WSJT-X / JTDX stops sending TX Audio to the Radio after sitting idle for a while.

Ken Wells

TLDR (Too long Didn't Read, summary)

If you are using a HDMI Monitor, but are not using the tv/Monitor's internal speakers, and you experience the loss of WSJT-X / JTDX TX Audio after things have sat idle for several hours:

DISABLE the HDMI Sound Drivers for the TV/Monitor. This will prevent Windows from reshuffling the audio devices when the TV/Monitor goes into "Sleep Mode" which results in WSJT-X / JTDX "forgetting" how to access the DAX Audio TX Device.

Longer Version/Explanation:

I have had this issue for some time. I had thought that it was an issue with WSJT-X / JTDX.

I often run three instances of WSJT-X on my 6600M and let it monitor overnight or for long periods of time after hours when I am not in the shack.

I use a TCL 50" ROKU 4K TV as a computer monitor. Whenever the computer shuts off the monitor or goes to Screen saver mode, the TCL disconnects from the computer and starts showing its own screen saver display.

Many times when I return to the shack and "Wake up" the monitor/TV I find that WSJT-X will no longer send audio to the radio through the DAX Audio TX stream.

If I restart WSJT-X, or change to a different configuration, the DAX TX Stream becomes active again.

I can also regain access by changing the WSJT-X "Settings Audio Output" to a different DAX device and back again to DAX Audio TX.

What was happening was that when the TV/ Monitor went to Sleep Mode, the HDMI Sound drivers essentially went to "sleep," too and the Windows Sound system renumerated the sound drivers/devices. When this happens, WSJT-X is no longer able to "find" the "DAX Audio TX" device.

I finally learned the solution:

Since I do not use the computer's HDMI Audio feed to the TV (I use some nice BOSE Speakers) I simply opened "Device Manager" and disabled the HDMI Audio Drivers for the TV.

Now, when the TV monitor "goes to sleep" nothing changes in the Windows Sound Drivers and devices and I don't lose the Transmit Audio when I "wake" it back up.

(NOTE: Simply disabling the HDMI Audio DEVICES rather than the DRIVERS may have been enough. But this is what I tried and it seems to work.)

I hope this helps if you have been experiencing "Random" loss of TX Audio from WSJT-X.

Juan TG9AJR

Thank you @Ken Wells I use only JTDX I see a lot of "Loss Audio" color code messages on JTDX, I don't use a TV monitor and only use PC monitors. Also I'd notice if I have the Windows Audio Speakers on (any sound coming from my PC) there will a moment that my 6600 will key to transmit but not audio is going out (no power output as well), and those are a bit more complicated because the easy solution is to close and open JTDX but some times it goes to a full shut down of all, and my PC doesn't to go sleep mode at all.

Andrew O'Brien

My symptoms are similar but the loss occurs usually after 10 minutes or so. I am puzzled as to why this happens with WSJTX and a Flex (SSDR) but not non-Flex radios.

Andy K3UK

Ken Wells

If restarting DAX restores transmit, then have a look at this article re: DPC's and DAX....

What are DPCs and why do they matter? – FlexRadio

k3Tim

Latest OS update from Microsoft:

"July 25, 2023—KB5028244 (OS Build 19045.3271) Preview"

has an audio fix:

• This update addresses an issue that affects certain display and audio devices. They are missing after your system resumes from sleep.  

May prove helpful for some.

Regards // Tim

Andrew O'Brien

Interesting OS update news. thanks Tim.

Andy K3UK

Erika - KØDD

Recently redid all of the computer monitors on my system. This problem reared its ugly head right off the bat, so I knew it was Monitor induced. The main radio monitors are a pair of 35" curved LG's using display port off the Nvidia GeForce 3060Ti GPU, above those monitors resides the Infinity 50" 4K TV using HDMI to the computer. ALL THREE monitors and Display Port and HDMI support internal audio... and needed to be deactivated. I have a big logitech surround speaker system with sub but don't use the rear speakers... it's a 12 but short of Bose audio... oh and because I could I added back in one of my old HP rotating monitors on the end with Outlook up on it all the time with my email. It's a DVI monitor so I use a Display port to DVI cable just for drill. I'd have already added a second video card, but there's other goober on this DELL blocking a second slot... I'd have to change out the muddaboard to something excessive.

Another problem for those who like desktop space, giggle... The best is to setup a screen saver on your computer, turn NEVER SLEEP, and NEVER turn off the monitors.... Then you need to bring up all of your RADIO software on the non-TV monitors first, leaving the TV off. My stepup I start SSDR first, with CAT and DAX, Then SDRMonitor as that windows sits atop the radio panel as an overlay, I then start HRD with all of its windows.... That leaves two spots for WSJT-X and one on the bottom of the other monitor for the WSJT wide graph. WARNING: the HDMI TV is off if I start the tv before bringing up WSJT-X it will place the wide graph on the TV, and within about a second or two WSJT-X errors and closes. It is a WSJT-X error. But Once the software is up and in its happy places I can bring up the TV, and that's used for all of my internet based stuff. Like right now this window is 50" and each letter is BIG about 3/8" or so. I could almost read it without my glasses. PLUS someday I'll hook the TV to the outdoor antenna, and it is on my Wifi and could be on the ethernet.

I thought adding an HDMI Tv would be easy, but don't ignore modern DP monitors that also have speakers and audio... turn off sleep and let the computer run its screen saver... it's pretty neat when all 4 monitors have ribbons going and they all are lined up and big... I'm sure I will find other issues, but if I follow my sequence for startup and shutdown I'm ok. but no damage occurs when WSJT goes poof, I just know to reboot the system and do the order correctly. I've only had all these panels here since the beginning of July so I'm still getting used to things...

David Decoons, wo2x

One thing I found is to disable the Nvidia card under sound devices in Device Mangler. Having a “sound device “ (monitors) that go into sleep mode can cause grief with Windoze device enumeration. I also set the PC power plan to high performance which disables CPU hibernate and sleep.

Dave wo2x

Gord-VA7GP

"disable the Nvidia card" and

"high performance which disables CPU hibernate and sleep"

I second both of these steps!

Erika - KØDD

Oh here's an update on the computer and 4 monitors. For the most part it behaves itself fairly well. I have found about 5 times whenever windows does and update it reinstalls the video card as a sound device and turns all the turned off stuff back on. I've gotten pretty good at deactivating the sound drivers on the NVidia card. I've been running not high performance but ultimate performance since getting this computer. It doubles the benchmark scores from stock. Doesn't seem to overheat it and has massive throughput. Every once in a while windows update throws me a bit of a loop. I have also setup the sound card audio for mono, and 24 bit studio quality at 48K I don' t believe the software in the radio can handle quicker like 184K or whatever. Very pleased with the way things work that a way except when the windows updates. Erika DD