Hi All,

I love this rig, a lot, but I am noticing a strange random wideband noise when using FT8 in WSJT-x via VAC. My setup is as follows:
Sunsdr2 pro V 1.3.1 update 5.
HP workstation 32GB RAM
VAC (full version)

The VAC settings are as follows:
https://drive.google.com/open?id=1-p7HqPIBczfhqrKD6Kj2k9FuqIh664kD

I have ESDR2 in DIGU mode and all seems fine using VAC but randomly either when I tune in WSJT-x or TX during a QSO cycle I see a strange wideband 'crack' or noise burst that looks like this:


The VAC settings in ESDR" are as follows:



Has anyone seen this before? Anyone have any solutions or suggestions ?? It behaves the same whether into a resonant antenna or a dummy load.

Thanks.
Jonathan
MM0OKG

Hi,
I am also noticed the same issue

73,

Gordan,

Hi!
Unfortunately these erroneous signals also occur on my Linux system, both under Ubuntu and Arch-Linux. I have been observing them for years. It seems to have something to do with audio frames and frame rates. I suspect that frames are lost at the time of the error. I have experimented a lot with frame rates, buffer lengths and settings in the audio system (pulseaudio). Up to now I could only minimize the problem but never really solve it.
The error occurs mainly in connection with the programs WSJT-X and JTDX. With FLDIGI I see the error only very rarely.

73, de Dieter, DK6OV

Change to the recommended version of VAC (4.15) and see if there is an improvement.

Thanks Dieter, Gordan and Erik !! Great to know it's not just me and my settings. Thanks for the feedback.

Hello all,
I am using 4.15 VAC really better but still give up distortion on TX sometimes..

73,
Gordan,

OK - if not already done so, enable volume control for the TX line in the VAC control panel. This then gives the OS access to gain control so that it can be adjusted. Then see if that has helped.

If you already have volume control enabled and have adjusted gain, recommend you post all settings here for examination: ESDR2 VAC, mode used (DIG or SSB), OS Sound Control Panel>Line for TX properties>Line for TX Levels and Line for TX Advanced (in case you are not using the correct number of audio bits).

Hi,
I am just testing with " enable volume control" need some time to be sure how is going now. I am wondering hot to set properly tx audio level with TX audio meter to be = 0 db ?

73,

Gordan,

Hello,
Enabling Volume control in VAC control panel has no effect on my windows audio setting?

Good point Gordon. I just had a chat with Muzychenko and actually Windows 10 version 1903 does not respond to VAC volume changes. The audio path is not through the OS - it is a change by Microsoft - and that is a good thing and I think you can discount any effect on distortion by Windows and look elsewhere. One point he mentioned though is to ensure that the sample rate and bit depth are correct: 2 Channel 24bit, 48000Hz (Studio Quality) as set in the TX Line properties, Advanced tab. This then matches our software when set up correctly, which yours is. You do not say, unless I overlooked it, but ESDR2 mode should be DIGu for FT4/8 and DIGl for RTTY and not USB. You probably have that set anyway.

The recommended VAC panel settings are different from yours (but I do not guarantee that changing them will help):

SR should be 8000 ... 19200
BPS 8... 24
MS per Int = 3

Also disable Volume Control now because its use takes up extra CPU cycles.

Thank you for info...
I am using USB mode with compressor turn off, on all other mode DIGIU or DIGIL I have offset in shift frequency in conjunction with WSJTx. Maybe my wrong setup or software bug?
What mode do you use for ft8 ft4?
I will follow your VAC setting and inform you here..

73,

Gordan,

I don't have to choose 24 bit studio quality ?? Yes, after restart pc I got..






Please can I get your screen shoot of VAC control panel to be 100% sure all settings.

Thanks,

It should be like this:




Because at 16bit, with wsjtx and jtdx, conversion will take place which means there is some millisecond delay on the audio line. Does this matter? Probably not but hey might as well use the recommended setting.

VAC Control Panel:





Note that your BPS will be 8 ... 24. Mine is at 8 .. 32 because I use the 32bit audio version of JTDX but the normal version is 16bit. For that 8 ... 24 is correct for the same reason as above.

Thank you very much!

Something is a wrong with DIGIU any suggestion?

Solved

DIGIU offdet need to be set to 0