Stephan Paukner :: syslog

(This time in English, as there isn’t that much mechanical vocabulary involved that I was too lazy to look up in the dictionary, as was the case with my report about building the folding hex-beam. )

Considering my root motivations that made me involved with ham radio, there were three main points I wanted to fulfill:

• Build (but not necessarily design) a TRX completely by myself to gain some making skills, and understand at least the main part of how that HF circuits work,
• Get a small and lightweight TRX for portable operations, no matter if that meant QRP or not,
• Have it only support CW to force myself using CW exclusively on the air, which is a requirement that became relevant to me when I started learning CW. (In addition, CW would help compensate for the QRP constraint.)

So, walking down the aisles of the HAM RADIO fair in Friedrichshafen this June, besides fetching my shiny new Begali morse key, I was looking around for the CW TRX kits, designed to be soldered and assembled by their new owners themselves. The first one I saw (model name skipped here deliberately) was already promising, but it lost against the QCX: The QCX is younger, it has less SMD components (only two, and they are already soldered onto the PCB), and it was way(!) cheaper, despite comparable features. The only advantage of the expensive kit was that one could change the band by replacing a small band-specific module. On the other hand, although the QCX is a one-bander only, with a price tag of only EUR 44.00, one could simply build another QCX for that other desired band. I decided to go for the 40 m variant, having the coming winter season in mind.

As a beginner, it was also important for me to be able to tune the finalized TRX without any troubleshooting that requires advanced electronics know-how, involving signal generators and oscilloscopes. The QCX fulfills this by offering a built-in signal generator and an initial tuning routine that YL/OM follows by adjusting some trimmers while watching an amplitude bar on the display.

Assembly

When the kit arrived with all its component parts, I was really looking forward to the assembly process. And indeed, it was a lot of fun, boosting my soldering skills with each installed component and checking each step with a jeweller’s loupe. The whole assembly took me about 20 hours, spread accross several tinkering sessions: