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Hello I hope you are well.
Today I used the QMX for the first time. I previously set up all the security measures. Set the SWR protection leaving a maximum of 2. Also set the voltage protection, setting a minimum of 7V and a maximum of 13. Use an EFHW antenna with a 49:1
I powered my QMX with 11.4V and then made the first QSO at 14.070 with no problems. Then it went to 28.050 and the high SWR protection was activated and TX was automatically interrupted.
After that, the QMX ran out of audio, you can't even hear the band noise.
Any suggestions?
73, Juan LU9CYV
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Please, some suggestion?
Thank you very much
73, Juan LU9CYV
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Hello everyone!
Please I need help. I am not undestand nothing of electronics and I want know the reason why my QMX is without audio.
I only turned it on once and I could only make one qso, then there was absolutely no audio.
Please, help me.
73, Juan LU9CYV
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Hello Juan,
there are many possibilities. ?So it’s a difficult question to answer. ?Is this a QMX that you built or built from the factory? ?Is this a Rev 1 or a rev 2 QMX? ?Do you have any test equipment?
jeff
W1NC
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Hi Juan,
Did you build the kit, or did you purchase a prebuilt QMX?? If it is a prebuilt unit, I suggest contacting QRP-Labs to see if they will repair it for you.
What was the voltage the kit was built for???
What was the voltage supplied when operating?
Does the QMX come on, and does the display show the version version number before switching to the frequency display?? If the display does not turn on, the first use of the DMM comes in to verify the current draw when the QMX is turned on.
Do you have any test equipment?? The most important is a digital multimeter (DMM) that can measure DC current.? Without test equipment, the only suggestion that I can make is to find a local Ham club and find someone who can troubleshoot the radio for you.?
There is a troubleshooting page on the QRP-Labs website:
The above is just a start.? There are a lot of possible things that can go wrong.? All are based on how the QMX was operated or constructed.? Please read the manuals (Assembly and Operating) and the Troubleshooting page.? Post back the answers to the above questions.
73
Evan
AC9TU
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Hello Jeff, thank you for you response. My QMX es Rev 2, firmware 1.00_011 and I bought it builded the factory.
The only instrument I have is a multimeter.
In my first message in this thread, I detail what happened.
73, Juan LU9CYV
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Hello Evan, how are you? Thanks for answering.
Buy the factory assembled QMX.
My QMX was built for 12V.
I configured all the security measures. Set the SWR protection leaving a maximum of 2. Also set the voltage protection, setting a minimum of 7V and a maximum of 13V. Use an EFHW antenna with a 49:1 ratio.
I powered up my QMX with 11.4V and then made the first QSO at 14.070 with no problems. Then it went to 28.050 and the high SWR protection was activated and the TX was automatically interrupted.
After that the QMX ran out of audio, you can't even hear the band noise.
After all that, I reset the device to factory settings and reset all the security settings (roe and voltage protection).
The QMX turns on and you can see the firmware version.
?
Now I turned it on again and I can hear audio!!!! but it is very low and the volume control does not work.
I don't understand anything
73, Juan LU9CYV
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I just realized that when the QMX starts while on the 20m band (freq 14.070) it has no audio and when changing bands it also has no audio, but when I turn it off while on a band other than 20m and turn it back on , I hear audio although very low and the volume control does not work!!!
The behavior is strange.
I still do not understand anything
73, Juan LU9CYV
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Hi Juan. When I first completed my QMX, I thought the receiver was dead as I could not seem to get any volume. I found that the volume encoder was defaulted to a setting of 0.25 dB per encoder step. I changed that to 2 dB per step and was able to control volume better and the receiver was working. Hope that helps .. 73 .. Ron
On Tue, Jan 2, 2024 at 12:58?PM Juan < lu9cyv@...> wrote: I just realized that when the QMX starts while on the 20m band (freq 14.070) it has no audio and when changing bands it also has no audio, but when I turn it off while on a band other than 20m and turn it back on , I hear audio although very low and the volume control does not work!!!
The behavior is strange.
I still do not understand anything
73, Juan LU9CYV
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Hello, again Juan,
I suggest starting with the operations manual available on the QRP-Labs QMX webpage:
You should upgrade the firmware as instructed in the operations manual.? The upgrade process is described on page 56 of the current operating manual.
Verify operation, and if there is an issue, then try a Factory Reset as described in the Operations manual.
Since you purchased a QRP-Labs built QMx, I would contact QRP-Labs support and request information on how to send them the unit to be repaired if the above can not resolve the issue.
73
Evan
AC9TU
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Juan,
I should mention that what you described was a bug that has been repaired in the current firmware version 1_00_014.
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A stupid question....
Does the QMX have to be connected to power for the computer to recognize it?
73, Juan LU9CYV
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Juan,? That's not a stupid question at all. QMX receives no power from the USB port, so unlike a thumb drive for example, it definitely requires a power supply to connect to the computer.
JZ KJ4A?
On Tue, Jan 2, 2024, 1:59?PM Juan < lu9cyv@...> wrote: A stupid question....
Does the QMX have to be connected to power for the computer to recognize it?
73, Juan LU9CYV
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Yes, The QMX can not get power from the USB cable.? It needs a separate power supply.? This is best done for the first time with a current and voltage controlled supply, starting at 6.5 to 7 volts, limited 250ma.? A power cycle is needed whenever the USB cable is disconnected from the PC.? The QMX does not always let the PC know how to connect.
73
Evan
AC9TU
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I was able to update the firmware to the latest version, but the volume control still does not work
73, Juan LU9CYV
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Juan, one possible solution for your volume control issue: please do a long press of the left small button to get to the menu. "Audio" will appear. Do a short press of the same button and "Volume step" will appear. If the step size shown is something very small like 0.25 dB , please change that to 2 dB by again short pressing the left small button, then rotate the right encoder to get to 2 dB, then press the right small button 3 times to get back to the operating screen. Now it takes less rotations of the volume encoder to increase volume.
Also, and before doing the above, if you just updated the firmware, it is sometimes necessary to do a factory reset to clean out anything left in the EEPROM. Did you do that??
Good luck .. Ron
On Tue, Jan 2, 2024 at 4:09?PM Juan < lu9cyv@...> wrote: I was able to update the firmware to the latest version, but the volume control still does not work
73, Juan LU9CYV
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Juan,
Did you do the factory reset?
73
Evan
AC9TU
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Thanks for your responses Ron and Evan. I did what Ron told me to do and I also did the factory reset but the volume control still doesn't work, that is, I can't raise or lower the volume from the volume knob.
73, Juan LU9CYV
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Juan,
Maybe the issue is the earphone jack?? Can you try connecting a speaker to the board connections of the jack?? The other possibility is the audio amplifier has failed.? Do you have a way to connect an earphone to the output of either C420 or C421?
73
Evan
AC9TU
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You might also use the terminal mode to run the diagnostic to be
sure that the encoder and all are working... That's all described
in the assembly manual.
Also, when you power on, is it showing you version 14?
Paul -- AI7JR
On 1/2/24 16:07, Evan Hand wrote:
Juan,
Maybe the issue is the earphone jack?? Can you try connecting a
speaker to the board connections of the jack?? The other
possibility is the audio amplifier has failed.? Do you have a way
to connect an earphone to the output of either C420 or C421?
73
Evan
AC9TU
--
Paul -- AI7JR
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Juan
Ronald Taylor
Paul - AI7JR