spikes in transmit waterfall with FT8

jim

I get  spikes (static crashes ) in my transmit waterfall  when  using WSJT or JTDX
and power  from 5w to 100w 
also the sig in the panadaptor  will hop (up and down) in place at the same time
I am using  FLEX 6500   rev 2.6.1
windows 10

please, what adjustments  should I make? 

thanks 73 de jim wb5aaa

Mark_WS7M

Hi Jim,

No idea on the "transmit spikes".  I do see my transmit waterfall moving around a bit and that is the signal.

On the pan adapter hopping up/down I assume you mean in receive.  This I'm told is likely due to static.   For example my 40m pan hops a lot when Thunderstorms are in the area (say within 500 miles).

Not sure this is what you are seeing but just to let you know I do see my "noise level" move up and down some.

I'm running a 6600

Mike - K6QY

This apparently arises when there is computer latency exceeding a couple milliseconds. You can check your latency using the app LatencyMon. To minimize this, I was able to adjust the number of cores and RAM allocated to Win10, as I am running VMware Fusion on a Mac Pro. I’m not sure how you’d fix this on a native Windows machine... reduce simultaneous processes and increase RAM?

jim

thanks Mark   
the hop  in the pan  is at the same time as the spikes  in the waterfall    all in TX mode

Mike - K6QY

Yes; this is from computer latency.

RoyS

Have you checked to make sure that TX DAX is not over driving? You might try reducing the drive and see if what appears to be splatter is reduced.

Roy - W5TKZ 

Mike - K6QY

While I won’t discount that possibility summarily, the intermittent and precipitous nature of these glitches is more consistent with latency issues. In my case, it wasn’t related to audio drive levels at all. Bur it definitely should be ruled out as a potential cause.

jim

ROY 
i have tried   but it  is still the same 

jim

Mike 
i am working  on  latency    
anything  special  i should  look for  that may help 

thanks 

Dudley WA5QPZ

Jim -

Mike has you on track,  it also has a certain timing to it..    check your CPU time,  and your video GPU timing.    Also some network NIC cards should use the vendor drivers rather than generic MS drivers,   this has been an issue for a long time with MS nic drivers.  If your CPU usage is high, then look for the source of high usage,  example ,  when I start my computer Acronis always starts up and cause high disk usage,  and therefore periodic delays,   maybe you are running some online back up,  these are notorious for causing latency issues in real-time programs.   Just a thought .  

73,
Dudley
WA5QPZ

jim

thanks  Dudley,
i will  start  looking     

TU 

Conny

I used Telnet and connected to the CAT port and started to send CRLF and I could get that same phenomena.
I did let Help Desk know. They opened a ticked and filed it for further investigation. Never heard anything more about it.
I have a 6600M and the only thing involved externally was quad core i7 computer with Windows10 and CAT and Putty running. LatencyMon show good performance.
BTW when I sent CRLF very rapidly it got totally messed up on the pan adapter.
I believe, need to check my notes, at that time I checked the spectrum with the my Company Anritsu Spectrum Analyzer and could see something there as well.

Conny

I should add that SDR was not running on the PC.
Only CAT was running on the PC connected to the 6600M

bahillen

I have worked with Tim on this exact problem last year with a help fest ticket for 6 weeks, step by step. All computer drivers need to be updated. Check Task Manager for any 100% CPU usage. 16 GB of RAM needed to reduce memory swapping Need separate video card, not on board video Turn off Spots especially if a lot of spots Minimize any apps that are not being use Chrome can eat up a lot of CPU and interrupts Shut down apps you don’t need at the time. Install LatencyMon Track what helps and what hurts. Eventually you can improve you computer performance. You may get to a point where you can use Spots etc. After you are not analyzing close Task Manager and LatencyMon because they can use CPU resources. Just when FT8 is crunching decodes other processes that use the bandwidth and causes an interrupt generates a transmitted blip. I was surprised that so many applications drivers have problems. Video drivers seem to be problematic. LatencyMon will identify which drivers may be causing a specific interrupt. I still get an occasional blip but have reduced it to a point where it doesn’t affect operating FT8. I have a Flex 6600, run multiflex, WSJT-X , Windows 10, I7-7700, SSD and run 4 instances of WSJT-X with JTAlert. I learned a lot about my system while working through this issue. 73 Bill W9JJB

Conny

This is how it looks like when I send CRLF to my 6600M during transmission using DAX.
I'm on the latest available software.

Mike - K6QY

bill - tnx. you summarize it well.

jim

Dudley  and Mike 

 this is the summary of what we tested last night: with Help of Charlie  N5WE

 

1.       Updated the drivers for both the onboard and separate video card. (intel and Amd)

2.       Updated the nic drivers (intel)

3.       Monitored CPU utilization and never saw any significant increase in cpu usage, disk usage or network usage in coordination with each spike.

4.       Confirmed spike is present when using WSJT, JTDX, WinWarbler in AFSK mode, and even when using the TUNE function with power reduced down to several watts.

5.       Did NOT see it present itself if the radio was keyed with MOX and the VOX button enabled, confirming that the USB headset microphone was hot.  Without any audio feed into the radio, the radio does not produce the wideband spike.  It only occurs IF the radio is fed, at the very least, some sort of constant audio tone including any type of AFSK program or the internal Flex Tune function itself.  Input levels do NOT change the effect, nor does output power.  It occurs with minimal audio drive as well as minimal RF output.

6.       Confirmed version 2.61 of Flex.

 

Besides that, the computer has sufficient memory (16GB), no swapping.  Its running on an SSD, therefor disk i/o is a minimum.  We ran all tests last night without any other program running except CAT, DAX, Flex, and whatever audio generating program we chose (MMTTY/Warbler, WSJT, JTDX, etc).  No Chrome, no logging program, no apps loaded in task bar.  

 

I will  try this LatencyMon, .

 

This audio blip IS audible over the air as monitored from my QTH.  20 miles away

Charlie

N5WE

jim

today I have backed up from 2.6.1  to  2.4.9 
now i am getting   less spikes but  still have some

jim wb5aaa

Conny

The last video was when I transmitted RTTY ****.
This is sending CRLF via TCP/IP direct to the 6600M.
Not CRLF via RTTY or something like that.
CRLF is just end of command line. But in this case there are no syntax for the 6600M to execute. It seems that even just parsing a new empty command line without any syntax interrupts the DAX modulation.
BTW if I just send some syntax to inquire the status of the 6600M I get the same result.

bahillen

Something I observed in the past with my problem. The pops were obvious during TX but on RX , as I recall, there were pops but were hidden by the audio. Also in FT8 key up there is a pop in tx audio. Some times I saw a consistent pop/spike 4 seconds into 15 second FT8 TX. Hope some one can figure this out. 73 Bill W9JJB

Val DM1TX

I have my 6500 running 24/7. I noticed same problem when transmitting in FT8/FT4. 
For me is simply solving by closing and opening of the SSDR. Then everything is normal again. It is coming back in few days but it takes seconds to solve it. I hope this helps. 73 DM1TX

bahillen

Conny This is an important observation it seems. If any command interrupts DAX audio that explains a lot. The command length may take too long for Windows to process and causes an interrupt. Normally an interrupt of 250 micro seconds can be handled but the interrupt quickly jumps to 1,300 micro seconds as operating system tries to handle the issue. This is as viewed in LatencyMon. I am not a Driver or OS person but have run and watched the test a lot. Seems like some investigation would be of benefit by the Flex Technical staff. As I have learned working with this in the past, Windows operating system is not a great performer for audio processing of real-time audio because of the interrupt handling structure. That is not to say other common OSs would be better. I also run my 6600 24/7 and have to stop and restart the TX button every 2-5 days or it sends our a 3kc band of audio and can be heard in the TX Monitor audio. This is a known DAX Driver bug. Unrelated to the subject here. 73 Bill W9JJB