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.

This Excel (2000 or later) spreadsheet has added the following to GM4ISM's WSPR data download sheet: Statistical analysis of frequency, SNR and Power dBm of downloaded WSPR spot reports; Charts of frequency and SNR of spot reports vs. Date/Time UTC; and Charts of frequency and SNR of spot reports vs. hour of the day (UTC)

I am on 144.489

When K6PZB and I first started up on 2m and 70 cm WSPR, we immediately saw interesting "Doppler" components in the waterfall displays. Sometimes, but not usually, these were such that signals wouldn't decode due to the QRM from the aircraft-scattered signal (ACS). We also saw some strange double-sided signals which we couldn't identify.

Now that a larger group has been on 2m WSPR in California for a couple of months, we have had a chance to both examine ACS better and also to study examples of these double-sided signals. I am becoming of the opinion that these are due to wingtip vortices being generated by large commercial aircraft. These pressure waves are well known and can be a problem for later aircraft. http://en.wikipedia.org/wiki/Wingtip_vortices

Because they are a cause of significant drag to powerful aircraft, a lot of energy can go into producing them and they can persist for many seconds or even several minutes after an aircraft passes by.
It is my suspicion that the large pressure differentials produced by these "curlicue pumps" may be sufficient to cause a sufficiently large and intense change in the dielectric constant of air such that significant 2m energy can be scattered from them. Since they are both (counter) rotating and moving it seems plausible that they may be presenting the two-sided Doppler components visible in the attached SignaLab shot of the strong 2m WSPR signal from K6PZB, located only 8 km to the west. The precise mechanism of the scatter, the sources and other details isn't clear. At this point, I'm only speculating. It does almost look like the aircraft is generating rapidly circulating volumes of air that can even criss-cross at times and go from net-pathlength-increasing to net-pathlength-decreasing vectors. This certainly could happen when oppositely moving WTVs cross the line between the 2m WSPR stations. There are also other possibilities.

Made some changes to the 2-way wspr reports at my website http://mardie4.100webspace.net/
added some .html files to make it easier to browse the reports. Use to be just a directory list of files.

Rig :SoftRock Ensemble RXTX 1W
Antenna :GAP TITAN-DX

Amazing! 17870km per 1 watt ... do I need more?
73, Ross OK5AZ

I teach physics at a high school. Two WSPR projects come to mind for my students to develop:

1) A solar powered WSPR beacon to be deployed in a challenging environment in the Atacama desert. I have contacts on the ALMA project:

http://www.guardian.co.uk/science/video/2011/oct/04/alma-radio-telescope...

2) An ocean current monitoring beacon using "on the fly" position encoding to measure currents in the North Atlantic.

Any other ideas out there?

73

I have put together some things I have noticed about using Wspr on 4m here:

http://www.qsl.net/g0mji/

Now that 4m is on the map it would be good to spot and be spotted by new stations.

73

Brian
G0MJI

Today I had the idea of using wspr as Position Reporting System while traveling through the country.
Just like using APRS but with much less power and on Shortwave.
So what do you need? Of course you need a transceiver and an antenna. But you also need a device, which is generating the WSPR-Messages. And what is the leigthest device you are taking always with you? Correct, your smartphone.

Yesterday I took the time to install on a virtual machine with ubuntu 12.04 the WSPR source.
Just to try if I'm able to do the job right.

An article from blog.marxy.org helped me to get basic information. In the chat section here someone mentioned it this week.

I use WINMOR -a program to send & receive email by amateur radio, great for RV's and Sailboaters. WSPR is great for checking when propogation is good for certain times & locations.

Thanks - keep up the good work!

W6DOM

I bought a great little QRSS kit from Hans and Stephen for the really cheap price of about £16. It runs the full range of QRSS modes and WSPR. IT'S GREAT! I can't believe how well it works for such a cost effective design. It is incredibly simple but the ATMEGA 168 and the built in firm ware make it a doddle to swap and configure modes and change the message you broadcast. The main programming is done when it arrives in the post, but you do need to enter your own call sign and Locator information and power output by using the two press switches on the board.

After a long hiatus, I am back to actively working on enhancing the WSPRnet.org site. In the past two days, I've done the following:

Comments and consensus needed !!

Uk rsgb bandplans for 4m

70.090-70.100 1 kHz Personal Beacons
70.091 MHz WSPR beacons +/- 500Hz

The above means a dial freq of 70.089500

and a tx freq of 70.091 +/- 500hz.

So can we have some sort of consensus on what freq we are using ?

Heres my settings for today 29/06/2012 on 4m wspr.

Dial USB 70.089500

TX USB 70.091050

Comments welcome !!!

Hurray!

Having been running WSPR on a cheap linux laptop and enjoying decoding for a few weeks, I felt it was time for some TX too! It is a straightforward job to connect both audio out and audio in via a microphone connector into an IC7400 and with the TX set to use VOX, and a couple of resistors to pad down the audio from the speaker output to the microphone input on the 7400, it took less than 30 mins, a microphone plug, two stereo audio jacks, a length of screened cable and two resistors (1K5 in this case) to get up and running. Now enjoying being spotted as well as spotting!

I have finally succeeded in getting my Raspberry Pi to WSPR, using the latest Debian Wheezy release, my previous attempts with Squeeze having failed. Transmission seems well within its power and I had a good cluster of spots from a few transmission cycles at 2-3 watts on 20 metres. But reception looks much more difficult, perhaps too difficult, as it is taking about 90 seconds to achieve a decode with the processor being fully loaded. By then it is logging the calls 2 minutes LATER than they actually occured. Perhaps a minor defect in the code that is not normally a problem.

Haven't been on the air much lately. Been modifying the softrock RxTx added motherboard, but old XP computer is on it's last legs, and have to coldstart it.

Might be xmitting soon. Keep up the great work everyone.
73's
vince
N2AIE

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