QMX - New 5 Band TRX from QRPlabs (Part 2)

Continuing the discussion from QMX - New 5 Band TRX from QRPlabs (Part 1) - #100 by OE6FEG.

Previous discussions:


First question for part 2:

Has anyone else had problems getting a QLG1 to work with the QMX? I get the heartbeat but no data.
73 de OE6FEG

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Hello Matt

Should work! If you log on to QMX with a terminal emulator you get a GPS viewer tool that is very cool. It should show whether you have data or not. Both the QLG1 and our current QLG2 GPS module GPS receiver kit QLG2 have 9600-baud output at the correct voltage levels to use with QMX.

73 Hans G0UPL


My QRPLabs family is growing !!!

It works !!! Just terminated, just tested from home with … of course …a SOTA activator ! TNX DC8YZ/P on DM/BM-309 for my first QSO with my new QMX. I will try it in the field/summit this afternoon !


There is the new FW version 1_00_010 available with important features:

from here:

  1. Single character battery voltage option instead of battery image
  2. Initialization sequence on display so if stuck anywhere we’ll know where
  3. PA voltage is always on in diag screen and green/red to indicate correct range
  4. Power and SWR added to diag screen
  5. Pwr and SWR meter on display; controlled by menu entry in Display/controls menu
  6. Bug fix: Battery now shown correctly at power-up, and when CW decoding disabled
  7. New protection menu, with SWR protection enable and threshold
  8. Supply voltage min/max protection including warn or optional TX inhibit
  9. SWR sweep added to terminal applications
  10. SWR Tuneup screen on QMX LCD

Here a video made by Hans.

Very useful in my opinion. I will test the next days.

73, Ludwig


i have tested today on I/LZ-059 Costa Sole my QMX and i have to say that is a little BIG radio, easy to use and with fantastic performance. Very very happy ! 73 And IW0HK


Hello Andrea,

nice to hear your rating. My QMX saved one activation during my last stay in the Swiss Alps this year. It was a long hike in relation to my current ability. With the QMX and a lightweight antenna I was able to reduce my gear by around 2 kg.

Did you use the latest Firmware 1_00_010? The last days I made some tests around the SWR features. These feature is useful to me on summits. Some values are with uncertainties but perfect to tune the antenna, rate the antenna as useable or not and to protect the TX.

73, Ludwig


Hello Ludwing, yes i have used the last firmware, the SWR reading it’s very useful and also the SWR protection that protect the tx. With this firmware you can look very easy at the SWR reading and the power… all together in the same screen like in a “classic” rtx.

73 And IW0HK


New firmware (1_00_011) came out yesterday:

Unfortunately, not the fixes we were hoping for, but in all fairness Hans was snowed under with problems from the V2 pcb. Hopefully, Santa will bring us a nice update with sidetone/AGC fix before Christmas.
73 de OE6FEG


Hi Matt

Yes that’s right, there were indeed problems with the Rev 2 PCB. I detailed it here: Re: QMX High Band Shipping? - all that is resolved now and my colleagues are frantically trying to ship out the backlog of pending orders for QMXs. This 1_00_011 release was really just to facilitate the Rev 2 fix and the High-band QMX 20-10m version.

I should have some bandwidth now to sort out the other issues AGC, sidetone etc.


AGC appears to be a priority for our ears !!! But as it is winter … we have time Hans !!! Fortunately, global warming is not yet strong enough to do many summits in winter… except for the brave who have snowshoes or skis…

New Firmware 1.00.012 is available thanks to hans !! new audio menu … need to be tested.
73 Nico

Thank you very much Hans! Will install tomorrow, looking forward to testing it out.
73 de OE6FEG Matt

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Hello all,

1.00.013 was released on Dec 13th, but forget it and go to 1.00.014 released on the day after !!! Glitch on CW seems to be resolved … to be tested !!!
73 Nico


With this new release 000.014 the keyer has been greatly enhanced (no more glitchs) … I have just made a test as SOTA QRP hunter with HB9CEV/P, HB9EVF/P, EC7ZT/P, F5HTR/P …
VY 73 Nico


I tested version 1_00_012 on Saturday and was very pleased with the results. One thing I noticed, is that it froze up while I was on 20m, but had no problems on 30m. I was using a 15m Fuchs antenna that was a perfect halfwave on 30m, but a 3/4 wave on 20m, which probably meant there was some CMC on the feedline. As I remember, the QCX was also a bit sensitive to CMC on the feedline. I will put a choke inline after the Fuchs tuner and that should take care of it.
I really enjoyed using the QMX with my noise cancelling headphones yesterday, very nice audio and good copy even at low volume. There’s a slight patter from the keyer, but that is common with noise cancelling headphones. Can’t wait to install version 1_00_014.
73 de OE6FEG


NICE product! Congratulations! The QMX looks like the final answer to a prayer…5 bands, plus multi modes and very small. My venerable FT-817 just seems to get larger and heavier every day to this old timer! I want a full-featured rig that’s WAY smaller!

Questions for Hans, the producer of this rig:

  1. SSB via a firmware update. This mode is very important - or even essential - to many chasers here in the USA. Have you already proven in testing that the rig will do SSB and approximately when can we expect the first firmware update that will provide this mode?

  2. Band lineup. Is there any chance we will eventually be able to assemble the rig with a CLASSIC 5 band lineup 80-40-20-15-10? IMHO, there is no more versatile a lineup that accommodates all different hours of operation and propagation conditions than the old CLASSIC band setup. Perhaps I’m showing my age (licensed in 1974) but I’d much rather have all the classic bands than any of the WARC bands. Activity is much higher on the old standby bands.

Vy 73,
Dennis W1LJ
Prescott, Arizona

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Hi Dennis,

sorry, I’m not Hans. Here are my thoughts.
A TRX for the CLASSIC 5 would be a nice thing. But there seems to be a problem.

Frequencies of 4 from these 5 are harmonic: 3.5 - 7 - 14 - 28. You could not use one LP filter for more than one band. But the QMX contains only 3 LP for all bands of the QMX.

73 Ludwig

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Thanks Ludwig, I am not familiar with the hardware architecture of the GMX and your point is well taken. It’s too bad that a 4th LP filter was not incorporated to provide a “Classic 5” band lineup.

Maybe there is a way to satisfy we “traditionalists” if Hans is willing to help us. I personally can do without 80m in my SOTA rig…the antennas are far too large and I can work stations from 0 km on 40m during daytime. What’s important to me is having 40 m for close in QSOs, and then 15 and 10m for the thrill of making long distance or DX QSOs from the summit!

With just 3 harmonic filters, and appropriate firmware - a 5 band 40-30-20-15-10m rig could be a reality. In my opinion, this would be the most versatile band lineup possible.

Dennis W1LJ
“Since 1974”

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Hi Dennis,

so far as I know the current firmware allows such a configuration. Its only a question of the LP filters and the BP filter.

When building th LP filters you may use toroids from different materials for each filter. The question is to get enough harmonic supression when using one LP for two bands in this config.

But for the BP filter there is only one toroid with taps at the windings. “You” have to decide the right type of toroid and where to place the taps. Maybe it could be possible.

73 Ludwig

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