Audio sampling clicks, pops, jumps and skips

Douglas Maxwell

I have a 6300 and a 6500 and have had the above receive audio sampling problem for the last 4 years on both radios and all versions of software up to 2.49. I am a cw contester and normally run and receive at 28wpm to 40wpm. At these speeds the slightest audio glitch is very apparent and normally the human brain can work through these audio glitches to guess what was sent. I find myself turning AGC-T back to a sub-optimal level (cannot hear weak callers) reduces the problem. My question is why are they there and what can be done to get rid of them? Instead of dreaming up new features, could Flex improve this problem?

Steve Sterling

Douglas Maxwell

Thanks for taking the time to share. I don't use WIFI for this reason. I have an ADSL router at the point where the landline enters the building, my 6300 is hardwired to the router. I then have a 10m long wired cat5e cable to the shack into a Netgear GS105 switch. The switch has my computer, 6500 and maestro hardwired to it. I have a 1 in 5 start up issue where the maestro shows poor network latency which manifests as red/yellow network indication and shows broken audio and lines across the screen. If I restart the maestro normally this resolves itself and low latency and green network indication results. Smart SDR does the same leading me to believe it's not a maestro issue. The 6300 and 6500 behave the same leading me to believe its not a Flex hardware issue. I've had various network topologies and equipment brands and all have shown this issue. I do not start operating until I get a green network indicator and no on screen broken lines, this can sometimes take several restarts (mostly one suffices). The audio pops happen mostly during large signal conditions (during a contest) and sounds like an audio sample has gone astray. This happens constantly until I back off AGC-T where I am unsure if they disappear or the audio volume is insufficient to hear them. I can work round them but when struggling with a weak signal the pops and clicks always distract me. It's easy to ignore/miss them when operating in a casual fashion outwith contests. I use the free edition of AVG and normally have N1MM+, SDR/CAT/DAX launch windows open on my desktop PC. I use a Dell xps430 PC with dual cores. It would be interesting to hear if anyone else recognises these symptoms.

Martin AA6E

Try running a direct connection radio-to-Maestro or -PC without router or Internet. If this helps, you've probably got a local network problem. Your router or cabling could be marginal. Are you running 1 Gb/s Ethernet? In my setup, a 100 Mb/s router works more reliably.

Jim Brown, K5JAZ

Martin is probably right on about the 100Mb reliability. I put an old SMC 100Mb switch with my 6500 and Maestro connected. Another port was connected to the main 1Gb switch. All of my audio problems disappeared. Seems as if either the 6500 and/or my Maestro (version 1) has a problem with Gb switches. I think Tim wrote up an article about it on the support site.

N8SDR

Disable all the Dell Bloatware on the 430XPS, Also I suggest you use a real AV as well being in the I/T field I cant tell you how many PC i see using free A/V solutions then wonder why they have undetected malware and or issues, , You didn't mention weather running win7 , 8.1 or 10 and how much ram. Also managed switched such as Business class switches have more buffer then the 12KB the GS105 has , and you could  be running into issues with actual bandwidth that is supported by that switch which is why there cheap, Start with rid the dell if still running the Dell image operating system of all the BLOATWARE and unneeded  items in startup, do a A/V scan with a better product, like Emsisoft, Heimdal or Eset  - Emsisoft and ESet both offer a 30 day full trial, Personally I have been using Emsisoft and Heimdal here for past years, no issues with either affecting the  Flex when in use and both find  items your free one doesn't even know about. also try using TSA malware / adware scanner- https://www.techsupportall.com/adware-removal-tool/ and do a scan in advanced mode.. You'll most likely be surprised at what your current free AV has missed malware, adware and PUP wise that is running in the background **** up network bandwidth. Mindspark.* is a common one I see weekly that many A/V  miss, its one of those hidden in registry types that runs in background and can bring a computer and network connection down considerably. 

bahillen

I worked with Tim when I submitted a help desk ticket. The previous inputs are right on target. Although I didn’t resolve 100% of the problem I did get to about 95% and doesn’t hamper my operation. I did get pops in Tx that was my main problem but did see pops in receive audio that I didn’t notice before. Heavy band activity definitely made it worse. I would bet running panadapters in wide mode could make it worse. If you can restrict panadapter bandwidth could affect the behavior. I don’t know how your radio works in the front end filtering area. I have a 6600 and no Maestro. I ran test with (free) LatencyMon software and was very helpful to make meaningful measurements. Of course it won’t help Maestro but it helps isolate issues and a learning tool. Testing with SmartSDR allows you to get into the middle of the system to make measurements. My computer is a Dell I7-7700. 1 added switch between radio and computer 2 updated all drivers on PC 3 turned off Spots 4 Video card important with driver updates. 5 5gb WiFi and on 2.4 gb restrict router protocols that are old, wide band “a”. 6 don’t open things you don’t need an minimize windows you don’t need. 7 add as much RAM as you can to computer. 16 gb is a minimum. Task Manager seams to show what you are using not what you need. Windows starts storing data and past data on hard drive that has to be reloaded next time you need it and you get interrupts. 8 Windows operating system does not handle real-time audio very well and system tasks and network traffic interrupt audio processes. I would bet the same can be occurring with the radio as well as the other front ends like Maestro. As Tim told me it is like pealing an onion. 9 check your filter bandwidth settings and set to reduce latency. May help Maestro. 10 Chrome can really over load your computer. It is always “Helping You”. I run email, Internet activities and other things on a separate computer. 11 Ferrites are your friend. 12 getting reproducible behavior helps zero in on what are the sources of you problems. 13 upgrading to V3.0 has solved some memory leak problems. May not technically be memory leaks but does behave like that. 14 dumped Norton virus software. Having done a lot of trouble shooting over the years write a log of what the circumstances you see and a running record of what you have tried and observed. When you look back at your log you may see holes in you test or assumptions that have hidden the source of the problem. Also it is easier to communicate to the support person. 73 Bill W9JJB

Asher - K0AU

I have the audio click problem as well. Mine is audible on the headphone and speaker ports. Are others reporting audio clicks on the PC Audio stream? I also have the intermittent DAX TX audio corruption problem. Running SW v2.49.115 on a 6700.

Ray - K6LJ

It is interesting that last night after finally getting my PG-XL operational I was trying the Maestro and it was popping sounds just like was described. It was on wifi as well as the computer. It sounded to me like network issues. Intermittent cracks and pops. I took some recomendations from above an hooked the Maestro and computer to a gigabyte switch. All cracks and popping sounds are gone completely. I suppose it's all about speed and quality of the wifi and router. Direct is good! Thanks for the good advice. Now must see how I can improve the wifi . Ray K6LJ

Douglas Maxwell

Update, I have replaced my Netgear GS105 gigabit switch with a Netgear FS105 fast ethernet switch (100Mb/s). Funnily enough the new switch was more expensive than the old one. So far I have gone through about 10 power ups with no issues. As for the audio clicks and pops, I have found no more re-occurrences. I suppose Flex requires real time QOS and some switches may introduce too much variable latency. Networks can do strange things with the spacing of packets which can cause effects such as these, however this is never regarded as the networks fault and the designer has to properly handle odd network traffic profiles. Hopefully Flex can fix this soon. Its a poor show that the customer has to buy specific network equipment to get round poor design. Thanks to all for the recommendations and solid advice.

Martin AA6E

Glad your system is working better. It does appear that Gb networking imposes some critical timing issues for an 'isochronous' (?) application like Flex. Who's at fault is not clear. I have wondered why Flex doesn't strap down the I/O to a maximum of 100 Mb on both the radio and the PC and Maestro.

bahillen

Douglas You may try LatencyMon software as an important test since you have two definable configurations. You will have to test with SmartSDR. Run for a couple minutes and observe the Latency interrupts and Latency times. Normal interrupts run 30 to 100. When they get to 1000 usec your audio will pop. This is not the 3 milliseconds you see in flex’s Network applet. It is the CPU interrupt duration. Anything that causes these long interrupts is beyond the usual interrupts that are ok. The software also identifies if it is a specific driver or network driver. Very cool. It is a good tool to have in your tool kit for analysis and understanding what is happening, don’t leave home without it. If you try the experiment let us know what you see. I have a GB switch and have not had a problem since having all radio network ethernet cables direct to switch and one cable from modem/router. I also converted to 5 gnome WiFi. I used an external WiFi usb device on the laptop as the internal WiFi antenna sucks. My local remote is 10 times better both at home and away. 73 Bill W9JJB

Thomas DF2LH

Douglas Maxwell

Thanks for your continued help. If I am using a maestro and headphones directly into the 6500 what have pc interrupts to do with audio pops?

Martin AA6E

Fair question! The exact data flow between radio, maestro, and PC in this case is not obvious to me. If the demodulated audio flows through the Maestro on its way to phone jack... Flex could do more to document signal flow in the common use cases IMO.

bahillen