Getting started with the QCX Mini

The QCX mini is a high-performance single band HF QRP CW transceiver kit available for just $55 with a 50W amp for an additional $29.50.

My QCX Mini kit from Hans Summers QRP Labs arrived just before Christmas and was sitting under the Christmas tree for me to open. I’ll be documenting the journey with some links to other useful sites along the way. Watch this space!

A bag of goodies! (actually 3 bags, the LPF bag is under the main component bag)
For scale against my watch
Checking the PCB, no obvious errors under the eye loupe
Earlier stages … transformer took about 30min to wind and install after checking continuity is correct and copper wire enamel removed with solder (10 seconds of heat … one thousand, two thousand ….)

Made sure to install the IC holder as far to the top of the PCB as possible to ensure sufficient space for the paddle socket and the TCXO board.

40m transformer
A few more caps fitted
1. BPF and LPF toroids wound and fitted (wondering if I should have wound them differently to allow for adjustment).
2. Multi-turn potentiometers added for alignment.
3. PCB connectors added for subsequent fitting of control board.
Getting there with the main board.
1. All 3.5mm sockets added (bottom right looked a bit skewed but lines up perfectly with side fascia)
2. BNC connector added (although wondering if I should have used an SMA?).
3. Main board almost finished – must remember to add a 10uF electrolytic across D33/voltage regulator IC.

Main Board connects to the display board …. phew it fits 🙂
She’s alive!

Now for a nice cup of coffee before alignment this evening

Alignment now done, no issues (once I had fixed a dodgy soldering joint on the TCXO!). I followed Hans’ video here: (117) Tuning up your QCX+ – YouTube


Initial findings are that it’s receiving very well and RF output at 12V is just a shade over 3W.

Having a Bud to celebrate progress so far!

Not a great quality video but enough to show progress, (Dodgy polarising filter over the LCD to prevent it washing out my iPhone camera!).

Transmit test to follow …

Testing the Mini QCX in WSPR TX mode:

My very first transmission tests on WSPR:

And the results – AMAZING – Decoded in Antractica on first transmission, how excellent is that for something that was a bag of components 2 days ago!

39 decodes in one transmission (first ever WSPR on my Mini QCX)

Received on both receivers at DP0GVN – Neumayer Station III
Ekstroem Ice Shelf, Atka Bay, Dronning Maud Land, Antarctica

Top 50 spots, all over 1000Km in less than 10min (note only ONE station is reporting drift). Ignore the power shown as 5W, it’s actually 3.6W!:

Top 50 in 10 mins

… and also DP0POL/MM the German Ice-breaker Maritime Mobile (at this very moment the Polarstern, a German research icebreaker is presently off the coast of Africa en route to the scientific station in Antarctica. )

Time to play with CW I think …

No reply to CQ call but picked up on the reverse beacon network in USA and Russia.

Now to bed … Looking forward to some CW QSO’s tomorrow 🙂 Anyone for a QCX to QCX sked?

I am going to put further WSPR posts here:

First CW QSO on QCX Mini – Willi DL2IAD

Very pleased to report working Willi DL2IAD (Herschweiler-Pettersheim, Germany) this morning on the QCX Mini. 599 both ways, a solid QSO. Exactly 600Km IO91SO <> JN39QL.

First QCX Mini QSO – 600Km with DL2IAD

Second QSO on QCX mini GM4ENF 489 (Al in in Cupar, Fife, Scotland)

Boxed up and finished! ( ….. for now!)

A few minutes in the New Year’s Day German AGCW contest on 40m using the Mini QCX


Reference Materials for the QCX Mini

QRP Labs: QRP Labs Kits (
The QCX Mini: QCX-mini 5W CW transceiver kit (
Order your QCX Mini here: QCX-mini 5W CW transceiver (

In the build I will be following some of the useful tips by Ryan Flowers (including his YouTube videos), link here:

I’ve just noticed that David Casler (Excellent YouTube channel by the way) has just received his QCX Mini and will be describing his build here: (117) The QCX-Mini 20m QRP Rig Kit Arrives (#342) – YouTube)

A link to Hans Summers QRP Labs videos including on the QCX Mini and a ‘lab’ tour is here:

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