QCX Mini 20 Meter Build

Yesterday I posted about my latest QCX mini kit from QRP Labs arriving. I had intended to wait until the weekend do dive into the build, but…

I couldn’t wait.

As I mentioned before, QRP Labs publishes incredibly well done documentation in their build instructions. You can see the latest version as of this writing here.

I ordered about a week prior, and it arrived via FedEx delivery in good shape and with everything well packed.

The kit is not necessarily difficult if you’ve built similar radios before, but I do recommend reading the manual through one time before starting. Everything is straight forward, but after a couple of hours of huffing solder fumes, it is easy to miss something and having read it first keeps things in mind along the way.

After taking stock of all the parts, I simply followed the manual step-by-step.

This is not a “how-to” post, rather a pic heavy of the steps I took when assembling.

First up is the *dreaded* T1 winding.

For 20 meters, it is 3×3 turns, with 1×30 turns

Actually T1 is really straightforward and simple to wind – if you read the instructions! The main point of the way they instruct you to wind it is so that all windings are the same direction. I think there are two in particular that have to match, but it is easiest to match all of them at the same time.

Soldered, checked, and ready for the next steps

With so many leads coming off of the toroid, taking it slow is needed. But again, follow the well laid out instructions and it comes together nicely.

Next up is the IC socket. Simple stuff, just make sure the notch is in the right place.

Capacitors are multiplying!
Band Pass Filter windings starting to show up
Main board is starting to get crowded

The Main Board comes together pretty quickly – there really isn’t a lot of parts to this kit that are not SMD and already on the board.

Next – moving on to the Display Board and Controls

The display is secured into place prior to soldering

NOTE: Do not toss the clipped leads from the components you’ve already soldered. You will need them for soldering the display leads. Take some of the clippings and use them as connections for the display to the PCB.

Soldering all the makeshift leads is – in my mind – the most tedious part of the build

I failed.

I didn’t remember to take any photos prior to the final smoke test shot below, but it is just mounting connectors and doing final connection checks prior to putting in some power and seeing if we let the “magic smoke” out or not.


If all goes well, then upon first boot up you should see the above.

No magic smoke erupted, and it was time to get into calibration.

Calibration in progress
The whole QCX-mini “sandwich”. Very tight tolerances, but if you follow the manual it all fits the first time

Due to the tight tolerances of the kit and the optional case, I choose to line the case with electrical tape to avoid any potential of having any contacts cause any issues.

It is also recommended to take a moment to ensure that any soldered leads are closely trimmed prior to casing it up.

The kit in its new clothing – I highly recommend the optional case for this little radio as it is well made and fits like a glove


I cannot recommend this kit highly enough. They have created a well laid out kit, manual, and final product. The size of this thing is tiny – but having full-band CW coverage, with additional modes like WSPR puts it in a category all its own.

If they came out with a multi-band CW rig – even only 20/30/40 meters – they would absolutely kill the QRP POTA/SOTA market.

Even so, for the price and size, having 2-3 of these is not too much. This is my second purchase from them and I’m already contemplating a 3rd.

Go get yours at https://qrp-labs.com/

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