Re: Circuit description around PS and its supply¡
I believe that Q507 is switched on during receive, however if you go to the diagnostic screen in terminal it is switched off and only switches on when in TX. ?I haven¡¯t got either of mine in bits to confirm, but from memory I believe it was set up this way so the modulator function could be tested. ?Don¡¯t take this as gospel, as I may have misremembered.?
Nick G0OQK
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Re: Circuit description around PS and its supply¡
Yes, the tx voltage is on during receive, and will be very close to the supply voltage.
Hans has given a good description of why this is done; it helps receive work better.
It is turned off when entering the diagnostics tool, so you can see a near-0V value in receive, and its full tx value during 'T' tx test.? It is turned back on when exiting that tool.? This is a good way to test Q507 - because if Q507 is broken, it won't go down to near 0V.
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Having the tx voltage on during receive is normally not a problem for the PA.? The TX signal is off, so the PA driver and gates of PA transistors are off.? It should only be an issue if there is something shorted/failed in that circuit (the BS170s or driver chip).
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Re: #qmx SSB Firmware beta 1_01_004 release
#qmx
FYI - Complete USB failure on two different machines running Windows 11 Pro
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One Ryzen 7 5800X machine with 32GB Ram
One 11th Gen Intel(R) Core(TM) i5-1135G7 with 16 GB Ram
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Edition ? ?Windows 11 Pro
Version ? ?24H2
Installed on ? ??31/?12/?2024
OS build ? ?26100.3775
Experience ? ?Windows Feature Experience Pack 1000.26100.66.0
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In Device Manager:
Unknown USB Device (Device Descriptor Request Failed)
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Device status:
Windows has stopped this device because it has reported problems. (Code 43)
A request for the USB device descriptor failed.
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Under Events:
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Device configured (usb.inf):
Device USB\VID_0000&PID_0002\8&29c54ea8&0&1 was configured.
Driver Name: usb.inf
Driver Package ID: usb.inf_amd64_8a7970bf56a67043
Class GUID: {36fc9e60-c465-11cf-8056-444553540000}
Driver Date: 06/21/2006
Driver Version: 10.0.26100.3624
Driver Provider: Microsoft
Driver Section: BADDEVICE.Dev.NT
Driver Rank: 0xFF0000
Matching Device ID: USB\DEVICE_DESCRIPTOR_FAILURE
Outranked Drivers: usb.inf:USB\DEVICE_DESCRIPTOR_FAILURE:00FF2000
Device Updated: false
Parent Device: USB\ROOT_HUB30\7&124f193f&0&0
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Device not started:
Device USB\VID_0000&PID_0002\8&29c54ea8&0&1 had a problem starting.
Driver Name: usb.inf
Class GUID: {36fc9e60-c465-11cf-8056-444553540000}
Service:?
Lower Filters:?
Upper Filters:?
Problem: 0x2B
Problem Status: 0x0
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---
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Functionality restored when going back to beta 1_01_003:
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USB Composite Device:
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Device configured (usb.inf):
Device USB\VID_0483&PID_A34C\8&29c54ea8&0&1 was configured.
Driver Name: usb.inf
Driver Package ID: usb.inf_amd64_8a7970bf56a67043
Class GUID: {36fc9e60-c465-11cf-8056-444553540000}
Driver Date: 06/21/2006
Driver Version: 10.0.26100.3624
Driver Provider: Microsoft
Driver Section: Composite.Dev.NT
Driver Rank: 0xFF2006
Matching Device ID: USB\COMPOSITE
Outranked Drivers:?
Device Updated: false
Parent Device: USB\ROOT_HUB30\7&124f193f&0&0
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Device started (usbccgp):
Device USB\VID_0483&PID_A34C\8&29c54ea8&0&1 was started.
Driver Name: usb.inf
Class GUID: {36fc9e60-c465-11cf-8056-444553540000}
Service: usbccgp
Lower Filters:?
Upper Filters:?
---
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If you need anything else Hans, let me know. 73 Tobias
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Re: QMX and WinLink/WARA HF settings
Chris, I've never used the Winlink auto-connect feature.? You will need to ask this question in a Winlink forum; it is independent of VARA and radio (QMX).
Stan KC7XE
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Re: My QMX is turning off, when I reduce voltage under 10V
Hello Ludwig and Hans,
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because I have planed a SOTA activation and my power supply has no current limit, I didn't want to risk with the check before that. Nothing was visible damaged or burned.
After my successful SOTA activation (there I suddenly met another OM, he had also a QMX :-),
I have tested it now - and, YESSS, it was D105!!!
Because I had no other SMD part, I took a "normal" 1N4148, there was enough space to bend and solder it comfortably.
Now, everything is working perfectly down to 7V.
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Ludwig, thank you for your support and explanation of the function principle, this was very instructive and inspiring.?Hans, thank you for your brilliant construction of QMX and your support.
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73 es CUAGN de Stojan, DK4SR
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Circuit description around PS and its supply¡
Evening all
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I have a question regarding the operation of the power control around the PA transistors¡does the DAC drive Q512-5 and therefore Q507 when the unit is in receive, meaning the PA supply is present on Q503-6 all the time?
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My unit¡¯s poorly PA draws excessive current (~2A or so) in receive and the transistors get too warm; I have spares on the way but now I¡¯m wondering about Q507¡
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Tra all!
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Re: #qmx SSB Firmware beta 1_01_004 release
#qmx
If I have done a successful calibration with 1.01.003 that I shouldn't have to recalibrate if upgrading to this new version?
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Re: 50 WAtt Amp, Hot and Low output
Here is a link to a YouTube video on testing the 50-watt amp:
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73
Evan
AC9TU
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Re: #qmx SSB Firmware beta 1_01_004 release
#qmx
This is a bit unrelated, but I was wondering if it would be possible to make the QMX do FM? Because then with a short 10m antenna you could have quite the portable rig with CW, SSB, and FM.
And from me. Lubuntu works well and hassle free. Nearly 30 years of Linux for me.
Roger
8P6RX
Get
On 24 Apr 2025, at 13:45, "codeleaf via " < gmail.com@ target=_blank>codeleaf=@> wrote:
Another vote for Debian. It's been nothing but trouble free for me for 15+ years. Install defaults and use it. Updates won't break your machine.
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Re: #qmx SSB Firmware beta 1_01_004 release
#qmx
And from me. Lubuntu works well and hassle free. Nearly 30 years of Linux for me.
Roger
8P6RX
Get
Another vote for Debian. It's been nothing but trouble free for me for 15+ years. Install defaults and use it. Updates won't break your machine.
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Re: #qmx SSB Firmware beta 1_01_004 release
#qmx
Another vote for Debian. It's been nothing but trouble free for me for 15+ years. Install defaults and use it. Updates won't break your machine.
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Re: #qmx SSB Firmware beta 1_01_004 release
#qmx
On Thu, Apr 24, 2025 at 10:56 AM, ta2rx bekir wrote:
I hope you are not going to suggest using one of the free GUIs that sit on top of Linux. Been there, done that and had to format the whole hard disk after the first update. Thank you for nothing.
FWIW I have run Linux on nearly all of my systems at home for many many years, using mostly the Debian distro, and no issues.? It runs a lot faster and far more stable than the one Windows 10 system I have left for gaming.
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Not sure what you are referring to by "one of the free GUIs that sit on top of Linux".? The major Linux distros include a graphical desktop by default.? Do a standard installation and the graphical desktop works out of the box, nothing else to add.
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Re: #qmx SSB Firmware beta 1_01_004 release
#qmx
I have windows 11 fw004 and everything is working great except about every 10 minutes Win11 drops all three com ports like clockwork. Power off QMX+ power back on and its up and running again for 10 minutes. Revert to fw003 no QMX+ config changes and its rock solid. I have reset to factory defaults after each flash.?
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On Thu, Apr 24, 2025 at 07:27 PM, Randy Paulson wrote:
And Q111 gave up trying to settle the 2.9 vs 3.3v battle
Randy, no battle. If VDD rail is higher than voltage from the linear regulator D103 will block the higher voltage toward IC101.
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73 Ludwig
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Re: QMX and WinLink/WARA HF settings
Stan:
Is there a way in Winlink/Vara to restrict to a given band in auto connect (channel select)?
Chris
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Sorry for the delayed response to your insights. I've been out of pocket.
It is a bit odd, but yes, R110 and R112 both measured 29k ohms which is a bit out of spec, but I doubt enough to cause an issue considering their purpose.
I have definitely identified a S-D short on Q102 which Ludwig guided me towards when he brought up that IC101 should not be on in LIN REG ENs current state.
Maybe this was the original perpetrator. And Q111 gave up trying to settle the 2.9 vs 3.3v battle for superiority going on between the linear regulator and the SMPS.?
Q102 is out of circuit now, awaiting the parts that are arriving later today. So no more measurements at this point.
I am going to start with Q102 and D109 and check quickly to see what happens with a current limited 7v supply.
Will report back.
Thanks!
--
Randy, N4OPI
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50 WAtt Amp, Hot and Low output
20M QCX_Mini driving the 20M 50 watt amp, 13.5 volts, 50 ohm antenna load?6 watts output and the mosfets get hot
Set QCX keyer to practice mode and everything checks Ok, set BIAS, mosfets are cool.
Removed all coils to check for shorts and winding procedure. Checked etches for shorts.
REplaced the Mosfets ¡¡¡ no change. Possibly a shorted cap in the output stages.
Any suggestions ? ? ?
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Re: QMX+ with ~1000 tone on 12M & 6M
Richard,?
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Digikey info
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PCM1804DBR
296-26306-1-ND
IC ADC/AUDIO 24BIT 192K 28SSOP
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Replacing this chip did absolutely no good on my QMX+. Others have had the same experience. It¡¯s not a universal cure.?
73
Dick
W4PID
?
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Gang,
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The QRPBuilder magnetically attached Iambic and Single lever Paddles are now back in stock. Also, this will be our fifth year at the Dayton FDIM vendor night on Thursday May 15, with all our products available. We hope to see you there.
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73,
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Ken - WA4MNT
Karen - KF4EEL
qrpbuilder.com
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Re: #qmx #SSB Firmware beta 1_01_000 release
#qmx
#ssb
Nice work btw..
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If the qmx is in Practice mode, no SWR measurement is possible, but it is showing everytime an SWR? 1.6-1.8, and SSB will still work.I was working on a linked dipol.
Maybe the should be an information for a nonworking SWR test, or the SWR test should work everytime, even in practicemode.
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Dj Merrill
Richard Dyer
Bill P.
Richard Hattaway