QCX-20 5 watt CW Tanciever
O Boy! This radio kit is superb! Ten out of ten to Hanns Summers
The QCX is a feature-packed, high performance, single-band 5W CW transceiver kit, with WSPR beacon and built-in alignment/test equipment. Available for 80, 60, 40, 30, 20 or 17m bands. It has rotary encoder synthesized tuning, VFO A/B/Split, Iambic keyer or manual, CW decoder on both receive and transmit, plus many more.
I pre-ordered my kit for the 20m version on the 06/11/2017 hoping to receive it in time for Christmas; my wife was going to give it to me as one of my Christmas presents. I was not disappointed, it arrived five days before; I was so pleased. I had a two week holiday for Christmas and I planned to build this kit over that time.
The kit arrived well packaged and all parts were present. The PCB was of excellent quality with two surface mount components already soldered to the board. I was very glad of this because the soldering of pin spacings that small is beyond my abilities.
The construction manual is extensive, with every parts location, type and value clearly highlighted page by page. The manual has to be downloaded and is best printed out so that you can mark your progress as you build.
Despite this, I still managed to place a resistor and electrolytic capacitor wrongly due to laps of consideration, so a hard copy of the manual is strongly advised. The manual is 141 pages and I found that colour was a definite advantage, so make sure your printer has plenty of ink/toner.
To start with, all the IC components were soldered in place, making sure they were soldered flush to the board. This is best achieved by soldering pin 1 and then the pin diagonally opposite holding the IC flat to the board.
The next stage is the placement of all the capacitors. These are very small with even smaller values printed on them so be careful. I double checked with a magnifier just to be sure.
Following on, the resistors are next and there is a lot of them. Just to be sure I checked them all with a multi-meter before finally soldering them in place. However, despite my best efforts, I still managed to put a resistor in the wrong place and had the difficult job of removing it without damaging the tracks. Fortunately, this was successful.Almost done, now it was time to wind the toroidal inductors and transformer.
The inductors for the low pass filter were easy enough, however, T1 was a very different matter. There are very clear instruction on the winding of this part and followed carefully it should not present too much of a problem. However, what I found difficult, was inserting the eight ends from the four separate windings, into the appropriate holes in the PCB, while keeping the separate windings nice and neat. This took me several attempts but I got there in the end. This was by far the most difficult part of the project, everything else was plain sailing
Next, the sockets, buttons, and control pots are soldered in and then the atmeg processor chip is plugged into its socket before installing the LCD screen.
Finally, that anxious moment when you connect to the power and turn on hoping for no smoke has arrived…
Thankfully all was well and I was welcomed by a comforting blue glow and when the backlight trimer was adjusted correctly, the message “Select band: 80” which is the default; appeared.
The alignment process was made really easy by the incorporation of the inbuilt test equipment, including a signal generator and frequency counter.
After alignment was complete, I connected an antenna and tune the CW portion of the 20-meter band.
The features on this transceiver are astounding for something of this size and price.
There is an extensive menu system with more than 80 different configuration or operating parameters stored in non-volatile memory (EEPROM). These are editable to control every aspect of the radio’s behavior.
Also, there are 14 configuration items in the Messages menu and much more.
My next task is to put this amazing little rig into a smart case that is worthy of it. I have some ideas for this and as soon as I have the time, will get out in my workshop and get started on it.
For anyone who is short on ideas for an enclosure for this rig, there are examples of what others have done and uploaded to the QRP Labs website here: https://www.qrp-labs.com/qcx/qcxgallery.html
It is my intention to use this little rig for caravanning holidays and also for some field trips etc. therefore my enclosure will need to be fairly rugged.
Much to my pleasure, several stations could be heard and the decode function was found to work surprisingly well. I plugged in my homebrew paddle key and sent a few CQ calls.
As there were no replies I searched my callsign on the Reverse Beacon Network and was very pleased to see how many spots I had well into Europe. Ironically, My very first QSO was a fellow member of the local club. I have now put the rig aside until I have put it into an enclosure, hoping this will spur me on to getting it done. sooner.
If you are new to CW, the decoded feature when sending is very good for checking the quality of your own CW. If your sending is correctly sent with good spacing, it will be decoded, however, if it displays a garbled message, you need some more practice.
Building a scratch built enclosure for the QCX
As I had some scrap aluminium box section that was once the main support beams for a lean to potting shed and several large pieces of smocked Perspex.
I thought I would use these materials to make my enclosure. I wanted the enclosure to be sturdy for portable use and yet still look a little classy.
I have used the aluminium box section for other projects with some success, however this time the section would need to be cut in half to make it easier to place the QCX board inside. The two halves would be joined together with aluminium strips inside.
The gain pot control and encoder shaft needed to be extended in order to protrude sufficiently through the top for the nobs.
The picture slides bellow show the various stages:-
This project wins the Trowbridge & District Amateur Radio Club kit build constructors cup 2018