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Re: RTC battery mistake

 

Thanks for suggestions Stan and co. Confirming that with GPS connected and RTC source set to "software" the clock became accurate within a few minutes.
de VK6XT?
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?
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Re: RTC battery mistake

 

On Thu, Apr 3, 2025 at 07:35 PM, Greg McCain wrote:
Using a small gauge of insulated wire instead of a lead cutoff and tubing would work too. Get it close and flat on the PCB.?
?
?
Extra style points for tacking the wire/tubing down with Krazy-type glue.
73, Don N2VGU
Re: QMX SMPS issues, and a possible cure

 

Don,
?
These are pretty dinky supplies, no need for your 3/8" copper bolts.
But the file certainly makes for lots of crud to study.
?
I loaded up the supply with 50 ohms on 5v, 25 ohms on 3.3v (100ma and 132ma respectively).
When scraping the 12v source to the supply across a file, I saw an occasional triangular peak
on 5v that got up to about 5.7v, the base of that triangle was about 100us.
This was overshoot as the supply recovered from a quick dip in 12v, and only when the?
5v rail didn't go below about 3v.? Scope photo attached.
?
This is exactly the case that was killing QMX's when 12v power was intermittent,?
though I can guarantee the overshoot then was far far worse.? That has mostly
been addressed through firmware changes, though I suspect issues remain.
?
In my Readme I say:
> Next rev of this board will have:
>? Larger inductors than the now 3x3mm, with pads large enough to do rework.
>? Inductors (1uH?) added at input to each switcher to reduce noise on supply.
?
Larger inductors, both physically larger and more uH.
Because the current through the inductors now rises and falls very fast,
it very nearly reaches 0 current in the valleys on VCC.? Planning to go from 4.7uH to 22uH.
That will slow the rate at which current rises, and I'd expect it to cure the spike.
Adding the 1uH up front of the switchers (cap still across the switchers Vin) should also
help, meant primarily to reduce noise on the incoming rail but may also help avoid
sudden dips on Vin to the IC's.
?
I also tried using the file as a load on both VCC and VDD, going from no load to 0 ohms.
Again saw spikes, the worst was still around 5.7v peak on VCC.
?
The 3.3v rail was relatively clean in all cases, in part because it is supplied from VCC.
?
Anyways, if there's enough interest and I have a few of these auto-stuffed,?
I'll plan on shipping a couple off to you for further tests.?
Also to Jeff Moore and Hans if they are interested.
These inductors are short and robust, the boards are small and cheap.
I'm confident the boards can go out as first class letter mail here in the US.
?
Attached is a scope photo of the VCC spikes when under load and?
running the 12v supply across a file.
?
Switching at 2mhz and a 100ma load on Vcc, 130ma on Vdd (typical for a QMX),
the efficiency is around 84%.
I don't expect switcher noise to be an issue, if so we can reduce it to around 500khz
by using a different variant of these IC's and significantly improve efficiency.
We may not quite reach the efficiency of the old scheme which operates at 100khz
but I for one am more interested in a robust design than the last few percent in efficiency.
?
Jerry, KE7ER
?
?
On Thu, Apr 3, 2025 at 01:18 PM, Donald S Brant Jr wrote:

From the readme:? "Behaves well when output is suddenly shorted and then the short is removed."??
Try this:
The most brutal power supply torture test I saw was to connect the supply output with heavy leads to two 3/8" copper bolts closely spaced in an insulating block.
Energize the supply, then take a coarse file and file the ends of the bolts simultaneously.??
Watch the sparks fly and monitor the supply for instabilities. ?The fast, random short/open transitions, with bonus negative-resistance arcs, will challenge any control loop.
I love getting paid to do stuff like that.
73, Don N2VGU

QMXPS_Vcc_Scope.JPG

Re: QMX+ Power Output Question

 

Greg,
?
I had to download the zip file version of Hamlib, that got it by Mcaffee.? Unzipping the file just to get the single .dll file I needed gave Malwarebytes a fit, so I disabled the anti-malware app, got my .dll and just copied it over to the Hamlib folder.
?
73! Mark K9TR
Re: QMX+ SWR sweeps with SSB firmware?

 

On Thu, Apr 3, 2025 at 09:59 AM, mux_folder2001 wrote:
but I kinda don't want to go back one firmware level and lose my calibration.
You won't lose your calibration settings if you re-install v_027 of the firmware, unless you do a Factory Reset.
Firmware update preserves all compatible configuration settings across update versions.
Just this week I downgraded one of my QMX to 027, then went back up to 01_003, and the calibration was all still there.
?
And I'm not seeing any improper behavior of SWR sweeps in 01_003 either.? They show my antenna behavior as expected.
Check to make sure you're really getting output power - SWR sweep will be wrong if the power isn't getting out (or back through T507).
Stan KC7XE
Re: QMX+ Power Output Question

 

It would certainly be nice for McAfee to fix it - I am pretty confident it is a false detection.
I checked the file with several other scanners; a couple had problems with it, others didn't.
Stan
Re: QMX+ rev 3 freezes shortly after boot

 

On Thu, Apr 3, 2025 at 04:28 PM, Michael Shiplet wrote:
I am getting some strange power readings across all the bands, and my SWR readings are all over the place
I would start by doing (from the Hardware tool page of the terminal app):
- LPF sweeps of each of the bands
- SWR sweeps of each of the bands
both with a dummy load attached.
?
But first make sure you didn't forget to install the jumper across the middle pads of JP501 by the BNC.
?
Look not only at the shape of the curve, but also the left-axis labels.
For SWR all bands should give between 1.0 and 1.2 at the band frequency, and most of the way across the display; except on the higher bands it will be higher above the band frequency.
For the LPF sweeps, the left axis should show something near 0dB (or a few dB positive) at the top, going down to -30dB or so at the bottom.? And there should be a reasonable LPF shape.? If the left axis is all around 0 dB top and bottom, it means you are not getting any tx power out then back through T507 back to the processor to measure.
?
So in addition, re-check all soldering of T501, T507, and L502 - a fault in any of these will cause havoc with TX on all/most bands.? Faults in single bands are more likely in the LPF toroids and their diodes.
?
?
Re: QMX+ Power Output Question

 

Thanks.

I knew about that option but want to try the 'send to McAfee' option to see if I get a response and closer validation from them. Might help others going forward.?

If not, successful with that, I'll dig into the memory banks and see if I can figure out how to run the package validation checksum from the SourceForge files.?

My current WSJT-X is recent and working fine for my QM's and QD's on two, fully up to date, Windows 11 laptops. So not desperate :)?

GREG


On Thu, Apr 3, 2025 at 7:32 PM, Stan Dye via groups.io
<standye@...> wrote:
On Thu, Apr 3, 2025 at 07:52 AM, Greg McCain wrote:
Now, if I can get McAfee to check and bless the latest hamlib release which gets immediately quarantined when I try to pull it off SourceForge I can try out the latest WSJT-X version. Sigh ....
Greg, I had to turn off McAfee virus scanning while downloading the file and unzipping it.
After I had the hamlib.lib file out of the zip and deleted the zip, there was no longer a problem with it, and I successfully dropped it in the wsjt-x folder.
?
A few other files (JTAlert) I had to put in the 'Excluded files' list on the real-time scanning tab of McAfee.
?
Re: RTC battery mistake

 

And as noted in the assembly instructions ...

WARNING: the jumper wire must sit flush
down on the board. Otherwise it will short
with the metal body of the SMA
connector!

I insulated mine with a thin piece of shrink tubing.
Using a small gauge of insulated wire instead of a lead cutoff and tubing would work too. Get it close and flat on the PCB.?

G


On Thu, Apr 3, 2025 at 6:23 PM, Rick Hill via groups.io
<6xraytango@...> wrote:
The GPS vdd or vbat setting is a wire link on the PCB.
de VK6XT?
Re: QMX+ Power Output Question

 

On Thu, Apr 3, 2025 at 07:52 AM, Greg McCain wrote:
Now, if I can get McAfee to check and bless the latest hamlib release which gets immediately quarantined when I try to pull it off SourceForge I can try out the latest WSJT-X version. Sigh ....
Greg, I had to turn off McAfee virus scanning while downloading the file and unzipping it.
After I had the hamlib.lib file out of the zip and deleted the zip, there was no longer a problem with it, and I successfully dropped it in the wsjt-x folder.
?
A few other files (JTAlert) I had to put in the 'Excluded files' list on the real-time scanning tab of McAfee.
?
Re: QMX+ rev 3 freezes shortly after boot

 

On Thu, Apr 3, 2025 at 02:17 PM, @Ludwig_DH8WN wrote:
and it looks like I'm getting about 0.1W on 20m
Let us know if you need some help.
Actually, now that you mention it, I am getting some strange power readings across all the bands, and my SWR readings are all over the place, even with dummy load & a tuned antenna.
?
Here's my power readings from diagnostics:
160m -> 4W
?80m -> 0.8W
?60m -> 1.6W
?40m -> 0.2W
?30m -> 0.0W
?20m -> 0.0W
(the rest) -> 0.0W
?
I'm assuming that means I've got something wrong in one of my toroids, is that a correct understanding?
Re: RTC battery mistake

 

The GPS vdd or vbat setting is a wire link on the PCB.
de VK6XT?
Another QMX+ became SSB capable

 

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Kudos to Hans - the beta was well worth the wait!
Thanks again to the folks that helped me earlier this year locate and replace the bad switch. I had not used the little beast that much after confirming the repair, mostly due to time commitments. Did get some good reports on CW, then shelved it until firmware beta 1-01-003 that covered SSB was dropped.
The firmware upgrade was straight forward. I constructed two Mic adapters, one for a spare ICOM HM-219 and one for a Heil ProSet Elite iC. Both worked well without adjustments of any kind.
First voice QSO was this afternoon on 40M with VA3XV up in Ontario (about 400+ miles). He reported the audio to be as very nice, as good as my 7610. The QMX+ even received a 54 sig report when the QSB and adjacent frequency QRM was not present.
Next up configuring it for fldigi - FSQ and other digital modes... and of course portable ops. So far this has proved an excellent and surprisingly full featured little rig.
--
Jack Spitznagel
KD4IZ FM19oo
Parkton, MD
Re: QMX Display Brightness

 

Wont stop the backlight running hot though? ..? ?resistors are even cheaper . .?
Re: QMX+ Power Output Question

 

You might check to ensure that you have not spoiled the harmonic suppression in the process.?
Hopefully the increased power is not due to harmonics also getting through; the presence of harmonic energy will cause inflated readings on a diode-based power measurement. ?
Thermistor-based power sensors (HP 848x for example) do not exhibit this effect and measure true RMS power which is why I prefer them.
73, Don N2VGU
When I did the initial LPF sweeps I noticed that filters were attenuating the signal within some of the bands.? Adjusting the spacing of the turns on the coils made little difference.? Backing off a turn on the coils for the appropriate LPFs moved the attenuation outside of the band.? The filters are still fully attenuating the second harmonic and above.

Hans posted a video on this process for the QCX+
--
Steve KA0SM
Re: QMX+ SWR sweeps with SSB firmware?

 

开云体育

Hmm. I just watched the external SWR meter during the "sweep" and it holds steady also. It is clearly not actually sweeping for some reason.

Tony
AD0VC

From: [email protected] <[email protected]> on behalf of mux_folder2001 via groups.io <canthony15@...>
Sent: Thursday, April 3, 2025 2:51 PM
To: [email protected] <[email protected]>
Subject: Re: [QRPLabs] QMX+ SWR sweeps with SSB firmware?
?
Thanks Chris, that is pretty much what I expected to see with my 6BTV. It's weird that mine seems to report the correct SWR for the band I select (as compared to my external SWR meter) but it shows it as being the same for all frequencies.? Maybe there is something in my band configuration settings that is not right.

Tony
AD0VC
From: [email protected] <[email protected]> on behalf of Chris <chris.rowland@...>
Sent: Thursday, April 3, 2025 2:45 PM
To: [email protected] <[email protected]>
Subject: Re: [QRPLabs] QMX+ SWR sweeps with SSB firmware?
?
Just ran a SWR sweep on a QMX+ running 1_01_003 into a Cobweb and got this:
It seems to be reporting about correctly, The Cobweb is designed for 20, 17, 21, 24 and 28m.
?
Chris, G5CTH
?
Re: QMX+ SWR sweeps with SSB firmware?

 

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Thanks Chris, that is pretty much what I expected to see with my 6BTV. It's weird that mine seems to report the correct SWR for the band I select (as compared to my external SWR meter) but it shows it as being the same for all frequencies.? Maybe there is something in my band configuration settings that is not right.

Tony
AD0VC

From: [email protected] <[email protected]> on behalf of Chris <chris.rowland@...>
Sent: Thursday, April 3, 2025 2:45 PM
To: [email protected] <[email protected]>
Subject: Re: [QRPLabs] QMX+ SWR sweeps with SSB firmware?
?
Just ran a SWR sweep on a QMX+ running 1_01_003 into a Cobweb and got this:
It seems to be reporting about correctly, The Cobweb is designed for 20, 17, 21, 24 and 28m.
?
Chris, G5CTH
?
Re: QMX SMPS issues, and a possible cure

 

Don (aka El Destructo),

Can you move that file at 700,000 files per second? Lol… your job sounds like a ton of fun. Hope you’re using the proper PPE. :-)

Tony AC9QY

On Thu, Apr 3, 2025 at 3:19?PM Donald S Brant Jr via <dsbrantjr=[email protected]> wrote:
From the readme:? "Behaves well when output is suddenly shorted and then the short is removed."??
Try this:
The most brutal power supply torture test I saw was to connect the supply output with heavy leads to two 3/8" copper bolts closely spaced in an insulating block.
Energize the supply, then take a coarse file and file the ends of the bolts simultaneously.??
Watch the sparks fly and monitor the supply for instabilities.? The fast, random short/open transitions, with bonus negative-resistance arcs, will challenge any control loop.
I love getting paid to do stuff like that.
73, Don N2VGU
Re: QMX+ SWR sweeps with SSB firmware?

 

Just ran a SWR sweep on a QMX+ running 1_01_003 into a Cobweb and got this:
It seems to be reporting about correctly, The Cobweb is designed for 20, 17, 21, 24 and 28m.
?
Chris, G5CTH
?
Re: Gibberish characters appended onto end of Message 1

 

By the way, I should clarify that when you look at Message 1 in text form, the gibberish characters do not appear. They only appear as the message is being sent on the air, and they are sent. The couple of times I dared to send Message 1 yesterday, I got the same characters added on at the end, which are: K0****AS
Best regards to all and 73!
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