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QDX + Raspberry 4 sound problem

 

My QDX seems to work, both on reception and transmision when? used with WSJT-X and a Raspberry Pi 4. However, all the decodes I obtain have a very low signal level, much less than what I usually get with my TS-850. I have the feeling that the sound configuration might be wrong and I tweaked it in different ways, but I do not really understand what I am doing. I enclosed some screes showing the the settings and WSJT-X main screen.

Is there anything obviously wrong? Ehat should I check next?

Tnx, 73, EA2BEE
 

Hi Fernando,
if you can use a terminal emulator such as ¡®Putty¡¯ to access the QDX configuration settings, you can increase the rx audio levels for each freq band. The default I found is a little low using Windows and wsjt-x.
Also, your wsjtx display seems a bit limited. For FT8 you need to set ¡®bin/pixels¡¯ to 1 to get a wider frequency range.
73 ken g4apb?
 

Thank you, Ken, I will do as you advise. Best, ft.
 

What value do you advise? I increased from 5000 to? 800, then 15000 for a rather mild improvement. What is the maximum value that can be set?
 

Hi Fernando,
not sure where you got these high numbers from.
Using firmware v1-05, Band Configuration - audio gain (dB)¡­. default is 54. Max is 99. Try a number between these.
73 Ken g4apb?
 

I? was looking at manual for ver. 1.03, which corresponds to what I have. Apparently, the default is 5000.? Audio gain can also be set through a CAT command, and then the scale is divided by 256: I assume the numbers you give correspond to this last scale. I have tweaked the audio gain, to no avail so far. I continue looking. Or perhaps it is a malfunction of my QDX.? Thank you again, ft.
 

Hi Fernando,
I suggest you update your QDX firmware. I think there was an issue with audio gain settings in earlier versions.
73 ken g4apb?
 

OK, I will. Although setting the audio gain to 18000 more or less cured the problem. Best, ft.
 

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Fernando,

Looking at your screen shots of the Pulse Audio Mixer you have the volume controls all the way max. The Volume Controls should all be at 100%. Going over that is not going to help and may cause distortion.?

I see since I started this that you seem to have got thing working, but still the volume controls all should be at 100%, an nothing more for best results. Adjust the QDX output to be what you need with the mixer levels at 100%.

73,
Cliff, AE5ZA

On Nov 12, 2022, at 23:02, Fernando TUSELL <qrplabs@...> wrote:

My QDX seems to work, both on reception and transmision when? used with WSJT-X and a Raspberry Pi 4. However, all the decodes I obtain have a very low signal level, much less than what I usually get with my TS-850. I have the feeling that the sound configuration might be wrong and I tweaked it in different ways, but I do not really understand what I am doing. I enclosed some screes showing the the settings and WSJT-X main screen.

Is there anything obviously wrong? Ehat should I check next?

Tnx, 73, EA2BEE <Captura de pantalla de 2022-11-13 05-31-42.png><Captura de pantalla de 2022-11-13 05-37-45.png><Captura de pantalla de 2022-11-13 05-46-15.png><Captura de pantalla de 2022-11-13 05-46-52.png><Captura de pantalla de 2022-11-13 05-47-42.png><Captura de pantalla de 2022-11-13 05-48-12.png>
 

Thank you, Cliff. I have corrected that, since Ken G4APB showed me how to set the audio level in the QDX.

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