开云体育

I recently purchased this microphone kit from Pacific Antennas https://www.qrpkits.com/microphone.html for $15. The kit was easy to build and seems to work ok with the QMX+ usng a MIC Gain set at 50. Anyway I made my first SSB contact today on 10m so I'm satisfied. I've enjoyed reading about what others are trying and look forward experimenting some more. Les, N1SV

Hell forum, please your help, I am building my QMX+ V3. On page 30 of the assembly instructions, there is a table were L518 is 268nH with 23 turns on the pink T37-0 core. This one turn less than L516 (435nH) with the same core. Measuring with the nanoVNA, L518 with 23 inductance is about 100nH higher. To reach the 268nH, I have to reduce multiple turns. So here goes my question: Should I keep undoing turns until I reach the 268nH or should I ignore the nano VNA and keep the 23 turns? The same applies to L517, were the number of turns seams high for the target 316nH. The previous coils were very close to the target inductance. Thank you for your help, Luis CU2IJ

Hello everyone, Ive been trying to clean up the transmit audio on my QMX and QMX+. I can’t seem to get rid of the distortion on either one. I have been able to get rid of background noises by reducing gains on different parameters. I’ve tried pretty much every suggestion I’ve read on the groups but it’s still distorted. It is usable but a bit distorted. I’ve tried different microphones. I’m currently running the QRP Guys microphone. I tried a rewired Baofeng spkr mic and while the mic works the audio quality on the QRP Guys mic is much better. Another benefit is it doesn’t drag the radio around like the coiled mic cable does. This appears on both the QMX and the Plus version. I’ve noticed on the Plus that whenever I’m in LSB mode above 17 meters I get a constant low level whistle or tone. If I switch to any other mode it goes away. It almost sounds like an AM carrier. It varies a bit in time and amplitude. It doesn’t do this on the QMX. Could it be the GPS on the QMX+ Causing it? I’ve disconnected the antenna but that doesn’t stop it. Is anyone else seeing this? On another note, what’s the possibility that Hans could have a troubleshooting seminar for the QMX line of radios at the Hamfest next month? Perhaps a course or workshop targeting the most common issues and how to resolve them. Like tx audio distortion and calibration issues. I’m still on the fence about going to the event. I could probably find a reason to fly across the country if a class were to happen. Don.

Hans, I'd like to have a CAT command to set the SSB Input device. For a while this morning, I couldn't figure out why my QMX wouldn't transmit for ardopcf. I finally realized that I had changed the SSB Input to Ext. mic the last time I used the QMX. With a CAT command to Get/Set this parameter, I could programmatically always ensure that it is set to USB when starting up a digital mode program. By also being able to get the current value, it might be possible to also remember this value so that it could be restored when done. Peter LaRue AI7YN

Hi Hans, thank you so much for the amazing little QMX, I'm loving it, and the fact that the SSB firmware allows me to run Vara/Winlink is amazing. I don't know if there is a feature request/wishlist somewhere, but it would be really amazing if there was some way to adjust (limit) the output power that could be adjusted from the front panel controls. I am primarily looking at it from the perspective of setting the CW or USB max output to a series of steps such as 250mW, 500mW, 1W, 2.5W, 5W. This would be especially useful if you were using the QMX to drive an RF PA for example, but didn't want or need it to put out it's full maximum output. I know the power level can be set when putting the QMX into tuning mode, being able to do this in operational mode would be really useful (to me at least). If there's a technical reason not to do this, fair enough, but if it is technically possible, is this something which could be considered? 73, Stefan MI0PYN

I have been trying to capture the digital signals driving the 2x16 LCD on my fully functional QMX transceiver. I am using an application called Scopy and the ADALM2000 learning module hardware from Analog Devices. I don't understand the captured data. I am hoping someone on this forum is familiar with this protocol and can provide some insight. My two main questions I have are: 1) Should the Enable line go high when the microprocessor of the radio is writing to the screen? From what I have captured so far these does not seem to be the case. However the reference material I read on line about typical 2x16 LCD screens indicates the Enable signal means write to the screen. 2) Should the Register Select (RS) line go high when the microprocessor is writing an ASCII character and low when it is writing a screen command? My data collection shows that there seems to be far more RS pulses than Enable pulses, which I don't understand. Am am attaching a screen shot of the data collected when I power up the QMX receiver with the factory reset splash screen. I have the Enable pin tied to input bit 0, the RS pin tied to input bit 1 and LCD data bit 0 through 7 tied to input pins 2-9 respectively. Any info on this would be greatly appreciated. Thanks in advance Mike (KC2EHR)

Yesterday my QMX got its maiden voyage in full kitted-out form. Went to US-3715 here in GA (Cartersville). It's been out in the field before, but with other radios till I was confident this one would be a good primary, and I wasn't disappointed this time. My kit is not a micro, SOTA-up-on-a-peak kit, but still very small and fits in a backpack with plenty of room for other stuff. Even though I had fine internet, I wanted to use the QMX to spot myself, so I didn't use internet for anything other than verifying. I have KM6LYW's Digipi set up on a Pi 0 2w. Added a GPS dongle to pull time off gps satellites (pi doesn't have an rtc), so once i got a gps fix and the time was locked, and chrony sets the pi's time from it, fired up WSJTX. With SotaMAT on my phone and the Georgia parks + CW on several bands configured, I found a good clear 20m CW freq. I set that freq up in SotaMAT, copied the POTA spot string from SotaMAT into the CQ message line in WSJTX, tuned over to 14.074 in digi mode, and let er rip. Watched on the pota spot page that I was spotted and sure enough, was spotted the first time within seconds. Switched back over to CW and the freq I spotted myself on, and got to work. Activated on 20, switched to 30 and got a few there. Didn't get to work any 40. I've done both FT8 and JS8Call on the pi02w with the QMX before but didn't here. QMX CW thumps? Yes. Bad enough I can't work? No. I have AGC on (I will not turn this off now that it's available, anyone who's used the QMX before AGC knows this well), sidetone relative, I forget what volume, I also forget what freq somewhere between 550 and 600, I like it low. Volume not up loud, I have earbuds in so hear it very well. In the kit: QMX rev 2 (qrp labs assembled, i had to replace the rx mux ic that I blew out by unknowingly using it without the diode fix which i've since done) Talentcell 6000 mah battery - (can't see it, it's under the tuner) this is way overkill but it's the same size as the tuner so kit-wise it just made sense. I like that it has both a 12v DC port (for the QMX) and a 5v USB port (to run the pi). ATU 10-0A - as cheap as they come, but man it just works. hard to beat for $30 Pi Zero 2W and a case, headers, and all the fun stuff like the screen --- Glonass gps dongle - i dunno, some cheap one, works fine 3d printed paddles - i've made several of these and have used them a long time but don't care for them, got boards for VK3IL's pressure paddles coming which will work much better for the kit Retractable 3.5mm cable for the paddles Retractable 3.5mm earbuds Couple right angle bnc adapters A few inches of rg174 stub between tuner and QMX A few inches of DC cable with 2.1mm right angle barrel ends for power ~16' rg174 feed External speaker I usually don't even use Right angle 3.5mm adapters USB necessities to power the pi and data to the qmx JSVer hard case --- Antenna is a homebrewed 20+30+40 tapped coil (22ga bntechgo) Coil is sitting on an unbelievably small camera tripod. Of all the things in the kit, that tripod makes me the giddiest. Whip is the Elecraft kx1 replacement whip which collapses to 6". I pressed in a 1/4-20 rivnut into the bottom of the coil, but the 1/4-20 camera stub on the tripod wasn't long enough to reach the threads so I had to add an extra coupler and some allthread to finish the mount 2 different radials - 13' 22ga bntechgo silicon for 20m, 33' for 30 and 40m (30 is wound in to 20-25', I haven't found the perfect sweet spot yet). They each have a fork and get clamped to the pvc tee with a screw+wingnut you can't see --- The antenna fits in the case underneath the QMX in a cardboard case I custom fit --- And after left open only a few minutes, enough pollen to choke a honeybee. Yep, it's March in Georgia.

Brand new, worked perfectly in the shack on Monday. Took it to a local park with a freshly charged 9 B Bioenno battery (it's a 9v build). No audio out No sidetone A bunch of letter "T" across the lower of screen, and as I tune, more of the letter "T" show on the lower screen cannot change band from default startup. After three factory resets, finally got audio out But no side tone. Factory reset again, and audio is gone. Antenna is a resonant fed halfway and is confirmed as SWR 1.2 to 1. After 10th factory reset, I see a message "initializing Si5351" and everything is back to normal. I create CW message but can't get it to repeat even though I have Repeat set to 8 and interval set to 3. It only plays the message once. Is there something funky going on, or operator error? Mark Lunday wd4elg@...

I post a message like this every 6months or so in hope... I'm looking for someone who has an original QCX Classic case they no longer want. This is the BaMa Tech case that was sold by QRP Labs for sometime. The case is not available new any more. If you have such a case or maybe a cased QCX Classic that is fried and dead and you want to sell, please contact me andy.mm0fmf AT gmail.com. I'm in the UK and Brexit etc. has made shipping to and from the UK much more "fun and challenging" now. But if you are in the EU or in the US I have friends/relatives in either that will handle shipping to me making it simple for you :-) Here's hoping. Thanks Andy, MM0FMF

QMX+, Rev1 board, 1-00-027 Program I checked the advanced section and all 3 items are set to Enable. I still have a horrible Clunk when keying the QMX+. No clunk when not in transmit mode. So I think its when the PA gets switched on?? Please advise!

I connected my QMX to a 20 meter QCX 50 watt amp and the result is failed QMX transmit (no power). My QCX does OK with this amp but the QMX took a permanent dive for some reason. Receive is fine, but transmit is now zero. Transmit does draw power from the supply but offers no RF. Supply power to QMX is exactly 12V Supply power to 50W amp is 20V Each has its own regulated power supply Ken AA7JC

The wiki page QMX QMX_plus Startup has been updated by @Ludwig_DH8WN <DH8WN@...>. Compare Revisions

Morning all. I recently received my QMX (hi bands) and I’m very impressed. I have a QCX Mini on 40m which is a fine radio but the QMX feels more smooth somehow; probably psychosomatic! Anyway, with all the discussion around the sensitivity of the finals to heat when running at 12V I was wondering if anyone had tried improving the heatsink on those transistors. I am pretty sure a small heatsink could be fitted in place of the washer and might help with avoiding issues when working that POTA DX at 12V. Thoughts anyone? 73 de G7RUX k

Hi, After the installation of the latest Beta, the LCD shows only processing. Is this normal? Few minutes later i un/replugged the powersupply and it works as expected, ok, a little bit better than expected. A big Thanks to Hans for this awesome peace of hamgadget. 73, Jens

On 4/12/25 I had a CW practice / rag chew session on 30 meters. I worked one station: Date / Time Call Bnd Mode Power Rec Snt Name SPC# Comments Off 4/12/2025 18:51 N5EEI 30 CW 100 579 339 Dave TN K3 at 100 watts 100 ft sloper doublet 19:10 Conditions were crummy. SSN = 120, SFI = 170, A = 18, K = 3. My next CW practice session will be April 20 at 09:00 EDT / 13:00 UTC on 30 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 - April 20 2025 Time - 09:00 EDT 13:00 UTC Band - 30 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