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For me South America, Australia, and Africa are quite rare on WSPR. But they all heard my tiny 0.2 W signal the night between 31 March and 1 April in addition to North America, Asia and Europe. That’s a new one for me and worthy a brag post on the blog, I think! Hopefully, it may also inspire others to try low power WSPR.

In Australia and South America I was heard on the 10 MHz band, in Africa on 21 MHz, in Pakistan on 14 MHz, while 7 and 10 MHz worked into Siberia. North American stations also heard me on the 7 and 10 MHz bands.

This was on my untuned 80 m horizontal loop fed with open-wire feeder and a 4:1 balun. This shows both that the bare-foot Ultimate 3 kit is very tolerant of loads with SWR much different from 1, and that WSPR gives amazing results.

I have never had any contacts on the 5 MHz or the 60 meter band. But I guess it’s time for that now.

Both my K2 and my K3 support it and about 40 countries now have access to this band according to K1ZZ in his column “It seems to us” in this month’s QST.

As a first test I ran my 0.2 W Ultimate 3 GPS-controlled WSPR transmitter over night and the image shows the result. I am using an 80 m long loop skywire antenna (horizontal loop) tuned to 60 m.

The results were encouraging with the best DX being UR5VIB in Ukraine at a distance of 1887 km. By the way, considering that it is 1093 km to LA9JO in the north of Norway, one sees the distortion in the map projection used for the Google map.

I have also operated the antenna as a vertical (about 8 meters) with top-hat loading by tying both feed-line conductors together and feeding it against a ground plane. The result is quite similar. The article by Dave Fischer, W0MHS called “The Loop Skywire” in QST November 1985 is the reference for both uses of the loop. The article starts out with this catchy phrase: Looking for an all-band HF antenna that is easy to construct, costs nearly nothing and works great DX? Try this one! This matches my experience exactly as this antenna has been instrumental for my 8 band DXCC.

I’ve used AutoCAD for a while (because I had a work licence) but since being promoted I didn’t need CAD software…boooo (I also had an inventor licence but that wasn’t used as much). Anyway, back to the point.

I made a couple of front and rear panels for the QRPLabs ultimate 3 WSPR transmitter and thought that someone else might like to make one. Well if you do the dxf files are below. You can modify them easily in Draftsight (A free 2D bit of CAD software) that accepts AutoCAD files. The file shows the parts embedded on a sheet that can be used for laser cutting and your local FabLab or similar.

Anyway enjoy

AutoCAD Files

For the first time ever I have been spotted on all the five bands that my Ultimate3 QRSS/WSPR kit (G0UPL design) is transmitting on. This is after 2-3 days of transmitting.

Right now I am using the beacon for discovering if the bands should open up on 24 and 28 MHz. The other three bands, and especially the 14 MHz band, serve as references to tell me that the transmitter is working. My antenna is not so optimal so I would be surprised if I am spotted far outside Europe. It is an end-fed 5 m long half wave vertical dipole which isn’t too bad for 28 and 25 MHz, and probably not very good at all on 21, 18, and 14 MHz.

Press image for a better view of the dummy load

Testing a transmitter means the use of a dummy load. Trying to be considerate, I don’t want to cause unnecessary interference with my signals. So when I want to test my Ultimate 3 QRSS/WSPR kit I also pull out one of my dummy loads.

It measures just 9-10 mm across and is the size of a BNC connector. It is simply one of the many Ethernet terminations that I have lying around. Its built-in 50 ohm resistor is rated at something like 0.25 W. Considering that the kit outputs something like 200 mW that should mean that there is enough margin and no forced air cooling or liquid cooling is required.

These terminators were used with 10BASE2 or 10BASE5 ethernet. They are not so common anymore so the terminators are not that easy to find any longer. But they are still very handy for testing QRPP transmitters.

The size of these dummy loads should point out in a very vivid way how tiny the power levels of these transmitters are. Despite that, when running with the effective WSPR code, they can still be decoded on the other side of the globe.

Showing just the back of a piece of equipment is contrary to my bragging instincts, so for completeness, the front of the Ultimate 3 QRSS/WSPR kit is also shown. It is housed in the minimalistic, but beatifully crafted acrylic enclosure from M0ION.

• Ultimate QRSS kits
• My first 24 hours on WSPR