LA3ZA Radio and Electronics

There is a recommended sequence for multi-band transmission on WSPR. It is given in the K1JT WSPR documentation . If enough receivers follow...

I have tried several oscillators in the U3S QRSS/WSPR transmitter from QRPLabs. First an analog devices DDS, then a Silicon Labs oscillator ...

Being spotted by the designer of my WSPR transmitter must be the ultimate WSPR spot! Perhaps only surpassed by being spotted by the design...

Step-down converter based on LM2596. Note the damaged chip Ok, now I've done the test. My QRPLabs U3S runs off a 12 Volt power supp...

These last few days I've been experimenting with my QRPLabs Ultimate 2 and Ultimate 3s transmitting on 7 MHz. In addition to WSPR, the ...

Ultimate 3S with 5-band relay module in front, variable LM2596 power supply (with voltmeter) for the power amplifier  behind left, a va...

The last issues of QEX have featured two interesting articles by Gary Cobb, G3TMG. He outlines the advantage of using Zolotarev designs for ...

As I have mentioned several times on this blog, I have thoroughly enjoyed WSPR modes ever since Hans, G0UPL came out with the first Ultima...

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...

This is a new one for me: Norway-South Africa on 30 m WSPR in the middle of the night. Again I am amazed at what this mode can accomplish...

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...

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 i...

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...

I'm a great fan of Hans Summers (G0UPL) and his effort in launching kits for various slow speed modes. In fact I have all three genera...