Re: Did I fry my QMX SMPS or is it likely worse?
#qmx
Hi Brad.?
I'm by no means an expert in this, but If you're reading single digits of resistance across the 2 rails on the main board to ground with the smps boards removed, then yes, your QMX has likely met its demise. I have a QMX on my bench (in the corner somewhere) that exhibits that condition, and after a quick exchange with Jeff Moore, who has repaired many these units, it became clear that the best way forward was to order a new QMX kit.
The good news is that that strategy has worked quite well for me, and I'm back on the air. ?
How frustrating your situation must be for you! So sorry!?
73
Roy - KI0ER?
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Re: Brainstorm question: How to "view" QDX LED status remotely?
On 28/02/2024 14:10, Alan G4ZFQ via groups.io wrote: an easy way of checking operation is looking for spots on WSPRnet. Or, presuming you are checking by VNC (?) click TX and be monitoring on a local RX.
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Re: Brainstorm question: How to "view" QDX LED status remotely?
Hi Nate.? One quick solution is to purchase a cheap USB enabled DVM with software.? Run the DVM software remotely to monitor the activity of the LED voltage.? Here's one example:
Glory to God in the highest, and on earth peace, good will toward men. Luke 2:14
On Wednesday, February 28, 2024 at 08:41:46 AM EST, natereik@... <natereik@...> wrote:
My QDX is generally "remote" in my attic at my main QTH, running off a laptop up there, 30 feet feet from where I'll sit and "operate." I like the QDX for remote digital work, because there's no audio routing involved, no other software needed to operate, and I don't need huge bandwidth if I remote desktop in.?
BUT, I have run into situations at home where I've accidentally bumped a slider in WJST-X....and eventually figured out I wasn't transmitting even though WJST-X seems to show that I am. I go up to the attic and then can see the LED status indicator and realize there's something wrong with the audio.?
? ? ?I'm looking at putting 2 or 3 QDXs to the same computer at my 2nd QTH eventually, and have realized this could be an occasional issue there, as I'll want to remote operate from home. From what I can tell, there's no way through Putty or any other native way to "see" the status LED (or read the status) via a computer... I have low bandwidth at my cabin, upload speed is slow there (600 kbps), so a camera with video is out of the question. So I'm curious as to how you think one could most easily "remote view" the status LED on a QDX or 2 without an insane amount of complexity??
Phototransistors into Arduino inputs? Somehow monitor the current of the LED, but fast enough to see what it's doing? (as in, need the resolution and speed to "Read" flashes vs the 1hz sine wave, etc) Of course this isn't an everyday need, so if it's just ridiculous to do so, I'll skip it. But was thinking there may be a simpler way than what I'm coming up with.?
Curious as to what others think, as this is not an area of my expertise.?
-Nate
N8BTR
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Re: Brainstorm question: How to "view" QDX LED status remotely?
On 28/02/2024 13:41, natereik@... wrote: But was thinking there may be a simpler way than what I'm coming up with. Nate, I do not know what you would do if a LED was not pulsing? But an easy way of checking operation is looking for spots on WSPRnet. I run WSP{R/FST4W on at least 3 RXTX QDXs and the situation you describe, no TX, is very rare. 73 Alan G4ZFQ
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Re: Brainstorm question: How to "view" QDX LED status remotely?
Could you add a webcam to the remote PC, and point it at the
devices, so you can view them remotely? You could also set up a
Raspberry Pi and camera, and use that for viewing.
--
Paul
MW7PAJ
toggle quoted message
Show quoted text
My QDX is generally "remote" in my attic at my main QTH,
running off a laptop up there, 30 feet feet from where I'll sit
and "operate." I like the QDX for remote digital work, because
there's no audio routing involved, no other software needed to
operate, and I don't need huge bandwidth if I remote desktop
in.?
BUT, I have run into situations at home where I've
accidentally bumped a slider in WJST-X....and eventually figured
out I wasn't transmitting even though WJST-X seems to show that
I am. I go up to the attic and then can see the LED status
indicator and realize there's something wrong with the audio.?
? ? ?I'm looking at putting 2 or 3 QDXs to the same computer
at my 2nd QTH eventually, and have realized this could be an
occasional issue there, as I'll want to remote operate from
home. From what I can tell, there's no way through Putty or any
other native way to "see" the status LED (or read the status)
via a computer... I have low bandwidth at my cabin, upload speed
is slow there (600 kbps), so a camera with video is out of the
question. So I'm curious as to how you think one could most
easily "remote view" the status LED on a QDX or 2 without an
insane amount of complexity??
Phototransistors into Arduino inputs? Somehow monitor the
current of the LED, but fast enough to see what it's doing? (as
in, need the resolution and speed to "Read" flashes vs the 1hz
sine wave, etc) Of course this isn't an everyday need, so if
it's just ridiculous to do so, I'll skip it. But was thinking
there may be a simpler way than what I'm coming up with.?
Curious as to what others think, as this is not an area of my
expertise.?
-Nate
N8BTR
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Re: Brainstorm question: How to "view" QDX LED status remotely?
What if you remove the LED and resistor and drive an Arduino pin directly?
--
Colin - K6JTH?
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Brainstorm question: How to "view" QDX LED status remotely?
My QDX is generally "remote" in my attic at my main QTH, running off a laptop up there, 30 feet feet from where I'll sit and "operate." I like the QDX for remote digital work, because there's no audio routing involved, no other software needed to operate, and I don't need huge bandwidth if I remote desktop in.?
BUT, I have run into situations at home where I've accidentally bumped a slider in WJST-X....and eventually figured out I wasn't transmitting even though WJST-X seems to show that I am. I go up to the attic and then can see the LED status indicator and realize there's something wrong with the audio.?
? ? ?I'm looking at putting 2 or 3 QDXs to the same computer at my 2nd QTH eventually, and have realized this could be an occasional issue there, as I'll want to remote operate from home. From what I can tell, there's no way through Putty or any other native way to "see" the status LED (or read the status) via a computer... I have low bandwidth at my cabin, upload speed is slow there (600 kbps), so a camera with video is out of the question. So I'm curious as to how you think one could most easily "remote view" the status LED on a QDX or 2 without an insane amount of complexity??
Phototransistors into Arduino inputs? Somehow monitor the current of the LED, but fast enough to see what it's doing? (as in, need the resolution and speed to "Read" flashes vs the 1hz sine wave, etc) Of course this isn't an everyday need, so if it's just ridiculous to do so, I'll skip it. But was thinking there may be a simpler way than what I'm coming up with.?
Curious as to what others think, as this is not an area of my expertise.?
-Nate
N8BTR
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Hans,
I was helping a friend who knocked off D103 from his SMPS (Rev2) PCB 2. I noticed that D103 is on the back of the board, while my Rev 1 has it on the front. While checking the pictures of the boards and the x-rays of the traces, I noticed that they are from the Rev1 boards.?
That made it slightly harder to figure out where to connect a leaded part on the front for a replacement.?
When you next update the Manual, updated images would be nice. ? Thanks.?
--
73, Dan ?NM3A?
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Re: Did I fry my QMX SMPS or is it likely worse?
#qmx
Easy way is to check for short across the big yellow tantalum capacitor on each board. Test in both directions with a multimeter on a low ohms scale.? It should read open in at least one direction.? If it fails this test the zener diode is toast.
------ Original Message ------
Date 2/27/2024 5:50:54 PM
Subject Re: [QRPLabs] Did I fry my QMX SMPS or is it likely worse? #qmx
Thanks for the reply! Could you guide me on where to test?
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Re: QMX HIGH BAND NO RF OUT AFTER ANOTHER 10 hour WSPR TRANSMISSION
good morning Michael, yesterday I replaced the 4 bs170s and the problem remained the same, the strange thing is that I made many QSOs in cw with 5/6W on the bands here in my area, then I tried to transmit in wspr on the 10 mt and after 10 hours of transmission the qmx died, no more rf came out, the problem is that I bought it already built from QRPLAB, I'm unlucky, now I have two non-working QMXs and I can't repair it because it's not clear what it is success, �250 wasted.? I hope you can solve your problem.? Good luck.? 73
Giuseppe iu8eun
OK so you have a different problem then I do.
My QMX just stops transmiting WSPR after 10 hours or so even though the display still shows the transmission when the time comes.
I have noticed this all along (with other firmware revisions).
If I turn the QMX off and on it will work fine again most likely for 10 hours in the WSPR mode.
Michael N2ZDB
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Did you only apply power, or did you turn it on? If the former, you might be OK. If the latter, what happened?
I wouldn't think just applying 26 volts would damage the supplies, if they were off... If you apply current limited (250mA) 7 volts, what happens? :-) Current before turn-on should be quite low and the receive current listed in the manual, after turn on. Higher current probably indicates damage someplace.
(If damage was done, it probably won't be made much worse by the?gentle prodding above, or so I think...)
Good Luck!
73, Paul -- AI7JR
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Re: Did I fry my QMX SMPS or is it likely worse?
#qmx
K3KDW,
No, I would not order the new boards.? I believe that you have damaged the 5 volt and 3.3 volt devices.? You could check with Jeff Moore W1NC on QRZ.com for his email address.? He can diagnose and repair the QMX and has had great reviews in this group.
73
Evan
AC9TU
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Re: Did I fry my QMX SMPS or is it likely worse?
#qmx
That pdf is gold. So I only have a few ohms between vcc and gnd and vdd and gnd. I don’t know what normal measurements are though. Is it worth ordering a fresh set of SMPS boards?
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Re: QMX Display Brightness
Thanks Hans,
I'd tried tracking through the labyrinth of documentation about this but it's very difficult without spending a shed load of time deciphering it.? It it's not obvious it isn't worth it.? I'll just change the resistor.
Thanks again,
Chris, G5CTH
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Re: Did I fry my QMX SMPS or is it likely worse?
#qmx
K3KDW,
You want to measure the resistance on the bottom of the mainboard with the power supplies removed.? Attached is a PDF with the pin locations.
73
Evan
AC9TU
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Re: Did I fry my QMX SMPS or is it likely worse?
#qmx
Thanks for the reply! Could you guide me on where to test?
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Same here.
I ended up finding a seller on Amazon a few weeks ago and grabbed one.
Todd K4MSW
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Re: Hyelec PS-28A 0-15 VDC, 0-2ADC power supply plus a simple crowbar circuit for protecting all of my QRP rigs
I agree, my Motorola Service Monitor has a TO-3 zener diode on a huge heat sink protecting its 5 volt supply. Gotta love brute force.
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Re: Did I fry my QMX SMPS or is it likely worse?
#qmx
Unplug the SMPS boards and check the resistance to ground of both the 3v3 and 5v0 supply rails on the main board. If the 3 volt rail shows only a few ohms or less there is a high probability that the MCU is toast.
JZ KJ4A?
I accidentally fed 26v to my QMX. That's what I get for keeping too many running projects laying around, especially when they require wildly different voltages but the same plug format. Next time I'll tag the only correct supply.
Am I probably safe once the SMPS boards are replaced or is there a good chance for more damage?
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Did I fry my QMX SMPS or is it likely worse?
#qmx
I accidentally fed 26v to my QMX. That's what I get for keeping too many running projects laying around, especially when they require wildly different voltages but the same plug format. Next time I'll tag the only correct supply.
Am I probably safe once the SMPS boards are replaced or is there a good chance for more damage?
|
Colin Kaminski
Paul - AI7JR
Tom - AJ8X