I submitted a previous topic regarding the audio migration settings. That may not be the problem. I finished my QDX build and am now trying to get it to operate. It comes on just fine and I updated the firmware to 1.10. Cat control is fine, as well. The problem I am having seems to be with the audio. My QDX is not hearing anything nor does it transmit. When I place the QDX, I get just a single flash of the LED. I l found in the operations manual this means my QDX is not receiving any audio. I did check the WSJT-X settings and QDX is set as my input and output. It also appears the audio configuration on my computer (win11) shows full levels for the QDX input and output. I've changed USB cables, but that didn't fix anything. So, what is my next troubleshooting step?

Thanks,
Wayne KB4DSF

Lex,?

A relatively simple version of CAT and Audio interface bundled in one:

73

Barb WB2CBA

I finished my QDX build. After hooking up to an antenna, I am finding my QDX is not receiving nor transmitting. It seems i may have a sound card problem. I checked the audio devices and I beleive I am having an issue with the device migrating:


Any thoughts?

Thanks,
Wayne KB4DSF

Hello all.

Is there a way to simplify the OCXO adjustment if a thermometer (having a miniature probe) is available?

Is there a way to simplify the OCXO adjustment if a drift-free reference receiver (as obviously assumed) is not available?

Greetings
Jens

Hi Razvan

Thanks for your input - I meant only to rig up temporary linear supplies on my bench to check through the main-board, not as a permanent change
The plan is :

• Remove both SMPS boards
• Supply +3.3 from linear regulator and check if the CPU runs
• Replace the 3.3V SMPS/linear regulator board and supply +12V from linear supply, check CPU again
• If all good, repair or replace the 5V SMPS board

Regards
Rick

Regards
Rick

Roger, I've been through the connections with a fine tooth comb, but no harm in doing it again., but it would be nice to know if "transmit enabled" should be permanently showing, as in my case, doesn't seem right.

Paul DJ0CU?

Important note : I know Hans is a very busy man doing great stuff for us, but the idea below came to mind this morning and had to write it down.

?

Not just owning QRP-Labs rigs?I have made my fair share of digimode and CAT interfaces for my other rigs.?

But playing with my QMX for a few days new and loving the single USB cable solution, the idea came to mind that it would be great to have a single USB cable digimode / cat interface for my other rigs.

And looking at the QMX and QDX basically everything is there :

• Built-in 24-bit 48ksps USB sound card (much better than most other USB sound cards)
• Built-in USB Virtual COM Serial port for CAT control (you could have one to configure the interface and one to pass through the rig).?
• The USB could be able to power the MCU etc.

Only thing missing is some good isolation for the audio and CAT signal lines, and a connector to which these signal lines would be available to the outside world.

If it would exist, I would immediately buy a 2 for my rigs.?

Just a though. And again, see?Important note?above.

--

73 Lex PH2LB?

Short form:
- QMX ordered
- waited ( waited, waited, waited patiently)
- built, => firmware installed, => turned on, => running.

Once again confirmed, the kits from QRPlabs are great.
To fit so much RF technology into such a small space is quite a challenge.
Even for the experienced solderer.
But it is exactly as described in the assembly instructions in many places: Read carefully, some things twice, look closely with a magnifying glass, and take your time.
I took my time, but nevertheless I was done with the soldering after about 15 hours.
The installation of the firmware is really very simple. I only had to get a USB C cable.
7 Volt, 250 mA, take a deep breath and....
no smoke, no smell, everything wonderful, the little wonder box is running.
Antenna on and immediately signals on the 40m band.
Now the installation in the enclosure takes place.
Fine thing.

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Like you posted.

Thinking a bit more the things involved in Rx but not Tx are the band pass filter components L401 and it's associated capacitors and the trifilar transformer T401.

The sweeps in the diagnostics are useful to check, if they are all giving a low max value that's an indication of a lack of connection.? Check the soldering of the toroids, everywhere, it's very easy to fail to get the enamel off.? I had this and redoing the soldering fixed it.

Chris, G5CTH

To put it another way, what does the same screen look like on a unit that is working normally in receive. Thanks

Paul DJ0CU?

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I have completed my QMX tx works fine on transmit but there is no receive on any band.?

Attached a picture of the configuration screen. It looks like it's permanently on transmit, what would be the cause?

Thanks anyone for tips.

Paul DJ0CU

Paul, maybe flashing your firmware, at that 180 mA limited current, was marginal for getting a good flash. Your startup delays, and failure to shutdown, sound more to me like software issues than hardware. Fingers crossed that something simple like a reflash, at normal voltage without current limits, and system reset, will normalize your QMX's startup and shutdown behavior.

On Wed, Aug 23, 2023 at 09:18 PM, Rick Williams - VE7TK wrote:

?The LED backlight pot is at about 50%

Turn that backlight pot completely counterclockwise to start. Ideal contrast might be a hair off of full left, but anything beyond that is blank screen territory. 50% is definitely a blank screen. As Paul mentioned, you've got to give it more juice. 25mA is way too low.? I started mine with the 250mA and 7V that Hans recommended. When I saw things were working, I went up to 11V. And soon after that, I just put it on my LiFePO4, no problems for me operating at 13.3V and even more than that, through a properly matched balance line fed antenna.

Paul, I'm glad you got the screen fixed. No, those long delays are not normal. Do a system reset, and if that doesn't work, try re-flashing firmware followed by a system reset. If the problem still exists after that, then you have more troubleshooting. I think somebody else had similar startup delays and failure to shutdown.

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All these things seem to be associated with controlling things.

Chris, G5CTH

Thanks for getting back Paul.

You are correct! In my case it should then trip the current limited supply. However, the QMX doesn't draw current at any time and never goes over my pre-set limit?

To confirm, when I apply power to the 2.1mm connector and long press the left encoder, the QMX should go into into Update mode whether it's connected to the PC via? USB cable or not?
--
73, Rick
VE7TK

Website:

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Have I misinterpreted something. Some comments on this site suggest that the QMX will turn on (no LED display) and draw current (~150 mA) without a USB cable attached when the left encoder is given a long push?

If you haven't loaded the firmware yet, it will come up in Update mode--it won't wait for any key press. ;-)