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.

callsign changed to ZS6AF



Great Software and Mode.

This really helps to see where ur sig is going to. Great for band openings. Saw this article in QST and discovered I had the same thing only different on UBUNTU. Just never knew what it was for.

FMT utility programs

This message is of interest if you will be participating in the ARRL Frequency Measuring Test on Wednesday evening, using the WSPR-based FMT programs.

Slightly amended versions of fmtave.exe and fcal.exe have been posted on the WSJT web site. Direct links to the new executables are:

Instructions for their use remain the same as those posted at

The previous versions could produce confusing results if you processed data in the "fmt.all" file format with both calibration and measurement data in the same file. This issue has been fixed.

-- 73, Joe, K1JT

PS: If you need the new program versions for use under Linux, let me know.

Matt OZ6OM is WSPRng from Denmark 7th November 2010 from UKSMG stand at Odense

From Robin M1DUD:

"Just to let you know that Matt OZ6OM is WSPRng from Denmark today Sunday.
He is running the UKSMG stand at Odense and will be on WSPR all of today
hopefully giving a demonstration of how it works!!!

If you can listen for him on 50.293 or can be QRV it would be most welcome.

73 Robin."


How is the snr calculated and what is the bandwidth of the channel?





I have been running the WSPR software since about the 20th of October 2010 and have really enjoyed it. It's amazing to see how far your signal goes when you are running very low power of 5 watts of less.

To see my WSPRnet Bio, go to



Strange shapes

Today I noticed some spots that didnt show up as spots, there seems to be a frequency drift of some 10hz form some folks on 10m. The signal should be perfectly redable but it slopes in the form of a J from about 155 hz to 124 hz. I'm wondering if their transmitter isn't as stable as it should be or if this is just some spurrious emission. I only seem to see it in the 10m and 6m bands. Other than that this has proved quite an interesting little program and beats the snot out of the CW beacon format. Cheers!

Computer Clock Errors

In the past several days I've seen quite a few WSPR signals that don't decode because they are mis-timed. This happens when one's computer clock is off by more than a few seconds, and it can be prevented by using an internet time service.

The best of these -- by far, in my opinion -- is one called "Meinberg NTP." It's free, and step-by-step instructions for downloading and setting it up in Windows are available at . It works well on all recent versions of Windows, including Vista and Windows 7.

Highly recommended!

-- 73, Joe, K1JT

Moment of Clarity

So I figured the mess out. My CLock update was not running and was pushed over 17 seconds ahead of CUT(GMT) CUT is COordinated Universal Time per NIST. HAHAH It only took me untill 2 am to figure out that I wasn't so coordinated. All fixed and appears to be working corectly using the NTP service as opposed to DIm 4. Still going to hang on to DIm 4 though It may prove more stable due to more requent updates.

CAT control, WSPR 2.11, and FMT

A slightly amended version of WSPR 2.11, with the FMT package, has been posted on the WSJT Home Page.

Direct links are as follows:



There are two significant changes since r2247:

1. A file was missing that prevented CAT control from working on some computers. This file is now included.

2. A minor bug has been corrected in program fcal.

If you are testing/using the new tools for accurate frequency measurement, please let us hear from you. Bug reports are welcome, of course.

-- 73, Joe, K1JT

Accurate Frequency Measurements

To all those who expressed interest in my software utilities that can help you make very accurate frequency measurements with your CAT-controlled WSPR setup:

These programs are now included in a new WSPR 2.11 package just posted on the WSJT Home Page:

Click on WSPR at the left margin, then on the appropriate link under Downloads. Don't forget to print and study the "FMT User's Guide", . These are not GUI programs, and they have no built-in help files. I guarantee that you'll have no luck using the FMT package without reading its User's Guide! (However, it should be easy reading...)

This has been something of a rush job, since the November 2010 ARRL Frequency Measuring Test is just 9 days from now. If you find errors in the instructions, please send me details.

Good luck with your measurements in the FMT!

-- 73, Joe, K1JT

Asymmetric SNR with TX vs. RX on the lower bands / Remoterig-control

There are many reasons why from a particular location the reported
TX and RX signal-to-noise figures can be very different. One obvious
cause is a different transmit power level at the station on the other
end of a particular WSPR-path. The positioning of the RX-antenna
relative to noise sources is however often the most determining factor.
This is perfectly evident if there is only one major local noise source,
and if it is OFF intermittently (during round-the-clock WSPR-operation).

At OH3MHA and similarly on various other locations we have observed that
things are generally fairly balanced at 10 MHz and higher frequencies, but
7 MHz and 3.5 MHz very often expose computer hash, internet data transfer
spectra (e.g. HomePNA), PLC, switching power supply harmonics and the like.
I do not have experience on the lower bands (1.8 MHz / 500 kHz / 137 kHz),
but there may be a slight advantage due to the fact that there the geophysical
background noise threshold is higher to begin with (to make a fundamental
distinction as opposed to man-made noise: geophysics cannot be manipulated).

OH3MHA was temporarily active on 7 MHz where antenna SWR is optimum with
a perfect 1:1 match, but the incoming man-made noise is very high, so that often
only a few stations are received for upload, while dozens of OH3MHA-spots
are reported by others. OH3MHA transmissions are now back on 10 MHz where
the situation is fairly symmetric, with about even numbers of in/outgoing reports
for each 2-minute transmission slot... We are presently experimenting with products (like the Webswitch 1216H) to have full TX-control
under all imaginable circumstances. Remote control could also be a solution
if one wants to install full WSPR-RX-functionality at a quiet remote location.

I will try to add figures and plots soon to my previous blog posting regarding the
analysis of the benefits of poor ground with vertical antennas for WSPR-traffic.

Interesting propagation

I have started to use WSPR only few days ago and I am exciting !
It was a lot of work to setup WSPR for my RX/TX Ensemble (KB9YIG SDR transceiver 1Watt output power). For receiving only I was able to use only Rocky 3.6, my external sound card Emu 0202 and internal Realtek sound card. But for transmitting I am using PowerSDR-IQ v1.12.20 by SV1EIA and EMU 0202 with VAC. I have found a lot of information about setup on
After first day of transmitting I have realized, that my long wire antenna (41 m long with antenna tuner MFJ-948) works well toward Australia :)

2010-11-01 05:22 LY2BOS 10.140199 -8 0 KO24or 1 IW4EGP JN64gb 1494 223
2010-10-31 22:02 LY2BOS 10.140190 -27 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 21:44 LY2BOS 10.140190 -23 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 21:34 LY2BOS 10.140189 -26 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 20:46 LY2BOS 10.140190 -22 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 20:38 LY2BOS 10.140190 -20 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 20:28 LY2BOS 10.140190 -20 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 20:16 LY2BOS 10.140190 -19 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 20:06 LY2BOS 10.140191 -20 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 19:54 LY2BOS 10.140190 -21 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 19:42 LY2BOS 10.140190 -25 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 19:32 LY2BOS 10.140189 -25 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 19:24 LY2BOS 10.140190 -24 0 KO24or 1 VK6ZRY OF78wd 12886 109
2010-10-31 18:48 LY2BOS 10.140192 -23 0 KO24or 1 VK6ZRY OF78wd 12886 109

WSPR Rig Alignment

I've come to the conclusion I need a more stable and accurate signal generator than my circa 1950 Precision E-200-C or my Heathkit Dip Meter to align the WSPR transceiver. I ordered an N3ZI DDS 2 VFO kit.

Question re: Az to Europe

K1JT's station is a little south of due east from my QTH (near Detroit, MI)at Az 291 that would imply Az of 0 degrees is about due south and increases in a counterclockwise compass direction. However, I noted that contacts in England or Germany as listed in the database at approximately the same Az - which I think is incorrect, please advise, thanks...

First Day Errors

I'm new as of yesterday, 30 October. I signed up because my local club has been interested in propagation and NVIS, and we will be working on some NVIS antennas during the next year. Thank you to QST for the links; thanks to CQ Magazine for the introduction to WSPR several months ago.

And, well, I'm probably an idiot. My first day set-up with my SDG SG-2020 was markedly less than perfect. I have a few minor variations between digital VFO reading and actual frequency, and I failed to correct the rig's band change, so that some transmissions during the first half of 31 October 2010 [UTC] were at 20 W, or 43 dBm, not the 5 W, or 37 dBm, sent out with my data signal.

All of the data on 20 meters, which I changed to before 14:00 UTC on 31 October, is correct.

Sorry guys. I've made the changes and hopefully it will be better hereinafter.

This is really cool. I have been heard as far away as Australia on 20 meters with only 2 watts. It's magic!!

Move your Tx Frequency!

Especially for new WSPR users, I call attention to the following text from step #7 of the quick-start instructions from the User's Guide:

"Select a desired Tx frequency by double-clicking somewhere in the graphical display area. Available Tx frequencies fall in the range 1400–1600 Hz above the dial frequency. Clicking near the bottom of the graphical area gives a frequency near the lower limit, and clicking near the top puts you near the upper limit."

As I write these words, I'm WSPRing on 80 meters, and quite a few signals are present. Unhappily, about half of them are right in the middle of the WSPR band -- where your signal goes if you don't do the step mentioned above. Of course this unnecessary crowding causes many collisions.

Folks, the 200 Hz "WSPR bands" are actually pretty wide. Spread out and use them, and you'll be spotted far more often!

-- 73, Joe, K1JT

Day 1 Setup

So I have a quirky setup, sometimes it works great sometimes...well no so much. I guess I'll list out the parts of the station first. PC Alienware area 51 (Old one 3ghz Pent 4) with a Sound blaster ZS2 Card for audio interfacing. This runs with a std COM cable to a Rig Blaster Pro connected VIA CAT to an IC-7000. Heres the tricky part, the RB uses 2 sets of connections both can be configured to do different things. COM1 is for (Currently set to) RIG control, PTT and CW. COM2 is set for FSK. Windows does not like the driver for the persistant USB to RS232 adapter. Hence this thing should nit run, or so we would think. The IC-7000 is smart enough to recognize certain types of input. I knows the difference between CW and FSK. When in RTTY(FSK) it performs the output appropratly, even with FSK in the RB disconnected it works right. The issue is that instead of using a digital mode Wisper uses USB...It's in USB that the radio gets stupid all of a sudden and wont recognize the damn signal. It transmits, you can even just barely make out the modulation, but there is no ALC use so the modulation is weak. I'd hazard a guess and say that you would not pull it out of the carrier mor than a mile(km) away. Once I get the FSK Rig control thing worked out I'll give it another test run.

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