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.

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

Well what can I say,

Set up the program connected the rig as easy as that, have had decodes from as as far away as 6800 km just with 1 watt of power on 30mtrs.

Wow - I like this mode :) I am now wondering what I could use this for is it possible to id a station and then arrange a sked on one of the other weak signal modes like jt6m ?

I think I need to have a play and see what happens.

Propagation was very good last Tuesday morning.
I was able to hit Antarctica with about one milliwatt using my Thunderbird 5 mk 2 at 60 feet.

I put up a delta loop for 30 meters. I am feeding the loop at its apex which is at 25 feet. TX power is set to 10 watts.
A 1/4 transformer for matching.

The loop appears to be doing well as I am being heard by:


I just set up a MEPT with WSPR, PowerSDR, a SoftRock RXTX Ensemble and a 40m delta-loop.
Power must be lower than 500mW but hard to measure for now.
I hope to turn the MEPT on during the following nights but I still have some details to sort out.

Yan - XV4TUJ.
Yannick DEVOS - XV4TUJ (Blog in french) (web page in english)

Finished my SDR Lite II last saturday for 30m. Last night I started VAC + Rocky + WSPR to see
if any good. And yes it works :-)

Slightly off frequency, but have no decent time marker available to adjust the single band setting
in Rocky. But hey it's good enough tot start with.

Antenna is a simple dipole, parallel fed with a Diamond W735. The W735 is now a 4-bander (80/40/30/20), just 2
meter above ground.

73 ON3JT