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.
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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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Re: Cannot change the mode on QMX+
Has anybody got a solution to my problem?
12 Oca 2025 Paz 21:58 tarihinde ta2rx bekir via <ta2rx.bekir= [email protected]> ?unu yazd?:
Turning the rig on shows 1_00_027 as the version.?
I initially set it to CW and then Practice mode. After I installed the USB cable, I could turn of the Practice mode via the Menu but cannot change the mode to Digi now using the mode knob. It is stuck at CW. Band change does not work either but I can switch the rig on and off without any problem. I tried tightening the knob a little away from the rig to no avail.
On the computer side, I use Windows 8.1. In the device manager when I turn the rig on, I can see "QMX transceiver" under an "Other devices" submenu. When I double click on it the screen says its drivers are not installed. (I had installed the virtual com port previously.) When I try the "Update Driver" button and direct my PC to the relevant folder, the computer says the driver could not be found.
OTOH In WSJTX Audio tab I can select "QMX Transceiver" without any problem. In radio tab selecting Kenwood 440S or Kenwood 480 both return a list of errors in testing the CAT. My PC sees only USB as the serial port. PTT is set to CAT BTW. Changing Transmit Audio Source from Front/Mic to Tear/Data does not help either. Interestingly I cannot revert this setting.
A photo of the errors screen is attached.
73! de Bekir TA2RX
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Re: QCX classic 40METER key click
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
On Sun, Jan 12, 2025 at 9:51?PM Howard Lamhut via <Howardlam= [email protected]> wrote: 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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Re: USBC connector not installed correctly on QMX+
My QMX looked exactly the same and worked with no issues. As others have said the primary solder pad / connection is on top of the board.
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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.
73
Charles - NK8O
On 1/13/25 07:10, Hans Summers via
groups.io wrote:
toggle quoted message
Show quoted text
A number of times I've had the situation in digital
mode where the QMX is not transmitting as expected. I
immediately get concerned that something is blown. The
last time this happened I connected a dummy load and went
to the diagnostic screen in terminal mode and still no
transmit. Only then did I think, oh, maybe transmit
lockout. Sure enough, cycle the power and its back working
again. I wish there was some indication on the screen for
transmit lockout. I've blown so many finals in the QCX and
QDX that my first thought is always something has failed.?
Are you running the latest firmware? In the latest
firmware, in the diagnostic screen there's a reason
indicated, above the transmitter testing section in the
bottom right, whenever transmitting is not occurring. It can
be things like the VFO is outside a defined band (and TX
outside band limits is disabled); or TX is disabled on the
band you are on. Most common is that SWR protection?has been
triggered, which would be indicated by an 'S' on the
screen.?
I don't know of any situation where the radio can be
locked from transmitting but there is no displayed
indication of why.?
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Re: Guide to optimizing bandpass filters on QMX+
Steve, with 4 of the QDX/QMX radios across my bench I have never had an issue with tuning the BPF, LPF, etc. I would like to experiment someday with them, but out of the box the filters are quite satisfactory. ?
73
Dick
W4PID
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A number of times I've had the situation in digital mode where the QMX is not transmitting as expected. I immediately get concerned that something is blown. The last time this happened I connected a dummy load and went to the diagnostic screen in terminal mode and still no transmit. Only then did I think, oh, maybe transmit lockout. Sure enough, cycle the power and its back working again. I wish there was some indication on the screen for transmit lockout. I've blown so many finals in the QCX and QDX that my first thought is always something has failed.?
Are you running the latest firmware? In the latest firmware, in the diagnostic screen there's a reason indicated, above the transmitter testing section in the bottom right, whenever transmitting is not occurring. It can be things like the VFO is outside a defined band (and TX outside band limits is disabled); or TX is disabled on the band you are on. Most common is that SWR protection?has been triggered, which would be indicated by an 'S' on the screen.?
I don't know of any situation where the radio can be locked from transmitting but there is no displayed indication of why.?
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A number of times I've had the situation in digital mode where the QMX is not transmitting as expected. I immediately get concerned that something is blown. The last time this happened I connected a dummy load and went to the diagnostic screen in terminal mode and still no transmit. Only then did I think, oh, maybe transmit lockout. Sure enough, cycle the power and its back working again. I wish there was some indication on the screen for transmit lockout. I've blown so many finals in the QCX and QDX that my first thought is always something has failed.?
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Re: question 50 watts amp
hanz YL3JD via groups.io <yl3jd@...> wrote: the ps for the amp us homebrew? I used a Dell laptop PSU. 19.5 V, 6.7 A.
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Re: QMX+ Toroids - To Glue or Not To Glue?
Rubbing alcohol will release hot glue. BUT on a torroid with wire wrapped around it, it will be more difficult. I don't think its hot enough to damage the coatings though.If you use it do so in moderation and try not to get it in the hole as its much harder to get it out than just a dab on the bottom side.
I have used a couple tiny drops of fingernail polish on my touchy band pass filters to help hold windings in place. Its strong enough to hold winding still if you brush it with your hand, but can easily be snapped loose if an adjustment is needed later for some reason. Again Dont drench it.
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In fact, just last week I was trouble shooting a problem with my qcx+. L1 had been inadvertantly bumped around so much that one leg did break off, so your concern is somewhat valid if you are not careful. Fortunately It was solderd to the top side and repair was easy. (HINT HINT)
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regards,
Bryan, N0LUF
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f6ehj via groups.io <f6ehj@...> 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 him (not distributed as a file to be loaded). This bootloader is then used to load the firmware downloaded from the website, and the firmware itself is encrypted in some way (so only this bootloader can decrypt and flash it). This ensures that the firmware can be loaded only onto boards bought from Hans (makes it more difficult to make and sell clones). If that's the case, then you won't be able to use the STM32 you ordered...
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Re: Your QMX output experiences @12volts...?..and by the way, what an amazing radio.
Stan Dye via groups.io <standye@...> wrote: I do not believe QMX finals are nearly as fragile as they are reputed to
be.? I have not blown any in my QMX+ nor the two QMXs that I own.? And
if you are only operating CW, 12.0V is a good guideline, but operating a
few tenths or more above that will likely not ever cause problems, if
you operate into a reasonably well-matched antenna system (which I
postulate is a 2:1 SWR or less). I blown finals in my QDX by driving a poorly matched load (including when the BNC connector made a poor contact). QMX has a protection against large SWR. And yes, if QMX had an output drive/power control, you could eliminate
most of the risk of failure in the finals by turning down the drive.? I
hope such a feature will be added to the firmware. There's hardware for that, so it should be easy to do in firmware... On the other hand, you can just lower the supply voltage.
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Re: Your QMX output experiences @12volts...?..and by the way, what an amazing radio.
Stan Dye via groups.io <standye@...> wrote: I'm not going to bother with that.? The QMX is supposed to be QRP, and
for highly-portable use.? I have a fine 100W transceiver if I want more
power at home. The problem, as always, is money vs time. For a long time I didn't want to spend money on a proper, factory-made, 100 W transceiver, especially as I'm mostly interested in CW, so a transceiver doing SSB would be an overkill. I'm still weighing pros and cons (DIY vs something that just works, plug and play, and is on warranty in case it doesn't). On the other hand, QMX isn't too complicated for me to diagnose and fix. It's a simple and elegant circuit. A factory-made rig, once warranty runs out, probably would be. My concern is with the receiver. How does the QMX receiver compare to the one in, say, Yaesu FT-891 (a rig I want to buy)?
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Ivica - YU1QRP
Daniel Conklin
Ronald Taylor
Richard Hattaway