Sticky
#qmx #Firmware release 1_02_000
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#qmx
#firmware
Hi all SSB firmware was released into beta on 17-Mar-2025 after 9+ months of development. Many thanks to everyone who bravely helped test it and patiently provided their feedback and observations. There are now quite a few YouTube videos, forum reports and other social media mentions about on-air successes with QMX SSB. Now that it has been at least 6 weeks in beta and I believe most of the issues have been resolved, it's time to promote it to an official version. I have called this version 1_02_000 and published it on the QMX page http://qrp-labs.com/qmx where I have also published the updated operating manual, which grew from 111 pages to 134 pages. The main changes are: SSB (obviously!) including CESSB, TX Equalization, Mic AGC, VOX, Pre-distortion and and and... Addition of up to two more USB Virtual COM serial ports (up to three total). All of the hardware tests such as RF and SWR sweep, and Diagnostics, are now available on the LCD too. New CAT commands for LCD contents, S-meter, AGC-meter, Power meter, SWR meter, SSB source Complete list (relative to 1_00_027 the previous official version): SSB modes added (USB and LCB), with CESSB, TX Equalization, Mic AGC, VOX, Phase pre-distortion and more Rationalization of menus, grouped into CW, Digi and SSB submenus (now Keyer and Decoder are submenus of CW) Added up to two more USB Virtual COM serial ports (configurable) LCD versions of AF, RF, Image, LPF, Test ADC I/Q sweeps (miniature graph on LCD) New function PA mod. test to check operation of amplitude modulator Diagnostics screens are now available on the LCD interface too Now remembers previous menu location on ALL menus regardless of nesting level Add way of forcing factory reset, press Menu (left) button during power-up Change TX color in diagnostics screen from red to blue, to avoid confusion since red things are errors Added CAT LC command to retrieve LCD contents Added CAT commands SA (AGC meter), SM (S meter), PC (Power meter), SW (SWR meter) Added CAT command SS (get/set SSB input source) Bug fix: PTT P did not work properly Bug fix: Incorrect PA voltage display on the Diagnostics screen 73 Hans G0UPL http://qrp-labs.com https://www.buymeacoffee.com/g0upl
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QMX+ CAT PTT bug?
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Rev 3 QMX+ running WSJT-x 2.7.0. When running with USB audio mode (SSB mode on QMX+), selected in both the QMX and WSJT-x the TUNE/TX ENABLE or PTT test only gives a momentary PTT signal the first time, try again and it keys the QMX+ correctly. In digi mode in both WSJT-X and QMX it works 100%. Anyone else seen this please? 73 Ken g4apb
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Blown Q504 - heat dissipation was not ok
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My QMX+ stopped working after a few FT8 calls. One of the BS170 transistors had blown and there was a short circuit to GND via Q507. While I was replacing the transistors, I realized the possible reason for this: The BS170 housings are not necessarily exactly the same height, one of the transistors was loose under the washer and slipped out. I only noticed this because I hadn't soldered them yet. If I had soldered the transistors first and then put the washer on later and tightened it, I wouldn't have noticed this. And I think that was also the problem that led to my burnt-out Q504 in the first place. The heat dissipation to the circuit board didn't work properly because the transistor wasn't pressed onto the circuit board properly. I took another look at the assembly manual. It does not explain exactly how to install the transistors and in what order. I think a comment on this possible problem would be good. gl tu es 73 de J?rg DJ4WD
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Another QMX+ Up And Running Sort Of
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I finally powered up my CMX+. On 60m and 30m, I get a full 5W output, but on the other bands (80m, 40m, 20m), there's barely any output. There are also some fairly loud birdies on 40m, mostly. I tried adjusting some of the toroid windings, but saw no difference in power output for 80m, 40m, or 20m. Any ideas where I should look first regarding the low power output levels? Should also mention the firmware update went smoothly no problems at all. Dave
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QMX+ manual and/or a "cheat sheet"
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I just got around to using it, it has sat on my desk for around a year. Maybe I am just overlooking it, but is there a manual for the QMX+? I can only find the one for the QMX and they are different. Also, is there a cheat sheet out there for it? -- Wayne S. KF7RCM
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High current draw on initial power up
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#qmx
#troubleshooting
I received my kit for a high-band QMX this Tuesday, and have been working off and on over the course of the week to assemble it. I've gotten to the point where it's fully assembled, and after several close inspections under magnifying glass and microscope, I can't find any significant defects that would lead to the problems I've been seeing, outlined below I'm powering the QMX from a 10V, 250mA current limiting DC power supply. The core issue is that the board (That I have never programmed) is drawing far more current than the assembly document suggests it should at this stage) The different cases I've run: Main board connected to power, no additional boards attached: 0mA drawn Main board connected to power, PS #2 board attached, all others detached: 0mA drawn Main board connected to power, PS #1 board attached, all others detached: Initially current limited to ~8-9V @ 250mA. After an inrush period, stabilizes to 10V @ ~100mA Fully assembled QMX: Current limited to ~6V @ 250mA. LCD screen turns on with solid black squares displayed. Appears as a usb device immediately upon plugging in to a computer, without pressing the potentiometer button. I've been focusing my troubleshooting efforts on the interaction points between the main board and PS #1, and haven't found any obvious shorts. Checking the pin header connection to PS #1 with the board attached, I didn't see any shorts to ground. I also double checked and ensured that there weren't shorts around the power amp transistors, and around X201 where I saw VCC being used. I've attached photos of the back side of the main board, and front side of PS #1 as installed under a magnifying glass below. If any other pictures are required let me know and I can provide. Note that there is some debris near the PA transistors in the second photo. I cleaned that and tried again, and the board still enters the current limited condition. Thanks and 73 de VA3KBY
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Firmware suggestion for QMX/+
Having just had a panic attack because I thought the LPF wasn't working on my newly constructed QMX+ I have a suggestion for an improvement. Would it be possible to add warnings or even totally disable diagnostic features when they are blocked from operating correctly? For example, on the LPF sweep screen when practice mode is turned on. Just in case anyone else is like me and can't spot the blindingly obvious - The LPF diagnostics can't work if the transmitter is disabled meaning that you just get a flat trace. In my case, I'd turned on practice mode because I was messing about with a plug-in GPS then spent some time trying to work out why my LPF traces were flat on all bands but everything else seemed to work. 73 Mark 2E0OIW (Apologies if there's already a thread somewhere that I've missed)
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40m and 20m RF Filter sweep peaks at higher freq
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Just finished my QMX+ build today, and after tracking down one bad solder joint on L502 I¡¯m up and running with good TX power. I do see RF Filter scan that shows both 40m and 20m peaking off-screen to the right (high freq side). It¡¯s like the whole curve shown in the manual is shifted about +3-4 MHz. The on-band level is about -10 for both 40m and 20m¡ but I don¡¯t see any change when spreading or compressing coils on L403 (that should be the RX filter for 40/20 right?). Not sure what to try next or if it even matters much. Other performance seems good and tests report results as expected. Thanks! Andy
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QDX Low Receive but Xmit fine with OSX
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Thank you Nick. I saw that in some messages but didn¡¯t know how to get in and gain access to change it. I wanted to use the terminal program you suggested but getting there was a yeoman¡¯s feat. I first had to install a number of programs to even install PuTTY for OSX. The first one was Xcode which was almost 30GB only to find out I didn¡¯t really need to. I really only needed to download Developer Tools for Xcode, then something called Quartz and then one called Maxports. Then it was just a matter of launching the PuTTY desktop icon on the Mac, fill in the proper blanks on the GUI (Quartz provided this for PuTTY) and away it went. There is a step by step tutorial on how to install PuTTY for OSX - https://phoenixnap.com/kb/install-putty-on-mac I raised every band to 70 from 54 and although it's still near the bottom of the range (about 1/3 scale) it's much much better. I¡¯m sure folks a lot more familiar with using a Terminal program to make all kind of changes, would have breezed right through this. You pointed me in the right direction which I really appreciated. 73¡¯s. John/K7RLD
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Programming Troubles
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I recently purchased an assembled QCX Mini. I absolutely LOVE this transceiver and I have been using it everyday on W1AW for code practice. I also copied the instruction manual and put it in a neat spiral spine, including a sturdy cover and I keep it beside my transceiver at all times for reference. Soon I plan to go on the air. My problem is, the way to program it is not sinking into my elderly and challenged brain. I'm sure the manual is written well but I often have problems understanding technical instructions so this, by no means, is a problem with the manual. It is instead, a problem in how I process information. Has anyone out there created a "cheat sheet" with step by step instructions? Example: Step 1, Do this. Step 2, To save your setting, do this, etc. Thanks in advance for any advice or "cheat sheet" you can provide. 73. .
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QMX+ - Should there be resistance between T501 primary and secondary windings?
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Greetings all, I am currently assembling a Rev 3 QMX+ and have a question regarding T501. When it comes to continuity between an A point and a B point, my DMM (a Fluke 12) does not beep, though it does display '2.006' on the screen. If I switch the meter to measure impedance, measuring from any A point to ground or a B point results in the meter showing a resistance of 9.77k ohms. Is this to be expected? Note: when I was separating out the winding leads when winding T501, there was NO short-circuiting between the primary and the secondary. I appreciate the help! Charles Johnson PS While I don't think that it would make any difference, for the record, L502 has already been installed, but the BS170s have not (I'm going to socket them, which means that it's easier (at least for me) to install T501 first).
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QMX+ with Talent battery. ATU 10 for Sale
#antennatuner
#ATU
A factory assembled ( Nov 2024) QMX+ with GPS and case. Talent battery YB 1201100 connecting cable with diode for Voltage reduction to 12V and ATU 10 by N7DDC complete in ufb condition. Tested for FT8 successfully. N4AN@....
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Jeff Moore repairs
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Recently, I sent my Rev 1 QMX, which I had problems with the right encoder, and not able to load the new firmware. Mr Moore, troubleshoot the radios, and fixed the issues he found, then did a complete test of all the features, and clean any possible cold solders, or spaltters of solder. Then provided a detail report of what he did, and parts that needed to be change. All of that for just a small donation. Thank you very much Mr Moore, and looking forward to have lots of fun with my improved QMX. Ed Cortes K4BQN
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[miqrp] Weekly Michigan QRP zoom chat
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I joined the waiting room just after 4pm ET, and it said the host has joined. It is now 426pm and I'm still waiting. -- 73, -- Dave, N8SBE, Hamshack Hotline 550-0971, HamsOverIP 101018, AmateurWire 1348
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Continuous tone on 14.053.5
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My home built QMX+ seems to be working great, starting to make good CW contacts as a rank beginner, but I have a consistent continuous tone on 14.053.5 regardless of antenna connected or not. Any pointers where to look? I have not installed any of the new ssb firmware.
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QMX+ - LPF array design question
2
Let me start by saying there is no evidence that the situation I will describe is occurring or has ever occurred in a real QMX+. There is nothing here to worry about. It is most likely just something I am doing wrong so no panicking! OK, I have set up a model of the entire QMX+ lpf array. I have figured out how to make the diode model give a long reverse recovery (Vp parameter). The issue is not with recovery though. I am seeing something that is clear and yet must be wrong. The situation is that I have LPF4 enabled and the others disabled (by switching the gate of the correct BSS123). I set up my source to drive a signal big enough to generate 5 watts out, roughly 22 volts peak. I set up the sim to run without signal for 10 millisecnds to give the simulation time to stabilize the various voltages, mainly the time needed to charge all of the lpf shunt capacitors in the disabled filters up to 12-.7 volts. At that point I discovered that it is a bad idea to simply switch on the 22 volt peak input signal full blast because it ends up creating a large enough input to forward bias the unused filters input diodes. Once the diodes switch on, they cannot turn off until the input signal stops (28MHz period is way less that TRR of the diode). Switching on the lpf0-3 filters puts a near short on the PA output and kills any chance of the doubler getting the reverse bias up above 22 volts so it is fatal. OK, so maybe I need to "shape" the PA output. I "modulated" the input signal amplitude with an RC charge and here is where I ran into the issue. If you do the math on LPF0 capacitors (4400 pf total) charging through a 470k resistor, it takes 5 milliseconds or more to charge. What I found is that I had to use 5-6 milliseconds of "shaping" on the startup of the input signal in order to avoid tripping the LPF0. This seems too long to me but it looks like it is the way it is designed. Note that these diodes are OFF and get turned on by the large input. This has nothing to do with TRR (which is for ON->OFF transitions). This seems to mean that filter input amplitude transitions that rise above 12 volts must do so SLOWLY. Everything in the model seems to be doing what it should. The doubler doubles and the bias begins to rise when the input approaches 12 volts amplitude but it rises at different rates on the load side of the six 470k resistors with LPF0 being very slow and LPF6 being much faster. I have to raise the input amplitude slow enough to avoid turning on the LPF0 input diode. So, where am I going wrong? I have never used a PIN diode but I THINK I understand how they are supposed to function as switch. Is there something that keeps them from turning on quickly? Again, this is SURELY a red herring. But I would really like to make this work right so I have to ask. Thanks, Tony AD0VC
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Jeff, W1NC saved my QMX
Took more shipping time than anything else. awaiting the return. Other than some of my ham-fisted soldering, he reports a bad PCM1804. This would coincide with the symptoms I observed. All the tests he did, and explanations in the email I got this morning, seem like I'm good to go. So awesome to have a resource like Jeff to support the QRP-Labs community. Can't wait to get it in hand! TU W1NC
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QMX+ USB audio?
This is not directly a question for this forum, but somebody may have worked it out: First: my QMX+ USB audio works great into WSJT-x on my Windows PC. Second: When WSJT-x is running on a Raspberry Pi 5, USB control of the rig works _but_, when I try to configure the audio, something strange happens. Under audio configuration, when I look for input devices, it show the QMX+ choices both as an alsa input device and an alsa output device. When I look for audio output devices, the QMX doesn't show up at all. Any ideas? I'm asking the same question in the wsjt forum. Thanks! -- Brent DeWitt, AB1LF Milford, MA
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Ladder Line
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as I was directly asked here are some pictures of what I used to make mine. -- Martin DK3UW
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