I am pretty sure that PWM_3V3 is constantly at 0V. I can check again on Monday. The QMX is at work, where I will have a better opportunity to make measurements.
In my opinion, the 0V at PWM_3V3 is also a sign that the MCU seems to be working correctly. Since VDD is at 4.27V according to the measurement, the MCU must be trying to reduce the voltage. So 0V is the correct value. The question is, why is VDD so high? Because of the low resistance between PWM_3V3 and ground, I suspect a defect in Q107. Is that a possibility?
73 - J?rg, DG0JDE
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On 16/09/2023 07:51, df2jp_1 wrote: On the one hand it should provide the missing bands for WSPR operation, Joe, For WSPR I do not expect the QDM to be any different. With latest firmware a QDX may be setup on any bands but there will only be 3 LPFs. Low frequencies will not work unless you remove the switching diodes and make it single band. External filters could be used to use it on more than one band. 73 Alan G4ZFQ
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HelloJpe,
The short answer is no; you can not switch multiband LPF with the diodes used in the QDX or QMX LPF selection.? The carrier persistence is not there for the lower frequencies.? This was one of the reasons for the single band QDX, as only one LPF is used with the switching diodes removed.? So far, I have seen 80 meters as the lowest for a multiband QDX.? Currently, there is only the 80 - 20 meter QMX offered.? You can mix and match any bands from 80 to 10 if you change the bandpass and low pass filters to match.
With the above understanding, it should be possible to build an external relay switched LPF assembly and change the BPF components to match as that is a MOSFET switched IC for selection.? For LPF selection, you are limited to only three possible.? This means to get more than three bands; you would need to share LPF for two or more bands.? Not feasible for the lower bands.
The above is my understanding at this point.? Others may have better information than I do.
73
Evan
AC9TU
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Hello friends,
I have a QDX which works here in WSPR mode and does an excellent job.
My model makes the bands from 80 - 20m. Now I have read that you can also equip the bands differently. I am now interested in the QMX. On the one hand it should provide the missing bands for WSPR operation, on the other hand it should also be used for (rare) CW-QRP operation.
Now my question: Is it possible to build a QMX with the bands 2200 - 630 - 160 - 17 and 15m? It is only about the technical feasibility, that there might be problems with the space for the filter cores is clear to me.
73 Joe
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Just checked, with version -06 I get transmission using FT8CN
from my Android phone. Only had a dummy load connected but the
current went up.? The dots and line Tx indication doesn't seem to
be implemented.
Chris, G5CTH
On 16/09/2023 08:13, Chris wrote:
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Show quoted text
People have reported that earlier
versions are OK, ...-06 maybe.? Check the release notes to see
if you are prepared to loose the things added in the later
versions.
Chris, G5CTH
On 16/09/2023 07:58, Nurlan wrote:
Thanks for the answer!
I am aware that the audio level is low. Is it possible to
solve this problem?
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People have reported that earlier
versions are OK, ...-06 maybe.? Check the release notes to see if
you are prepared to loose the things added in the later versions.
Chris, G5CTH
On 16/09/2023 07:58, Nurlan wrote:
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Show quoted text
Thanks for the answer!
I am aware that the audio level is low. Is it possible to
solve this problem?
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It seems there is a known issue…
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Re: Enclosure for 10w linear amp
Are miniboxes the folded aluminium type that were made by Bud Industries and the like, or diecast?
(Two nations separated by a common language)
PeterS?? G8EZE
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Hi Nurlan, ?There is some more detail on Page 49 of the manual and suggests software master volume to max. ?Afraid I’m not familiar with FT8CN but have tried it from a PC running WSJTX and it works using the instructions in the manual. ?
Clive
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Hi Hans,
can you give us an update on how far you are with the implementation of the AGC and the SWR meter?
Since the qmx hasn't implemented an AGC yet, i'm still traveling with 4 QCX minis,
it would be great if I only had to take one qmx with me :)
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Thanks for the answer!
I am aware that the audio level is low. Is it possible to solve this problem?
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Re: Vacuum-tube final for QRP transmitters?
Just ordered a few to try. With the 0-3.3 v drive from the IC should get 5W out on 630M. Will let you know in a few weeks. 6N7
N0UU
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Towards the back of the operating manual…
Best 73, ?Clive
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Hello everyone!
When connecting from a smartphone using the FT8CN app, there are two dots on the display. Has anyone tried it? How to fix the problem?
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Re: Done with the build and it wooorrksss :)) Have a strange issue with volume control
#qmx
When switching on the 80m band the volume is missing, when switching on all other bands the volume is there. Then I switch to the 80m band and the volume is there too, everything is normal. Whether with or without grounding.
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Re: QDX not providing audio after bootup
On 15/09/2023 22:04, Dr. Pedro E. Colla (LU7DZ) wrote: QDX takes ?around 5-10 secs to complete the boot, the RBpi boots to the point of being detected on the network about 20-30 secs after power up and WSJT-X is launched about one minute after that. Pedro, This is the way it must startup. If the QDX is not booted then WSJT-X will not connect. I presume you are frequency hopping? When the QDX boots it starts on its preset configured frequency. Does WSJT-X always start on this frequency? When WSJT-X starts it reads the QDX frequency, it does not change it. I run a single frequency QDX with a Rpi. It never started properly until I set the QDX start frequency to the same frequency that WSJT-X is set. I do not understand your comment about CAT and the audio connection. This has never been reported before and I read all posts in the WSJT-X group. CAT does not affect the audio connection. 73 Alan G4ZFQ
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Re: Done with the build and it wooorrksss :)) Have a strange issue with volume control
#qmx
This morning I started the Qmx on the 80m band, the volume remained silent. When I started the QMX on the 40 m band, the volume was there and everything was normal. My ATU100 was turned off. I have a 2x27m dipole that resonates on the 40m band. The ATU100 adjusts the dipole on the 80m band.
Is it possible that the QMX checks whether there is resonance when it is switched on?
So far, I have the impression that the variations in volume control come from the software.
Greetings from Rhineland-Palatinate, Axel
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Re: Q: Destructive experiment on a dead BS
On Thu, Sep 14, 2023 at 03:20 AM, Rod Smith wrote:
And yet in the QxX series of designs the specifications are not exceeded.
what about understating the specs? I am most happy running between 2 and 3 W for almost all my portable rigs (some ATS, some MTR and some QxX). And I even can understate this understatement if instead of using 12V I just stay happy at the level given by 2 LiPo cells. Whatever problem arise from this doing does not have anything to do with the gross power yield during TX but with the fact that I hear much too many stations unwilling and much too little willing to answer my call, even if they would hear it (they all lure big dx). And this issue does not have anything to do with the difference between them 2W that make sense to me and those 8W on the cuting? edge of what the poor BullS170 are willing to give..? Never had a 807, let alone two of those beasts... Sometimes, I just carry a poor 9V alcaline battery with me. It will give me hours and hours of delightful SWLing, but as soon as I press the PPT button, the poor 9V cell drops like a rock and ... most of the qrp rigs I own, just perform a reset. A qmx might do other things, much less amusing. What I would really, honestly do, at least me, for myself, if I would have to engineer a stable solution: I would refrain from large power level yields pulled out of the sensible rig and? if qrpp would NOT be an option, I would use an external big-bang qro PA. There are sooo many of them out there, either from qrp Labs or from the far east, all costing a flower and a smile. All QxXes provide enough interfacing network to drive them even in qsk modus. Only band-switching might need some refinements. Give it a tought. There was a G-QRP say saying that : "there's nothing like a big bang to compensate for the lack ..." Happy and most of the time very content of any reflections, but, alas, bitterly knowing that they are not of much help in the situation given. It is the common sense that is missing, at least to me. yours, Razvan dl2arl
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I haven't tried that (don't have that amp), but I know that Hans is aware that the PTT out from the QMX is not yet enabled in firmware. Hopefully that'll start working when he releases the next firmware version, though I don't know if that particular issue is intended to be fixed with the next release or not.
73!
Roy - KI0ER
Littleton, Colorado
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Re: QDX not providing audio after bootup
Ok, the hard part is to delay the power up of the QDX so the OS is up before the QDX starts. Hope you figure how to do it. Maybe some remote control relays that reset off when the power goes off then waits for a signal to turn power on to the QDX. If you get it working you'll have the pretty neat system.
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On Sep 15, 2023, at 17:04, Dr. Pedro E. Colla (LU7DZ) < lu7did@...> wrote:
It's quite difficult to reproduce the problem because as said it occurs about once every 3 or 4 times, actually seems to be random.
Yes, I tried to delay the start WSJT-X but the problem seems to be the opposite, being QDX starting first when no communication is still being made with the host. QDX takes ?around 5-10 secs to complete the boot, the RBpi boots to the point of being detected on the network about 20-30 secs after power up and WSJT-X is launched about one minute after that.
73 de Pedro LU7DZ
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Clive - G4KCM
Nurlan
DL2ARL