QMX+ with ~1000 tone on 12M & 6M
63
The radio is a Ver. 1 QMX plus that in general performs exactly like I expect. It does not have the GPS option installed, and there is no battery in the clock battery slot. The radio is used for CW only. As the title suggests, I have an approximate 1000 tone on only 12M and 6M bands. It is internal, in that I can remove antenna and it's still there. It does not change in level or tone while tuning around the band. It appears to de-sense the receiver a bit, as a signal must be pretty strong for me to be able to copy it on 12M. There is normally a 'beat' frequency between the received signal and the tone when I can copy someone. I have run the I/Q sweeps in Putty, using a raspberry pi computer. The tone is present with or without the computer attached. The I/Q sweeps look very nice on the lower bands, and begin to deteriorate as the frequency goes up. They are still showing the two sine waves, but are a bit distorted( not a perfect line of x's ). This deterioration is also noted on 10M and 15M ( to some extent ) and the sweeps for 12M and 6M are not suspiciously worse than others. 10M works flawlessly, as do the other bands. The remaining filter sweeps look good, with some tweaking needed possibly, but totally functional as is. I have a set of QMX HB and LB radios to compare symptoms, and the HB QMX does not have the 'tone' on 12M when swapped into the system. I am curious what path to take troubleshooting this issue. I did not find anything in the archives that addressed this strange behavior. Thanks & 73 Dick W4PID
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Updated Wiki Page: Home
#wiki-notice
The wiki page Home has been updated by @Ludwig_DH8WN <DH8WN@...>. Compare Revisions
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Updated Wiki Page: QMX QMX_plus Debugging
#wiki-notice
The wiki page QMX QMX_plus Debugging has been updated by @Ludwig_DH8WN <DH8WN@...>. Compare Revisions
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QMX SSB QSOs
4
Hi Guys, the SSB modus for the QMX is awesome. Even with a small Magnetic Loop antenna. I?m Using a microphone of the QRP-GUYs from California, USA. At the Antenna connection (bnc) I also use a LED SWR bridge from the QRP Guys. So I can tune my magnetic Loop antenna with full power about 4 Watts with 11V Supply(3 Watts keep in the bridge resistors..lol, 1 Watt will be used for the measurement) . When the LED goes out, I can switch into the operation mode. I NEVER switch of the SWR Protection off (SWR3 in the Menue of the qmx). Has anybody an idea, if the internal microphone can be activated in the nearer future or will there maybe have to do any hardware change ? enclosed my video :) : https://www.youtube.com/watch?v=NKZ_0NkJAIA By the way, I?m using a DC-DC converter to reduce the voltage to 11-11.5V . And yes, it doesn?t make any noise, believe me, Its a quality module from an european electronic supplier and not a cheap piece of sh.. from Temu ! Im using toroids around the voltage supply cables (lpf). Have much fun with the QMX. YOu really did a great job Hans , 72 de Matt, DL1SER
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QMX 40-10?
5
Is it possible to build a QMX that would cover 40, 30, 20, 17, 15, 12 & 10? I¡¯d much prefer that instead of 60-15. Don W6CZ
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QMX battery suggestion
17
Wanted to give a heads up - I haven't seen this battery in stock for a bit and I think it is a perfect match for the QMX. I thought they were discontinued... It's the Turnigy 9xR 3S LiPo cell, very small (approximately a stick of gum sized, a little larger), and it has a protection PCB built in to prevent over discharge or over current. 2.2AH of capacity, 3.3A max continuous current, 12.6v fully charged Can't argue with the price either at under $10 https://hobbyking.com/en_us/turnigy-9xr-safety-protected-2200mah-3s-1-5c-transmitter-pack.html
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Hermes Light 2 vs. QMX+
12
Hello. While I await my QMX+ to arrive so I can experiment, I joined this Group and searched for a few topics that come to mind, but did not find much information. The users here are very knowledgeable about the QMX+ and I am hoping others will provide some insight to these questions. Thank you all in advance: 1. Can the QMX+ be controlled by Thetis? 2. If yes to question 1, do "Radio Model" profiles for the QMX+ exist in Thetis? I only see Hermes and ANAN profiles. 3. Will the developer kit allow the addition of an Ethernet connection? 4. If yes to question 3, will it also allow PoE? 5. Could the QMX+ be powered by USB-C? 6. Could WiFi be added to the QMX+? 7. Can the QMX+ be operated remotely over the Internet? 8. Can a USB microphone connected to the PC be used with the QMX+? 9. It appears that the QMX+ makes use of some form of pre-distortion. Can this be used with an external amplifier (e.g., Mercury Lux)? The Hermes Lite 2 has an additional SMA connector for Pure Signal. I don't see one on the QMX+. 10. Any heat concerns with high-duty cycle modes (e.g., FT8)? The Hermes Lite has a heat sink shim that dissipates heat via the enclosure. I did not see anything like that for the QMX+. I really like my Hermes Lite/Hermes Lite 2+ but appreciate the wider band coverage and some of the intelligent engineering present in the QMX+. I look forward to experimenting, but hopefully others further along in this journey have already sorted out answers to the above questions. Thanks in advance for any replies. 73, Frank - KG9M
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USB audio level boost QMX+
5
I don¡¯t know if anyone else has experienced this, but I was checking out FT8 on 10M and the audio levels were in the red -too low, with no decodes, despite seeing faint signals on the waterfall. I¡¯m using a Surface Go tablet with Windows 11 Pro. I¡¯ve checked the recording control in Windows and it is maxed at 100%. I¡¯m using digi mode and usb audio from the QMX+ plenty of level and good decodes on the lower bands Nick G0OQK
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Amazon Microphone for QMX ? QMX +??? Suggestions
5
Just updated firmware to SSB. on my QMX +, and am waiting a bit on the QMX. My ancient Icom HM 125 ( rewired) worked for a few minutes and quit. I had expected that the official release would enable use of the internal mike?? disappointed. These mikes seem quite inexpensive SO ---- Can anyone recommend a plug in ready to go mic from Amazon USA. Hopefully a product which has actually been tried and works decently with good sensitivity. Yes,I am lazy and impatient (been waiting for SSB for over a year )and also 82. and a bit of a rant I'm also biased against manufacturers who cannot be bothered to have their websites work with safari - the qrp dudes want me to use firefox or whatever. If they don't have the competency to work this out, what about the product( mic) they are trying to sell me?
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QMX+ Case - Screws
3
#QMXplus
Can anyone kindly inform about the M3 black screws used in the QMX+ case ? what'is lenght ? 6 mm 8 mm ? This afternoon after assembly and performed all tests i was presented with 8 black screws that dit not fit, they are M2.5. In the assembly manual is stated they are M3 but no info about lenght. Ahh, by the way the QMX+ worked first power on but with a garbled screen. Had to disassembly the front panel and retouch the LCD pins. Its a big PITA to properly solder them by the manual. Now everything is ok. Greetings //Eduardo
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To socket or not to socket, that is the question!
15
Gotta replace the PAs. To socket them, good or bad? See numrous sockets on ebay and online, but which to order, oh me oh my, what spacing or whatever. What do you say? -- 73 ChuckR
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Ultimate 3S Issue
3
It has been a while since I've used my Ultimate 3S for WSPR and it has worked flawlessly in the past. However now, no signal seems to be transmitting and the oscillator calibration with GPS keeps increasing the frequency constantly. It is now up to 27,011,491 and climbing. This can't be right. Any ideas of what the problem may be?
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It¡¯s Summers-time!
9
It¡¯s May, 2025! Time to take your Qrp-lab equipment outside and enjoy the coming summer, assuming you are in the northern hemisphere. If southern hemisphere, then get that last fling in before bad weather sets in.
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No TX or RX ¡ª Seeking Next Steps for Troubleshooting
5
#qmx
Hi everyone, I recently completed building my QMX kit and it seemed to go well on the surface. The unit powers on just fine, the display works, menus respond, and voltages on the 3.3V and 5V SMPS look normal. However, I'm getting no power output on any band, and I haven't heard any received signals either (just noise). Here's what the diagnostics look like: I've verified all diode orientations match the silkscreen and build guide, and I've done my best to verify good continuity on the pads for all of the toroids. Maybe there's a bad solder joint somewhere less obvious. Does anyone have advice on where to look next or more checks you¡¯d recommend to further narrow this down? Any help would be much appreciated! Thanks, Joe
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QMX 9v Power Supply
14
#9v
Hello, I am getting ready to build my QMX and want to do so in the 9v configuration. Question is the manual says it runs at 9v or "a little over", so the question is. Will the radio be happy and safe to operate with a Bioenno 9v battery. Their website says the battery is regulated to discharge "around 9.6v" Anyone have any experience with using this configuration of Bioenno 9v and the QMX? If so how is it working for you? Thank and 73's W7YWF. (Mike)
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CW Practice / Rag Chew
4
On 4/29/25 I had a CW practice / rag chew session on 17 meters. I worked four stations: Conditions were OK with some QSB. SSN = 134, SFI = 154, A = 4, K = 1. My next CW practice session will be May 06 at 0900 EDT / 13:00 UTC on 20 meters. Anyone and everyone is welcome. This practice is intended for operators who are new to CW or they need some practice. IT DOES NOT MATTER HOW POOR YOUR CW IS. Mistakes are OK. Poor fists are OK. Slow speed is OK. Really slow speed is OK. This practice is meant for you to improve your CW. I will do my best to adjust to your skill level. Operate at any power level. If several stations show up, I will operate as a round-table control station. I will do it as a round-table so everyone gets a chance to transmit. Please listen to my directions. Details: Date - May 06 2025 Time - 0900 EDT / 13:00 UTC Band - 20 meters How to find me - I will find a clear frequency and call CQ. Go to the Reverse Beacon Network and search for my call sign AB8DF. That will tell you what frequency I am on. Tune your station to that frequency and if you hear me give me a call. If there is a QSO in progress, please wait for a break in the action. Then send your callsign. If I hear you, I will invite you to join the QSO and start a round-table QSO. Reply to this email if you have questions. IT DOES NOT MATTER HOW POOR CW IS Ed AB8DF
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QRSS mode and other capabilities of Ultimate 3S
5
Hi anyone, I would like to learn more about weak signal modes? Please suggest a good book for beginners. TNX, George K3GK
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QMX+ Final failure on 12m
6
I have an odd situation here with my 12V QMX+. I could transmit normally on all bands with a 9V power supply. But at 12V when I transmitted on 12m (24.910 MHz) the current draw was quite a bit higher than on the other bands. My power supply's current limit was set at 1.0A and it hit that. All other bands drew less than an amp. After transmitting at that frequency the receive current had jumped to 300 mA (previously about 100 mA) and all the other bands transmitted about half the output power they had before. I replaced the finals and it happened again. Transmitting on 12m at 12V caused a failure in the finals. (Possibly Q507 as well. I get no RF output at all on any band now.) Any ideas on what might cause that one band to zap the finals? I've looked over its lowpass filter and don't see any visible shorts, and the inductors have the correct cores and number of turns. I was able to transmit on 10m before trying 12m and it seemed to work, although with less power out than the other bands.
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QRPLabs 50W Amplifier - 20V Power Supply Solution
4
Just wanted to share my 20V power supply solution that I made that works well for me. The upfront cost was $138 + tax, which includes a charger and a 96Wh portable Li-ion battery. Key features: ? Air travel approved (under 100WAh) ? Shock protected ? Uses 18650 Samsung cells ? Easy to charge ? Built-in charge display ? More compact than LiFePO? ? Weighs only 680g ? Dual purpose if you have other HF power tools. ? Comes with a 3-year warranty! A few photos: A shopping list:
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