This is a review about the QRP Labs QCX (Qrp Labs Cw Xcvr) kit for 40 meters. Functionally, and except for some band specific parts and coil windings, this kit is exactly the same as any other QCX kit. These are very popular kits, and although very reasonably priced, expect to wait some time, up to a month or more, for your kit to arrive.
The QCX is an impressive kit with a construction and operation manual that is on par (I think in some ways better) than many of the Heath and Elecraft manuals I have used in other kit builds. The manual is arranged very deliberately to step you through populating the board in a fashion that minimizes confusion, and keeps the frustration low. The illustrations are of very high quality, including illustrations, with component legends,for both the front and the back of the board. What a great troubleshooting aid those pictures can be.
The one more complicated aspect of the build, the winding of the T1 transformer, is more intimidating in description than actual practice. If you can count to a reasonably high number without losing your place, and can thread a fine copper wire through the eye of a reasonable-sized toroid, you can easily do this part of the build. At the end, you'll have to place 8 transformer wires from this toroid onto the board into 8 small holes without mixing them up. Testing these for continuity and proper placement with a VOM is pretty essential before you solder those leads down. Hans Summers, G0UPL, the designer of the kit and owner of QRP Labs, has recently told owners that building T1 was put in a place in the build where builder confidence had been buoyed by previous work on less complex components, but acknowledges that building and placing T1 as a first step is considerably easier. Your choice if you want to do that first. Other parts of the build require straightforward component placement (some of which must be placed according to pin-out or polarity) and good soldering skills.
All told, it took me 4 weeknights and half of a Saturday to build my kit, which I did very slowly and methodically. Perhaps a total of 12-14 hours. I am not a fast builder. Your speed probably will exceed mine.
At $49.00 U.S., this is a very inexpensive kit for the value and features (more on that later), but I recommend that you more than double that investment if you do not have some things on hand first to make this build a bit easier.
Among these, first and foremost, is a printed copy of the manual, preferably bound, and in color. You can download the manual from the QRP Labs website when you order your kit and send it to a office superstore (Staples in the U.S. for instance) and they will professionally print and bind this impressive manual for about another $45.00. This made construction so much easier because I could mark things off as I added them to the board, something harder to do on a PDF displayed on a computer monitor. After the build, the printed manual also becomes your general operation and reference manual. By the way, make sure the kit board revision you are getting matches the manual you print - revisions don't happen often, but I managed to catch Hans changing boards, and the Rev 3 board I received did not match the build in my V2 manual. Helpfully, Hans provided an errata sheet in e-mail, which worked perfectly, so I was not required to spend any more money for a new manual. As I've learned, this is typical of his helpfulness towards his customers and the kit building community in general. What a helpful gentleman!
2nd, is a good circuit board holder. The one I bought is on Amazon for about $13.00 from Aven, and it was perfect for the QCX. Being able to rotate the board is critical as you build. This holder can do that.
3rd is a good lighted magnifier tensor lamp, or a head band with light and lenss (I found that the $20 I spent on Amazon for the "Yoctosun head mount magnifier with 2 LED Professional Jeweler's Loupe Light Bracket and Headband are interchangeable" (gotta love the literalness of the Chinese-to-English translators) was money well spent.
Finally, I'm assuming you wouldn't be ordering a kit without having a good quality pencil iron of reasonably small size, but I would think carefully about making sure you have a small tip on any soldering iron because board space is very tight in some places.
So, for an investment of about $49.00 plus printing and parts totaling another $60 or so, what do you get?
You get an amazingly compact, highly feature rich and very handy single-band CW and WSPR rig that would blow you away at a price point three times as high, but will floor you for what you get for less than 50 dollars. The QCX has too many clever features to detail here (and that is done well on Hans' website), but the neatest little touches tell you a lot about the care and thought that went into this kit. These include a replaceable or programmable Microprocessor with custom firmware, the little on board micro-switch CW key, the on board suite of test equipment used to align the transceiver (DVM, Frequency Counter, Signal Generator), the 200Hz CW filter, the very intuitive alignment process, and other nice touches that make this a real keeper. I have had a great time with this rig on the air, with contacts all over the world, which I am sure impresses no one, but the 4-5 Watt CW note is sharp, clear, free of artifacts, and the receiver is plenty sensitive. This is no toy, and if packaged in an appropriate case, would pass for a much more expensive single-band rig like those sold by several other manufacturers. I have used my QCX for literally days with a 3AH Bioenno battery, which I never depleted despite frequent use. It's a good backpacking or mountain topping rig.
In fact, I was so impressed, that I ordered two more QCX radios because building them is as fun as using them. My next kits are for 20M and 30M, and that's from someone who already has an FT-817ND which I dearly love. These QCX rigs are just the best bargain I've seen in Amateur Radio in a long time. As an active SKCC member, and sometime QRP'er, this rig impresses, as does Hans and his superb customer service.
You won't regret buying one of these and putting the time in to build it.
73
Harv
K2PI
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