			
		||||
designed particularly for the LF and MF bands.  On these bands their
 | 
			
		||||
fundamental sensitivities are better than other _WSJT-X_ modes with the
 | 
			
		||||
same sequence lengths, approaching the theoretical limits for their
 | 
			
		||||
rates of information throughput.  FST4 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 time
 | 
			
		||||
synchronization and phase locking of modes like EbNaut.
 | 
			
		||||
 | 
			
		||||
*FT4:* Corrected bugs that prevented AP (_a priori_) decoding and/or
 | 
			
		||||
multi-pass decoding in some circumstances.  Improved and extended the
 | 
			
		||||
algorithm for AP decoding.
 | 
			
		||||
The new modes use 4-GFSK modulation and share common software for
 | 
			
		||||
encoding and decoding messages.  FST4 offers T/R sequence lengths of
 | 
			
		||||
15, 30, 60, 120, 300, 900, and 1800 seconds, while FST4W omits the
 | 
			
		||||
lengths shorter than 120 s.  Submodes are given names like FST4-60,
 | 
			
		||||
FST4W-300, etc., the appended numbers indicating sequence length in
 | 
			
		||||
seconds.  Message payloads contain either 77 bits, as in FT4, FT8, and
 | 
			
		||||
MSK144, or 50 bits for the WSPR-like messages of FST4W.  Message
 | 
			
		||||
formats displayed to the user are like those in the other 77-bit and
 | 
			
		||||
50-bit modes in _WSJT-X_.  Forward error correction uses a low density
 | 
			
		||||
parity check (LDPC) code with 240 information and parity bits.
 | 
			
		||||
Transmissions consist of 160 symbols: 120 information-carrying symbols
 | 
			
		||||
of two bits each, interspersed with five groups of eight predefined
 | 
			
		||||
synchronization symbols.
 | 
			
		||||
 | 
			
		||||
*FT8:* Decoding is now spread over three intervals.  The first starts
 | 
			
		||||
11.8 s into an Rx sequence and typically yields around 85% of the
 | 
			
		||||
possible decodes, so you see most decodes much earlier than before.  A
 | 
			
		||||
second processing step starts at 13.5 s, and the final one at 14.7 s.
 | 
			
		||||
Overall decoding yield on crowded bands is improved by 10% or more.
 | 
			
		||||
Systems with receive latency greater than 0.2 s will see smaller
 | 
			
		||||
improvements, but will still see many decodes earlier than before.
 | 
			
		||||
 | 
			
		||||
SNR estimates no longer saturate at +20 dB, and large signals in the
 | 
			
		||||
passband no longer cause the SNR of weaker signals to be biased low.
 | 
			
		||||
Times written to cumulative journal file ALL.TXT are now correct even
 | 
			
		||||
when the decode occurs after the T/R sequence boundary.  In FT8
 | 
			
		||||
DXpedition Mode, AP decoding is now implemented for Hounds when the
 | 
			
		||||
Fox has a compound callsign.
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
*JT4:*  Formatting and display of averaged and Deep Search decodes has
 | 
			
		||||
been cleaned up and made consistent with other modes used for EME and
 | 
			
		||||
extreme weak-signal work on microwave bands.
 | 
			
		||||
 | 
			
		||||
*JT65:*  Many improvements have been made for averaged and Deep Search
 | 
			
		||||
decodes, and their display to the user.  For details see <<VHF_JT65,JT65>>
 | 
			
		||||
in the <<VHF_AND_UP,VHF+ Features>> section of this guide.
 | 
			
		||||
 | 
			
		||||
*WSPR:* Significant improvements have been made to the WSPR decoder's
 | 
			
		||||
sensitivity, its ability to cope with many signals in a crowded
 | 
			
		||||
sub-band, and its rate of undetected false decodes.  We now use up to
 | 
			
		||||
three decoding passes.  Passes 1 and 2 use noncoherent demodulation of
 | 
			
		||||
single symbols and allow for frequency drifts up to ±4 Hz in a
 | 
			
		||||
transmission.  Pass 3 assumes no drift and does coherent block
 | 
			
		||||
detection of up to three symbols.  It also applies bit-by-bit
 | 
			
		||||
normalization of the single-symbol bit metrics, a technique that has
 | 
			
		||||
proven helpful for signals corrupted by artifacts of the subtraction
 | 
			
		||||
of stronger signals and also for LF/MF signals heavily contaminated by
 | 
			
		||||
lightning transients.  With these improvements the number of decodes
 | 
			
		||||
in a crowded WSPR sub-band typically increases by 10 to 15%.
 | 
			
		||||
 | 
			
		||||
*New message format:* When *EU VHF Contest* is selected, the Tx2 and
 | 
			
		||||
Tx3 messages -- those conveying signal report, serial number, and
 | 
			
		||||
6-character locator -- now use hashcodes for both callsigns.  This
 | 
			
		||||
change is *not* backward compatible with earlier versions of _WSJT-X_, so
 | 
			
		||||
all users of *EU VHF Contest* messages should be sure to upgrade to
 | 
			
		||||
version 2.2.0.  See <<CONTEST_MSGS,Contest Messages>> for details.
 | 
			
		||||
 | 
			
		||||
*Minor enhancements and bug fixes*
 | 
			
		||||
 | 
			
		||||
- *Save None* now writes no .wav files to disk, even temporarily.
 | 
			
		||||
 | 
			
		||||
- An explicit entry for *WW Digi Contest* has been added to *Special
 | 
			
		||||
 operating activities* on the *Settings | Advanced* tab.
 | 
			
		||||
 | 
			
		||||
- The contest mode FT4 now always uses RR73 for the Tx4 message.
 | 
			
		||||
 | 
			
		||||
- *Keyboard shortcuts* have been added as an aid to accessibility:
 | 
			
		||||
*Alt+R* sets Tx4 message to RR73, *Ctrl+R* sets it to RRR.
 | 
			
		||||
 | 
			
		||||
- The *Status bar* now displays the number of decodes found in the
 | 
			
		||||
most recent Rx sequence.
 | 
			
		||||
 | 
			
		||||
- As an aid for partial color-blindness, the "`inverted goal posts`"
 | 
			
		||||
marking Rx frequency on the Wide Graph's frequency scale are now in a
 | 
			
		||||
darker shade of green.
 | 
			
		||||
 | 
			
		||||
=== Documentation Conventions
 | 
			
		||||
 | 
			
		||||
In this manual the following icons call attention to particular types
 | 
			
		||||
of information:
 | 
			
		||||
 | 
			
		||||
NOTE: *Notes* containing information that may be of interest to
 | 
			
		||||
particular classes of users.
 | 
			
		||||
 | 
			
		||||
TIP: *Tips* on program features or capabilities that might otherwise be
 | 
			
		||||
overlooked.
 | 
			
		||||
 | 
			
		||||
IMPORTANT: *Warnings* about usage that could lead to undesired
 | 
			
		||||
consequences.
 | 
			
		||||
 | 
			
		||||
=== User Interface in Other Languages
 | 
			
		||||
 | 
			
		||||
Thanks to Xavi Perez, EA3W, in cooperation with G4WJS, the _WSJT-X_
 | 
			
		||||
user interface is now available the Catalan language.  Spanish will
 | 
			
		||||
follow soon, and other languages when translations are made.  When a
 | 
			
		||||
translated user interface is available for the computer's default
 | 
			
		||||
System Language, it will appear automatically on program startup.
 | 
			
		||||
 | 
			
		||||
=== How You Can Contribute
 | 
			
		||||
 | 
			
		||||
_WSJT-X_ is part of an open-source project released under the
 | 
			
		||||
{gnu_gpl} (GPLv3). If you have programming or documentation skills or
 | 
			
		||||
would like to contribute to the project in other ways, please make
 | 
			
		||||
your interests known to the development team.  We especially encourage
 | 
			
		||||
those with translation skills to volunteer their help, either for
 | 
			
		||||
this _User Guide_ or for the program's user interface.
 | 
			
		||||
 | 
			
		||||
The project's source-code repository can be found at {devrepo}, and
 | 
			
		||||
communication among the developers takes place on the email reflector
 | 
			
		||||
{devmail}.  Bug reports and suggestions for new features, improvements
 | 
			
		||||
to the _WSJT-X_ User Guide, etc., may be sent there as well.  You must
 | 
			
		||||
join the group before posting to the email list.
 | 
			
		||||
*We recommend that on the 2200 and 630 m bands FST4 should replace JT9
 | 
			
		||||
for making 2-way QSOs, and FST4W should replace WSPR for propagation
 | 
			
		||||
tests*.  Operating conventions on these LF and MF bands will
 | 
			
		||||
eventually determine the most useful T/R sequence lengths for each
 | 
			
		||||
type of operation.
 | 
			
		||||
 | 
			
		||||
@ -14,7 +14,7 @@ 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 payload for FT4, FT8, and MSK144 contains 77 bits.
 | 
			
		||||
The 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
 | 
			
		||||
message types signifying special message types used for FT8 DXpedition
 | 
			
		||||
Mode, contesting, nonstandard callsigns, and a few other
 | 
			
		||||
@ -54,7 +54,7 @@ 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 FT4, FT8, and MSK144 protocols use different lossless compression
 | 
			
		||||
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}.
 | 
			
		||||
@ -71,6 +71,21 @@ _WSJT-X_ modes have continuous phase and constant envelope.
 | 
			
		||||
[[SLOW_MODES]]
 | 
			
		||||
=== Slow Modes
 | 
			
		||||
 | 
			
		||||
[[FST4PRO]]
 | 
			
		||||
==== FST4
 | 
			
		||||
 | 
			
		||||
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
 | 
			
		||||
payloads contain 77 bits, and a 24-bit cyclic redundancy check (CRC)
 | 
			
		||||
appended 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
 | 
			
		||||
 | 
			
		||||
@ -225,6 +240,20 @@ information the least significant. Thus, on a 0 – 3 scale, the tone
 | 
			
		||||
for a given symbol is twice the value (0 or 1) of the data bit, plus
 | 
			
		||||
the sync bit.
 | 
			
		||||
 | 
			
		||||
[[FST4WPRO]]
 | 
			
		||||
==== FST4W
 | 
			
		||||
 | 
			
		||||
FST4W offers T/R sequence lengths of 120, 300, 900, and 1800 seconds.
 | 
			
		||||
Submodes are given names like FST4W-120, FST4W-300, etc., the appended
 | 
			
		||||
numbers indicating sequence length in seconds.  Message payloads
 | 
			
		||||
contain 50 bits, and a 24-bit cyclic redundancy check (CRC) appended
 | 
			
		||||
to create a 74-bit message-plus-CRC word.  Forward error correction
 | 
			
		||||
is accomplished using a (240,74) 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.
 | 
			
		||||
 | 
			
		||||
[[SLOW_SUMMARY]]
 | 
			
		||||
==== Summary
 | 
			
		||||
 | 
			
		||||
@ -239,17 +268,28 @@ which the probability of decoding is 50% or higher.
 | 
			
		||||
 | 
			
		||||
[[SLOW_TAB]]
 | 
			
		||||
.Parameters of Slow Modes
 | 
			
		||||
[width="90%",cols="3h,^3,^2,^1,^2,^2,^2,^2,^2,^2",frame=topbot,options="header"]
 | 
			
		||||
[width="100%",cols="3h,^3,^2,^1,^2,^2,^2,^2,^2,^2",frame=topbot,options="header"]
 | 
			
		||||
|===============================================================================
 | 
			
		||||
|Mode |FEC Type |(n,k) | Q|Modulation type|Keying rate (Baud)|Bandwidth (Hz)
 | 
			
		||||
|Sync Energy|Tx Duration (s)|S/N Threshold (dB)
 | 
			
		||||
|FT4  |LDPC, r=1/2|(174,91)| 4| 4-GFSK| 20.8333 | 83.3 | 0.15| 5.04 | -17.5
 | 
			
		||||
|FT8  |LDPC, r=1/2|(174,91)| 8| 8-GFSK| 6.25 | 50.0 | 0.27| 12.6 | -21
 | 
			
		||||
|FST4-15   |LDPC |  (240,101)| 4| 4-GFSK| 16.6667 | 67.7 | 0.25| 9.60  | -20.7
 | 
			
		||||
|FST4-30   |LDPC |  (240,101)| 4| 4-GFSK|  7.14  | 28.6  | 0.25| 22.4  | -24.2
 | 
			
		||||
|FST4-60   |LDPC |  (240,101)| 4| 4-GFSK|  3.09  | 12.4  | 0.25| 51.8  | -28.1
 | 
			
		||||
|FST4-120  |LDPC |  (240,101)| 4| 4-GFSK|  1.46  |  5.9  | 0.25| 109.3 | -31.3
 | 
			
		||||
|FST4-300  |LDPC |  (240,101)| 4| 4-GFSK|  0.56  |  2.2  | 0.25| 286.7 | -35.3
 | 
			
		||||
|FST4-900  |LDPC |  (240,101)| 4| 4-GFSK|  0.180 |  0.72 | 0.25| 887.5 | -40.2
 | 
			
		||||
|FST4-1800 |LDPC |  (240,101)| 4| 4-GFSK|  0.089 |  0.36 | 0.25| 1792.0| -43.2
 | 
			
		||||
|FT4  |LDPC |(174,91)| 4| 4-GFSK| 20.8333 | 83.3 | 0.15| 5.04 | -17.5
 | 
			
		||||
|FT8  |LDPC |(174,91)| 8| 8-GFSK| 6.25 | 50.0 | 0.27| 12.6 | -21
 | 
			
		||||
|JT4A |K=32, r=1/2|(206,72)| 2| 4-FSK| 4.375| 17.5 | 0.50| 47.1 | -23
 | 
			
		||||
|JT9A |K=32, r=1/2|(206,72)| 8| 9-FSK| 1.736| 15.6 | 0.19| 49.0 | -27
 | 
			
		||||
|JT9A |K=32, r=1/2|(206,72)| 8| 9-FSK| 1.736| 15.6 | 0.19| 49.0 | -26
 | 
			
		||||
|JT65A |Reed Solomon|(63,12) |64|65-FSK| 2.692| 177.6 | 0.50| 46.8 | -25
 | 
			
		||||
|QRA64A|Q-ary Repeat Accumulate|(63,12) |64|64-FSK|1.736|111.1|0.25|48.4| -26
 | 
			
		||||
| WSPR |K=32, r=1/2|(162,50)| 2| 4-FSK| 1.465| 5.9 | 0.50|110.6 | -31
 | 
			
		||||
|FST4W-120  |LDPC |  (240,74)| 4| 4-GFSK|  1.46  |  5.9  | 0.25| 109.3 | -32.8
 | 
			
		||||
|FST4W-300  |LDPC |  (240,74)| 4| 4-GFSK|  0.56  |  2.2  | 0.25| 286.7 | -36.8
 | 
			
		||||
|FST4W-900  |LDPC |  (240,74)| 4| 4-GFSK|  0.180 |  0.72 | 0.25| 887.5 | -41.7
 | 
			
		||||
|FST4W-1800 |LDPC |  (240,74)| 4| 4-GFSK|  0.089 |  0.36 | 0.25| 1792.0| -44.8
 | 
			
		||||
|===============================================================================
 | 
			
		||||
 | 
			
		||||
Submodes of JT4, JT9, JT65, and QRA64 offer wider tone spacings for
 | 
			
		||||
@ -259,12 +299,10 @@ threshold sensitivities of the various submodes when spreading is
 | 
			
		||||
comparable to tone spacing.
 | 
			
		||||
 | 
			
		||||
[[SLOW_SUBMODES]]
 | 
			
		||||
.Parameters of Slow Submodes
 | 
			
		||||
.Parameters of Slow Submodes with Wider Tome Spacings
 | 
			
		||||
[width="50%",cols="h,3*^",frame=topbot,options="header"]
 | 
			
		||||
|=====================================
 | 
			
		||||
|Mode  |Tone Spacing  |BW (Hz)|S/N (dB)
 | 
			
		||||
|FT4   |20.8333 | 83.3  |-17.5
 | 
			
		||||
|FT8   |6.25 |  50.0  |-21
 | 
			
		||||
|JT4A  |4.375|  17.5  |-23
 | 
			
		||||
|JT4B  |8.75 |  30.6  |-22
 | 
			
		||||
|JT4C  |17.5 |  56.9  |-21
 | 
			
		||||
@ -272,7 +310,7 @@ comparable to tone spacing.
 | 
			
		||||
|JT4E  |78.75|  240.6 |-19
 | 
			
		||||
|JT4F  |157.5|  476.9 |-18
 | 
			
		||||
|JT4G  |315.0|  949.4 |-17
 | 
			
		||||
|JT9A  |1.736|  15.6  |-27
 | 
			
		||||
|JT9A  |1.736|  15.6  |-26
 | 
			
		||||
|JT9B  |3.472|  29.5  |-26
 | 
			
		||||
|JT9C  |6.944|  57.3  |-25
 | 
			
		||||
|JT9D  |13.889| 112.8 |-24
 | 
			
		||||
 | 
			
		||||
							
								
								
									
										24
									
								
								doc/user_guide/en/tutorial-example5.adoc
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										24
									
								
								doc/user_guide/en/tutorial-example5.adoc
									
									
									
									
									
										Normal file
									
								
							@ -0,0 +1,24 @@
 | 
			
		||||
FST4 is is designed for making 2-way QSOs on the LF and MF bands.  Do
 | 
			
		||||
not confuse it with FT4, which has a very different purpose!  Most
 | 
			
		||||
on-screen controls, auto-sequencing, and other features behave in FST4
 | 
			
		||||
as in other modes.  However, operating conventions on the 2200 and 630
 | 
			
		||||
m bands make it desirable to have additional user controls that set
 | 
			
		||||
the active frequency range for decoding.  Spin boxes labeled *F Low*
 | 
			
		||||
and *F High* set lower and upper frequency limits for the FST4
 | 
			
		||||
decoder.  
 | 
			
		||||
 | 
			
		||||
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 needed, since
 | 
			
		||||
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
 | 
			
		||||
checked, the decoding range is further limited to the *F Tol* range
 | 
			
		||||
around *Rx Freq*.
 | 
			
		||||
 | 
			
		||||
							
								
								
									
										16
									
								
								doc/user_guide/en/tutorial-example6.adoc
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										16
									
								
								doc/user_guide/en/tutorial-example6.adoc
									
									
									
									
									
										Normal file
									
								
							@ -0,0 +1,16 @@
 | 
			
		||||
FST4W has significant advantages over WSPR for use on the 2200 and 630
 | 
			
		||||
m bands.  As for WSPR, the default Rx Freq is 1500 Hz and F Tol is
 | 
			
		||||
100 Hz, so the active decoding range 1400 to 1600 Hz.  However, for added
 | 
			
		||||
flexibility you can select different center frequencies and F Tol values.
 | 
			
		||||
We expect that usage conventions will soon be established for FST4 activity on 2200 and 630 m.
 | 
			
		||||
 | 
			
		||||
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,
 | 
			
		||||
and 3/3, for example, their FST4W transmissions will occur in a fixed
 | 
			
		||||
sequence with no two stations transmitting simultaneously.  Sequence 1
 | 
			
		||||
is the first sequence after 00:00 UTC.  For WSPR-like scheduling
 | 
			
		||||
behavior, you should select Random with this control.
 | 
			
		||||
@ -32,6 +32,9 @@ include::introduction.adoc[]
 | 
			
		||||
[[NEW_FEATURES]]
 | 
			
		||||
include::new_features.adoc[]
 | 
			
		||||
 | 
			
		||||
[[INTRO_SUBSECTIONS]]
 | 
			
		||||
include::intro_subsections.adoc[]
 | 
			
		||||
 | 
			
		||||
[[SYSREQ]]
 | 
			
		||||
== System Requirements
 | 
			
		||||
include::system-requirements.adoc[]
 | 
			
		||||
@ -162,6 +165,14 @@ include::tutorial-example3.adoc[]
 | 
			
		||||
=== FT4
 | 
			
		||||
include::tutorial-example4.adoc[]
 | 
			
		||||
 | 
			
		||||
[[TUT_EX5]]
 | 
			
		||||
=== FST4
 | 
			
		||||
include::tutorial-example5.adoc[]
 | 
			
		||||
 | 
			
		||||
[[TUT_EX6]]
 | 
			
		||||
=== FST4W
 | 
			
		||||
include::tutorial-example6.adoc[]
 | 
			
		||||
 | 
			
		||||
[[MAKE_QSOS]]
 | 
			
		||||
== Making QSOs
 | 
			
		||||
include::make-qso.adoc[]
 | 
			
		||||
 | 
			
		||||
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