The Weak Signal Propagation Reporter Network is a group of amateur radio operators using K1JT's MEPT_JT digital mode to probe radio frequency propagation conditions using very low power (QRP/QRPp) transmissions. The software is open source, and the data collected are available to the public through this site.

Not being very computer language literate...wonder if any MAC versions of WSPR are around for download? Thanks

I'm trying out the Si570 CMOS USB-controlled RF Synthesiser kit from
If all goes well I shall adapt this for use as a WSPR beacon.

WSPR 2.1 r2210 is now available for download at:

This version corrects a bug found by LA3JJ, and it controls the SoftRock in the same way that it controls all other radios, by using the hamlib program "rigctl".

IMPORTANT: on the Setup | Station parameters screen, you must select a new Rig number for SoftRock control. Scroll down past the Kenwood entries and select this one:

2509 SoftRock Si570 AVR-USB

So far so good. Had WSPR stop once unexpectedly but was also running VirtualBox with another Linux distro, MySQL server and a few other applications running at the same time.

As noted here yesterday, the "Tx dB" slider was inadvertently left in a disconnected state in WSPR 2.1 r2206. This omission is corrected in r2207, available at:

I have also updated the "WSPR 2.1: Supplement to User’s Guide". A new version is posted at

Many thanks to all those who tested and reported a bug in WSPR 2.1, r2198. The bug caused Tx image rejection to disappear and re-appear without notice. Very bad!

This problem has been fixed, and WSPR 2.1 r2206 is now posted at:

Changes since r2198:

1. Intermittent Tx phasing bug has been fixed.

2. Added a Help-menu item to call up the WSPR 2.1 Supplement to the User's Guide.

Compiling WSPR for my 64bit system gave me a bit of a headache, because of a missing library. I found a package containing the missing bit and together, the following commands led to a success:

1. Install required packages

sudo apt-get install subversion python2.6-dev \
python-numpy python-imaging-tk python-pmw \
libportaudio2 portaudio19-dev libsamplerate0-dev \
gfortran cl-fftw3

2. Either check out the latest version of the code

2/10/2010 Just built a quad-band dipole for 15,20,30 & 40Mtrs. Going to use it for the RSGB 21/28Mhz Contest tommorrow.
Still no sign of my Softrock RXTX ensemble in the post. As soon as it's made, I have the antenna...

WSPR 2.1 r2198 has been posted at:

Changes since r2194:

1. On some computers, a bug in r2194 caused errors in Tx timing. Although none of my machines exhibited this problem, I believe it has been fixed. Please let me know if not!

2. Negative values of Fiq are now permitted. You can use an LO on the high side of the desired WSPR band.

WSPR 2.1 r2194 has been posted at:

Instead of listing the essential changes since r2179, I direct you to the document "WSPR 2.1: Supplement to User’s Guide" now posted online at

I've almost finished building my WSPR transceiver using the W3PM design. All of the individual modules have been assembled and individually tested. I still need to finish interconnecting them, debug and align it, and put it in the case. I'm waiting on some RG-174 coax I ordered for the interconnects.

A quick check of the transmitter module last night indicated that it should have no trouble putting out 1 watt of RF power.

Hi all,

The 3 dB deficiency in signal-to-noise of WSPR 2.10 has been traced and corrected. It was an image-rejection problem: not the image about the SDR's LO frequency, but rather the image about the "digital BFO" converting WSPR signals to audio around 1500 Hz. An easy fix, once I understood what I had done wrong.

If you want to use WSPR 2.1 with 3 dB better Rx sensitivity, you can download it from:

Other changes in r2179, relative to r2165:

1. As many users discovered, the "0 dB" level had been set much too high. It has been re-defined at an appropriate level.

2. I/Q mode setup parameters have been moved from menu item "Setup -> Advanced" to "Setup -> IQ Mode". The checkboxes for "Enable I/Q mode", "Reverse Rx I,Q" and "Reverse Tx I,Q" behave as in previous versions.

3. New controls have been added for "Tx dB", "Tx I/Q Balance", and "Tx Phase". You can use "Tx dB" to reduce the amplitude of Tx audio tones (and thus your Tx output power, assuming a linear transmitter) by a specified number of dB. The Balance and Phase controls are not yet functional, see below.

Still to Come

Since starting out on 137.5kHz WSPR a few weeks ago I'm pleased to be able to report some successes with 6 different stations now reporting reception of my sub-20uW ERP signal. Best DX is to G3YXM at 148km.

At OH3MHA we use for WSPR-communications presently a 4 x 3 m vertical (28/25/22/19mm Alu-tubing, totally 11.5 m in length) attached to a wooden fence support, with the fence's wires (cut for various lengths) functioning as the radials. SWR is excellent on 7 MHz. On the 10/14/18/21 MHz bands it can be forced to accept some RF-power with matching circuits. There is considerable loss in the long RG-58 cable. Finally it is the magnitude of the current in the vertical element that is forming the amplitude of the radiated field in cooperation with the properties of the surrounding soil.

The station is situated in an industrial area with poor ground (assuming a dielectric constant of ε = 5 and a conductivity of 5 mS/m). Pending future site improvements it was decided to run some simulations with a design frequency of 14.15 MHz using the free MMANA simulator. To get rid of the radials, a J-pole structure seemed suitable, while the matching section is usable as a mechanical support to get the radiating part of the [vertical dipole] element up in the clear. Starting at 1 m elevation with the structure base the top of the structure arrives at 17.7 m height (guying ropes certainly needed, unlike with the first vertical).

The simulation was done for Ocean water (dielectric constant ε = 80 ; conductivity 4000 mS/m), Lake water (ε = 80 ; 1 mS/m), Good ground (ε =20 ; 20 mS/m), and Poor ground (ε = 5 ; 5 mS/m). Though the maximum intensity of the radiated far field does not change more than 1.5 dB between the cases, its dependence on the take-off angle is huge. Over Ocean water one is able to launch into a low angle of 5 degrees, but there is a -13 dB relative dip at 20 degrees take-off, and even a stronger wide maximum peaking at 44 degrees vertical elevation.

It's been quite an effort to get WSPR to run stably on an FBSD 8 system. The best course I have
found, after lots of false starts, has been to use the windows version inside a VirtualBoxOSE
emulation. This runs fine but I haven't had any luck getting the CAT (CI-V for Icom types)
interface to work. PTT is no problem.