Very loud attling Noise / QRM when outside menu?!

[SP2WLF]

Hey,
https://www.youtube.com/shorts/wNnfbmoj ... ture=share

I've been using OpenGD on my TYT-MDUV390 for over a month now, and so far, it has performed well on DMR. Today, I programmed analog repeaters, and unfortunately, on certain frequencies, there's a constant, clicking noise that makes it impossible for me to listen to transmissions. This noise occurs only on specific frequencies. The S-Meter fluctuates up to S9. Interestingly, the noise disappears completely when I enter the menu. Can this be addressed in the next update?

[F1RMB]

Really poor FM signal (what is the frequency of this transmission ?). It's far from S9 in the video.
While in menu, there is no RSSI bar update.


BTW, I deleted your other post on the same subject (please don't cross post), and fixed this one as the youtube tag was wrong (only the video ID is needed), and shorts aren't supported by the youtube tag.

Cheers.
---
Daniel

[F1RMB]

There are birdies, it's a fact. You could hear buses traffic sometimes (like when you increase the volume, as it redraws the screen).

[SP2WLF]

Sorry for that second post, I completely forgot that I posted it herę.

The QRMs are solid. They are definetely connected with screen updates. Any hope that would be fixed in new beta releases?

[G4EML]

Many of the Chinese radios with colour screens have some interference from screen updates. This is nothing unique to this firmware. There is not much that can be done to prevent this other than not updating the screen. It is really a hardware design problem.

So it is unlikely to be fixed in a new release.

[SP9TA]

I confirm in my RT3S the problem with the frequency of 438.550 MHz.

Many of the Chinese radios with colour screens have some interference from screen updates. This is nothing unique to this firmware. There is not much that can be done to prevent this other than not updating the screen. It is really a hardware design problem.

I do not agree that it is only a hardware problem, because it is the software that decides how it uses the hardware. For example, you can use a different clock frequency on the bus for the display. Usually the slower, the less interference. A different bus clock frequency also means that the interference will be at other frequencies, perhaps you can choose this so that the interference is outside the amateur bands. Of course, if you slow it down too much then the display refresh will be too slow, you have to look for a compromise.
The second thing is the configuration of the GPIO pin. In STM32 we can adjust the steepness of the port's edge. Look at: "GPIO port output speed register (GPIOx_OSPEEDR)". I don't know if OpenGD uses this functionality, because I haven't looked into the sources. Perhaps something can be improved here.

[KC6WOG]

If you want to hear a loud, strange noise, use the APO function and wait for it to kick in. When the little warning trill is playing, turn the volume control back and forth. You won't miss it, it's not subtle!!

And no, I don't want it "fixed." It's kind of a fun sound. In the pro audio world, we call this a "zipper," an artifact created by a stepped, digital volume control passing a tone or other simple signal. It's not nearly as obvious on complex waveforms like voice.