Distortion on DAX Audio RX 7 and RX 8

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  • Updated 2 years ago
I am seeing distortion occur on dax audio rx 7 and rx 8 after a period of time (about 1.5 hours). 
I'm running smartsdr 1.8.4 and wsjt-x 1.6.0 r6263.
win10 v1511, 16GB ram, I7-2700K

I'd originally commented in this thread https://community.flexradio.com/flexradio/topics/1-8-4-distortion-query but now that I see its not just one rx stream or restricted to one band, I've opened a new thread.

I typically run 3 wjst-x sessions on 3 different bands; I've typically had the last session on 6m and have been observing that audio stream gets distorted in the wsjt-x waterfall and fails to decode. My xmits are received, so it appears to be a DAX Audio RX issue only.

To try to nail down the issues, I ran a test with 4 wsjt-x instances, along with smartsdr. I had all other apps I'd normally run turned off (no jtalert, no dxlab, etc); I put 4 wsjt instances on 20m and let them sit; The two instances on rx 7 and 8 got distorted.. restarting dax resolved the issue.

I then did a factory reset as Tim had recommended in the above cited thread (I didnt restore any profiles yet). I then did as above, and ran just 4 wsjt-x instances and after almost 2 hours I noted the distortion was back.(in fact based on when the two corrupt streams stopped decoding it was 1 hour and 20 min ).

I've attached a picture which shows the 4 wsjtx sessions and you can see when the rightmost 2 streams failed, and then where I did a dax restart and they recovered.

I'm not sure this is directly related to 1.8.4; I know Tim mentioned they hadnt made any changes that would cause this.. I dont recall seeing it as predictably in 1.8.3; 

Has anyone else noted this? Ideas?
Thanks
-jim NM1W


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NM1W

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Posted 2 years ago

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Jim Gilliam

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I have both a 5000 and 6500 both of which I run almost 24/7. I noticed (this is remote audio) after an hour or so the audio on the 6500 is somewhat degraded from the audio of the 5000. I just turn off the 6500 for a while and bring it back up. It always seems to occur. Nothing scientific but noticeable enough to comment on. I have noticed this problem on all runs of SmartSDR.


Jim, K6QE

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Al K0VM, Elmer

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Jim,
I would be interesting to know how many network errors accumulated during the 2 hour time period..

AL, K0VM
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NM1W

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Al - how can I see this? (ipconfig isnt reporting errors that I can see)
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Al K0VM, Elmer

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If your using DAX on the same PC as SSDR, just click on the network icon in lower right corner of SSDR  I would expect the error rate to approxiamte what DAX sees.

AL, K0VM
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NM1W

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This morning I've done a reinstall of the dax drivers based on https://helpdesk.flexradio.com/hc/en-us/articles/204017069-How-to-Manually-Re-Install-DAX-Drivers
and been running 8 wsjt-x's (and only wsjtx and smartsdr) to see how dax holds up.

Its been going for almost 2.5 hours. Here are the network stats:
 "Network: Excellent; Latency (RTT): < 1ms; max latency: 18ms, dropped 50 out of 2,810,900 packets (0.00%)"   the rig and computers are on a gig network connected to the same switch..

What I see different with the dax reinstall is:
1) I'm not getting the obvious distortion in the wsjtx waterfall display
2) the wsjtx windows are not all decoding; several are failing to decode during some minutes. which ones tends to move around at times...

Investigating further I stopped the monitor function on 6 of the wsjtx windows, and turned off the dax rx streams by clicking on the stream # in the dax window. I now have slice A and B decoding. Every few minutes I'm seeing differences in the number of decodes in each minute and every once in a while one of them just gets no decodes.

I've tried saving off the files (wsjt-x>Save) and opening the wave files to see if the decodes change from what I got originally, and they dont. Now since I didnt run this test under win7 I'm not sure if this a win10 issue or some dax or wsjtx anomaly...
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NM1W

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This morning I've done a reinstall of the dax drivers based on https://helpdesk.flexradio.com/hc/en-us/articles/204017069-How-to-Manually-Re-Install-DAX-Drivers
and been running 8 wsjt-x's (and only wsjtx and smartsdr) to see how dax holds up.

Its been going for almost 2.5 hours. Here are the network stats:
 "Network: Excellent; Latency (RTT): < 1ms; max latency: 18ms, dropped 50 out of 2,810,900 packets (0.00%)"   the rig and computers are on a gig network connected to the same switch..

What I see different with the dax reinstall is:
1) I'm not getting the obvious distortion in the wsjtx waterfall display
2) the wsjtx windows are not all decoding; several are failing to decode during some minutes. which ones tends to move around at times...

Investigating further I stopped the monitor function on 6 of the wsjtx windows, and turned off the dax rx streams by clicking on the stream # in the dax window. I now have slice A and B decoding. Every few minutes I'm seeing differences in the number of decodes in each minute and every once in a while one of them just gets no decodes.

I've tried saving off the files (wsjt-x>Save) and opening the wave files to see if the decodes change from what I got originally, and they dont. Now since I didnt run this test under win7 I'm not sure if this a win10 issue or some dax or wsjtx anomaly...
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Bill W2PKY

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When I upgraded to Win 10 Pro from Win 7 Pro I had the exact problem. Also run multiple instances of WSJT-X. Found couple of DAX channels with scratchy distortion after sometimes a shot time. Those instances did not decode properly and sometimes not at all. Seems to be connected to Win 10 Upgrade. Went back to Win 7 Pro and 1.8.4 is solid. Not ready to try a from scratch install of Win 10 Pro at this point.
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NM1W

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Bill,
Thanks for responding. If true that really sucks; I did a win7 ult->win10 pro upgrade since it sounded like the DDE issues for DXLAB were fixed.. I didnt expect a DAX issue like this..

I've done some more testing and configured to run all 8 slices with wsjtx, and was getting slice A to fail within the first few minutes... And I had one slice simply stop rcving anything, no sound at all after probably an hour or so...

Not encouraging.. I'll see if Flex has some thoughts, but I may have to consider going back to win7..
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Bill W2PKY

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Hi Jim-
Yes, I also had instances lose receive connection to DAX as well. I filed a ticket with FRS on this issue. However, Tim has been running Win 10 for a year with not problems. Of course, scratch install! And FRS thinks Win 10 is okay. I'm sure that is the case for them. It does look like the upgrade process causes issues with DAX, however. Thought I had heard similar remarks before about audio problems with the upgrade process. Too bad as I like Win 10 overall.
PS. Only takes a little time to down grade to Win 7.
Let us know if you find a fix.
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NM1W

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Tks;For the record I did as I think Tim suggested, and did a full uninstall of Flex and the drivers before the upgrade.. I've got til next Friday to revert (my one month mark). Hopefully there is a solution...
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Bill W2PKY

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I downloaded the scratch file and burned a DVD in case I decide to go ahead with the Win 10 scratch upgrade in the future.
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NM1W

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Bill - if you run multiple instances of wsjtx on the same freq, do you always get the same decodes or do they vary (as I indicated I'm seeing in a comment above to Al K0VM) ? 
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Bill W2PKY

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Now and then I get different decodes. Have seen this for ever. It's usually the weak ones -20 and weaker. But sometimes a -1 signal will go un-decoded by one of the instances. The capability of the decoder becomes less reliable when the signal gets real weak. Fading, noise pulses and any other disturbance can effect the decoding. In the winter, however, I was 8th in the world on PSKreporter for # of countries and total decodes. Not bad for one radio and a fiberglass stick in the backyard. I think most of the differences are because of band conditions. Could also be on the transmitter side as well, timing.. overdrive etc. As Joe would say if you give the app the same input the decodes will be the same. I agree on the saved files, if no original decode then it's not on the file either. Not knowing how the app gets the audio signal and develops the saved file it's hard to say where the problem could be. Anyway multiple instances are the workaround for now.
So when I'm serious about a band I will run at least two instances or more. On 160 I pile them on to get every last possible decode, and it pays off occasionally. I really like this mode of communication. On 6M use all available modes. The JTMSK can transmit a set of calls in a tenth of a second, so great for Meteor Scatter.
Finally, in the right hand lower task tray, open the speaker recording devices tab and click the DAX channel in trouble, properties then listen and click listen to this device to hear the DAX sound from your computer speaker. Do not use Audacity on Win 10 as it crashes on Dead Locked threads, may crash SSDR as well. Been back on Win 7 Pro for several days and the station is completely reliable. Let me know if you are curious about anything else.