WSJT Home Page

                                                 April 10, 2009

                                 Current WSPR Release Version 1.1

                                Current WSJT Release Version 7.03

                                Current MAP65 Release Version 0.9

                              Current MAP65-IQ Release Version 0.9 

Version History
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WSPR (pronounced "whisper") stands for "Weak Signal Propagation Reporter."  This program  implements transmitting and receiving for a digital soundcard mode usable with extremely weak signals.   If you are presently using WSPR version 1.01, you should upgrade now to v1.1.  Here is a  screen shot showing WSPR in use on the 30 m band.

Click here to download WSPR. Then run the resulting executable to install the program.  A full manual for WSPR  has not yet been written, but a Quick Start guide is available.  Program changes since version 0.5 are described in the Changelog.  A basic description of the WSPR protocol can be found at

Please send feedback on WSPR and its use to k1jt at arrl dot net.

WSJT is a computer program for VHF/UHF communication using state of the art digital techniques.  It can decode fraction-of-a-second signals reflected from ionized meteor trails, as well as steady signals more than 10 dB weaker than those required for conventional CW.  One of its operating modes, JT65, is particularly optimized for amateur EME (Earth-Moon-Earth) communications.  WSJT is open source software and is licensed under the GNU General Public License.  It has an active development group: for details see

WSJT version 7.03 (r1090) is available for download here.  This version includes several experimental modes that may or may not become permanent features of WSJT.   An older program version, 5.9.7, is still available here.  A WSJT6 User's Guide and Reference Manual is also available, and translations into many other languages can be found on the Documentation page.

MAP65 is a computer program designed to provide the "back end" of a wideband, polarization-matching receiver for JT65 signals.  In works together with Linrad (by SM5BSZ) and suitable RF hardware to receive and decode all detectable JT65 signals in a 90 kHz passband.  MAP65 runs under Windows or Linux.  Its principal intended application is EME or "moonbounce" on the amateur VHF and UHF bands.  A MAP65 status report is available, as well as a MAP65 Quick Start Guide for users who who wish to participate in beta testing.  Click here to see a screen shot of MAP65 in action, and here to download the installation file for MAP65.  A paper on MAP65 has been placed on the Documentation page.  To use MAP65 you need a functioning Linrad system, a dual-polarization antenna, and a computer with at least 1.4 GHz CPU and 1 GB memory. 

MAP65-IQ has all features of MAP65 except the polarization-matching capability.  It uses a single-channel (rather than dual-polarization) antenna and receiver, and is designed to work with the SDR-14, SDR-IQ, and Perseus receivers.  The MAP65-IQ installation package includes the latest version of Linrad for Windows, as well as full sets of parameter files for the SDR-14, SDR-IQ, and Perseus.

A Windows-based WSJT simulator called SimJT (version 0.9.5) is also available.  You can use this program to test performance of the JT65 modes of WSJT, and to compare them with CW.  Be sure to read the SimJT User's Guide, included with the distribution on the download page.

If you would like to help with future development of WSJT, WSPR, or MAP65, please send me email (k1jt at arrl dot net).  

We (the WSJT developers) hope you will enjoy using these communication programs.

                                         -- Joe Taylor, K1JT


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