Saturday, November 01, 2025
Long awaited firmware update for the QMX
Sunday, August 03, 2025
A New Microphone for the QMX
With the advent of SSB on the QMX it was time for a better mic option. Hans, on his QRP-Labs website, refers to Adam K6ARK who has designed a nice miniature 3D printed microphone including PTT button. I don't have a 3D printer (yet) so I put out a call to any club members with one, and Brian, VK8BDM, responded. I sent him the link to the design for said mic and within days he dropped one (actually four) off to me. Brian did an excellent job with the printing as you can see in the images below. Note, the printer used was a Bambu X1.
The references in the (brackets) relate to the QMX operating manual (firmware 1_02_002).
Saturday, May 03, 2025
It's Official - The QMX now includes SSB.
QMX SSB functionality has now been promoted to official version 1_02_000
Thursday, April 17, 2025
The QMX Resurrected
Friday, March 28, 2025
One Dead QMX :(
Well after the high of loading the beta firmware and getting the SSB calibrated and working on my QMX, a downer was bound to follow. The other night I was listening to some CW and the QMX was decoding this reasonably well too. (Better than me, actually!) But I decided to connect the PC up and use the IQ output to get a waterfall display up and running using the NaP3 software. I plugged the PC in, using the USB-C connector on the radio, and then went to power it up. Nothing.... no initiated boot up sequence.... dead!
On inspection I could see that the 3.3v regulator was getting hot. I switched over to another power supply so I could check the supply voltage and current, and I could see that the there was lots of current, so much so, that the voltage protection on the power supply kicked in. There was a short. I removed the 3.3volt buck module and repeated the exercise. This time their was just a few milliamps draw on pressing the on button. I measured the resistance between the 3.3volt line and ground on the main board and this seems normal. These factors are pointing to the 3.3v buck convertor as the culprit. But I'm still not sure why this failure occurred. Was there some voltage differential between the USB-C connector and the 12 volt supply? Not sure.
Be assured an update will follow.
Thursday, March 20, 2025
QMX SSB beta release
I just noticed that Hans has released a SSB beta firmware update for the QMX and QMX+. This is only for the brave.
https://qrp-labs.com/qmxp/ssbbeta.html
The question is, 'am I brave enough?'
The answer is yes!
I firstly, modified a microphone that was in the junk box. The original curly cord had perished in the tropical climate. And then I gave it a quick test.
An update to the firmware was released (as I was on the site). This fixed a number of bugs, so I loaded the firmware (1_01_002 SSB Beta) into the QMX. After reading Hans's calibration notes I duly followed them, with a dummy load connected. The calibration does take a while, (as mentioned in the notes). After the calibration a quick test and the QMX just works, as it should.
This is an amazing achievement by Hans and all credit goes to him. It has been worth the wait!
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| Calibration screen showing 20m USB Sync |
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| The QMX, now with a mic! |
Note: there has already been another update to the firmware. (21 March)
Thursday, February 27, 2025
FT8 with my QMX and an Android phone
A few months back I build a mid-band QMX. I've not had the opportunity to play with it much, but that changed a few days ago. By brother, who is also an Amateur Radio operator, and about as active on the bands as me, was operating FT8 portable. I was 880km from home and had some time on my hands. So, I put up a long wire tuned in 20m, connected my phone to the QMX and opened the FT8CN app. After some minor configuration changes we were up and running. There were a few contact into VK2, (so I knew we were getting out) and then I could see VK6BI/P (my brother) in the RX window. after several attempts we managed a two way contact. This was a first on the HF bands using FT8. 4 or 5 watts was all that was needed.
This was a bit of fun, so I must do it again sometime soon.Friday, October 11, 2024
SSB and CESSB from a QMX+
What is CESSB, I hear you ask. Wiki has the simple answer. CESSB (controlled-envelope single-sideband) is a narrowband modulation method using a single sideband, whose peak envelope level is controlled so that the peak-to-average power ratio of CESSB is much reduced compared to standard SSB modulation and offers improved effective range over standard SSB modulation while simultaneously retaining backwards compatibility with standard SSB radios.
See also David L. Hershberger, W9GR's paper here: - http://www.arrl.org/files/file/QEX_Next_Issue/2014/Nov-Dec_2014/Hershberger_QEX_11_14.pdf
Hans, from QRP Labs, is getting very close to releasing firmware that will add (CE)SSB to the QMX and the QMX+. These are amazing QRP radios in a small form-factor, and getting better with each software release.
Monday, August 19, 2024
A Birthday Paddle
I've been working on getting my CW up to a usable standard, and thought I should treat myself to a new paddle for portable use. The QMX is an amazing radio and it required a suitable paddle. I bought a cheep one (Whiterook Products - Model MK-44) a year or two back, but it more of a toy and wasn't up to scratch.
My next effort was to make one using two Capacitive Touch Sensors . The concept worked reasonably well. The CW purist would hate it but for a novice like me it worked well enough. However the capacitive nature of the sensors meant that even if your fingers came close to the sensors it would trigger which meant that there was a real lack of tactile feedback.
Time to spend up big. Well not really. I settled on a PUTIKEEG paddle from China, for about $54.00 (AU). Not the BaMaKeY TP-III - ultra compact twin paddle at 161,00 EUR plus postage. Maybe later!
The PUTIKEEG paddle, I find, is a great for the price and I'm very happy with its build quality and performance.
I just need to connect the antenna and go for it!
Wednesday, July 17, 2024
QMX mid-band (60 to 15m) compleated
After about four sessions, and lots of coil winding. My mid-band QMX build is now finished. This is an amazing little radio, with more software updates still to come, which will only improve it! The construction is not for the fainthearted as there is no room for error. I build it using a magnifying glass and good lighting and even that was at my limit. It certainly was great powering it up for the first time and running through all the checks to find everything as it should be. Oh joy!
It is paired with a QRP Guys tuner, and a linked End Feed Half Wave antenna. This still required some adjusting to make sure it is resonant on 40, 30, 20, 17 and 15m. A couple more trips to Lee Point will be required! If this proves successful then I might make up some traps to replace the links.
A bug in the software was discovered and Hans has been informed. So good to be able to connect with the developer and have him respond in a timely way.
Wednesday, July 10, 2024
QMX mid-band (60 to 15m)
Thursday, August 12, 2021
Neumayer Station III and my WSPR signal
Wednesday, January 13, 2021
QCX-mini #4
The QCX-mini is now assembled! It when together without a hitch and is receiving CW as it should. The operator just needs to improve his decoding abilities and take the plunge to make that first CW contact. OK, so I've held an Advanced AR License for over 30 years but you just can't rush these things!
Friday, January 01, 2021
QCX-mini #3
My QCX-mini arrived yesterday (31 December). That is only ten days to traverse the world. Not bad for the time of year, and in particular the time of year this year! I'm looking forward to starting construction.
Friday, December 11, 2020
QCX-mini #2
The QCX has undergone a third iteration. I built the original QCX three years ago, then the QCX-plus was released and now the QCX-mini. See below for an introduction to the mini. Hans informed me that he's 'received over 1,000 orders in 3 days'. Looks like there is a second batch coming in the new year.
The original was an excellent kit, and most enjoyable to assemble. Looking forward to assembling this one over the holiday season!
More information can be found here.
Sunday, September 27, 2020
QCX-mini
Hans, G0UPL, is in the process of prototyping a QCX-mini for portable and or SOTA operations. He has made good progress thus far, as can be seen in the photo below.
Hans states that the: -
QCX-mini uses basically the same schematic as the QCX+ and the same firmware chip. Operation and performance are the same. This is NOT therefore being undertaken as a large, time-consuming project. Specifically, the scope is restricted to keeping it QCX-compatible, to minimize development time. Just make-it-smaller. The project therefore is a mechanical re-engineering task, with some documentation towards the end, and a small firmware change to facilitate the configurable LCD backlight.
Wednesday, June 24, 2020
WSPR from Lajamanu NT
Friday, June 19, 2020
QCX Software updated to 1.05
Monday, May 18, 2020
QCX+ 5W CW transceiver kit
I built the original QCX when it first came out and it was one of the best kits that I've ever constructed, this one will be even better, and complete with an enclosure.
QCX+: 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 synthesised tuning, VFO A/B/Split, Iambic keyer, CW decoder, and more...
For complete details see http://qrp-labs.com/qcxp
Hans is looking to ship the first batch in June.
Friday, December 13, 2019
QCX Software updated to 1.03
As I don't update software all that often I thought I would take a screen shot so I'll have a record of which software I used (so I'll know for next time).
There is some added functionality, which includes the following: -
- CAT Control (TS-480 subset, see manual)
- Real time clock option, in bottom right of display, enabled by menu "7.8 Show clock"
- Clock will be automatically set from GPS if it is temporarily connected
- GPS plugged in, puts the radio in Practice mode AND does not key it anymore
- When GPS is plugged and removed, Practice mode is automatically switched off again
- Setting speed to 0, puts the QCX in Straight key mode
- Remove spurious short TX enable at power-up
There is an updated manual with additional info for Version 1.03 .
See: -
Custom splash and Clock function on p.101.
CAT Control commands (PC remote operation) on p.109.
VK8MT Status (Last 3 hours)
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With the advent of SSB on the QMX it was time for a better mic option. Hans, on his QRP-Labs website , refers to Adam K6ARK who has designe...
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I thought I'd make a Rotator Controller for my 2m/70cm Arrow antenna . There were a couple of options and I'm gleaning information ...
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What is CESSB, I hear you ask. Wiki has the simple answer. CESSB (controlled-envelope single-sideband) is a narrowband modulation method ...



























