Distorted Transmit Signal

Mike NA5U/K5D/K1N

I came to this party a little late but Mike, N8SMA got me up to speed. I have a 6500 and was bringing WSJT-X on-line for a second time after rebuilding the PC. I noticed what I believed to be a distorted signal on JT65 transmit. I asked the question on the WSJT-X reflector and Mike recommended rebooting the 6500. I did and the problem went away. Here are three images of the before and after. The first is the 6500 in Tune mode, the second is WSJT-X Tune mode and the third is the same after the reboot. I wonder when the fix mentioned earlier will be coming out?
Regards,
Mike, NA5U

Bill -VA3WTB

Mike. the problem with the 6300 a while back was found and corrected. Very few have mentioned a problem with the 6500. At the time of booting your radio, there are lots of things that happen for all systems go. If for any reason something is not right as you mentioned a re-boot should work.

Al K0VM

Mike,
   I believe that what your showing in the second Pix is the result of TX DAX stream becoming corrupted.  The next time it happens, close DAX ( using the EXIT selection from the quick start, not the red X) and then restart DAX.

AL, K0VM

Bill W2PKY

My radio is on 24X7 monitoring various bands, when sending any JT mode I monitor the audio because DAX becomes corrupt frequently. The panadapter presentation is a give-away of the problem but monitoring the audio confirms the distortion. I use the task manager to cancel DAX and start a new instance. My computer it a 4GHz I7 w/8EX Units. Plenty of power.

Mike NA5U/K5D/K1N

Bill et all,
Thanks for the input. I agree something is corrupting the DAX. The strange thing is that this is a really bare **** set up at this point. What I mean is that I have just reformatted the hard drive and reloaded Windows (10), SmartSDR, DXLab and WSJT-X. Also, this has happened when SmartSDR is first opened and then other times after the machine has been running fine and then there it is. I'll begin to carefully note the situations when is happens and begin narrow thing down. Thanks again.
73,
Mike, NA5U

Douglas Maxwell

This is not true. The tx problem for the 6300 has not been fixed. I have a 6300 that has been plagued with transmit problems since purchase 6 weeks ago. The issue is firmware related and affects all 6300s and is temperature related. The next attempt for a fix is v1.6 of the firmware/software.

Tim - W4TME

Sorry for the late reply.  I suspect you have a DPC latency issue.  For those not familiar with DPCs (deferred procedure calls) and why they are bad for systems processing real-time audio (like DAX is doing), I recommend reading this HD article https://helpdesk.flexradio.com/hc/en-us/articles/202118398-What-are-DPCs-and-why-do-they-matter-

Now to verify me assumption.  You need to run a program called LatencyMon while you are using the radio in digital modes.  It is best to let it run for a while to collect a lot of data points and if you can run it when the TX audio corrupts, that is even better to catch it in the act.  Here is another HD article that explains how to collect your system's latency data.  https://helpdesk.flexradio.com/hc/en-us/articles/202118698-Using-LatencyMon-to-collect-DPC-Latency-D...

Once you have the data, I recommend that you submit a HelpDesk ticket so one of our tech support engineers can evaluate it.  I recommend this because it is possible that I might miss your response and I'd hate for you not to receive a reply.  Opening a HelpDesk support ticket will ensure our highest level of customer service we can provide.  For details on how to submit a HelpDesk support ticket, please refer to the following URL: http://helpdesk.flexradio.com/hc/en-us/articles/202118688-How-to-Submit-a-Request-for-Technical-Supp...