Re: QCX classic 40METER key click
The key clicks are only on the side tone.
The actual transmitted signal is beautiful and produces a perfect sine wave on My oscilloscope.
in the version 3 board it’s 2 -10?F Polarized Caps.
Should the two replacement 1 Mf ?caps still be polarized?
thank you
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Re: QCX classic 40METER key click
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Re: USBC connector not installed correctly on QMX+
The pin-in-paste method is used for this connector instead of (selective) wave soldering. Therefore one step less is needed during the PCBA production.
Due to this method less tin can be seen on the connector pins but the connections are okay. If not, than you can manually solder these pins again but the pins are very close together so I would only do this if you have a problem with the USB connection.
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Re: Cannot change the mode on QMX+
On Mon, Jan 13, 2025 at 05:17 PM, ta2rx bekir wrote:
... tried updating the firmware, although not necessary, to see if the PC-rig connection is working. QMX+ was connected as an external device without any problem. To cancel the whole thing, I turned the rig off. ...? So I pressed the button again to make sure it is off. When I disconnected the USB cable the PC binged to warn me that an external device was disconnected. That meant the rig was still on and in firmware update mode.
From the operational manual:
In the firmware update mode, the LCD backlight is OFF,
nothing is displayed on the LCD, and none of the buttons
or controls or connections are operational,
There is no way to switch off from firmware update mode by using the encoder button.
So, I have got a feeling the problem is with the QMX+ On/Off button not responding to Mode and Band change clicks.
If you are able to switch off by long pressing the encoder button than the hardware should be ok. Click, double click and long press are going the same way to the controller.
?
73 Ludwig
?
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Re: Cannot change the mode on QMX+
On 13/01/2025 13:49, ta2rx bekir via groups.io wrote: My PC sees only USB as the serial port. Bekir, You are saying that the PC is not showing the QMX+ as having a COM port? Here is my updated page for installing the driver Hans used my write-up but this has a few extra notes. 73 Alan G4ZFQ
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Damon,
?
You previously said:
?
" After replacement of all, I left off the PA’s and the radio powered up fine. All RX alignments were completed satisfactorily and performance is impressive.?
? The new PA’s were placed and I powered up again with 12v and current limited to 250mA.? ?On the display, I have a blinking “6” low voltage alarm. Today’s results probing with my oscope:? 12V rail at 6.68Vdc"
?
So the receiver works fine without the BS170's installed,
but once you install the BS170's your? power supply goes into current limit, dropping to 6.68 Vdc?
?
The final will be getting 12v from the power supply during receive (I forget why, but there's a good reason for this).
However, the gates of all BS170's should be at 0 volts when receiving, and so the BS170's are not conducting.
I don't understand how installing the BS170's would cause the rig to pull so much power.
Verify that the gates are 0 Volts (you can do this without installing the BS170's just check the gate pads).
?
There could easily be a short in T501 that could suck the power supply down like that.?
But I don't see how removing the BS170's would make such a short go away unless the gates are not at 0 Volts.
?
When you say "it drops about 4.3 Vdc", does that mean your power supply
is now at 12v - 4.3Vdc = 7.7 Vdc??
Previous measurements was 6.68 Vdc, but that difference could just be due to a change in part temperatures.
?
You say "No signals present on IC403 other than Vcc, Vdd."
If the receiver is operating correctly, then CLK0 and CLK1 must be present at pins 2 and 19 of IC403.
They will be within a few KHz of the receive frequency on the dial, and are 90 degrees out of phase.
?
Jerry, KE7ER
?
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On Mon, Jan 13, 2025 at 08:00 AM, Damon wrote:
I have my power supply set for 12.00Vdc and current limited to 250mA. The radio is being tested in RX only and with PA’s installed at this point. When the radio is powered on, it drops about 4.3Vdc as indicated on the supply display and my DMM/o scope. This is measured on all points of the 12V rail within the radio.
?
Good VFO CLK0&1 signals on IC204. No signals present on IC403 other than Vcc, Vdd.
I have not yet tried to take any measurements in TX mode yet. As for T501, I was not clear… In RX, I read 900mV from T501 into the PA’s, 0V at the gates.
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Re: QMX+ Toroids - To Glue or Not To Glue?
Here:?
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A good visual guide to soldering:?
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73, Don N2VGU
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Re: QCX classic 40METER key click
Note also that there were firmware versions which addressed key click issues. So check the firmware version on your QCX and check the firmware revisions history to see if anything affects it. It could be a matter of updating the firmware.?
73 Hans G0UPL
Howard. If you are talking about actual key clicks on the transmitted signal that others would hear as wider than normal CW reception, then you need to look at the key shaping circuitry around Q6, like R41, R42 and C31. If you are instead talking about a clicking sound in your own sidetone when you key the radio, then you might look at changing C21 and C22 from 10 uF to 1 uF as was done in Rev 4 and Rev 5 boards.?
Good luck .. 73 .. .Ron
I have the QCX classic 40 m PC board revision 3… I have seen some topics on this issue but it was on the revision 5 version which has different capacitors than the revision 3 board.
I may be thinking of selling this in the future but I thought it would be interesting to see if I can eliminate the key clicks before I sell it.
thank you everyone.
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Thank you for sharing the case!?
Would it be possible to share the folding legs and accessory platform?
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In addition, I discovered almost immediately that too much audio
drive into the radio for digital modes will inhibit transmit.? I
thought something was wrong with my QMX when it wouldn't transmit
but for a brief second, but when I turned down the audio drive to
100% (Linux pavumixer) it behaved normally.? Presumably it can
overwhelm the ADC.? The audio was turned up for another
application but the laptop thought it applied to the QMX as well.
There is no ADC involved. All transfer from the PC to the QMX is digital via the USB audio sound card emulation of QMX. So what happens if you have a sinewave at full 100.0% volume, the sinewave peaks and troughs hit the peak numbers the digital transfer is capable of. If you go beyond that, then the peaks "wrap around" so you then get a frequency component at even harmonics, at a lower amplitude; QMX will then measure the incorrect frequency, as well as determine that the amplitude (of those wrapped peaks) is below the threshold and it will switch off the transmit.?
It's all correct behaviour of QMX.?
73 Hans G0UPL
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Re: Cannot change the mode on QMX+
Thank you Ludwig. I have already done those.?
Furthermore, I had also tried updating the firmware, although not necessary, to see if the PC-rig connection is working. QMX+ was connected as an external device without any problem. To cancel the whole thing, I turned the rig off. The screen was already dark so I tried turning it on to see if it would go back to normal operation; it was still dark. So I pressed the button again to make sure it is off. When I disconnected the USB cable the PC binged to warn me that an external device was disconnected. That meant the rig was still on and in firmware update mode. To make sure the rig is shut down, I disconnected the power cable and connected it again. With the cable removed I turned it on and it went back to normal operation, still in CW mode.
So, I have got a feeling the problem is with the QMX+ On/Off button not responding to Mode and Band change clicks.The fact that it got stuck in firmware mode (i.e. not responding to OFF click) when connected to my PC is probably another sign that the problem is with that button.
73! de Bekir TA2RX
On Sun, Jan 12, 2025 at 07:58 PM, ta2rx bekir wrote:
On the computer side, I use Windows 8.1.
Bekir, QMX audio devices and the QMX serial port are different USB devices. Each needs his own driver. The audio drivers already are present in Win7, Win8, ...
?
(I had installed the virtual com port previously.)
Maybe you installed the special driver for Win7 and Win8 (see the link above)? If yes, sometimes a driver "update" is to be done like described in the QLG2 document (see link above). Some times ago it worked for me.
?
And did you go this way:
- start PC and Win
- connect USB to QMX
- switch on QMX (only here the QMX offers the serial port to Win)
73 Ludwig
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Re: QMX+ - digital audio output suddenly went away
Have you checked that the correct devices are still selected in WSJT-X?
73, Paul — AI7JR
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On Jan 12, 2025, at 5:04?PM, Stan Dye via groups.io <standye@...> wrote:
? This is more likely a problem with windows connection with NaP3 or the USB cable (more things to break on this side of the interface).
Does Windows still see the device?? (Open Sound Settings -> Sound Control Panel -> Recording tab: it should be in this list)
Does NaP3 still see the device, and in run mode?
If you turn I/Q mode off on QMX+, is there change in the NaP3 display?? ( the spectral display should change to just show the two adjacent energy humps of the left and right audio channels, at a different center offset)
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Did you try to restart the QMX+?
From QMX+ perspective, all of the 'missing' functionality is software (firmware), so restarting the unit should fix it if the problem is on the QMX+ side.
?
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On Mon, Jan 13, 2025 at 12:47 PM, Daniel Conklin wrote:
buttons on the front
Space just under the display is perfect.
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Nice woodworking?
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Re: QMX+ Toroids - To Glue or Not To Glue?
I can’t paste a link but if you search: NASA-STD-8739.1 It will take you to a wonderful PDF that explains everything to do with staking down electronic components.
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On Mon, Jan 13, 2025 at 03:55 PM, Damon wrote:
The new PA’s were placed and I powered up again with 12v and current limited to 250mA.?
On the display, I have a blinking “6” low voltage alarm.?
Damon, blinking "6" only in TX mode or also in RX mode before try to TX or after try to TX? For TX mode 250 mA is much to low and the power supply will hit the limit. When the power supply is going below 6 V the QMX is disabling the PA, the current is below 250 mA again and the voltage comes up to the value from before. (Such a fast down and up of the supply voltage is dangerous for the QMX.)
12V rail at 6.68Vdc
How much external voltage?
6.68 V in which mode (TX, RX)?
Good VFO clock output from CLK0 & CLK1 into IC503.?
I guess you mean IC403.
Good and expected values shown from IC’s 501-503.
Like described in QMX QMX_plus PA problems, broken BS170? With or without BS170?
PA’s dropping 980mV as measured at T501.
Dropping in which way?
980 mV DC or AC rms or AC pp or what?
Measured at which point of T501.
What is your oscilloscope showing at the drains of the BS170 (AC and DC, RX mode and TX mode)?
?
73 Ludwig
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Re: Cannot change the mode on QMX+
On Sun, Jan 12, 2025 at 07:58 PM, ta2rx bekir wrote:
On the computer side, I use Windows 8.1.
Bekir, QMX audio devices and the QMX serial port are different USB devices. Each needs his own driver. The audio drivers already are present in Win7, Win8, ...
?
(I had installed the virtual com port previously.)
Maybe you installed the special driver for Win7 and Win8 (see the link above)? If yes, sometimes a driver "update" is to be done like described in the QLG2 document (see link above). Some times ago it worked for me.
?
And did you go this way:
- start PC and Win
- connect USB to QMX
- switch on QMX (only here the QMX offers the serial port to Win)
73 Ludwig
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Re: Your QMX output experiences @12volts...?..and by the way, what an amazing radio.
Adam,
I had a Yaesu FT-891, and the receiver is hot, maybe too hot! Also it has a strong audio output amplifier designed to mobile use. I sold the FT-891, even though I loved it, and bought a QMX, then a QMX+. I have not been disappointed, but the QMXs definitely have different quirks from the FT-891, and even from each other. The FT-891 is in a different class and is designed for different purposes from the QMXs, so it's difficult to compare them fairly.
--
73, Dan - W2DLC
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Adam via groups.io <qrp-labs@...> wrote: I deduced that only the STM32 remained. I put it down and the short
disappeared. I ordered one from Farnell. the QMX and QMX+ (I assume we're talking about QMX), and it's guarded by
Something went wrong. There was another line here: "From my understanding (correct me if I'm wrong), the STM32 shipped with". I guess starting lines with "From " might not always work (it's a message separator in mbox format)...
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Re: Your QMX output experiences @12volts...?..and by the way, what an amazing radio.
Adam,
The receivers in my QMXs compare very favorably with my K3, which has a superb receiver. I really don't think the receiver is a concern once the QMX is finished and working.?
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73, Dan? NM3A
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Howard Lamhut
Donald S Brant Jr
Paul - AI7JR
Ivica - YU1QRP
Daniel Conklin