mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-21 11:31:51 -05:00
96 lines
5.0 KiB
Plaintext
96 lines
5.0 KiB
Plaintext
|
||
__ __ ______ _____ ________ __ __
|
||
| \ _ | \ / \ | \| \ | \ | \
|
||
| $$ / \ | $$| $$$$$$\ \$$$$$ \$$$$$$$$ | $$ | $$
|
||
| $$/ $\| $$| $$___\$$ | $$ | $$ ______ \$$\/ $$
|
||
| $$ $$$\ $$ \$$ \ __ | $$ | $$| \ >$$ $$
|
||
| $$ $$\$$\$$ _\$$$$$$\| \ | $$ | $$ \$$$$$$/ $$$$\
|
||
| $$$$ \$$$$| \__| $$| $$__| $$ | $$ | $$ \$$\
|
||
| $$$ \$$$ \$$ $$ \$$ $$ | $$ | $$ | $$
|
||
\$$ \$$ \$$$$$$ \$$$$$$ \$$ \$$ \$$
|
||
|
||
|
||
|
||
Copyright (C) 2001 - 2019 by Joe Taylor, K1JT.
|
||
|
||
WSJT-X Version 2.1 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 a number of advantages over
|
||
JT65, including better performance on the very weakest signals. We
|
||
imagine that over time it may replace JT65 for EME use. 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. QSOs are possible 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.
|
||
|
||
ISCAT, MSK144, and optionally submodes JT9E-H are “fast” protocols
|
||
designed to take advantage of brief signal enhancements from ionized
|
||
meteor trails, aircraft scatter, and other types of scatter
|
||
propagation. These modes use timed sequences of 5, 10, 15, or 30 s
|
||
duration. User messages are transmitted repeatedly at high rate (up to
|
||
250 characters per second, for MSK144) to make good use of the
|
||
shortest meteor-trail reflections or “pings”. ISCAT uses free-form
|
||
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.
|
||
|
||
WSPR (pronounced “whisper”) stands for Weak Signal Propagation
|
||
Reporter. 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.
|
||
|
||
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.
|
||
|
||
WSJT-X provides spectral displays for receiver passbands as wide as 5
|
||
kHz, flexible rig control for nearly all modern radios used by
|
||
amateurs, and a wide variety of special aids such as automatic Doppler
|
||
tracking for EME QSOs and Echo testing. The program runs equally well
|
||
on Windows, Macintosh, and Linux systems, and installation packages
|
||
are available for all three platforms.
|
||
|
||
WSJT-X is an open-source project released under the GPLv3 license (See
|
||
COPYING). 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. The project’s source-code
|
||
repository can be found at https://sourceforge.net/projects/wsjt, and
|
||
communication among the developers takes place on the email reflector
|
||
https://sourceforge.net/p/wsjt/mailman. User-level questions and
|
||
answers, and general communication among users is found on the
|
||
https://groups.yahoo.com/neo/groups/wsjtgroup/info email reflector.
|
||
|
||
|
||
Project web site:
|
||
|
||
https://www.physics.princeton.edu/pulsar/K1JT/wsjtx.html
|
||
|
||
Project mailing list (shared with other applications from the same
|
||
team):
|
||
|
||
https://groups.yahoo.com/neo/groups/wsjtgroup
|