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.

You may have noticed that a few of us have been playing with a version of WSPR that does automatic "frequency hopping" from band to band. For this we owe a big vote of thanks to Sivan Toledo, 4X6IZ, who wrote most of the initial frequency-hoppping code.

If you would like to try WSPR with frequency hopping, a beta-release of WSPR 2.20 is now available at



Select "Frequency Hopping" on the Seup menu, and you'll get a screen allowing you to select any desired mix of bands and Tx fractions. Then check "Frequency Hop" in the main window, and WSPR will start its normal 2-minute sequences, switching bands randomly after each one.

Depending on your station and antenna setup, you might need to accomplish other switching besides re-tuning your radio. To make this possible in an automated way, whenever WSPR executes a successful band-change command to a CAT-controlled radio, it looks for a file named "user_hardware.bat", "user_hardware.exe", or "user_hardware" in the working directory. If one of these is found, WSPR tries to execute the command

user_hardware nnn

where nnn is the band-designation wavelength in meters.

You will need to write your own program, script, or batch file to do the necessary switching at your station. I wrote a very simple Python program for this purpose. One of my antennas is an "all band" dipole fed with open-wire line through an automatic antenna tuner. Others include a 160m vertical and a tri-band trap dipole. The antennas are selected automatically, by band; and when a transmission on a new band starts on the all-band dipole, the tuner adjusts itself during the first few seconds of the transmission.

My wife K4PRM and our daughter were inspired to WSPR by
Joe's lecture at Georgia Tech last Saturday for the Ham Jam.

This is what I've learned so far, after trying to setup WSPR the wee hours.
As it happens sometimes, the computer does not work for you, rather you work for the computer!

In this case, I am working with:

* Windows 7 on an el-cheapo Lenovo laptop
* Laptop audio provided by the internal Conexant High Definition SmartAudio 221 sound card.
* A Navigator USB rig control connected to the CAT-V port on an Icom 756 ProIII.
* Some resonant wires strung in the trees.

But nothing showed up in the waterfall.

Here is a list of things that I encountered before I could WSPR:

1. I heard that newer Windows platforms may prevent recording audio from an external or streaming source.

2. My details are a bit sketchy, but Leo LaPort talked about how the
RIAA and the DRM crowd may have influenced PC mfg's to prevent users from recording audio streams.

3. I first ran into this problem when trying to record Neal Boortz streaming
from with Audacity.
I got "Error opening sound device when recording".
Therefore - if Audacity could not hear Neal Boortz, then WSPR could not hear the Icom radio either.

4. Audacity has some very good help that applies to being able to record streaming audio,
and "hear" WSPR audio when using Win 7 here:

5. My work-around is to use an external sound-card. In my case, I'm using the Navigator USB sound card-to-CAT-V interface.

6. I had to add WSPR to the list of "allowed" programs to punch through the Windows firewall.

7. You'll know this problem when you know you have RF coming into the radio, and the radio
is sending audio to the sound card in your PC, but you don't see much color change in your waterfall display.

Ham radio competitions are much more fun when you don't need to wait six months to see how you did! Results for last week's ARRL Frequency Measuring Test are already available at . Hearty thanks to those responsible for running this interesting and highly educational event!

Today, I think for the first time, I have unleashed one of my "old ladies" into WSPR action.

The "old lady" I am referring to is an FT-101ZD Mk3 which I brought back from the dead a few years ago. An EBay "tech special" in US terminology, or "spares or repair" in terms of UK terminology.

This features on my web site ( so I won't repeat too much I have already covered elsewhere, but I think I have proved to myself, at least that these old radios can, with care be used reasonably successfully on today's modern computer-generated modes.

I have been spotting stations with this radio for a couple of days, and today, I enabled transmission and others have spotted me.

The principal disadvantage with the older radios is that of frequency stability, or rather the lack of it.

On my "to do" list for this radio is to (hopefully) improve this facet, probably by replacing the zener diode based voltage stabiliser to the VFO with something of somewhat higher specification (eg low-dropout IC regulator, or similar) as this is where I think the thermal stability weakness lies with this particular radio.

However, having allowed the radio to warm up for some considerable time (four hours) the case temperature of the radio is still gradually increasing but at a very gentle rate. Yesterday the case temperature crept up ALL DAY, as did the VFO frequency error!

Nevertheless, I regard the performance as just about good enough for me to join in the WSPR fun. The results will be stashed away in a spreadsheet on my PC and used in a "before" and "after" type comparison once I decide to tackle the thermal stability issue.

In the meantime if any other WSPRers are wondering why their "drift" as received at G4FUI isn't quite as good as they think it ought to be, then the above hopefully provides some sort of explanation!

On the air since 1948, Signal Sgt. of the Royal Scots Greys (Second Dragoons.)

I'm sure 1 watts or half is nice choice when too many people using WSPR. This is weak signal propagation tool, not digital DXCC way !


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.

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:

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



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!

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.

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.

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:

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: