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.

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.

The following is a minimalistic design of a standalone MEPT beacon used for WSPR broadcasts. It is based on a Si570 programmable crystal oscillator ( which is controlled by means of an AVR attiny45 microcontroller. The Si570 device is FSK modulated by the AVR via a sequence of I2C control commands that are sent to slightly change the frequency for every transmitted WSPR symbol, allowing multiband operation on frequencies like:

BeaconTNG does it's first transmits! - Check

Today I got to a point in software development, where I could TX my first WSPR sequences on 14 and 10MHz.
The framework is more or less ready, a lot of cosmetics left, but all building blocks work just fine.
The most impressive facts:
Frequency accuracy : < 0,02Hz
Time accuracy : < 10ms
Time and frequency base : Navsync CW-25TIM
Power consumption in sleep mode : < 10mW
Frequency range : 1MHz - 55MHz
Power Range : 10dBm - 40dBm
Number of filters : 8
Log file memory : 1MB
Processor : PIC 18F87J60
Interfaces : serial terminal, Ethernet (Telnet), 3x16LCD display
I/O ports : 8 opto isolated digital outputs (eg for antenna relays, power or temp management)
2 opto isolated digital inputs (eg external wake up or shut down)
10MHz GPDSO reference out

Because of an overwhelming level of interest, discussion among those testing WSPR 2.1 -- designed for stand-alone operation with the SoftRock RxTx Ensemble and similar SDR transceivers -- has been moved from a private email list to the WSPRnet "Questions and Answers" Forum. See the topic "WSPR 2.1, for I/Q SDRs".

You may still send bug reports to me directly.

-- 73, Joe, K1JT

As of the 15th September 2010, I'm waiting to recieve a kit for the new Softrock RXTX ensemble.
Idea being it will run 24/7 on 40/30/20 Mtrs totally seperate to my main station.
1 Watt output, think that will give a good indication as to which of the bands are open.

I am currently experimenting with a WSPR version that controls and operates radios like the SoftRock RxTx Ensemble.

With WSPR 2.1 you can check a box labeled "Enable I/Q mode" on the Advanced Setup screen. The program will then use 2-channel sampling at 48000 Hz for both input and output. Your SoftRock sends its I/Q baseband signal to the computer's soundcard input; the soundcard output, also in I/Q format, goes to the SoftRock's Tx audio port. T/R switching is accomplished over the USB port. You need no other software such as Rocky or PowerSDR, and there's no need for anything like Virtual Audio Cables. Setup is extremely simple.

Over the past several days I've been running an early version of WSPR 2.1, in Rx-only mode. Right now I'm running in Tx-only mode, Txing 33% of the time, on 30 meters. It seems to get out well. I'll probably finish the T/R switching code and be in full operation within a day or so.

Currently running 500mw through an FT-817 into a BigIR vertical. Station operating 15M 9/17/10. Heavy power line noise from 500kV line 300ft from station.

Joe, K1JT, officially published a beta version of WSJT9 (
Unfortunately this version doesn't support WSPR (including the QSO Mode) any longer without any further notice.

Some apparently bad entries are showing up in the 600meter database from aa 'station' called DO3BOX at GS JO30ix.
Anyone know what is happening with these entries?

73 - Dick w7wkr wd2xsh/26

I just saw some weird log entrys in the database, which are listed for my call as listener with no frequency and with dates in the future.
I uploaded yesterday some log-data to the database. That log was from some wspr activity while I was not connected to the Internet and I wanted to make the heared stations public. It seems that something gone wrong during the import of the log.
I'm very sorry for that.

I've finished my full sdr transceiver, based on free HASDR.
Special thank's at: F6ECI, PE0SSB, DL2JTE, F8BOJ, and others OM's for their technical support.
Best 73!
Franck F1SSF