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.

What is an alligator? In radio terms it's a person who is all mouth and no ears. If we apply the same idea to radio stations (not people), do we have alligators on WSPR?

On a typical overnight (midnight to 8am my time UTC+8) session on 40 metres, I will hear around 6 Europeans and a small handful of North Americans. Yet most nights I am only heard by a small few of those stations.

What does it say about a station's Rx capability (including environmental issues)? Where are the principles of reciprocity when I hear a 0.5 watt signal from 14,000 km away and my 10 watts is not heard in return?

The reciprocal principle says that, all being equal, two stations should hear each other the same, however it's clear to me that all isn't equal.

It's not sour grapes driving me to write this. I just wonder why a station with a Tx antenna good enough to make a 0.5 watt 14,000 km trip, can't receive a signal much greater in magnitude over the same distance/path. Are the paths really one-way so often?

I think I'll take an aspirin and lie down for a while - too much thinking :)


Vacation time - radio time, right ?
The very same day my summer vacation started, which I usually spend at the summer/ weekend QTH, 30 km SE Stockholm, I started to check out this "WSPR thing".
A friend of mine, SM0IKR Goran, had been whispering about this incredible, impressive digital mode.
I´ve been into some digital modes already, but I had heard Gorans voice in my head, for the last weeks, over and over again: "...running just a watt or two... with VK... .working the world..."
So, now I had time, so let´s check it out.

And now I´m stuck.

The software is really impressive, not talking about the result itself. Until now, I´ve roughly two days of experience of WSPR.
Amazing mode.
The rig here at the summer/weekend QTH is a FT-897, and a number of wireantennas hanging around in the pine trees.
The house is in a forest area in the archipelago of Stockholm, so antenna support is directly available.
With the pine trees surrounding the house, some vertical 1/4 wireantennas have seen the light, and today, I got a new 7 MHz 1/4 wave wire vertical with two radials up in the sky.
The 10 MHz antenna is also a vertical 1/4 wave with two radials.

I left the rig on 40m for most of the activity period running from early on the 15th to around 08:00 on the 16th.

Using a very low doublet (~5m agl), the following were heard :
Europe....usual stations although DL6NL with 50mW was weak but consistent for the whole day.

DX...the following were logged :
VE3ODZ (5w)
WB4KLJ (2w)
KE7A (5w) in Texas...consistent signal for ~4-5 hours both mornings.
PY8ELO (20w)

I'm quite new to this WSPR hobby and I'm playing with quite moderate toys: IC-718 + Windom. I'm still only listening, but hopefully I'm soon sending also. My first interesting finding in the log was found last night: PY8ELO was heard on 40 meters. Not bad.

Just got going as a receive only station. Took a while to figure out where the correct 200 Hz band was on 30m ;o)

My current receive set-up is very modest. Rig is a Kenwood TS690s. Antenna is a doublet antenna.....which is basically a 40 and 80 metre dipole in a fan arrangement and fed with 300 ohm twin cable. Height is very low.....only about 4 to 5 metres high.

090701 0124 23 -8 1.2 10.140194 K5XL EM12 30 0 1 0
090701 0126 23 -9 1.1 10.140194 K5XL EM12 30 0 1 0
090701 0128 14 -18 1.4 10.140168 WB3ANQ FM19 30 0 1 0
090701 0128 24 -8 2.5 10.140242 K3SIW EN52 30 0 1 0

090701 0128 5 -26 2.5 10.140251 5H1/4A1LSM R S8 -4 11664 -36

I have designed and built a versatile WSPR beacon that works on 160m to 6m with up to 15W.
It derives time and location information from a GPS mouse and creates WSPR data locally without the need of a PC.
It has a LPF switch module and a attenuator switch module. It can run multiple DDS/PA modules concurrently.
Initial config is done with a Windows utility over USB. Details on the project are available at

Have a look. I would be happy about comments

73, Gernot, OE1IFM

26 june 2009: I've made some mistakes setting right power in WSPR. All the day it was 2,5W

The results from my Home Brew DDS Multimode test on 28MHz using 300mW have been truly amazing. The time has come for it to be switched off shortly. Many thanks for all those who looked just below the WSPR band for my signal and particularly for the Visual Mode Screen Grabs.

Next test in the future may be with approximately 50mW as 28MHz opens up.

Is active with the new temorizzazione beacon IQ4DJ a 10140Khz (Radio Club Carpi) only transmission.

T1 = 1W : T2 = off : T3 = off : T4 = 50mW :T5 = off: T6 = 1W :T7 = off: T8 = off : T9 = 1W : T10 = off

HOME MADE MP3 Logic Control, Logic quartz timer and clock synchronization radiocontrollato (DCF 77.5KHZ).

The beacon is activated IQ4AX a 10140Khz (Radio Club Modena) only received
Upload spots 24H NO STOP

In my first blog, I discussed getting my WSPR station receiver system working. In this installment, I'll describe the work I've done on a stand-alone WSPR transmitter.

Thanks to Andy G4JNT, I began working on the MJB stand-alone beacon controller designed by Johan Bodin SM6LKM. I implemented the schematic pretty much as shown. I had a small board with a RS-232 to TTL converter on it, a MAX236, so that's where I started. I wired in the PIC 16F628, the DDS-30 board from AmPRO and a hex-inverter for the I2C Clock, Data and Chip select lines. I wasn't sure I needed them, so I tried it both ways, but he definitely inverts the signals in his software so the inverter is necessary. I didn't have a 74HC14 that he recommended so I used a 74LS04 which worked fine. The pin-out is different but he didn't show it so that was an easy change.

I recently joined into the WSPR throng and wanted to share my experiences in making it all work. This was a very challenging project to me, harder than it should have been. I have been a ham for almost 30 years, I am an Electrical Engineer and have been an electronics hobbiest for over 50 years. However, in my older years, the ADD has really set in and I don't comprehend all I read as well as I should so most of the problems are my own and might not affect you at all.

To begin with, I downloaded the WSPR V1.11 software for my PC, installed it and connected my Sony ICFW-7600G Shortwave receiver through its earphone output to the microphone input of my PC. Tuning to 10.1402MHz proved very difficult. The Sony only has 1 kHz tuning digitally and a BFO knob for fine tuning. There is a USB/LSB switch, but it doesn't really give you good USB/LSB selection. The BFO is the thing. I don't own a regular ham receiver so the Sony was it.

Have just used WSPR for the first time. And am quite amazed on the first night of reporting.

Using Just 1Watt I received a report from VK, wow!

I can see this as a great tool for seeing how my signals propogate on the various bands on the Doublet antenna I am using.
The Doublet is about 102ft Long 30ft up at the apex and has the last couple of metres of one leg drooping down to fit it in the garden/backyard.

I would like to see how the reports look when overlaid on an EZNEC modelled antenna to see if the signals coincide with the main lobes of the antenna.

First of all, I want to apologize for not being able to put in the time to keep up with the various administration tasks to keep this a first-class site. As you all probably know, the spam bots found the site a few weeks ago and posted hundreds of bogus messages to the forum, and one was even posting on the chat room.

I cleaned that up today, and I also changed the site to only allow new accounts after administrator approval. This may lengthen the time to register and be active on the site by a bit, but it lets us get the bogus registrations back under control.

thanks for the reports, very exciting.

Brian VK5BC