On 21/06/2021 04:48, Yvon AE7YD wrote:

Hello,

I apologize if this has already been covered but search didn't bring it up.
After some time WSJT-X will stop sending audio. That time is variable. If I close the program and restart it, it works again. But after a while it will stop again.
All other functions keep working fine.
The problem is not related with the radio or the PC as I have tried with two different PC (one running Win10  home and the other running Win10 Pro).
I also tried with 4 different radios Omega 900, Elecraft KX2, FTDX10 and DR-4020, same problem.

Thank you for any help.

73, Yvon

Hi Yvon,

the issue you describe is often due to MS Windows deciding to power down USB audio devices it thinks are not being used. You must disable the power management options for each USB Hub Device listed in Windows Device Manager under "Universal Serial Bus Controllers" (right-click device, select Properties, then Power Management, and uncheck the allow option).

You also must disable the USB Selective Suspend option in the Windows "Power Options->Change plans settings (on the current plan)->Change Advanced Power Settings" open "USB settings", then "USB selecting suspend setting", and click the "Plugged in" option to select Disabled.

As Bob, G8HGN, points out, there is another issue with HDMI monitor connections. HDMI connections include a USB audio connection which too can be unexpectedly powered down when a screen-saver or power-saver function activates. I don't know of any settings to stop that other than making sure graphics card/chip power management settings for the monitor and screen saver are disabled, YMMV.

The root problem is that USB devices are "hot-pluggable" and adding or removing a device, while the system is running, will cause all other devices to be re-enumerated, this can change device identities but Windows does not inform applications using them that they have been shuffled.

Note this issue affects audio devices but not virtual serial ports like those often used for CAT control, virtual serial ports over USB connections seem to be capable of blocking such power saving options, presumably because they are one-to-one connections and Windows can be sure when they are in use.

73
Bill
G4WJS.