WSPR-X and WSPR-15

Some of you may be interested in trying WSPR-X, a new version of WSPR that includes the slow mode WSPR-15. WSPR-15 uses 15-minute T/R sequences, rather than the standard 2-minute sequences; at MF and LF it is 9 dB more sensitive than WSPR-2, decoding signals as weak as -37 dB in the standard 2500 Hz reference bandwidth. WSPR-15 is not recommended for use at HF: the tone spacing is only 0.183 Hz, less than the Doppler spreading typical of many HF paths. The main intended application for WSPR-15 is for very difficult paths at 137 kHz and the new 472 kHz band. It may be interesting to try on 160 meters, as well. Note that the recommended WSPR-15 sub-band is a 25 Hz slice just above the 200-Hz WSPR-2 sub-band, i.e., 1600-1625 Hz above the standard "dial Frequency". This will be handled automatically if you set up WSPR-X in the normal way.

A brief online User's Guide for WSPR-X is posted at , and the Windows installation file is posted at .

At present, WSPR-X does not support I/Q audio (for use with direct conversion receivers and transceivers) and does not do “band hopping”. Otherwise most familiar WSPR features are present and working well.

For software enthusiasts: Unlike older versions of WSPR, the user interface of WSPR-X is written in C++ and the Qt programming framework. My expectation is that this shift will make for easier development and program maintenance in the future. At present a click-to-install package is available only for Windows. Source code for WSPR-X is available from the open-source SVN repository at Anonymous checkout of the full WSPR-X source code can be accomplished with the command

svn co svn://

User comments, suggestions, and bug reports will be very welcome!

-- 73, Joe, K1JT