Re: Available Hand Mics for QMX SSB ?
Just got mine from Erick for my QMX. Used a tiny hot glue gun spot to add just a touch length to button to make it easier to use. Thankyou @Erik Larson, The blue is nice, good choice.
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Re: QMX+ new build AGC does not work.
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On Apr 4, 2025, at 7:49?PM, Stan Dye via groups.io <standye@...> wrote:
? It may work to turn down the agc threshold to about s6 or even lower.? My agc didn't often activate when I used the default threshold.
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I had the volume turned up to hear quiet cw signals, and so my speaker was being over-driven by the few very strong cw signals. So I needed to turn the agc threshold down to make the strong signals weaker.
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Re: QMX+ new build AGC does not work.
It may work to turn down the agc threshold to about s6 or even lower.? My agc didn't often activate when I used the default threshold.
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I had the volume turned up to hear quiet cw signals, and so my speaker was being over-driven by the few very strong cw signals. So I needed to turn the agc threshold down to make the strong signals weaker.
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Re: SWR and PWR does not show lcd
On Fri, Apr 4, 2025 at 12:16 AM, <ec7zv0@...> wrote:
The tests are in DIGI mode, that's why SWR & Power don't appear during TX.
No, you misunderstand.? The power and SWR indicators should work fine in DIGI mode.? It is only the agc and s-meter that are not implemented.
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If your power and SWR indicators are not working, please check that they are enabled in the menu.? If they are enabled, you may have a bad connection at T507 such that the processor can't read the power and swr.
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Stan KC7XE?
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Re: QMX output is always 2W on all bands
A few more data points w/ power supply connected:
Supply Voltage | TX Voltage | TX Power | SWR |
10.8 V ?| 9.4 V | 1.9 W | 1.18 |
11.8 V ?| 10.2 V | 2.1 W | 1.18 |
12.8 V | 11.0 V | 2.3 W | 1.17 |?
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Re: QMX(+) Build experience, Poor Audio Filter Sweep/RF Filter Sweep/Image Sweep/ADC IQ test and resolution with new PCM1804
Stan, you must be in Houston, because we have a problem! No matter the freq the signal is present on all L40X coils....there is a whole lot of switchin' not goin' on!
--
73
Karl
KI4ZUQ
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Re: Gibberish characters appended onto end of Message 1
On Fri, Apr 4, 2025 at 05:53 AM, Braden Glett wrote:
Do you happen to know if there's a list of recognized bugs to be fixed,
Hans regularly reads messages posted here, and puts the bugs on his list.? As far as I know such a list is not published.?
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I have a QMX (80-20) for 12 V that I built last year. It worked fine on FD, and was used occasionally since. A few weeks ago I was running it into a dummy load. Controlled by fldigi. Power was a LiFePO? through a regulator at 12 V with a 1.5 A current limit.
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After messing around with the fldigi settings until I got it to "transmit" into the dummy load. Output power and input current looked good.? Then I got distracted doing something else. After some time I looked at the regulator and it was showing 6.1 V at 1.5 A out. The radio is on, and the display works, but obviously something is seriously wrong.
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WSJT-X communicates with it. I can change frequencies and modes.
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I looked at the back of the main board with my IR camera.? The hot spots appear to be associated with Q507 and Q504.
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So I've blown it up, but I don't know what I did. Is there a troubleshooting guide? I've opened it up and there's nothing visually apparent.
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In talking this out I've sort of convinced myself that I have a shorted Q504, drawing too much current and heating up Q507. Does anyone have any better ideas? Is there any way to test this hypothesis other than cutting Q504 out of the circuit and seeing if the excess power draw goes away?
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Take this one, it's the same.
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73, Rajko DC0IT
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Re: ProgRock2 programming??
?Hi Alan,
I measured the voltage on the HC6 socket and found negative .1 volts on one side and zero on the other. All the sockets measure the same negative voltage in the instrument. This obviously isn’t an over voltage issue for the PR2 and maybe the negative voltage killed the one I configured for the frequency I needed. Like I said, it appeared to work for a minute or so, then stopped.
I’m not sure what I can do here other than pull filament voltage (tube equipment) rectify it and then put a 5 volt regulator on the rectified voltage. I would do that only on the three crystals I planned to use the PR2. I’ve got plenty of room under the chassis for the extra components but the time needed to get the 5v regulator (I don’t know if I have one handy) just adds time to my solution and in hindsight I may have been better off just ordering the crystals.
Thanks,
Tom N5AMA
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On Apr 2, 2025, at 7:12?PM, Tom Smith <n5ama@...> wrote:
?Thanks Alan, I’ll measure the xtal socket and see what’s on each pin. I’ll have to be careful to put the voltage pin on a socket with 5v regulated voltage.
73 Tom
On Apr 2, 2025, at 1:50?PM, Alan G4ZFQ via groups.io <alan4alan@...> wrote:
?On 02/04/2025 14:59, cct314159 via groups.io wrote:
- Even though they are "rated" for "12 volts" *don't even think about running one at that voltage:* I'd avoid going above 10.0 volts. Yes, that reminds me. I tested with 12 volts and it certainly got a lot hotter than I expected.
The ones I use are fed from 5 volts and keep cool.
73 Alan G4ZFQ
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Re: ProgRock2 programming??
?Hi Alan,
I measured the voltage on the HC6 socket and found negative .1 volts on one side and zero on the other. All the sockets measure the same negative voltage in the instrument. This obviously isn’t an over voltage issue for the PR2 and maybe the negative voltage killed the one I configured for the frequency I needed. Like I said, it appeared to work for a minute or so, then stopped.
I’m not sure what I can do here other than pull filament voltage (tube equipment) rectify it and then put a 5 volt regulator on the rectified voltage. I would do that only on the three crystals I planned to use the PR2. I’ve got plenty of room under the chassis for the extra components but the time needed to get the 5v regulator (I don’t know if I have one handy) just adds time to my solution and in hindsight I may have been better off just ordering the crystals.
Thanks,
Tom N5AMA
toggle quoted message
Show quoted text
On Apr 2, 2025, at 7:12?PM, Tom Smith <n5ama@...> wrote:
?Thanks Alan, I’ll measure the xtal socket and see what’s on each pin. I’ll have to be careful to put the voltage pin on a socket with 5v regulated voltage.
73 Tom
On Apr 2, 2025, at 1:50?PM, Alan G4ZFQ via groups.io <alan4alan@...> wrote:
?On 02/04/2025 14:59, cct314159 via groups.io wrote:
- Even though they are "rated" for "12 volts" *don't even think about running one at that voltage:* I'd avoid going above 10.0 volts. Yes, that reminds me. I tested with 12 volts and it certainly got a lot hotter than I expected.
The ones I use are fed from 5 volts and keep cool.
73 Alan G4ZFQ
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Hi Chris,
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Stan had mentioned about Vbat but I didn’t know where to look. The QMX+ was assembled and the GPS module came already installed. Vdd is linked to VBat which I assume is the pre-assembled default. ?With the rig powered off a probe on Batt and the other on the Gnd (on top of the GPS module) there is no voltage - the battery is installed and shows 3.17V (via the battery connections to the pcb). With power VBat shows 3.27V.
Paul, G8MAD
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QMX output is always 2W on all bands
Hi everyone,
I built the QMX kit configured for 12V operation (the kit was ordered on 13/04/2024), and while everything appears to be functioning correctly, I'm only seeing about 2W of output power across all bands.
Here are some data points and measurements I’ve taken:
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Input voltage to QMX: 11.2V (measured with a Fluke DMM), very stable with minimal drop during TX.
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Antenna/dummy load: SWR monitor seems to be functional and correspond to nanoVNA measurments.
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Power display: Only 1 bar (4–5 dots) shows on the PWR display while connected to QRPLabs' 20W dummy load.
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Measured voltage: The DMM reads ~11V across the dummy load during TX.
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QMX Console app: Shows 9.5V and between 1.8W to 2W output during TX across all bands.
I’m not sure where to start troubleshooting this issue. What would be the best way to begin isolating the cause?
For context, I have the following test equipment available: oscilloscope, multimeter, bench power supply and another working QRP radio for reference/testing.
Please let me know if there’s any other information I can provide to help identify the problem. I’d be very grateful for any suggestions or guidance you can offer.
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Thanks in advance for your help!
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Best regards,
Igor — W6ETA
73
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Re: Qmx plus rev 2 not powering up
The controller was not powering up from the beginning only when I bypassed the q102 it started. Than my idea was (thanks Stan :)) to trace why I need to do it and found the the micro was probably pulling down the signal probably from the beguining. Probably There was never a blown q102 and sure not a via or track issue. For me was just disappointing because it never worked properly from the first moment because a controller issue.?
I wanted to know why, other wise would be cheaper just order other board, I just spent time, plus parts, shipments, etc. at the end I still don’t know why this pin 88 on the controller was defect, specifically when the power is supplied the rest of the controller seams to work, this puzzles me.
Anyway I live in Germany (Nuernberg) so probably should get a chip from turkey.
73 Azgael
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QMX+ new build AGC does not work.
Everything else seems to work, but no AGC. As a result, there is distortion on loud CW sigs. Yes, it is enabled in the Audio menu. 027 firmware.
Any ideas would be appreciated. Thanks, Dick, K5AND
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Alas, the Radtel Speaker-Mic does not appear to be available in the USA from Amazon.
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73, Dave K3DX
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Re: shorted PA on TX, dead SMPSU?
On Fri, Apr 4, 2025 at 09:49 PM, Damon wrote:
with IC204 CLK2 into IC501 is 100% @ 3.3V on pin 4. Not sure yet if IC204 or the main mCPU are faulted,
Damon, I wouldn't enjoy the RX. I wouldn't switch on the QMX in this state. Maybe voltage at IC204 is wrong because of IC503 died together with the PA. Best way is to remove IC503 and check output of IC501 and IC502.
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And if the main mCPU would be faulted you couldn't switch on the QMX.
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73 Ludwig
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$75 shipped in the Con US
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-Nate
N8BTR
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Re: shorted PA on TX, dead SMPSU?
Dan, its a bit risky but I did it with success. You may do it on your own risk!!!
Set the supply to 3.0 V and current limit to 200 mA. Remove all subboards and connect the bench power supply direct to Vdd and GND. I guess the voltage will drop. Check all IC connected to Vdd for temperature. If you find one hot or significant warm, his should be the culprit. If no IC is hot increase the current to 300 mA, maybe later 400 mA but not more. But be sure while increasing the current the voltage is not going over 3.0 V.
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2 Ohm and 0.4 A will produce 320 mW heat, enough to feel it.
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73 Ludwig
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Re: Qmx plus rev 2 not powering up
One question, reading older posts in this thread the QMX+ was running. But when and why died the controller now?
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73 Ludwig
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Paul K7VIQ
Dick Hanson
Igor
Karl