THE QCX MINI FROM QRPLABS

 

I haven't built a full kit since building my K2 back in 2004.  I don't count the several K3's that I built as they are really just slotting boards together.  Actually getting the soldering iron out was brilliant!

The QCX Mini from QRPLabs is a lovely little kit.  It's a single band, 5W CW transceiver with some great features.  A lot of the components are surface mount but these are already soldered on to the board. This is brilliant for me because there is no way my eyes would allow me to use surface mount components these days :)

You still get the joy of winding toroids and fitting discrete components and hardware.  The manual is excellent and you start by winding the main transformer.

I also fitted the socket for the IC at this point.  Some care needs to be taken to ensure you don't get your soldering iron close to any installed surface mount components and melt the solder there but it really is not difficult.  The quality of the board is superb and solder flows well.  The transformer and other toroids are wound with enamel coated wire and this acts as an insulator of course.  I find the best way to work with this is to install the toroid and hold the iron onto the wire, add a little solder and leave the iron on for 10-12 seconds.  This melts the enamel and you can actually see when it happens.  Make sure you have got good connections by checking with a multimeter.  All it takes is a little patience and care.

I have put a short video on YouTube explaining how to wind toroids, which is also a part of my QDX video.  I thought it was worth putting out as a single short video though, so here it is.

The rest of the board goes together quite well and you end up with something that should look like this...

At this point you build the controls board and complete the kit, ready for testing and alignment.

Now comes the scary part! Get a bag handy, just in case you need to catch the escaping smoke! However, with any luck, the radio should turn on and the LCD should illuminate.  You will probably have to adjust the contrast to actually read what is on the display.

Now it is just down to alignment.  This is done via 4 pots and a menu item.  It could not be simpler.  The manual explains everything.

I did a short video on my build of the QCX Mini for 40m and you can find it below.

You might also find it useful to watch the following video by Hans Summers, G0UPL.  It shows the whole procedure of setting up the QCX.  Although this is not based on the Mini version of the QCX, it is exactly the same procedure on the Mini.

I have had several contacts on the QCX and it's really great fun.  It's a great receiver and the built in reader works very well.  There are memories as well.

If you want a nice little kit to build that will give you lots of fun, I can thoroughly recommend the QCX Mini.

The information below is taken from the QRPLabs website

Special portable-friendly features:

• Small size: 95 x 63 x 25mm enclosure (plus protusions)
• Low current consumption (for example 58mA receive current, with 12V supply and display backlight off)
• Low weight, 202 grams
• Sturdy extruded aluminium enclousre
• All-metal BNC short connector, bolted to enclosure

List of features: 

• Easy to build, two-board design, board with main circuit and connectors, display panel board with LCD; all-controls board-mounted on a press-out sub-board. No wiring, all controls and connectors are board-mounted
• Professional quality double-sided, through-hole plated, silk-screen printed PCBs
• Choice of single band, 160, 80, 60, 40, 30, 20 or 17m
• Approximately 3-5W CW output (depending on supply voltage)
• 7-14V recommended supply voltage
• Class E power amplifier, transistors run cool… 
• 7-element Low Pass Filter ensures regulatory compliance
• CW envelope shaping to remove key clicks
• High performance receiver with at least 50dB of unwanted sideband cancellation
• 200Hz CW filter with no ringing
• Si5351A Synthesized VFO with rotary encoder tuning
• 16 x 2 yellow/green LCD screen
• Iambic keyer or straight key option included in the firmware
• Simple Digital Signal Processing assisted CW decoder, displayed real-time on-screen
• On-screen S-meter
• On-screen real time clock (not battery backed up)
• Full or semi QSK operation using fast solid-state transmit/receive switching
• Frequency presets, VFO A/B Split operation, RIT, configurable CW Offset
• Configurable sidetone frequency and volume
• Connectors: 2.1mm power barrel connector, 3.5mm keyer jack, 3.5mm stereo earphone jack, 3.5mm stereo jack for PTT, 3.5mm stereo jack for CAT control,  BNC RF output
• Built-in test signal generator and alignment tools to complete simple set-up adjustments
• Built-in test equipment: voltmeter, RF power meter, frequency counter, signal generator
• Beacon mode, supporting automatic CW, FSKCW or WSPR operation
• GPS interface for reference frequency calibration and time-keeping (for WSPR beacon)
• CAT control interface
• Optional 50W PA kit
• Optional aluminium extruded cut/drilled/laser-etched black anodized enclosure