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Re: QMX and QMX+ won't boot.

 

On Sat, Jun 22, 2024 at 04:19 PM, Niels Jalling wrote:
All the smps-boards was tested and working in a rev.1 QMX.

Strange I have the same problem in both a QMX and a QMX+!
Niels,

so you produced the same failur in both, but where???
Or did you use for both the same power cable, maybe a broken one?

When pressing the poweron they both try to draw more than 1A at 8.8V
If not the cable please limit the current to around 250 mA for more tests.

But before testing voltages check resistance from VDD to GND and VCC to GND with all the subboards removed from the mainboard. The linked document contains a link to a sketch to find the signals on the QMX. For QMX+ the signals are marked in the assembly manual.
All these values should be around 10 kOhm or more. If only a few ohms something is wrong related to the VDD rail and / or the VCC rail.

Please read this QRP Labs Wiki document about the start, section "switch on power".
There you find information about some signals and voltages to search for the problem.

73, Ludwig


L506 Winding Gap Improves Filter Sweeps

 

I just finished building my second QMX+ and the 160m filter sweep had rather ugly oscillations on it.? L506 in the 160m filter has so many windings that the start and end windings had butted against each other likely adding some parasitic capacitance in parallel.? I found that by creating a small gap between the start and end winding the sweep greatly improved.? This also improved the sweeps on almost all other bands although to a lesser degree.? I went back to my first QMX+ (which did not have ugly oscillations on the 160m sweep) and added the gap and also noticed improvement in the sweeps on almost all bands.? Has anyone else experienced this?

Andy KY4DF


Re: QMX stopped transmitting

 

On Sat, Jun 22, 2024 at 10:39 AM, luigi vkw wrote:
What I have noticed is that the Voltage on transmitter is only 0.4 V.
Luigi, TX voltage 0.4 V is for not transmitting, it's ok. But voltage for transmitting around 5.x V is a bit low compared to the supply voltage. Maybe to much current is drained from the PA?
1. So please show current for all the three reported bands while transmitting or something is wrong in the supply of the PA.

2. Please check the solder joints to connect L502.

3. Please check voltages at S, G and D of Q507 when transmitting.

4. Did you measure the output by an external meter? If not could you do this?

5. Please check the solder joints to connect T501 and T507.

73, Ludwig


Re: QMX+ dev board question

Ham Radio
 

Jim and Hans

100% in agreement.

C++/C ?syntax is horrid. ?If you inhale it every day, ?I guess you get acclimatized to it. ?Miss a bracket pair and you can spend hours figuring out what the code is doing. ?

I even used APL - extremely cryptic (but powerful and totally unmaintainable)?

The choice of Basic is excellent and mere mortals can figure out what the code is doing.
??

--
73, Bernie, VE3FWF


Re: QMX stopped transmitting

 

Hi Donald, did the test: confirm square wave at the gates, 180 degrees out of phase. Also with DMM, about 2.5 V from to gate to ground for each FET.


Re: QMX+ failed with power issues on first power up

 

Enjoy the FD weekend Mark! We will hit it again when you rest up.

JZ

On Sat, Jun 22, 2024, 3:21?PM w8gu via <w8gu=arrl.net@groups.io> wrote:
Thank you.? Time for me to walk away for a while.? Must have entered the numbers in the calculator wrong.?

Time to go to field day anyway.? Thank you for your help!

Will go back and look at power supply on the oscilloscope tomorrow morning.? ?If things look iffy, I may just order new power supply boards.? I have been looking to put in an order for the GPS module anyway.


Re: QMX+ failed with power issues on first power up

 

Thank you.? Time for me to walk away for a while.? Must have entered the numbers in the calculator wrong.?

Time to go to field day anyway.? Thank you for your help!

Will go back and look at power supply on the oscilloscope tomorrow morning.? ?If things look iffy, I may just order new power supply boards.? I have been looking to put in an order for the GPS module anyway.


Re: QMX goes into SWR protection mode during WSPR transmission

 

Hi Bruce,

thanks for the reply! I do not have a CMC choke on the antenna feed at this time (need to build one first).

Transmitting into the dummy load seems to be working fine. SWR shows 1.3 and external power meter shows 4W. LPF sweep looks perfect.

When transmitting into the real antenna (10m J-Pole vertical), SWR shows 1.6 and the external power meter shows 4W also.

I'll try with a CMC choke and see what happens.

73,

Andreas


Re: Antenna tuner companion for QMX? #qmx

 

Did you build the pocket tuner? If yes, would you be willing to share your experience with it?

73, Peter HB9EBE


Re: QMX+ failed with power issues on first power up

 

Mark, I calculate?
i=e/r = .042/1.25 = 0.0336A = 33.6 mA which is altogether reasonable.

JZ


On Sat, Jun 22, 2024 at 3:01?PM w8gu via <w8gu=arrl.net@groups.io> wrote:
L201 measures 1.3 ohms on my Fluke.
My old Kiethley measures 1.2 ohm.? Not sure which to believe.

Voltage .042 vdc

350 mA

Datasheet says 5351 is 33 mA typical.? We are getting 10x that.

Based on this, the problem is most likely in the 5351, IC202, or the TXCO (or, of course, in something that is driven by one of their outputs).

(kind of makes me wonder how hot the hidden components under the 3.3 volt power supply are getting.? Thinking about making a short temporary extension cable to run the system with the 3.3 volt power supply set off to the side)


Re: QMX+ failed with power issues on first power up

 

L201 measures 1.3 ohms on my Fluke.
My old Kiethley measures 1.2 ohm.? Not sure which to believe.

Voltage .042 vdc

350 mA

Datasheet says 5351 is 33 mA typical.? We are getting 10x that.

Based on this, the problem is most likely in the 5351, IC202, or the TXCO (or, of course, in something that is driven by one of their outputs).

(kind of makes me wonder how hot the hidden components under the 3.3 volt power supply are getting.? Thinking about making a short temporary extension cable to run the system with the 3.3 volt power supply set off to the side)


Re: QMX+ failed with power issues on first power up

 

I think that is the right interpretation, Mark.

JZ


On Sat, Jun 22, 2024 at 2:06?PM w8gu via <w8gu=arrl.net@groups.io> wrote:
So if the decision on when to jump from linear to switching is made based on the 5 volt output, and if the 5 volt output is actually 5 volts, but if the 3.3 volt output is actually 3 volts (10% low), then the ADC in the microprocessor is probably using the 3.3v as a reference and saying the 5volt output is 5% high (the screen shows 5.54) and therefore not going over to switching mode.

That also explains the 8.1 volts on the screen when I put 7.5 volts in.

That makes me a lot happier that the microprocessor is still OK.


Re: QMX+ dev board question

 

开云体育

For sure - absolutely nothing wrong with Basic. My programming career started out in the 60’s with RPG and then COBOL and IBM Assembly language. I’ve looked at C++ and wonder how the developers ever came up with a command syntax like that. In recent years I started using XOJO here at home - it is a resurrected version of Basic, and the command structure and syntax of Basic make life real easy for beginners and pros alike. Good choice, Hans!

Jim

On Jun 22, 2024, at 9:54?AM, Hans Summers via groups.io <hans.summers@...> wrote:

Hi Mark

> Hans...how about MicroPython or Ruby instead of "basic" ?...;-)

Yes, various people could make good arguments for all sorts of programming languages.?

In my former software development career?I never really minded what language the company required. Maybe I was unusual in this. I always thought once you have a programming mentality, it's more important the logical construction of the application, than particularly what programming language it's in.?

Remember?too that we are operating here on relatively small microcontrollers, in terms of the Flash memory available and RAM. It isn't trivial, neither in relation to developing it, nor the resource requirements on the hardware, to write a Virtual Machine and a Programming language and interface it to all the functions of the radio. It so happens that I had already done all that for U4B and I chose BASIC for several reasons; one of which was that I could relatively?simply write a compact and performant implementation?of it and a VM for it to run on. Another key reason was that it's called BASIC for a reason, it's a lot easier to learn, for non software people, than many more advanced languages. Yet you can still accomplish everything you need to do, particularly on a relatively small system like this.?

One of my favourite stories in this regard: in 2007-2011 I headed a "Rapid Application Development" team at a large investment bank in London, pricing exotic commodity derivatives. We had a large server estate with 1,000 parallel computer nodes, to which the high intensity simulations got distributed. It was a very complex system. But as we were "Rapid Application Development" we were doing everything with Excel and VBA.?

Speed was critical, by which I mean delivery of new deal pricing types etc. Famously the mainstream Commodities IT department had taken 13 months to implement pricing of Asian Barriers but we were able to turn around such demands within 1-2 days. Which was critical because by the time 13 months had elapsed every other bank can also do it already and there is very little money in it. So we were cutting edge and we had to be fast fast fast even though sometimes that involved cutting some corners and taking some risks.?

Yet as I said, it all ran on Excel/VBA calling some C++ libraries written by the rocket scientists department (mathematicians). In the end as we were so so so fast, we were doing the official pricing and risk management which used to run for 10 hours overnight on those 1,000 blade computers in the server room. The Excel processes were all kicked off by a scheduling system called "AutoSys" but basically Excel was under huge stress, expected to cope with all that; so it was always failing horribly. When that happened (nearly daily) me or my team had to wake up, log in, and restart it, and sometimes it didn't get finished in time for the market open the following morning, and then we were yelled at by trading who were then trading blind with no risk simulations to rely on. Sometimes we couldn't even get it finished until the SECOND day.?

Chronically under budgeted, yet it came to the point where the thing got more and more unreliable, the more and more we got to be the victims of our own success, because more and more complex deals came onto the system. So at some point, tired of being yelled at and all the stress, it came time to urgently find a solution.?

Excel/VBA is very close to Visual Basic (VB6 at that time, if I recall). What I did was rewrite the whole system in VB6 instead of Excel/VBA; I single handedly took on the task (as I said, we had no budget, no resources, nothing) so it was a matter of finding a solution, despite having nothing to work with; and in the end I just had to do it myself, alongside all my other responsibilities. So it was critical that VB6 and VBA are the same syntax and similar in many ways.?

I completed the whole re-write?in 3 weeks.?

Excel still kicked off the process but immediately handed over to the VB6 executable, which did everything. The results were written into a plain csv text file, appended to the file as they came in. Then at the end VB6 signaled to the Excel host that it was finished, and Excel VBA read the results file. So from the user perspective everything looked totally the same, but under the hood, instead of Excel/VBA doing the heavy work, it was handing off to a VB6 executable.?

Our problems were completely solved and I didn't get woken up at night at all even ONCE in the following 6 months and neither did any of my team, it was 100% reliable. After that I left UK and went to Japan, so I don't know what happened after that. The .csv results file was super simple and as it was a matter of just appending results as they came in, if there ever was any failure, the VB6 program read all the results it saw in the previous .csv file and didn't need to repeat those calculations; basically it could resume where it had failed and not waste time repeating any calculations.?

Success? I thought so. But you can't imagine the barrage of criticism I was in for. Mainly from the mainstream IT departments. Why had I used VB6, not some more advanced programming language? Well because it was similar to VBA, my back was against a wall in a corner, we had to have a solution super quickly, and nobody gave me any development resources or budget or anything, what was I supposed to do, except make the job as small as I could do and sit there all evening doing it myself? Next: why did I use a .csv file? I should be using a proper relational database. Or at least .xml files etc., not plain csv! How low tech was that! Well again - who gave me time or resources, what was I supposed to do, except do it the easiest quickest way I could think of? Not to mention that writing out a huge xml blob is also a non-trivial process and if it fails, things are not properly terminated so there isn't a "resume" option easily available.?

Anyway I didn't care about the criticism. I thought it was a great example of KISS (Keep It Simple Stupid), not making anything more complex than it needs to be. As dear old George G3RJV (SK, RIP) was wont to quote from Occam, "it is vain to do with more, what can be done with less".?

Sorry for the long waffle. KISS. And I always had a love of simple, BASIC - when I put it in QMX everyone will be able to learn it if they want and do what they want. Or ignore it completely if they wish. The simplicity, compact implementation, low resource demands, are pretty hard to beat!?

73 Hans G0UPL



On Sat, Jun 22, 2024 at 6:10?PM Mark Ennamorato via <mark.ennamorato=gmail.com@groups.io> wrote:
Hans...how about MicroPython or Ruby instead of "basic" ?...;-)
Mark




--
Jim / K7TXA
Eagle, ID

SKCC 10447T
BUG 301


Re: QLG3

 

Both are in very lousy locations in my basement, but QLG1 usually locks up in 2-5 minutes, the other two in 5-10 minutes.?
--
73, Dan? NM3A


QLG3 Altitude Units

 

After a few hours troubleshooting why my QLG3 was not working (there's a separate thread on that adventure) I was in the GPS viewer watching it latch onto the satellites when I noticed that my QTH had suddenly gone from 2,600 feet ASL to 790 meters. Thought the GPS was whacky, then I realized that the number showing is in meters. Kinda threw me for a loop, as my older QLG2 & QRP Labs Clock gave me a display in feet. :-)

Any way that the GPS viewer can be changed to show both units?
--
Jim / K7TXA
Eagle, ID

SKCC 10447T
BUG 301


Re: QMX+ failed with power issues on first power up

 

So if the decision on when to jump from linear to switching is made based on the 5 volt output, and if the 5 volt output is actually 5 volts, but if the 3.3 volt output is actually 3 volts (10% low), then the ADC in the microprocessor is probably using the 3.3v as a reference and saying the 5volt output is 5% high (the screen shows 5.54) and therefore not going over to switching mode.

That also explains the 8.1 volts on the screen when I put 7.5 volts in.

That makes me a lot happier that the microprocessor is still OK.


Re: QMX+ - Another One Comes To Life!

 

This one is resolved - mostly. It turns out that when the CR2032 battery is inserted into its holder, the connectors on the right side (the minus side) short out against the positive part of the battery. I've looked at this rather closely under my magnifiers and for the life of me I cannot see how this holder ever can work as designed. So, either I've got a defective battery holder or there is a design flaw in this thing. I was able to circumvent the problem by placing a small (very small) piece of tape on the edge of the battery. Thus, when it is inserted into the holder, the two little prongs still contact the minus side of the battery, but the base of those pins no longer come in contact with the slightly larger positive part of the battery.

Has anyone else come across this situation? Wondering if Hans has followed this thread...?
--
Jim / K7TXA
Eagle, ID

SKCC 10447T
BUG 301


Re: QMX+ failed with power issues on first power up

 

The system does come up in linear mode initially.?
LIN_REG_EN is an output of the MCU. It disconnects the linear regulator when the MCU decides the SMPS supply voltages are ready.
IIRC the MCU monitors ADC_5V to make that decision.
The ADC_3V3 signal is what is displayed as the 3.3V SMPS output.

JZ


On Sat, Jun 22, 2024 at 1:27?PM w8gu via <w8gu=arrl.net@groups.io> wrote:
I do not really understand the enabling of the linear versus switching 3.3.

Does the system come up in linear initially and get moved to switching by the microprocessor?
Is LIN_REG_EN an output of the microprocessor?
If so, what does the microprocessor use to determine that it is time to go to switching mode?

Is the 3.3 voltage on the hardware diagnostics the voltage of the output of the switching mode 3.3 (i.e., ADC_5V)?

=================
still on my to-do list is
- checking the resistance/voltage on L201
- Looking at the outputs CLK0/1/2 on a scope.

Not likely to get to these until tomorrow.? Planning on visiting our club's field day operations.


Re: QMX+ failed with power issues on first power up

 

Probably will go through the 3.3 v power supply with a scope documenting all voltages on a copy of the schematic to see where the power is moving.


Re: QMX+ failed with power issues on first power up

 

I do not really understand the enabling of the linear versus switching 3.3.

Does the system come up in linear initially and get moved to switching by the microprocessor?
Is LIN_REG_EN an output of the microprocessor?
If so, what does the microprocessor use to determine that it is time to go to switching mode?

Is the 3.3 voltage on the hardware diagnostics the voltage of the output of the switching mode 3.3 (i.e., ADC_5V)?

=================
still on my to-do list is
- checking the resistance/voltage on L201
- Looking at the outputs CLK0/1/2 on a scope.

Not likely to get to these until tomorrow.? Planning on visiting our club's field day operations.