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I just built a Pacific Antenna mic kit for my QMX+ and it works great!! If you need a mic for your QRP-Labs transceiver kits I would look at this unit. Very simple to build and inexpensive. 73/GL

President Trump has signed an Executive Order that ends the tariff/duty exemption on small value shipments (i.e. < 800 USD) sent from China to the US. It is not made clear if this change will apply to shipments from other countries as well. This will certainly impact those of us who purchase PC boards, electronic components and modules, and equipment in pursuit of our hobby. 73, Ben K0IKR Here is text from the US government: ¡°Today, President Donald J. Trump signed an Executive Order eliminating duty-free de minimis treatment for low-value imports from China¡­¡± ¡± Following the Secretary of Commerce¡¯s notification that adequate systems are in place to collect tariff revenue, President Trump is ending duty-free de minimis treatment for covered goods from the People¡¯s Republic of China (PRC) and Hong Kong starting May 2, 2025 at 12:01 a.m. EDT. Imported goods sent through means other than the international postal network that are valued at or under $800 and that would otherwise qualify for the de minimisexemption will be subject to all applicable duties, which shall be paid in accordance with applicable entry and payment procedures. All relevant postal items containing goods that are sent through the international postal network that are valued at or under $800 and that would otherwise qualify for the de minimis exemption are subject to a duty rate of either 30% of their value or $25 per item (increasing to $50 per item after June 1, 2025). This is in lieu of any other duties, including those imposed by prior Orders. Carriers transporting these postal items must report shipment details to U.S. Customs and Border Protection (CBP), maintain an international carrier bond to ensure duty payment, and remit duties to CBP on a set schedule. CBP may require formal entry for any postal package instead of the specified duties. The Secretary of Commerce will submit a report within 90 days assessing the Order¡¯s impact and considering whether to extend these rules to packages from Macau.¡±

Last night while playing with my qmx the receiver went deaf. This happened after txing on ssb with IQ mode on and panadapter open. I was using a mic connected to the radio. The S meter with antenna dropped to nearly nothing and I can only hear white noise now. The radio will still put out 5w. I ran my little signal generator into qmx and on receive I hear nothing at -33dbm. At 0dbm (I know quite strong) the signal will get through. Any thoughts? Thank you Ryan KK6DZB

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

Hi all, This is my first post here so I hope it lands in the right place. A while back I purchased the U3S kit and having constructed it found it to work perfectly on the single band . I have just added the LPF relay board to provide an additional 5 bands. The U3S board has the relay fitted and diode along with the LPF and I have removed the 2 relevant wire links. I must be programming the U3S board incorrectly as the unit only transmits on Band 0, that is it will only show its transmitting on band 0 even though I have set the 5 new bands with band 1 being the highest in frequency. Can anyone shed some light on what I could have missed, Thanks. -- Steve Shuff.

Hello, Has anybody tried this microphone preamp : https://www.analog.com/en/products/ssm2167.html Evaluation boards can be found for about 5€ looks good to me but I am no expert ! 73, Yannig - F4IUJ

I know¡­.. lots of postings on QMX+ microphones here. Does anybody have a single list of working good/cheap mics? Thanks de K2RMA

I finished my QMX+ build last week and it is time to admit this is the first kit in my entire life that doesn't work right away, dating back until about 1980. Since all those other kits worked just fine, I never invested in lots of bench hardware nor are my trouble shooting skills well developed. So, having just finished my piece of humble pie, I am trying to figure why my LCD remains blank. The backlight works. There are no characters or blocks, regardless of the potentiometer setting. I haven't hooked up an antenna or earphones so I don't know about the RF/AF sections. I was able to get my Linux Mint PC to connect via USB-C and using Putty, I put the QMX+ into firmware update mode. It was 1.0.27, now it's 1.02.00 as the firmware update worked fine. The terminal mode confirms that the firmware update went okay. I can browse the terminal mode. All of the front panel controls show "Press", right or left arrows as is appropriate for the control. The only thing is the display never shows anything. It is completely blank. I disassembled the case and removed the front pcb and checked every solder joint on the connectors on both the main and front pcb's. All look good, shiny, no bridges, dry joints, nor whiskers. I'm looking for advice. All I have is a DMM to test with. Lincoln N9IN

Hey guys. Any idea where i can buy the electret capsule, working with the QMX - AOM-5024L-HD-F-R? I have found it only in Mouser and Digikey and the minimum shipping price is 20 euro. Any ideas of other compatible mics with -24db sensitivity? Thanks in advance, 73 de LZ3OM

I posted here before about building a 40-10 qmx. I did a little more looking and thinking. Looking at AI6XG's mod: https://www.ai6xg.com/post/a-40-10-meter-qmx#viewer-cl0z424097, it seems to preform well and has motivated me to go out and buy a QMX. However there are some questions that I have that I want to confirm/ask. In the blog, he mentions: "According to simulation, adding 100pF to the already installed C402 56pF should lower the peak frequency to about 11MHz. I found that adding 150pF instead, for a total of 206pF, provides good results" In the conclusions, he says to use a 210pF capacitor in C402. However, such a capacitor does not seem to exist. There are plenty of 200pF and 220pF capacitors on the likes of digikey and mouser, however I can't find a 210pF capacitor. Since he says adding 100pF should work, would a 150pF, 180pF, or 200pF capacitor work in the place of a 210pF one?

Hello all, Recently completed a mid band QMX build. First serious electronics kit build and I'm a bit out of my depth for sure. But after correcting a few mistakes during the build I powered on the QMX with a current limiting PSU and ran through hardware test last night on a dummy load. All appeared well, or at least the sweeps matched what the manual describes and what others have posted. CW transmit into the dummy load was no problem and between 4-5W on all bands. This morning I decided to try SSB Calibration. Hooked up to the benchtop PSU and a dummy load and let the QMX run while I did some computer work. About a third of the way through I heard a faint crackle and looked up to see 1.5A draw on the power supply and 7V. QMX was still trying to perform calibration. I shut down the PSU and smelled some hot electrical components. Disassembled and do not see anything obviously wrong. I decided to power it back up and this time connect to the terminal diagnostics. QMX powered up but right after the firmware splash screen it immediately began drawing 1.5A again. I quickly connected to the terminal application and as soon as I did the increased draw went away and the diagnostics screen showed normal readings. The moment I disconnected the terminal app the draw came back. Hot electronics smell persists. This is where I don't know enough to continue to track down the issue and am looking for help. Any advice would be great. Thanks, Mike KR4CNM

I am having difficulty getting the compressor to work on my QMX+ on software 1_02_00. There are no performance issues with this build and the SSB calibration runs fine. When I use the config settings shown in the manual pictures the audio sounds good on a nearby receiver using an external mic. This is with the compressor off, the default. If I go back into the terminal and turn on the compressor I get high distortion. It is nearly solid noise and transmits near peak power continuously. It doesn't matter what compression value I use, always the same. Even a value of zero. If I unplug the external mic and plug in just a PTT switch, I get the same noise. The only way to get the noise to go away is to do a factory reset. Again, SSB is all good until I turn on the compressor. I have done factory resets twice now. I would really like to use compressor to add some punch but I haven't been able to figure out what I am doing wrong. -- Regards, Earle KC0KVR

The clock on my QMXplus seems to drift many minutes every day. When I do an operating session or a POTA activation I will need to remember to set the clock when I sit down and power it up. I set the time to UTC to make paper logging easier. I have a new quality CR2032 battery in my QMXplus in case you wondered. i haven¡¯t yet measured the clock drift, but was surprised it was significant. I think a number of contacts I uploaded to LoTW had no QSL because my estimate of the correct time was wrong. (A day or two later I discovered the time was way off before I uploaded, and changed the times in my electronic log to my estimated corrected time) Or I could get the OLG3 GNSS module which I think will set the QMXplus time, but that requires another component and setup to my portable kit. I probably won¡¯t bother but keep thinking about other solutions. My Home QTH transceivers are spot on the correct UTC time. I can take a PC or IPad and do my logging on it. Another component to take. Q: Before I decide what to do, How much does your QMXplus clock drift?

At Hamvention last week, I found an unbuilt CMX, #345 at a nice discount with case, board is REV 1. No markings to indicate low band, mid band or high band. Is it likely low band? Thanks, Mark W4ZIP

We had four folks join the MI QRP Zoom Chat on 15 May. Please join us Thursday, May 22 (and every Thursday) at 4PM Eastern for the Michigan QRP Club weekly QRP Chat where the main topics will be QRP and other ham interests. New hams are encouraged to participate and ask questions. It's fun, it's easy, and it's free. You only need a computer, a smart phone, or a tablet that can connect to the Internet. OR if you can't be close to any of those you can join by audio with any standard phone. Just follow the directions below. No software needs to be loaded or installed. Anyone can join and non members are welcome. Details are here: https://www.miqrp.net/zoom Zoom ID: 811 0835 6229 We had 3 check ins today. Stan, Casey and - they talked mostly about satellites. I listened and did paint touch up in my radio room as I disassembled it. Have Fun and don¡¯t forget to visit U.S. Tower booth if they have one. Pete WK8S Stan WB8QJZ Casey KC9IH Tom WW8AL They talked mostly about satellites. The topic for Thursday, 22 May will be FDIM, Michigan Mighty Mite Revival and Hamvention. The agenda for the 22 May QRP Chat: Ernie to do a short introduction and acknowledge any new folks to the Zoom chat. The topic for next May 22 will be FDIM, Michigan Mighty Mite Revival and Hamvention. During the open forum anyone can take the floor. We will go one by one until all have had a chance to have the floor. Files, pictures and presentations can be shared if you have any. Please try to stay muted when someone has the floor. Thanks Ed AB8DF

Ok ..I have tried fldigi on other radios - always gave up after too much trying to make it work. So trying one last time with QMX+. Is there a simple "HOW- TO" for getting to work ? I want to use it for RTTY mainly . So far no fun...?thanks