Re: QMX Draws 200mA when Power Applied

#108401

Hi Glenn,

There is a short somewhere. ?VCC (5V is getting pulled down). ?Also what concerns me most is the LIN_REG_EN signal. ?It is supposed to be at logic levels (0V to 3.3V) and is directly connected to the cpu. ?unfortunately, that kind of voltage on the cpu is usually not healthy for that chip.

Re: QDX xmit one flash

#108400

Good morning, Evan. I tried that and it didn't solve my problem. Thanks, though. I'm still trying some things. I'm also in the process of getting a PI together to give a try.

Re: QMX, do not forget to set the current limit high before sending!

#108399

I just did exactly the same thing, but I think the jump in the power supply voltage from going in and out of current limiting toasted something in my unit

Re: No receive QMX

#108398

开云体育

That's so dead that it seems to be more than bad L401 or T401 soldering, not sure it would look that bad with them not even fitted. It doesn't seem to be detecting any signal at all. This might explain the problem with the RF scan, a divide by a zero signal error.

I'd check everything on the top half of the receive page of the schematic, ICs 402, 403, 495, 406 and 407 and everything round them.

If you have a scope check that the test signal is coming into R518 and if possible follow it through the receiver.

Chris, G5CTH

On 25/08/2023 09:07, Paul Harrison via groups.io wrote:

Show quoted text

Tried that, no change. Below couple of screen shot, maybe they tell you something? I have no idea?
Thanks Paul DJ0CU?

Re: No receive QMX

#108397

If it were me I'd redo T401 (the trifilar). If that is not wound
properly then the Rx will not work at all.

-mike/w1mt

On Fri, Aug 25, 2023 at 4:08?AM Paul Harrison via groups.io
<dj0cu@...> wrote:

Tried that, no change. Below couple of screen shot, maybe they tell you something? I have no idea?
Thanks Paul DJ0CU

Re: QMX and FT8CN audio issue - HANS PLEASE CAN YOU NOTE??

#108396

OK Folks,

So, today I reverted to 1.06 Firmware on the QMX and can confirm FT8CN works perfectly with that firmware but fails to work properly (as described in my original thread) with later versions. Out of interest, I also tried a USB C to C cable with 1.06, but still no luck there. So the FLDigi issue described by others seems to be releated as suggested by Mike KK7ER

HANS - CAN YOU PLEASE CONFIRM YOU ARE AWARE OF THIS ISSUE FOR FUTURE UPDATES WHEN TIME PERMITS?

Thanks.

Daimon. G4USI

Re: QDX Success story

#108395

Paul,

QMX has no spike voltage issue at end of transmission because of the built-in wave shaping system.

Regarding Zeners for QDX, they may provide some protection against the hi-Z SWR case, but they are not a good solution to the inductive spike problem. At the moment the BS170 transistors turn off, there is approximately an amp +/- of current flowing through L14. That current will now go to the Zeners, where it most likely will be shared unequally as they are not identical. The datasheet for 1N4756A shows a maximum current of 95 mA.

The voltage at the BS170 drains will be well above the Zener voltage of 47 volts, as that high current and the Zener diode resistance conspire to elevate it well above the BS170 breakdown spec. The diode instantaneous power will be very high, perhaps as much as 75 watts each for a very brief time.?

These are not healthy conditions, either for the Zener diodes or the transistors. A commutating diode across L14 which is capable of handling the coil's current avoids all these problems.

JZ KJ4A

QMX, do not forget to set the current limit high before sending!

#108394

Yesterday I have successfully energized the QMX for the first time. As recommended, voltage to 7 volts, current to 250 milliamps. So far everything is fine.
Today I wanted to send for the first time. However, every time I pressed the paddle, a crackle and the QMX shuts down. Well, a loose contact? Are my soldering skills not good after all?
So I unscrew the case and start to examine the PCB and the paddle socket, but all is well.

But no, silly me, the QMX needs much more than 250 milliamperes to send. I just forgot to turn off the current limiter.
"If one has no work, one makes oneself some. :)
To the web SDR Heppen to Belgium, 220 km, with 3.8 watts to hear perfectly. What a dear little magic box!

Re: Blue screen of death U3s

#108393

I'm going to order the basic 5351 synthesiser board, I have 3 mcu chips here, tried all but no change so I'll change the 5351 as they are cheap. In the meantime I'll play with sdrconnect for wspr receiving.
Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.

Re: QMX AGC... any progress?

#108392

Hi Don,
Yes, I remember your original posts and did try the diode method on a couple of QCX's until the little AGC module was developed. As I said, I'm sure Hans will include AGC limiting in a future firmware update so I'll not bodge this radio for the time being.

An external adaptor is an option, as you say, but it's yet another thing to pack/forget/lose.... besides, it's just limiting the level of an already badly distorted signal. Much better to have the levels controlled gracefully at an earlier stage in firmware and avoid those nasty square waves in the first place.

Cheers,
Ronan

Re: New QRP-Labs product idea? A QMX/QDX based digimode / cat interface?

#108391

Maybe this is what you are dreaming of?

That is indeed a dream come true. Thanks for the pointer.

And Barb, I like the idea, but do need the CAT option. But I have it bookmarked for later.
--

73 Lex PH2LB?

Re: No receive QMX

#108390

Tried that, no change. Below couple of screen shot, maybe they tell you something? I have no idea?
Thanks Paul DJ0CU?

Re: List of QRP Labs USB Vendor and Product IDs for Serial Ports - ChromeOS

#108389

?
Probably not a lot of people needing this feature but if you would like to use a QRP Labs product on a chromebook then click the link and "star" the issue. This helps them prioritize appropriately.?

Re: accurate time source

#108388

I use NetTime 3.14 from www.timesynctools.com on all my windows machines, no
problem. Just install it and forget its there. Seems to work, flawlessly for
me, over wired networks, Wi-Fi,networks 3G and 4G networks using mobile 
routers and pocketable 'hotspots', Cannot speak for 5G, there are no 5G masts 
anywhere near, nearest I believe is 75 miles away.

 Linux, the sensible OS, just does it without any user intervention..

Show quoted text

On 24 Aug 2023 at 6:34, wb2cba@... wrote:

Dimension 4 is a reliable time sync software.

73

Barb WB2CBA

Re: QMX - TX shift thrshld bug?

#108387

Thanks Dan, Noted, I will fix it in the next firmware version.

73 Hans G0UPL

Show quoted text

On Fri, Aug 25, 2023 at 2:43?AM N7SHM <n7shm@...> wrote:

I think there's a bug in the "Configuration --> Digi interface --> TX shift thrshld" entry field.? It defaults to '500' (milliHertz), but no more than two digits (00-99) can be entered from the terminal or directly.

This is with firmware versions 006 and 009, at least.

73,

? Dan
? N7SHM

Re: QMX - smoke - another C107/Q108 failure

#108386

Hello Razvan

If you use linear 3.3V and 5V power supplies it will work fine, and there is no harm in the 5V coming alive before 3.3V. In order to make the processor complete the boot process you will need to arrange the 3.3V and 5V ADC measurements to both be above 1.65 and 2.5V respectively; the easiest way to do this is simply connect them to the 3.3V supply rail.?

73 Hans G0UPL

Show quoted text

On Fri, Aug 25, 2023 at 12:38?AM DL2ARL <dl2arl@...> wrote:

On Thu, Aug 24, 2023 at 01:46 AM, Rick Crowther wrote:

I meant only to rig up temporary linear supplies on my bench
hello Rick, Hello Hans,

this is exactly what I was aiming for myself: a temporary replacement of the smps boards until all other smoke tests have been succesfully passed.

Hans: really no offence intended! I am of an older school and do not trust these new-age gadgets piloted by software, not because of paranoia, but because of the fact that they do not belong to my trusted analog world. I find the ideas standing behind the SMPS concept of the QMX most refreshing and innovative: this is the main reason I am glad of having purchased a QMX, without having been in need of yet another qrp toy.

But now.. I am sort of discouraged by my own courage and would like to go one step behind into those quiet linear waters I am used to. Not for good, but at least for the first current intake of the fine rig. Afterwards, having thanks to Chris a test checklist for the SMPS boards outside the rig, without danger of damaging the main professor, I would maybe gain some courage and "replace the linear replacement" with it's new age microprofessor controlled switching PS.

This is what I meant. You might help by telling me if this is doable or if I am to expect some latch-up phenomena during power-up due to the fact that the 5V rail would come alive before the 3,3V would do. But latch-ups are not harmfull, so if you do not have an answer to this question, just forget it: I will find it out by myself.

Yours friendly, Razvan dl2arl?

Re: QMX - Short from 5V to ground somewhere on the main board

#108385

I should add -

No current draw on initial powerup. Significant current is drawn while pressing left knob. Current goes back to zero after releasing left knob.

Re: USB Device not recognized .... another one #qmx

#108384

Rick,

Great to hear about your success. However................

Here is a little more about the USB-C connector. The connector is designed around 8 pins and the shields. The connector is designed to accept a USB-C plug which can be plugged in right side up OR?upside down. The connector has 2 rows of 8 pins? on both the top and the bottom of that center insulator. Of course, one goes left to right and one goes right to left ......makes sense. I believe that Hans wired identical pins together between the 2 rows. This would increase the probability of making a connection to the few pins actually used but it does not fix the problem.?

I even saw a picture of someone who had added 16 solder balls to his USB-C connector.? However, you can't see how well the solder has wicked to the very short pin, so maybe.

A much more solid connection can be had with the "toothpick and flux technique" described in my other note. That way you can SEE to solder wicked from the pin to the via barrel. When I examined my kit USB-C connector the 16 pins are all helter skelter inside the via barrels. Some look like they picked up a small dab of solder out of the plated barrel, some were touching, some were not. Talk about "iffy connections". Manufacturers typicall do not use solder paste screening on PIH parts. No wonder there are multiple? USB-C download tries, may require a new (flipped) USB-C plug, may require a little connector wiggling, etc. The net is that it may have an "iffy" contact and may fail later.?

A GOOD, much more solid, connection can be had with the "toothpick and flux technique" described in my other note.?

73 Kees K5BCQ

.

QMX - Short from 5V to ground somewhere on the main board

#108383

Booted up the new QMX on my bench power supply, managed to flash firmware, hooked up a dummy load to test TX and forgot to increase current limit on the power supply, so it browned out on TX. Then it died, and I'm showing a short from 5V rail to ground that is not on the power supply daughter card, it's on the main PCB.... somewhere. Any tips for figuring out where it is (and why that would have happened) are appreciated.

Re: List of QRP Labs USB Vendor and Product IDs for Serial Ports - ChromeOS

#108382

Hi

> idVendor=0483, idProduct=a34c

All QRP Labs products use this same VID/PID which is licensed by ST Microelectronics to QRP Labs for exclusive use by QRP Labs amateur radio products using STM32 microcontrollers. I'm very grateful to ST for this assistance as full USB-IF membership and VID/PID is prohibitively expensive for small businesses.?

73 Hans G0UPL

Show quoted text

On Fri, Aug 25, 2023 at 7:20?AM jlloydham <captlloyd@...> wrote:

I'd like to get the cdc_acm serial port on the QDX to work on ChomeOS in the Linux (Crostini) container. I'm looking for the Vendor IDs(VID) and Product IDs(PID) for all QRP Labs products so everyone can benefit, not just QDX owners.

On ChromeOS USB devices can be passed through to a Linux container. Currently the QDX works great on Crostini(Full OS container on ChromeOS) except the /dev/ttyACM* device from the cdc_acm driver is not passed through to the container. You can still use a terminal app from outside the container to manually send CAT commands and use VOX but there's no ability for WSJT-X or JS8Call to talk to the serial port.?

I'm opening a request to have these added to the list of devices allowed for pass through. They've done this for other cdc_acm devices when requested. I'm going to ask if all cdc_acm devices can be passed through but they may have a reason to stick with white listing by VID/PID.

I have the VID/PID for my QDX but I'm not sure if there are any other chips/IDs being used on other QRP Labs products and/or versions. If someone has a comprehensive list that would be great, but I'll take them individually here if people want to post them. I'll collect what I get over the next few days and submit a request to the Chromium bug tracker.?

Linux users can plug in their device and check the output of 'dmesg'. I'd be looking for a block of text like this:

[ 1410.951927] usb 1-1.1: new full-speed USB device number 8 using xhci_hcd

[ 1411.134168] usb 1-1.1: New USB device found, idVendor=0483, idProduct=a34c, bcdDevice= 1.00

[ 1411.134181] usb 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 1411.134185] usb 1-1.1: Product: QDX Transceiver

[ 1411.134188] usb 1-1.1: Manufacturer: QRP Labs

[ 1411.177327] cdc_acm 1-1.1:1.0: ttyACM1: USB ACM device