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My guess is that this is a firmware bug.
My QMX Low Bander does the same thing if I leave it on over night.

Hans is making great progress though with all the updates:)!

Hello,

Isn't the "IQ mode" setting in the "Digi interface" menu enabled, by any chance?
If not, you may also try a factory reset.

Regards,
YO3GFH
op. Adrian

Hi OMs

I could not remove the original problem - a large current on the receiver (about 168mA), but I use the QMX radio in both DIGI and CW mode and it works fine.

I tested the radio again in Terminal applications using the LPF sweep function - all ok.

I also tried the Terminal test using the RF filter sweep function and it was bad on all bands. In the permeable part of the curve, in the middle of the band, where the attenuation should be a few dB, it is always around -20dB. Around -30-45dB at the edges of the curve. It looks like the transmission is heavily muffled by something (-20dB) during reception on all bands, but the radio still works!?

Can anyone think of what could be wrong and if there is a connection between the attenuation of the RF filters and the high current during reception??

OK2PKT Roman

Additional information:

using terminal - Hardware tests
rotate the encoder in a medium speed
the arrow shown is ok but sometimes for a moment an arrow in the wrong direction is flashing up

I finished assembling a high-band QMX on a 2023 Rev 2 board. First power up, no smoke! Everything seems pretty good except for when I tap the left encoder to enter digital mode, a horrible screeching noise emanates from the Audio port. With headphones on, this is a painful surprise!?

Has anybody else noticed this? Is it a known issue?

Firmware is 1_00_017 16-Feb-2024

On Fri, Feb 23, 2024 at 05:54 PM, Eric W. Hansen wrote:

I set my bench supply to 6.8V with a very low current limit.

Be aware you need around 160 mA to start the QMX.

On Fri, Feb 23, 2024 at 05:54 PM, Eric W. Hansen wrote:

ViFly ShortSaver 2

Which current if you remove the power connector from the QMX? How much power consumption by the ViFly ShortSaver 2?

73, Ludwig

Hi,

sorry if this topic was discussed before but I couldn't find it.

Yesterday I finished my second QMX (20 m - 10 m). I found problems related to the right rotary encoder.
When dialing the frequency sometimes after one step the same frequency is shown. It looks like the step is done and in the same moment the step is removed (same value shown again.)
In the menu mode around 10 ... 20 % of the steps bring the wrong submenu (e.g. "Audio - Presets - Audio" or "Audio - Audio - Presets - ... - Digi interface - Beacon - Beacon - Beacon - Display"). Sometimes going backwards one Submenue is skipped (e.g. "Protection - Beacon").

Using my first QMX I have simular effects but considerably rare.

In the moment I dislike to swap the controls between the two QMX, both are in the enclosure.

Are there any information about this? May be debounce is a little bit to tight and for most of encoders are sufficent but for some are not?

Ludwig

The QRP Labs ecosystem is a great place to live.
--
Chris / W2BPL

I finished construction of high-band QMX rev2 (2024), 9V version.? Checked and rechecked all my soldering under magnification and probed for shorts with an ohmmeter.? Time to apply power and do the smoke test.

I set my bench supply to 6.8V with a very low current limit.? I'm passing the power through a ViFly ShortSaver 2 (per recommendation on this forum), but since the current limit on the power supply is set well below 1A, I don't expect the ShortSaver to actually function as a circuit breaker right now.? When I turned the bench supply and the ShortSaver on, the meters on the supply read 6.8V and 40mA.? I stopped there, and did not press the rotary encoder to power up the radio.? Before I do, I want to know if things are OK so far (after all I've read on this forum, I really want to be careful not to blow the QMX up.)? Should there be a quiescent power-off current draw?

Thanks,
Eric

Firstly please don’t drill the holes out.
It’s a multi layer board and there may be inter-layer connections, I don’t know for sure but just saying.

I soldered a capacitor in the wrong place on one of my kits and managed to successfully remove it and get the holes cleaned out. I used solder wick with a little flux, but I first added some fresh solder to the holes to give the solder wick something to grab on. I had to do it a couple of times on one hole, trying from both sides, but it worked.

Another way is to not clear them but to introduce the fresh wires whilst heating the pad/hole (preferably and easier from the top side if access allows). Hold the wire relatively close using some fine forceps and push the wire in and through when the solder is wet. Then follow up again with your iron and a dab of fresh solder to re wet the joint.

Or, if you need, solder the new wires to the top side, I did that to one toroid on my QCX Mini 40M, where I was changing turns to optimise power. Though could be difficult to get to all on that transformer.

73.
Rowan.

?

In this URL you can find the method used to measure the output impedance.

No, I did not. I'll look into that as well. It may be Sunday before I can fiddle with it, but I'll post my results here. Thank you!

Have you tried increasing the Audio gain (dB) in the configuration table? You can access this in terminal mode.

--
73, Rick
VE7TK

Website:

Have decided to remove T507, rewind and reinstall. Now I must ask HOW did you clear the through-holes of solder?

I have a hot iron solder sucker but it is way too big. Have also solder wick and have used to clean up the pads but still have thru-holes with solder in them.

I will wait to see your answers before I drill out the holes....
--
73
Karl
KI4ZUQ

Hans,

On 2/19/24 I received an email stating my QMX high band shipped.??

Today FedEx shows "label created" as status.? Will my order #82084?have Q202 problem?

Charles Murrell
K5KXJ

Correction! He fixed my QMX Rev2!