Sticky
#qmx #SSB Firmware beta 1_01_003 release
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#qmx
#ssb
Hi all I updated the SSB beta testing webpage of the brave, here: https://qrp-labs.com/qmxp/ssbbeta.html and released firmware version 1_01_003 to it. These are the changes: Bug fix: Initial value for noise gate samples was 100 (should be max 99) - makes no real difference but it needed to be fixed Added TX indication underlining the A character when transmitting from USB sound card in SSB mode. Note that the two possible states for this indication are a single dot (indicating PTT has been applied and now the radio is in TX mode) and the solid bar (indicating audio is being received from the PC and transmitted). There is no double-dot like there is in Digi mode indicating insufficient volume, because in SSB mode the radio transmits whatever you give it, even if the volume is low. Bug fix: CAT command TQ1; did not cause transmit when in SSB mode. Now TQ1; and TQ0; work properly in SSB mode. Bug fix: Prevent button presses from accidentally activating VOX, which was happening due to sound picked up from the internal (cancellation reference channel) microphone when you pressed buttons right next to it, and that prevented band change because the second click of the double click was ignored because by then the radio was in transmit mode. All fixed! Now you can click buttons however you like and when button clicks are done, VOX is temporarily disabled until your button pushing frenzy is over. Power meter now reads Peak Envelope Power (PEP) when in SSB mode. Previously it was just reading a sampled value (NOT an average); so if the power meter was updated 10x a second, the updates would just randomly pick a value from the SSB amplitude envelope, which was most unlikely to be its peak value. Bug fixL Calibration hung at DAC 1300 when run on LCD. Now the calibration completes properly when run from the LCD. Many thanks for all the feedback so far, SSB in QMX is getting better and better! 73 Hans G0UPL http://qrp-labs.com https://www.buymeacoffee.com/g0upl
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Broken L512 toroid.... T37-10 (Black)
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#toroid
#problem
I've broken one of the T37-10 (Black) L512 toroids. Do you know where I might get a replacement? Thanks, Bill
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Swr meter in SSB mode
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When I use SSB mode do the 2 m by the USB icon change? Because I'm on an antenna with 1.3 SWR but it's showing much higher when I use SSB mode.
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Broken L512 toroid.... T37-10 (Black)
I've broken one of the T37-10 (Black) L512 toroids. Do you know where I might get a replacement? Thanks, Bill
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QMX+: Broken L102
I finished building my QMX+ today and on inspection I see I've broken the core of L102, one of the switching power supply inductors. It looks like both leads of the winding are still connected to the board. I'm not going to try powering it up until I get a couple of questions answered. 1) It looks like the core snapped off almost flush with the bottom flange, which is still attached to the PC board. The ends of the winding are still connected to the board. Would it still work if I just used cyanoacrylate glue to put the core back together? 2) If the answer to #1 is "no," can anyone suggest a suitable replacement inductors that's available in the U.S.? Digi-Key doesn't seem to carry anything of similar size that's greater than 220 uH. This one is 330 uH. Dave, WD8CIV
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QMX+ 0watts output
2
Everything seems good when tx 0 watts jumper in were do I start to trouble shoot?
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QMX(+) Build experience, Poor Audio Filter Sweep/RF Filter Sweep/Image Sweep/ADC IQ test and resolution with new PCM1804
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Good evening! Big thank you to Hans and everyone else in this forum! I had a lot of fun building these kits and I couldn’t have successfully completed them without the folks who ask and answer questions here. I wanted to make this post to thank everyone but also to detail some of the problems I encountered, the equipment I used, and also how I resolved them. This is a long post for anyone who’s interested but TLDR: I built 2 QMX+s and 1 QMX and all three needed new PCM1804s. I purchased a QMX+ in May and a couple weeks later got to work. I had built a couple other kits and antennas previously but this was the most involved so far. I was able to make it through the build and load firmware but I couldn’t run all of the self-tests and the audio was loud static. I didn’t have enough experience or equipment to troubleshoot myself but luckily Jeff Moor W1NC reached out and offered to help. See /g/QRPLabs/message/126274 for my original post. I mailed him my QMX+ and he got it back to me in about a week with several fixes. It had several bad joints, insufficiently scraped enamel, a bad PCM1804, and a bad inductor. Thanks Jeff for your knowledge, experience, and willingness to help the community with your excellent service! I’m extremely pleased with the outcome and my QMX+. I used: A Weller 70W digital soldering iron 63/37 Kester .20 solder 30X/60X loupe https://www.amazon.com/gp/product/B078N34WZR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 LED Head Magnifier https://www.amazon.com/gp/product/B07T4KPYN2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Crescent shear cutter/pliers set from Home Depot A couple of different helping hands type devices Solder wick & plunger type desolderer Flux paste I primarily used the conical soldering iron tip with success but in retrospect, I should have primarily used the wedge tip. The head magnifier with 3x magnification, plenty of light, solder wick, flux, and desoldering tool were critical. The loupe was ok but the head magnifier would have been enough. I ruined the side-cutters on solder wick. Pleased but not content apparently because in July, I purchased another QMX+ so that I could use the lessons learned from the first unit and hopefully successfully build another myself. The kit stayed in the box until my wife & kids went on vacation for about a week. Over a couple of evenings, I had a great time building the kit, using all my new knowledge and experience, but when running the terminal tests, I had bad results on Audio Filter Sweep/RF Filter Sweep/Image Sweep/ADC IQ test. I reworked some of my joints but to no avail. Some example scans, before and after 1804 replacement, are attached. With bad PCM1804 I started diving into groups.io posts and determined that maybe I should invest in more test equipment and that I might have a bad PCM1804 chip. I ordered two more PCM1804 chips (just in case I ruined one). I also ordered a QMX because I was more confident in my kit building skills. In the mean time, I also purchased an LCR meter, a TinySA Ultra (for its signal generator), and an oscilloscope. Probably overkill but I had my eye on them for a while. Over the winter holiday break, I built the QMX. I enjoyed and had more confidence in my build but I had very similar problems to my 2nd QMX+ build during self-tests. During this build, I used a grounding strap/bracelet the entire time so I was pretty sure it wasn’t static discharge related. What are the odds I’d have the same problem twice? I found this post /g/QRPLabs/topic/109639794#msg133769, indicating the PCM1804. I did the diagnostic tests from /g/QRPLabs/wiki/37111 and determined that replacing the PCM1804 was my next step. Luckily I had two new PCM1804’s in stock although I previously intended on only needing one. After doing research here and on youtube for replacing SMDs, I got a ChipQuik kit and a hot air rework station. After doing some tests, I decided I would just use the ChipQuik, which is basically easy-mode for low-skill chip removal. My process was basically, remove the c
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QMX WSPR Anomaly
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I was trying out WSPR with my high band QMX with settings as depicted in the instruction manual. I had my QLG2 attached and working with the green light blinking. I had the transmit set to 4 after the hour as in the instructions, and when that time arrived, the rig kicked into transmit mode. All appeared to be going with when the display suddenly changed to read the following: 14,097,140 CW 5 0 On the next line: VK4JAZ QG62 30. And there it remained, as if stuck. After a good few minutes I shut it down as nothing appeared to be happening. Any ideas what this means?
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About calibration
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I have a QMX built by QRP Labs. I haven't updated to the SSB firmware yet. Do I need to calibrate? How do I do the calibration process? Thanks.
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QMX quit working
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#qmx
#troubleshooting
I have a QMX (80-20) for 12 V that I built last year. It worked fine on FD, and was used occasionally since. A few weeks ago I was running it into a dummy load. Controlled by fldigi. Power was a LiFePO through a regulator at 12 V with a 1.5 A current limit. After messing around with the fldigi settings until I got it to "transmit" into the dummy load. Output power and input current looked good. Then I got distracted doing something else. After some time I looked at the regulator and it was showing 6.1 V at 1.5 A out. The radio is on, and the display works, but obviously something is seriously wrong. WSJT-X communicates with it. I can change frequencies and modes. I looked at the back of the main board with my IR camera. The hot spots appear to be associated with Q507 and Q504. So I've blown it up, but I don't know what I did. Is there a troubleshooting guide? I've opened it up and there's nothing visually apparent. In talking this out I've sort of convinced myself that I have a shorted Q504, drawing too much current and heating up Q507. Does anyone have any better ideas? Is there any way to test this hypothesis other than cutting Q504 out of the circuit and seeing if the excess power draw goes away?
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Available Hand Mics for QMX SSB ?
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Do any of the commercially available hand microphones for existing QRP radios work with the new QMX SSB? Or perhaps pre-wired adapters for those mics already in the marketplace? Bill W3WJ
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My Ffirst QMX SSB POTA
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#20m
#amazing
#antenna
#qmx
#ssb
Hi all, I finally got outside with the QMX to do a POTA activation. My objective with this setup is to have a HF kit as small and light as possible to keep in the glove box of my car for impromptu activations or in between kids sports games, practices etc. QMX is a recent kit built 20-80m version 12v and kit includes: 12 ah lithium ion battery kit built Tufteln QRP EFRW 71’ antenna Retevis mic (Kenwood jack version modified for QMX) thin paracord Weaver 12 oz throw weight 10m RG316 coax Cheap earbuds Toiletry bag from some airline Antenna was set up as a sloper with radiating end about 25’ in a tree and feed end down to a picnic table and tied to a BBQ. SWR was 1.9. Conditions on 20m were good but lots of activity from POTA and the Mississippi QSO party. I got my 10 contacts hunting since it was easy pickings. Great contacts and signal reports from all directions and I’m looking forward to many more outings with the QMX!
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QMX+ no power output, low SMPS bias current
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I finished assembling my QMX+ (including a battery mod) and finally got the chance to test it. In the diagnostics everything appears to check out, until I press P. At that point the SMPS bias current for every band is ~4.6mA (where the PIN forward bias is 30mA). If I press T (while connected to a dummy load), the RF output and the Transmitter Voltage turn RED, with the Voltage reporting ~9.5-10.0V. Power is consistently listed as 0.0W, and the SWR (into the 50 Ohm dummy load) is all over the map. Any ideas what I did wrong? I've looked at all of my soldering connections multiple times and don't see any bad joints or bridges. I've checked everywhere I can think of for continuity, and everything has checked out so far.
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QMX shutting off at 10.5V
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Hello all, My QMX suddenly shuts off at around 10.5V. Is it normal ? I can't recreate it but last summer I think had it giving me high voltage warnings when in fact, voltage was low even if I didn't understand at the time that the radio was suddenly shutting down when voltage is low (/g/QRPLabs/topic/110264408#msg135921)... It is problematic for me as I use a nominal 12V drill battery that goes down to 10.5V relatively quick before stabilising there.... I've already fried the SMPS once so I have a new set bought in April 2024. I am not too sure how to investigate this further. 73, Yannig - F4IUJ
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Tariffs?
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Will USA tariff laws affect the import pricing of Hans’ great radios/kits into the USA?
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beta 1_01_003 FW strange behaviors
I just got back from the Pacific NW robotics district championships where N7BIN and team were competing. There are a couple parks just off the highway near Spokane so took time for POTA on the way to/from. I noticed a couple strange things with the 1_01_003 firmware on my QMX rev 2. At one point, after powering down to swap cables, the display showed USB mode but the rig was clearly in LSB mode. I switched to LSB on 20m and everything sounded normal again. It appears that there is some way for the displayed mode and actual mode to get out of sync. When in SSB mode, I noticed that the SWR meter was swinging wildly into territory where SWR protection should have tripped, but SWR protection did not trip. When in CW mode, it behaved as expected. This was transmitting through a ZM-2 tuner adjusted for 1:1 SWR. Despite this, and the challenge of 5W SSB with a low antenna, the activations were still a lot of fun. 73, Mike KK7ER
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QMX and power bank PD
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Is the QMX itself in any way capable to negotiate the required voltage with the power bank PD? In other words is a 12V trigger cable required or not? I feel more comfy with a trigger cable as it steers away from any negotiating. 73 es dx
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Updated Wiki Page: QMX External Microphone Options
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#wiki-notice
The wiki page QMX External Microphone Options has been updated by Chris <chris.rowland@...>. Reason: Add Headset-Mic with Heil or PC Plugs Compare Revisions
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Wiki Page: QMX External Microphone Options
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#wiki-notice
The wiki page QMX External Microphone Options has been created by Andreas DM7AK <mail2dm7ak@...>.
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QCX+ TCXO
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Just to satisfy my curiosity : which TCXO chip comes with the QCX+ TCXO option? 73 - Pierre - FK8IH
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