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repeated split-second audio dropouts

Ken - NM9PKen - NM9P Member ✭✭
edited June 23 in SmartSDR for Windows
I jist finished running about 30 feet or so of CAT6 from the family room, where my Uverse modem/router/wireless head is located, to the ham shack.  I am feeding that to a TP-link TL-SG108 Gigabit switch, then to my 6500 and desktop are fed from the switch.

After powering up, I am now getting a split second audio dropout that repeats about every 13 seconds.  I never had this problem when I fed the 6500 directly into the Gb ethernet port on the desktop and used WiFi for internet on the computer.  Things worked fine, except that I couldn't used K6TU's iPad interface program.  Thus the new CAT6 cable and Gigabit switch.

I know that this is a networking problem, but I don't know what steps to take, 


Technical Info:
FLEX-6500 running V.
Win 8.1
Lenovo K410 w/ i3 processor & 6 Gb RAM.  AMD video card HD 6570 2G  dual monitors (HDMI & DVI)
Gigabit Switch
ATT270 Uverse modem/router/WiFi  (Just installed on Wednesday)


  • Steve N4LQSteve N4LQ Member
    edited September 2015
    Well that makes the second time within the past week I've read about folks having trouble with their Flex going through a switch. The other guy couldn't even get a connection until he bypassed the switch. There must be some setting for the switch we don't know about. 73 Steve N4LQ
  • DonSDonS Member ✭✭
    edited January 5

    You can install wireshark (freebie network sniffing tool which may or may not be your area) and then monitor the ip address of the radio to see what kind of activities are occurring in the packets. Wireshark does a nice job decoding the packets.  I am also running the same gigi enet switch without any issues.  

  • Jon_KF2EJon_KF2E Member ✭✭
    edited July 2018

    A quick and easy thing to try is to start a ping session from your Lenovo to the Flex. Try this...

    ping 'IP address of your Flex' -t

    The -t switch will keep the pings going until you tell them to stop with a control C. Watch the ping times when the Flex hickups. If they are high your problem could be latency in your network.

  • Neil K2NFNeil K2NF Member ✭✭
    edited March 2015
    What happens if you disconnect the 30 foot cable and Internet service and just run the flex and your desktop on the Gb switch ? If the problem clears it may indicate that the Gb switch is powering down ports due to intermittent internet traffic ( energy saving feature on that particular switch ) and that the power down / power up of ports on the switch is somehow interfering with the flex audio traffic.
  • Ken - NM9PKen - NM9P Member ✭✭
    edited June 23
    UPDATE...After letting it run for about two hours and fiddling with opening additional slices and panadapters, and changing bands all over the place (My typical night of "hunting"...)  it has been working fine for the past several hours.  I guess things had to get sorted out.

    I will do a total power shut down tonight and see if it behaves OK in the morning.
  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited June 23
    In a lot of consumer Ethernet switches there is a feature called "Green Ethernet", which temporarily powers down the port at time of no activity and reduces the port transmitter power based on the cable length connected to the port via a TDR (time domain refractometer).

    There have been several reports that in some consumer Ethernet switches, turning this power saving feature off, which is usually on by default, improves throughput and reduces data errors.
  • Ken - NM9PKen - NM9P Member ✭✭
    edited December 2016
    Thanks, but how do I turn it off? I thought it was an unmanaged switch.
  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited December 2016
    Check the doc that came with the switch.  Being un-managed, you may not be able to disable this feature.  Being an old network guy, I am not a fan of un-managed device ;-)
  • Robert -- N5IKDRobert -- N5IKD Member ✭✭
    edited March 2015
    Here is a link to the manual. http://www.tp-link.com/resources/document/TL-SG108_V1_User_Guide_7106504.pdf It mentions the Green Ethernet feature, but not a way to disable it. I would double-check your power connections and make the the Ethernet cables are "clicked in".
  • RegReg Member
    edited March 2017


    Is your CAT6 LAN cable routed near any potential emitters on their route from you family room to your ham shack?  When I got the 6700 I saw three different sources of RFI that I didn't know existed.  The band scope on other radios didn't show the noise sources but they were very evident on the 6700.  (TS-990S and IC-7600)  I still have on periodic noise, not at my QTH, that I haven't located.  (70 kHz spacing, 20 kHz wide, smooth shape, no noise is detectable by SSB, AM, CW detectors and the noise is intermittent.)  My remaining RFI causes my noise floor to raise by 20 dB at intervals of 70 kHz. 

    The other two noises were eliminated by converting all wired LAN runs to CAT7 cable.  I carefully opened one end and attached a ground wire to the outer shield.  (Only ground one end.)  My previous CAT5 and CAT6 cables both emitted RFI noise AND suffered from induced pulses from motors switching on, etc. 

    Good luck and let us know what your final solution is.  That's how we accumulate knowledge.


  • Ken - NM9PKen - NM9P Member ✭✭
    edited June 23
    Additional update... After power down and cold restart of the rig. the "pop" was back. (actually sort of a "reverse pop" because it was a very short drop out of all audio)  It repeated about every 12-35 seconds for about 45 minutes or so.  Then everything was clear and has remained so all afternoon.  

    Strange... The best I can think is that the "green" circuitry seems to take that long to finally shut down unused ports and adjust the power output of the three ports being used for the rig, the computer and the line to the router.  

    Oh well.  For right now it is working.  Not it is time to get out the 31 MIX beads and isolate the Uverse phone/internet router, it's backup UPS, and the switch because I saw a 4 dB rise in background noise all across the spectrum when it came on line.

    It's always something!
    Thanks for the input, guys.

    Ken - NM9P
  • Stan VA7NFStan VA7NF President Surrey Amateur Radio Communications Member ✭✭
    edited February 2017

    Regarding the shield of the cat-cable.  Purchase pre-made STP or SSTP (single or double shielded) cable.  A longer length for the main run, and a shorter cable which is joined by a non-shielded double female joiner.  That will isolate the ground to one side only and prevent ground loops.

    FRS was not fond of STP/SSTP cables because they could introduce problems.  I just make sure there are no ground loops created.

    There is no RF pickup on fiber optics, nor lightning paths either.

  • RegReg Member
    edited March 2017
    For clarification, CAT7 has 4 twisted pairs, each in their own shield, and a second shield around everything.  That solved 2 of my 3 RFI issues.  (Grounded at one end only.)

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