SSDR V1.7 appears not to have addressed the ongoing DAX Distortion Problem that has been reported on over the past year or so. This problem is seen here at K3VAT when running the JT modes, usually after a period between a few hours and several days. Other user postings have reported DAX distortion with other modes - screen captures have additionally been included to show exactly what is occurring to the DAX output when this problem occurs. I'm also including three screen shots from the last couple of days showing 1) clean signal 2) 'start' of the distortion 3) full distortion. Other important notes include that Flex Engineering has been made aware of this problem and that mentioned earlier this year reported, "... that this is probably a memory leak issue ...". There are dozens of past postings on this topic that provide background and additional info (primarily from Tim). HelpDesk folks (Dudley and of course Tim) have been very understanding and supportive; and I realize that this is a very unique problem affecting only a small cohort of specialized users; nevertheless, it would be great if this issue is resolved (so I don't have to restart my system in the middle of a JT QSO [essentially loosing the QSO]). 73, Rich, K3VAT (please see QRZ.COM page for more info on my station and operations).
Top screenshot: 'start' of DAX distortion; Middle: 'full' distortion; Bottom: clean signal
Top screenshot: 'start' of DAX distortion; Middle: 'full' distortion; Bottom: clean signal
Posted 3 years ago
Still on 1.61; with this release have been noticing problems with the receive side. Will see signals on the panadapter but no decodes. Restarting DAX restores decoding on the problem slice.
Have tried running DAX as RealTime priority with no help. My computer is 4ghz I7 8 execution units with 16 gigs memory. Usually run my radio 24X7, have to restart DAX now and then.
Have tried running DAX as RealTime priority with no help. My computer is 4ghz I7 8 execution units with 16 gigs memory. Usually run my radio 24X7, have to restart DAX now and then.
Tim - W4TME, Customer Experience Manager
Based on your problem description, I suspect you have a long duration DPC latency issue. The What are DPCs and why do they matter? HelpDesk article explains what they are, how to measure DPC latency and the types of things needed to reduce DPC latency.
If your issue is intermittent, you may need to run LatencyMon for a while until you trap the event.
If your issue is intermittent, you may need to run LatencyMon for a while until you trap the event.
FWIW Tim, I have the same issue. Happens in the same way as others seem to experience - only after several days where DAX is running 24/7 doing things like monitoring WSPR or JT65/9. A quick shutdown/restart of DAX fixes the problem for me.
My wish is some day that software can detect that a killer DPC occurred and just drop the audio for a moment and reset itself without my intervention.
If I can click close and re-open DAX to fix it then why couldn't it be done programmatically? Perhaps Flex doesn't have fine grain enough control over Microsoft's audio driver?
My PC doesn't seem have DPC issues when I'm using it. It seems to happen when I walk away for awhile then perhaps the backup or anti-virus decides to start or the video is powered down automatically. Then I come back to find I have no TX audio.
If I can click close and re-open DAX to fix it then why couldn't it be done programmatically? Perhaps Flex doesn't have fine grain enough control over Microsoft's audio driver?
My PC doesn't seem have DPC issues when I'm using it. It seems to happen when I walk away for awhile then perhaps the backup or anti-virus decides to start or the video is powered down automatically. Then I come back to find I have no TX audio.
thanks Ed
Eliminated any DPC latency issue about 1.5 years ago with all new hardware and optimization by Neil.
Yes, I run USB with NO EQ or compression so I can use the 4 kHz bandwidth to cover all of the JT band (usually xxx.076 to xxx.080).
Finally, thanks for the four JT QSOs (160, two on 80, and 40M) !!
73, Rich, K3VAT
Al K0VM, Elmer
Rich,
I think you could use DIGU and cover the 4khz for JT I do..
AL, K0VM
I think you could use DIGU and cover the 4khz for JT I do..
AL, K0VM
Al, thanks. On my SSDR selections under DIGU are either 3.0 or 5.0 K.
Tim - W4TME, Customer Experience Manager
Those are just filter presets. Adjust the filter to what you need for the digital mode you are operating.
I created per band memories for WSJT-X operation, and then edit the filter high and low values for a 4kHz filter width. When I open WSJT-X and it selects the frequency the memories auto select the 4kHz filter width, or to return to a 4K width after trying either a 3 or 5 kHz mode preset, i just reselect that bands memory.
I also save and store the same as favorites in FRStacks which is usually also running.
73, Jay - NO5J
I also save and store the same as favorites in FRStacks which is usually also running.
73, Jay - NO5J
Al K0VM, Elmer
Rich,
You can set up DIGU, RX pass band, TX High cut, 14076 and other JT unique things once and then save it to a SSDR memory. Recall to active slice as needed and use WSJT CAT to move to other bands..
AL, K0VM
You can set up DIGU, RX pass band, TX High cut, 14076 and other JT unique things once and then save it to a SSDR memory. Recall to active slice as needed and use WSJT CAT to move to other bands..
AL, K0VM
