Last night I downloaded the latest firmware and threw together a rather basic microphone, and after going the the calibration tests it appeared to be working well into my main station transceiver. This afternoon I went to my local SOTA summit and was very pleased how well the QMX on SSB worked. Although I'm mostly a CW op its great to have another another mode available in such a small radio, ideal for SOTA.? ?
?
Thank you Hans for all your hard work on this project, I enjoy building and learning about your radios just as much as I do operating them.
?
73
Roger MW0IDX
?
|
Re: QMX shutting off at 10.5V
Thank you Dan,
?
I've removed the battery pack out of the equation and I use my lab linear power supply which can deliver 1A. I let the QMX in receive mode and I slowly decrease voltage and suddenly it shuts off at around 10.5V.
?
With the battery it was more erratic and sometimes I got a high voltage warning whereas the voltage was definitely below 12V.
?
In the menu I have min voltage : 7V, max voltage : 13V, supply voltage : prevent TX
?
I think there is probably something wrong with my QMX but I am at loss at what it could be...
?
73,
?
Yannig - F4IUJ
|
Re: #qmx #SSB Firmware beta 1_01_001 release
#ssb
#qmx
Hi All,
I enjoyed spending two evenings with my QMX 20-10 ver 1.01 and 1.02.
Noticed some oddities during calibration on 11 and 10 meter bands, calibration does not complete on 11 meters, stops at the DAC value of 700, restarted it many times - unsuccessfully. On the 10 meters calibration passes, but the graph is very different from the 20-12 meter bands. A sharp dip in the DAC 700-1300 area. Now I see other group members has the same problem for other bands.
On the control receiver 11 and 10 m.b. signals sounds without any audible and waterfall-visible problems, there is no difference with the 20-12 meter bands.
Internal microphone is active even if external is selected, but I read that this is not a bug but a feature and calmed down.
I tested 4 looking identical microphone capsules, three no-name?and one marked CZN-15e. All give approximately the same levels at a gain of +50. The CZN-15e signal sounds good with a predominance of high frequencies and one of the no-names emphasizes low frequencies it sounds good for me, will use it.
I would like to thank Hans again and again for the wonderful radio and SSB update!
73
Igor oh2jxa
?
?
|
Re: QMX/QMX+ architecture
On 21/03/2025 15:18, Anders Helmersson via groups.io wrote: The frequency to the mixer is the dialed frequency minus the
IF frequency of 12000 Hz minus the side tone frequencey of 700 Hz Anders, Presuming the QMX is like the QDX, in IQ mode there is no 12KHz offset. The QDX manual has a good circuit description. 73 Alan G4ZFQ
|
jd
I believe the QMX+ Rev 1 use the same SMPS boards as the QMX Rev 4.
72 de Russ, va3rr
|
Re: #qmx #SSB Boom-Mic Headset and Radio Jumper for QMX/QMX+
#ssb
#qmx
Another thought...
?
Make the whole mess into something that's mounted to (or under) the Key/Paddle and use it as a convenient junction block where you plug in your headset!
?
M
|
Re: #qmx #SSB Boom-Mic Headset and Radio Jumper for QMX/QMX+
#ssb
#qmx
Here's an interesting idea I just had!
?
I usually prefer to use TRRS headsets myself - since they're clearly the most widely available and inexpensive choices, so I built an adapter similar to what you are selling for my Sennheiser headset and that's what I've been using with good results.
?
I just tried paralleling my paddle with the headset and found that with all my headsets, the headset does not key in CW mode. What this means is that by adding a pass through 3.5mm socket, you can leave the paddle always connected - better yet, if you swap the polarity and leave a straight key connected you can use the straight key for PTT in SSB and for keying when in CW with no plug swapping.
?
This might be ideal for many users, since SSB is probably a more casual use when in the field.
?
It's probably a good idea to keep the key cable short and shielded.
?
I'm going to replace the PTT button in my cable with a 3.5mm inline stereo jack and wire a PTT button to plug into it to have the best of both worlds.
?
M
?
?
|
Re: #qmx #SSB Firmware beta 1_01_002 release
#qmx
#ssb
I might be confused, but I think there's a bug in the digital mode switching in 1_01_002 from the knob press.
?
I'm listening on 20 Meters USB and when I switch to DiGi mode by pressing the button 3 times, it appears to me that the receiver is set to LSB. I don't know if this wasn't noticed because most people switch over via CAT commands or what.
?
Perhaps I missed a configuration setting or something?
?
This might affect casual digital listeners that don't use CAT.
?
thanks,
?
M
|
thanks.? ill look into this after work.? i see the spare smps boards for sale but the page says they're for Rev 2 or below.? mine is Rev 4 board.? Am I misunderstanding the webpage?
jd
|
Re: QMX shutting off at 10.5V
Yannig, what do you have your lower protection voltage parameter set at? (protection menu, min voltage)
It should probably be at 7V.? But this setting should not cause your QMX to "shut off" - just disable TX or flash a warning.
?
It is not normal for a QMX to "shut off" at any voltage above about 6.5V.? It will not transmit below about 7V, but the receiver works below that.? So if yours is powering off at 10.5V, there may be some problem with your QMX.? Or maybe not.
?
With your battery pack, you may be able to measure 10.5V terminal voltage, but it may have no capacity for current.? The QMX will need up to 200mA at 10.5V in receive mode, and 1A in TX.? So if the battery is near depleted, it may not be able to deliver that current at 10.5V, so the QMX will "shut off".?? The way to test this is to put a mA meter inline, to see the current.? Or when the battery is at a point when the QMX "turns off", take just the battery and do a simple load-test on it to see how much current it can deliver.
?
Stan
|
Re: QMX shutting off at 10.5V
And to be crystal clear, it is a 12V QMX...
|
Re: #qmx #SSB Firmware beta 1_01_002 release
#qmx
#ssb
Wanted to hop on here and report a successful exchange of messages using Pat and the ARDOP protocol on a Raspberry Pi 5 with the QMX+ running the 1_01_002 software.
?
Thank you Hans, this is awesome!!!!
Yes I agree, I'm having fun with it too! I am using Pat pn a Pi400 with ardopcf?and I have had no trouble at all contacting my nearest server LZ3CB 635km away?on 20m multiple times per day over the last 4 days. Due to a stupid thin power supply cable (I will fix this soon!) I'm losing 2V on the cable so the QMX+ only gets 10V. About 2.5W output. Unless we've had 4 days in a row of super unusual?propagation I'm calling it a success!
73 Hans G0UPL
|
QMX shutting off at 10.5V
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?
|
I recently received my assembled QMX+. It is a very neat transceiver,
well designed and nicely built.
I have played with the USB, reading the IQ samples from the 20-bit,
48-kHz ADC. The QMX+ is in CW mode and IQ is enabled. I cannot find
information on the architecture, but I guess it is like follows.
The antenna signal passes through the bandpass filters to the Tayloe
detector. The frequency to the mixer is the dialed frequency minus the
IF frequency of 12000 Hz minus the side tone frequencey of 700 Hz. If I
dial 7020 kHz the mixer will use (7020000-12000-700) Hz = 7007300 Hz.
The resulting product passes through an amplifier with a lowpass filter
in front of the ADC, about 24-kHz bandwidth. The sampled signal has two
channels, I and Q, real and imaginary part. These signals, which have a
bandwidth of ±24 kHz, are available at the USB port. If I listen to a CW
signal tuned to 7020 kHz, it appears as a +12700-Hz signal on the USB
port.
The CPU in the QMX processes the signal by mixing it with 12 kHz
(complex sine, exp(jwt)). The resulting signal, I/real part only,
(appears at +700 Hz), is then passed through the CW bandpass filter,
nominally adjusted around 700 Hz. I have attached a PDF sketch of my
understanding.
Is this description correct?
I experiment with a configuration where the CW filter is a (IQ/complex,
two equal channels) Gaussian low-pass filter around zero frequency with
a bandwidth of 10-50 Hz. This corresponds to 20-100 Hz bandwith in a
bandpass configuration. Consequently, I mix the USB signal with IF+ST,
before feeding it to the filter. The LP output is then mixed with the ST
frequency to the speaker/earphone. (Note that zero beat is not useful in
the analog implementation due to noise and bias.)
Best regards
Anders, SM5KAE
PS I get some tiny spikes 1 kHz apart in the FFT of the USB data. Are
these generated in my setup? DS
|
Re: #QMX 60-15 initial power output
#qmx
If you are getting more than 5 watts out on any band that you use a lot, then I recommend backing off the input voltage a little to relieve some stress on the finals.?
--
73, Dan - W2DLC
|
Re: #QMX 60-15 initial power output
#qmx
Yes and no. The mid-band QMX (and high-band QMX) has a LPF for 17/15 whereas the QMX+ has a LPF for 20/17/15 so it will be a little more 'fiddly' to get even power output on all 3 bands, IMHO.
GL de Russ, va3rr
toggle quoted message
Show quoted text
Would this rework also apply to the QMX AND the QMX+?
|
Re: #qmx #SSB Firmware beta 1_01_002 release
#qmx
#ssb
Wanted to hop on here and report a successful exchange of messages using Pat and the ARDOP protocol on a Raspberry Pi 5 with the QMX+ running the 1_01_002 software.
?
Thank you Hans, this is awesome!!!!
?
-Dj
?
|
Re: #qmx #SSB Firmware beta 1_01_002 release
#qmx
#ssb
Hans,
?
Each time you update the Beta, please pin the latest to the top and unpin the obsolete ones.
?
Or just pin one thread and edit the thread name.
?
Thanks,
?
Incoming SSB Coffee!!!
?
Robb K5RAB
|
Re: Available Hand Mics for QMX SSB ?
On Fri, Mar 21, 2025 at 06:19 AM, VA3CJO - Chris "CJ" wrote:
Are we completely sure the wiring pin-out matches the (tr)uSDX?
Yes it's the same, I just tried it, and the two radios work fine with the same mic.
?
Joel
N6ALT
|
Re: Software Development and Requirements Creep
Hoorah. Gets more done before breakfast .. Stunning achievement.
FB Hans.?
GREG KI4NVX?
On Fri, Mar 21, 2025 at 10:52 AM, Hans Summers via groups.io <hans.summers@...> wrote: Hello John
Yes, I believe you are 100% correct. Much of it could indeed have been released piecemeal as releases in their own right.?
And yes, I also don't know where I found the endurance to push through to the end. But I am pleased that I did manage it! On Fri, Mar 21, 2025 at 5:49?PM john.christopher2 via <john.christopher2= [email protected]> wrote: ?
I haven't loaded up the firmware implementing SSB on the QMX (I don't have an antenna at the moment so no HF for the time being) but I've looked through the documentation. It's an impressive list of features that have been implemented in this release. My own experience in software development inclines me to believe that's why the process took so long, and why Hans felt so frustrated.
?
The initial requirement was direct -
?
? ? ?1) implement basic SSB capability (polar modulation)
?
However, as Hans was working on that, he saw other features that would complement this requirement?
? ? ?2) agc / compression
? ? ?3) CESSB
? ? ?4) pre-distortion / self calibration
? ? ?5) noise cancellation
? ? ?6) UI reconfiguration
? ? ?7) VOX
?
Each of these requirements could have formed the? basis for a separate release. (And as for my breakout of the requirements, I reserve the right to be wrong about how the enhancements would be grouped). However, Hans went for doing development on all of these all at once. Ouch! I am not criticizing the work - I'm impressed that he was able to hold everything together as well as he did. Early in my career I was involved in a project that had requirements creep - the project eventually collapsed and I suffered burnout (I found myself unable to code for about a year - fortunately I recovered)
?
As I indicated, I'm seriously impressed that he managed to get to a deliverable product with all that.?
?
John, KI3J
?
|
Roger Dallimore
va3rr
Daniel Conklin
Dj Merrill
Joel Caulkins/N6ALT