Hi all
I hereby officially retire the QSX project which was started in 2018 and aimed to provide a low cost, high performance multi-band multi-mode QRP transceiver. QSX was an ambitious project, probably TOO ambitious. I did probably bite off more than I could chew. As a result of publicity around the project it also caused a lot of pressure and stress.?
But things developed regardless; and it was a happy?day when I decided to take a break from it, and put it on the shelf for a while while I continued with other developments. Numerous new kits came about including the QCX 50W PA, then the QCX+, QCX-mini, QDX, QMX and QMX+. Many people noticed and commented that many of these new kits took steps towards my original goals for QSX. I was getting there, step by step.?
Now with the implementation of SSB and CESSB in QMX+, there is at least a 95% overlap between the planned functionality of QSX and the planned/delivered functionality of QMX+. In many ways QMX+?surpasses the QSX plan in features and performance, and does so at a lower price ($125 compared to my $150 target for QSX, both without enclosure).?
I am measuring for example, IMD -40 dB PEP two-tone test results in QMX+ on 40m; that compares to -30 dB PEP measured on the 10W Linear module of a QSX, -35 dB PEP for Elecraft K3S (ARRL lab measurement in QST review) and -36 dB PEP for Elecraft KX2 (ARRL lab measurement in QST review). Of course two-tone testing isn't everything but as a single number comparison point, it's not a bad indication.?
So we'll continue and focus on QMX/QMX+ firmware development. And consign QSX to history, with respect to the ambition, innovation and ongoing development which it inspired, and whose end result is now the QMX-series.?
