LA3ZA Radio and Electronics

My QMX+ has some minor mechanical improvements: Slimmer knobs. I decided to replace the knobs as I often touched the bottom one while adjust...

I got an unassembled QMX+ for Christmas this year, and here are pictures of it coming together. First the winding of toroids for the low-pas...

Envelope Elimination and Restoration, from Kahn 1952  There is a method for SSB generation which is now becoming popular with digital signal...

I have now used both the low- and the high-band QDXes daily as  EA8/LA3ZA  for a period of two weeks without destroying the four BS170 final...

My QDX twins from QRPLabs:  On top, the high-band version, 20-10 m, with a revision 4 PCB In the bottom, the original 80-20 m version with a...

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...

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

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...