locked Re: Decode cycle dropped #FT8

Hasan Schiers N0AN

I have observed the same problem of occasional skipped sequences, sometimes worse than others.
WSJT-X > DXLabs > JTAlert  Intel Core I5 with 8 gB RAM, Win10 Pro. Sometimes it will alternate sequences as others have described, sometimes it will miss one, then be fine for a few sequences and then miss another.

In every case, all I need to do is close JTAlert and restart it and the problem goes away, and returns a few hours/days later.

I am NOT blaming JTA. I went through a similar problem with another computer, where it would stop decoding altogether overnight (sometimes). In that situation, where there was no DXLab stuff running, again, closing JTA and restarting it, and all was well again for a "period of time" When I moved on to a newer computer, the problem appeared to go away. It has been several months.  Now it's back, but not as severely. I have not observed X stop decoding altogether, just alternate sequences or skip an isolated sequence.

Something is obviously causing a load on the system that results in data corruption or data missing.
I repeat, I am NOT blaming JTA. There are interactions taking place that I cannot account for.

I have no idea what's causing it. I do know how to easily restore proper operation, for a while in my case. Your mileage may vary.

I only recently started observing the alternating sequences of failing to decode on this new computer in the last few weeks. It may have been going on for longer, I just didn't notice. Now that I have a parallel setup running that NEVER misses a decode cycle, it makes it more than obvious when my main X machine does.

I have another computer running WSJT-X and SDRC v3 (as a receiver). This computer is not running JTAlert or any other ham software. it NEVER drops a decode sequence. It is using the same antenna as my main WSJT-X computer.

So, this is just another data point to work with for whomever might be involved in investigating this issue. Considering the ill will and intemperate comments I was exposed to the last time I mentioned this, (and how to work around it), I was hesitant to post my observations this time, so I will drop out of the discussion at this point and not post further. Take my observations for what they may be  worth. If they are useful, fine. If not, ignore them, but I ask that no one further engage me on this topic.

It is easy enough for me to work around this dropped decode sequence behavior, that I don't need a solution, but if my post helps others, good enough.

73, N0AN

On Wed, Jan 22, 2020 at 12:27 PM Al Groff via Groups.Io <al.k0vm=yahoo.com@groups.io> wrote:
If you monitor total CPU load in windows Resource monitor, you may notice that there is a peak in CPU loading at the end of each decode cycle in which decodes did not fail.  If the cppu load approaches 100%, the following cycle may not have any decodes (and no .wav file is saved).  A portion the that cpu loading peak is the FT8 decode and a portion  of the peak is database lookups in DxKeeper and SpotCollector that occurs when there are decodes.

Shut down the wsjt-x feed to DXlabs for a while and see what happens to the dropped decode cycles.


On 1/22/2020 1:43 AM, marsip@... wrote:
I have the same problem with occasionally dropped decode cycles.

I'm use the internal audio drivers in my Icom ic-7300, and the receive level is always on abt 60 db. I have no problem with non-synced clock. I see spikes on the cpu utilization, in the end of cycles to abt 70-80%. (But can we be sure the graphic display really shows the maximum value?)

I'm using Windows 10 with a new computer. Cpu: AMD A9-9425, with 5 cores, 3.1 GhZ. Memory 8 GB. Running applications: WSJT-X, DXlab: Commander, Dxkeeper, Spotcollector. I usally also have Firefox running, which take lot of memory. But it doesn't make any difference if it's running or not.


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