WSJT Home Page
Weak Signal Communication SoftwareWSJT, MAP65, and WSPR are open-source programs designed for weak-signal digital communication by amateur radio. Normal usage requires a standard SSB transceiver and a personal computer with soundcard. Some SDR-style hardware including the SDR-IQ, Perseus, SoftRock, and FUNcube Dongle are also supported.
SimJT is a utility that generates simulated signals for test purposes. Ready-to-run Windows versions of all four programs are available for free download. Installation files for Linux are available for WSJT and WSPR. For other operating systems, see the Program Development page.
WSJT ("Weak Signal Communication,
by K1JT") offers specific digital protocols optimized for
meteor scatter, ionospheric scatter, and EME (moonbounce)
at VHF/UHF, as well as HF skywave propagation. The
program can decode fraction-of-a-second signals reflected
from ionized meteor trails and steady signals 10 dB below
the audible threshold. Check the WSJT page for
details about new modes in WSJT 9.3 and the experimental
program release WSJT-X.
MAP65 version 2
implements a wideband receiver for JT65
signals. It can be used together with Linrad
(by SM5BSZ) or SDR-Radio
(by HB9DRV), or with direct input from a soundcard.
The program decodes all detectable JT65 signals in a
passband up to 90 kHz wide, producing a band map of
decoded callsigns sorted by frequency. The principal
application of MAP65 is EME on the VHF and UHF
bands. In a dual-polarization system, MAP65
optimally matches the linear polarization angle of each
decodable signal, thereby eliminating problems with
Faraday rotation and spatial polarization shifts. Check
the MAP65 page for details on modes JT65B2 and JT65C2 in
WSPR (pronounced "whisper") stands for "Weak Signal Propagation Reporter." This program is designed for sending and receiving low-power transmissions to test propagation paths on the MF and HF bands. Users with internet access can watch results in real time at WSPRnet. Version 2.11 of WSPR includes FMT, a package of command-line utilities that can help you make highly accurate frequency measurements without expensive laboratory equipment.
SimJT generates JT65 and CW test
signals with a user-specified signal-to-noise ratio.
It is useful for testing the JT65 decoder and the
relative capabilities of these two modes.