QMX 5-band 5W digi transceiver – ordered

Hans does it again!

Synchronised with the Dayton Hamvention I was delighted to see the annoucement of a new transceiver from QRP Labs. Ordered this morning without hesitation and looking forward to reporting on progress on the blog!
I think it will be some time before they are shipped – this will be a popular kit from QRP Labs.

Information so far:
The “QMX” (QRP Labs Mulitmode Xcvr): a feature-packed, high performance, five-band (80, 60, 40, 30, 20m) 5W multi-mode transceiver kit. , including embedded SDR receiver, 24-bit 48 ksps USB sound card, CAT control, synthesized VFO with TCXO reference. QMX transmits a SINGLE SIGNAL, it is not an SSB modulator with associated unwanted sideband and residual carrier, or intermodulation due to amplifier non-linearity. QMX outputs a pure single signal. QMX is currently only suitable for single tone FSK modes, which covers the majority of digital modes in use today (if it later supports SSB, multi-tone and phase shift digi modes will be possible). This includes everything in WSJT-X, JS8Call, some fldigi modes e.g. RTTY, Olivia and more. QMX is also suitable for on/off keyed modes such as CW because it has click-reducing RF envelope shaping; it is not suitable (until and if SSB is implemented) for phase shift keyed modes such as PSK31 or modes involving multiple concurrent tones such as WinLink.


  • 80, 60, 40, 30 and 20m
  • CW and FSK Digi modes
  • All features of QCX-mini (VFO A/B/Split, RIT, Message and frequency memories, beacon, keyer)
  • 5W output at 9V supply (can be built for 4-5W at 12-13V supply)
  • SWR bridge built in
  • Single signal transmission (zero unwanted sideband, zero residual carrier, zero intermodulation distortion)
  • Solid-state band switching and transmit/receive switching under CAT control
  • High performance embedded SDR SSB receiver with 60-70dB of unwanted sideband cancellation
  • Built-in 24-bit 48ksps USB sound card
  • Built-in USB Virtual COM Serial port for CAT control
  • Si5351A Synthesized VFO with 25MHz TCXO as standard
  • Easy to build single-board design, Professional quality 6-layer, through-hole plated, silk-screen printed PCBs
  • All SMD components factory assembled
  • Connectors: 2.1mm power barrel connector, USB B (for audio and CAT control), BNC RF input/output
  • Built-in test signal generator and testing tools
  • Switched mode regulators
  • Receive current 80mA, Transmit current 1.0-1.1A for 5W output with 9V supply (around 0.7A for 5W with 12V supply).
  • Optional aluminium extruded cut/drilled/laser-etched black anodized enclosure

After my success with the Ultimate 2 and 3, QCX Plus, QCX Classic and QCX Mini, and QDX, I am excited!

Info here: http://qrp-labs.com/qmx

Order: http://shop.qrp-labs.com/qmx?search=qmx

(tr)uSDX working! – first day tests!

Having messed up slightly by installing a turned pin SIL socket on one PCB and then realising I didnt have a turned pin SIL header the trUSDX project has been on hold whilst I waited for some of the correct header pins to arrive. The header pins actually arrived a couple of days ago but I have been too busy to return to playing with the radio.

Saturday morning came and at last I have had the time to complete the build (well, apart from putting it into a nice enclosure – that will come later). So, a strong cup of cofffee with BBC Radio 4 in the background, and I wound the last couple of toroids (actually it was the FT37 transformers which I had left as a ‘treat’ until the end!) and then fitted the RF amplifier devices (3 x BS170 FETs).

First tests to check the receiver (HF wire antennas) and I was pleasd to find that the bands were alive with strong CW and SSB signals from 80m through to 20m (helped of course, as is customary on a weekend, with lots of Contest QSOs). So, I made a quick YouTube video of the radio on receive (see YouTube clip below). A couple of CW calls on 20m were quickly answered (HA, HB9 and IT9) and some decent reports on the Reverse Beacon including VE2WU in Quebec, Canda) I’ve also shown below the results of later CW tests on 40m and 80m

Next, it was time to wire up a microphone (I am not using the onboard electret – I used a spare (and larger) module left-over from an old BiTX project. A quick tune through 40m looked promising with lots of PA stations working away in the PA contest. I promptly worked over 10 stations and made a clip of SSB QSO #1 on this radio with PI4CC, again see below.

So what next? I need to wire up a proper microphone and then fit the radio into an enclosure. As far the the enclosure goes I am not inclined to put it in one of the 3D-printed organge cases (ie. the DL2MAN original), time to have another look in the junk box I think!

I’ll probably have a go on FT8 and RTTY also because, er … why not!

Running at just 5V (0.45W out) on 20m.

CW at 4W on 40m
CW at 80m

and later in the evening…

SSB Audio quality



and testing transmit, 40m QSO with PI4CC

New Digital modes transceiver from QRPLabs – QDX

Hans Summers has done it again with an amazing new product for kit builders, QRP and digital enthusiasts with the new QDX transceiver. News of the new product release broke last week sending QRP Labs fans into a frenzy on the QRP Labs Google group. An initial batch of 450 units was released on at 1800Z on 11 October with all units sold in 12 minutes! Wow, that’s popular!

The initial batch has been limited in number due to a current global lack of semiconductors although Hans has promised at least one further batch will be available once his supply situation improves. In the meantime, I was pleased to get my order in (despite a number of glitches caused by the online sales portal being overloaded by the sheer number of folks trying to secure their QDX).

All being well the QDX will be here in the UK in a week or so and I will then, as time permits, document the build and operating on here.

Outline details and specs are here:

  • Four bands 80, 40, 30 and 20m
  • 5W output at 9V supply (can be built for 4-5W at 12-13V supply)
  • Single signal transmission (zero unwanted sideband, zero residual carrier, zero intermodulation distortion)
  • Solid-state band switching and transmit/receive switching under CAT control
  • High performance embedded SDR SSB receiver with 60-70dB of unwanted sideband cancellation
  • Built-in 24-bit 48ksps USB sound card
  • Built-in USB Virtual COM Serial port for CAT control
  • Si5351A Synthesized VFO with 25MHz TCXO as standard
  • Easy to build single-board design, Professional quality double-sided, through-hole plated, silk-screen printed PCBs
  • All SMD components factory assembled
  • Connectors: 2.1mm power barrel connector, USB B (for audio and CAT control), BNC RF input/output
  • Built-in test signal generator and testing tools
  • Receive current 100mA, Transmit current 1.0-1.1A for 5W output with 9V supply (around 0.7A for 5W with 13V supply).
  • QFU firmware update for lifetime free firmware updates, easy installation on any PC without drivers, software or hardware e.g. programmer
  • Optional aluminum extruded cut/drilled/laser-etched black anodized enclosure

See Hans’ website for more details: https://qrp-labs.com/qdx.html and the DRAFT manual here: https://qrp-labs.com/images/qdx/manual_1_00.pdf The ordering page is here: http://shop.qrp-labs.com/qdx2?search=qdx

Finally, to whet the appetite, here is a YouTube video outlining the new kit:

Another QCX mini (this one for 20m … and 30m!)

… just need to box it up!

Delighted that it worked first time, I just need to box it up now and connect it up to the GPS unit. Information on the QCX Mini is here and the GPS unit (QLG2) is here.

I’ve just been playing with the QCX on WSPR and very happy to see my signals being received in Antarctica.

See my other post for the adventures tracking the MV Polar Stern (polar resupply and research ship) as she headed south on my first QCX Mini (on 40m) here: https://m0icr.com/tracking-dp0pol-mm-as-she-heads-south

This in 12min of operating (3 calls):

As an added bonus the QCX Mini 20 also seems to work ok on 30m:

RX in Australia, 0.5W on 20m and 30m with the new QCX Mini

Both receivers in the German Neumayer III Antarctic Station receiving me on 30m!

QRP Labs QLG2 module arrived

Delighted by QRP Labs QLG2 GPS module and patch antenna arrived this morning. Especially pleased because the item is has gone of of stock in the last few days as Hans is having supply problems with the microcontroller due to the current global semiconductor chip shortage. The microcontroller is based on a 32-bit STM32 ARM processor.

With optional 16×02 LCD diplay:

Features of the QLG2:

  • Supply voltage range 3.3 to 6V.
  • Board 80 x 37mm (Same as Ultimate3S, VFO and Clock kits).
  • Multi GNSS satellite constellation receiver supports GPS (US), Galileo (Europe),
  • GLONASS (Russia) and Beidou (Chinese) – (default GPS + Beidou) – giving a faster
  • more accurate position fix – Module is E108-GN01 (GK9501 GNSS chip set)
  • β€’ Serial to USB converter, using onboard USB B connector, for convenient interface to
  • PC software if required – no drivers required. Jumpers select either the GPS serial
  • data, or your own externally connected serial data, for example you could use this as
  • a USB to Serial data converter for CAT control of QCX, QCX+ and QCX-mini
  • transceivers.
  • β€’ Can optionally be connected to a standard 1602 LCD, in the same style as the
  • Ultimate3S, VFO and Clock kits, to GPS date, time and satellite information using
  • the onboard microcontroller.
  • β€’ Supplied with included magnetic-mount active antenna, approx 2m coax and SMA
  • connectors
  • β€’ Supply voltage range 3.3 to 6V.
  • β€’ Board 80 x 37mm (Same as, and compatible with, Ultimate3S, VFO and Clock kits).
  • β€’ Onboard LEDs for status indication: Red (Power), Yellow (Serial data) and Green
  • (PPS).
  • β€’ 2.8 to 5V logic level conversion to provide 5V serial data for full compatibility with all
  • QRP Labs kits.
  • β€’ Supports 2.8/3.3V logic OR 5V logic (jumper wire selected)
  • β€’ SMD assembly already undertaken by factory facility – only SMA connector, and
  • optional USB B connector to solder.
  • β€’ Space provided for optional ultra-capacitor for faster hot-start

The QLG2 will be used to provide the GPS controlled time synch signal for both my QCX range of QRP Labs transceivers and also my Ultimate 3 WSPR beacon. I’ll post ‘build and boxing’ images here soon. I am considering adding the device to a clock module using a 20×4 LCD display for more information including Maidenhead locator, Lat and Lon and altitude.

The clock module is available here: http://shop.qrp-labs.com/clock

Once back in stock the GPS receiver module can be purchased here: http://shop.qrp-labs.com/qlg2
In the meantime, Hans has temporarily replaced the module with a QLG2-SE which provides the same functionality as the QLG2 without the microcontroller functionality. http://shop.qrp-labs.com/kits/QLG2SE

Building a K16 CW Keyer for the QCX Mini

The marvel that is the QCX Mini is already equipped with a rudimentary electronic keyer for Iambic modes and including memories, beaconing and practice modes but I wanted to add a K16 keyer for increased features.

The K16 Keyer from Steve Elliot K1EL is perfect for both contesting and casual use and fits on a PCB measuring just 38mm x 35mm. I am using the Kanga UK version of the board available here. Detail of the full range of keyers from K1EL (US site) are here. The K16 chip can be purchased separately if you wish to design your own PCB here (US) or in the UK, again from Kanga UK, here.

Further details of K16 features and operation can be found here.

I have previously built a K14 keyer into an Altoids tin but on this occasion I am salvaging a defunct USB soundcard case to build the keyer into (matches the QCX Mini styling) and will be supplying the power from 2 x CR2032 cells (the keyer only draw 1mA when on and uA when in standby mode) rather than the larger PP3 specified by Kanga.

This is the original soundcard and box:

The K16 keyer in progress:

I intend to integrate my old K14 Keyer into my 20m QCX (vanilla).

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 πŸ™‚
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 πŸ™‚ Anyone for a QCX to QCX sked?

I am going to put further WSPR posts here: https://m0icr.com/category/wspr

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 (qrp-labs.com)
The QCX Mini: QCX-mini 5W CW transceiver kit (qrp-labs.com)
Order your QCX Mini here: QCX-mini 5W CW transceiver (qrp-labs.com)

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

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: https://www.youtube.com/c/QRPLabs/featured

GQRP Convention 2020

Thank you to Steve Hartley G0FUW and all the team at GQRP for the excellent virtual GQRP Convention run over the weekend 5-6th September.

A thoroughly enjoyable event. I have attended a number of the conventions in person over the years and was a little apprehensive about how well it would run as an online event. Whilst I admit I missed the face to face conversations and annual ‘meet-up’ given the circumstances this year I thought the event was a huge success, so much so that I hope the online element continues in future years – if nothing else it provides a much greater global reach and provided a valuable source of videos to watch over again for ideas and stimulation.

A link to the event webpage and links to all the presentation (now on YouTube) is here: http://www.gqrp.com/convention.htm

A direct link to the GQRP YouTube channel is here: https://www.youtube.com/channel/UClhe-ybLZzpnJh80VmFuS-A

Playing with the uSDX

Intrigued by the potential I have converted a spare 40m QCX from QRP Labs into an SSB transceiver, it’s not without it’s issues but it’s remarkable piece of coding. Here’s mine boxed up (groovy orange 44870 LCD unit!).

An earlier manifestation of my build, do you think I need a bigger VFO knob?

Here’s a short video of it working on receive:

Everyone loves Brew Dog IPA!

Here’s me playing with FT8 and the uSDX using an ancient laptop rescued from the bin!

Guido’s GitHub page full of QCX-SSB info, manual, schematic and firmware (*.ino): https://github.com/threeme3/QCX-SSB

If you want a technical explanation of the coding, look at Guido’s page here noting this began with work on a RPi back in 2013: http://pe1nnz.nl.eu.org/2013/

The latest version of the QCX is this QCX Mini and Hans has kindly included a PCB module to enable the uSDX to be built into the Mini. Alternatively you can ‘go the full hog’ and build the uSDX ‘sandwich’, full details are at the DL2MAN website here: DL2MANΒ΄s HAM Radio Page – home of the uSDX Sandwich, it’s also worth checking-out DL2MAN’s YouTube channel here: Manuel K – YouTube