mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-15 16:42:12 -05:00
68 lines
4.1 KiB
Plaintext
68 lines
4.1 KiB
Plaintext
|
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.
|
|||
|
|
.
|
|||
|
|
WSJT-X Version 2.0 offers twelve different protocols or modes: FST4,
|
|||
|
|
FST4W, FT4, FT8, JT4, JT9, JT65, QRA64, ISCAT, MSK144, WSPR, and Echo.
|
|||
|
|
The first eight are designed for making reliable QSOs under extreme
|
|||
|
|
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. FST4, and its quasi-beacon companion
|
|||
|
|
mode FST4W (see below), are designed for LF and MF and offer
|
|||
|
|
significant advantages over JT9 and WSPR on those bands. 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. 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 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 (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 -28 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. WSPR has a new companion
|
|||
|
|
FST4W which has a similar message content but offers up to 30 minute
|
|||
|
|
transmission periods for greater sensitivity on LF and MF.
|
|||
|
|
.
|
|||
|
|
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.
|
|||
|
|
.
|
|||
|
|
Be sure to read the online WSJT-X User's Guide.
|