Long awaited firmware update for the QMX

Hans has been actively working behind the scenes to address some of the bugs in his QMX firmware. I'm sure that the amount of energy that this project has drained from him has been enormous.  Nonetheless, he keep plugging away, and with amazing results to show for it.

The latest update(version 1_02_006)  addresses the following (sourced from the QRPLabs groups.io site):-

 

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 rest of the parts were sourced and two mics were constructed.

 

 

The QMX has a lot of test options built into it so it was easy to check that the mics were working as intended. All you need to do is connect your QMX to your PC via the USB-C connector, open PuTTY and entered the terminal application mode (8.2).  Go to 'Hardware Test' and scroll down to the 'Microphone Test' (8.6.9).  Press 'R' to run the test and you should see something resembling the video below, when you speak at a normal level into the Mic.  Gain can be adjusted using the + and - buttons on the PC keyboard and Ctrl-Q will quit the test.

The references in the (brackets) relate to the QMX operating manual (firmware 1_02_002).

It's Official - The QMX now includes SSB.

 

QMX SSB functionality has now been promoted to official version 1_02_000

 After six weeks of Beta releases, the QMX is now officially a CW, Digi and SSB transceiver!

 

On the 2nd of May, Hans made it official. This small pocket sized radio is feature packed, and the feature will, no doubt, still continue to be rolled out. 

 

This major update relates to both the QMX and the QMX+.    

I wonder of the fun in Amateur Radio is inversely proportional to the the amount of money spent on the gear.  The QMX would have to be one of the cheapest investment in AR that I have made, and yet seems to have provided me with the most fun.  And we all need a bit of fun in our lives, don't we!

 

 

The QMX Resurrected

Well, after a well deserved break in WA I'm back home, and the QMX 3.3 Volt buck converter module that I ordered has also arrived. After some quick resistance measurement it was installed. With the supply voltage set to 7 volts and current limited to 200mA, I gingerly switched the QMX on. Oh the Joy of resurrection! It's alive again.

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.

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!

Calibration screen showing 20m USB Sync

 

The QMX, now with a mic!

  

Note: there has already been another update to the firmware. (21 March)

 

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.

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.

 

 

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!

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.

QMX mid-band (60 to 15m)

Well, after thinking about it for over a year I finally purchased a QMX. It only took a week to get here.

So here we are at day one of the build.

I will try and take it slowly so as not to make mistakes. Also, it is very important to read the well written manual, over and over. Just to be sure 😊.