DAX distortion

Greg Zenger [N2GZ]

My radio is on 24/7. Occasionally I find that when I transmit on DAX, There is terrible noise/distortion that occupies the entire TX bandwidth.  I used to resolve this by cycling power to the radio, but I have found that disabling and re enabling the DAX audio stream corrects this.  This doesn't happen often, but it can happen mid QSO.

Attached are screenshots of the transmitted signal. On the left, the signal with the noise/distortion; on the right, a normal signal. (The vertical scale was adjusted between screen captures).  Single tone 'TUNE' carrier is from WSJT-X v1.3, r3673.



Radio Flex 6700, software v1.4.3.132

Dave -- W7IWW

Have experienced same situation running PSK31 (HRD v. 6.2), and have resolved the transmit distortion by disabling and restarting the DAX channel.  Anxious to learn if others have experienced same, and if FRS is aware possibly correcting issue in future s/w update??  Or advise on how to "permanently" correct issue locally??

George KF2T

I've seen it too. It's rare, but real, and Dave's workaround does the trick. Probably some little gremlin in the DAXWorks...

Sergey R5AU

I have similar problems on my previous iMac27(from 2010) with any Virtual Machine, however on the native Win PC or my new iMac27 5k with any VM I have not any more such issue.

Patrick

One thing that can help with noise and distortion is to adjust the Pwr Slider on the right side of the App window and set it so that it is something around half way then adjust the levels with DAX Channel. Some adjustment of the power slider in SmartSDR may be required.  For me this has resulted in a much cleaner signal output.

Patrick

On just a couple of times I have had distortion from DAX cause major IMD that spread up and down thr JT65 band.  I noticed it right away thanks to being able to see the transmit waveform.  Rebooted SmartSDR and the Radio and that cured it.  But also applied the what I did in the previous post and all has been great. 

Greg Zenger [N2GZ]

This is not the problem here. Once this has happened, no adjustment of available sliders will make the distortion better. It's as if something gets out of sync within DAX. Only stopping and restarting the DAX stream clears it up.

DrTeeth

Same here. Not seen it for a while but will recall the DAX tip for the next time.

Patrick

I used to see the distortion as in the pictures you have presented. But all changed when I loaded the newest version of 1.4.  I am wondering, and this is just a question.  Did the newest version of DAX get loaded and are you using it?  Just a question and I apologize if I am wrong.  Check and see if the 1.4 version of DAX is running. I am sure that already has been checked. 

Greg Zenger [N2GZ]

The version of DAX running is identical to the version of Power SDR that is running (1.4.3.132).

I think I see this less than I did with 1.3.8, however my operating habits have not been consistent (I was operating digital much more frequently then than I am now).

Patrick

OK on your versions, does pay to check as I had 1.3 DAX SW come up instead of DAX 1.4.  Saw it right away and fixed it.  Don't know how it happened and could find no explanation for that situation other than op error when I cleaned up and deleted the wrong version.  In Version 1.3  DAX there was distortions and found that my ability to copy signals with DM780 was much reduced.  When 1.4 came out DAX became remarkably clean and I could copy almost all signals, even those close to the noise floor.  On JT65 and 9 The IMD noise was bad with 1.3 on signals above -12 db. and again 1.4 cured that. 

rich

I have this problem also with both V 1.4, 1.4.3 and earlier versions.  Happens rarely, often after switching modes/bands.  I have been forced to turn off the 6300, then turn back on.

73, Rich, K3VAT

GM4WCE

I also have seen this problem, although infrequently.  I restart DAX and it clears.
Peter GM4WCE

K1DBO

...and I thought it was just me.

Gary Ashdown

Unfortunately I started suffering the dreaded distorted rx audio via DAX on all 8 channels. It would occur randomly and restarting SDR and/or DAX only temporarily resolved it, it would return again at very random times - which resulted in wsjt-x not decoding and the audio containing pops.
I noted via task manager that SmartSDR would occasionally turn red, indicating that the program had momentarily stopped? So...I connected my 6700 (signature series) directly to my pc via the ethernet cable but alas the problem returned. But...the next step resolved it permanently:- by starting up each copy of wsjt-x individually x 8, then starting up Smart SDR, and then (the most important part), turning on each DAX channel one at a time. This process of starting up each day has been faultless.
My pc is a quad core I7 32mb of ram and SSD. 
On a side note, I previously un-installed/reinstalled all SDR software, including signed DAX drivers a few times without any improvement.

Looks like it was a Denial Of Service issue?

regards
Gary VK8AW / VK4ABW

WX4F

Gary, this procedure still working well? I’m at wits end with mine the past week and very frustrating with failures mid QSO becoming quite frequent every 30 minutes. Will try it!!

Ed Stallman

Gary Ashdown

Yes, it is still working fine. I have played around a bit more and found that you can start Smart SDR 1st if you want, and then all copies of wsjt-x but....don't enable any of the DAX channels until all your programs are running. I currently run eleven (11) copies of wsjt-x without any issues....using several radios. I allow a few seconds between enabling each of the 8 DAX channels, to ensure that they are working.
The audio failures were quite evident whilst trying out Slice Master....which I deleted from my PC due to the horrible things that Slice Master does to your decoding programs configurations.

This method works fine every day for my setup and I do change my configurations between HF / VHF bands regularly.
regards
Gary
VK8AW / VK4ABW

K1DBO

Gary,

I'd really appreciate if you could describe the problems you had with Slice Master.  I cant make it better without feedback.

Slice Master doesnt change your WSJT-X configuration at all unless you ask it to.  Normally, it just copies your default WSJT-X configuration into a slice specific "--rig-name" folder of your choice, then works only with that.  Even then, the only setting changes it makes are those that are needed to run it with the slice you have chosen.  Worst case, you have to change your "rig", com port, and audio device settings.

If your experience was any different than this, a description of the trouble you had could save one of our fellow Flexers a bit of trouble. Feel free to drop me an email.

--Don

Gary Ashdown

Hello Don,

Please don't get me wrong as I believe your program is a fantastic idea. I spent time playing around with the way it works but unfortunately the end results were not dependable.

1. the placement of 3rd party programs on the display is not consistent. They would invariably end up in random spots, which then requires time to move.

2. the configuration of port settings, PTT, additional frequency bands and tailored receiver bandwidths is over written every time it loads. I modified your program but the changes did not take. Flexibility in settings is required.

3. Slice Master loads all 3rd party programs at once (if set that way). My feedback above details some of the issues this causes eg: corrupt DAX audio after random time frames which results in no decodes or total failure of the audio steams. Random failures of single audio steams occurs as well, which I could not pin down. Please also see my feedback as my method of loading 3rd party programs before allocating DAX assignments has resulted in ZERO audio failures to date.

4. Slice Master does not always remember mode settings for WSJT-X V2.0.0. I have seen it load JT65 instead of FT8, despite changing the mode back and reloading again. Is this a save issue or clearing of old cached data?

5. Slice Master will not load if Smart SDR is loaded 1st. Why would this be?

The issue of corrupt / degrading DAX channels may or may not be directly linked or associated to your program, but I did notice an extremely high incidence of audio issues whilst using via a LAN. Bypassing the LAN lowered the rate of incidence.

Something to think about Don....an option to change call sign SPOTS to abbreviated country allocations (displayed)?  As amateurs, many of us focus on chasing new / rare countries. This is why PSK reporter is so heavily used by the community, outweighing the current  'eye candy' of hundreds of call signs on Slice Master and trying to pick out that rare one. It takes time for the brain to process what is being displayed during pileups...Food for thought?

I have provided my feedback via this medium as you may find other users with similar problems or suggestions and that is worth sharing.

regards
Gary
VK8AW / VK4ABW

K1DBO

Gary Ashdown

Hello again Don,

Thank you for the update. I do run up to 11 instances of wsjt-x at a time hence my raising the placement concern. I hope I haven't come across as too strong with my comments. I will endeavor to work through your suggestions as time permits. i really do hope that you take up for spots to be displayed as the country prefix in lieu of call signs in the overlay. I believe this will reduce screen clutter and allow amateurs to pick out entities much quicker.

Individual settings for multiple instances of wsjt-x would be great. I prefer to run below the 3k bandwidth on some bands due to atmospheric noise, birdies etc. This improves the spectrum scope/ waterfall ability to pick out weaker signals which you can then focus on by moving the slice receiver to peak on them. This was very evident during our mid-year 50 MHz opening to EU. FT8 / JT65 is opening new doors every day on 6mtrs!

I currently use 2 x 55" HD displays due to the amount of programs running.....Flex 6700, Ic7851, 756pro etc so it does get hectic with organisation. Hence some of the issues I raised would not apply to someone running single instances of wsjt-x or fewer slice receivers.

regards
Gary