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Smart SDR 3.5.9 Is shutting off.

KG5PTE Member ✭✭
edited November 2023 in SmartSDR for Windows

Hi this is about the third time my Flex 6400 lost connection to Smart SDR version 3.5.9 here on my LAN side on my Windows PC Dell Laptop running MS Windows 11. Just by being on and listening (No Transmit no PTT) I just looked at the dialog that stated the Flex has lost connection with smart sdr. Radio was one and I was listening. Why is this happening ? I was running Slice master and FR-Stack and N3JFP logging software at the time too,

Thank you.


  • Neil D Friedman N3DF
    Neil D Friedman N3DF Member ✭✭✭✭

    How is your laptop connected to your 6400?

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    When you lose connections, it is due to a networking issue, even during receive.

    That can be caused by the following things:

    • The PC - is the LAN or WiFi on the laptop going to sleep due to power saving?
    • Bad CAT cable on the radio cause the switch/router to keep retrying
    • Bad CAT cable to the PC - same issue and lots of retries
    • The PC is just very busy with lots of network communications
    • What is the make of the Network switch?

    Now, how do you narrow this down? You start to change things, one at a time.

    I would try a new cable to the radio and/or maybe a different switch. My first guess is that the switch is not of the best quality and is 'flapping' some of the ports.

    Sorry, but I wish I had a simpler answer.

  • KG5PTE
    KG5PTE Member ✭✭

    Hi Mike I use top grade Cat 6 Ethernet cable that plugs into a eight port Netgear GS 108 Gigabyte switch that in turn plugs into one of the open LAN ports on my ASUS RT AX82U Router, The laptop is also Ethernet hard wired. Even if I loose my spectrum internet I should still be able to maintain a connection to the Flex 6400 on my side of the network. The Flex is also using Category 6 cable too and is brand new.

    Thank you

  • Bob  KN4HH
    Bob KN4HH Member ✭✭

    I am experiencing the same situation. I am running a Flex 6500 SmartSDR V3.5.9 using a windows 11 pc with 64Gb ram, also running a Asus RT AX 82U router all hard wired with CAT 6 network cable. During the day, after about two hours of the 6500 being in the receive mode, I get a message that the radio has lost contact.

    All other functions of the PC are normal and never losing contact with the internet or internal apps.

    Bob, KN4HH

  • Trucker
    Trucker Member ✭✭✭

    Are both your laptop and your radio on the same switch? I just received the same unmanaged switch from Amazon today to replace a 5 port Gb unmanaged switch from Netgear to add more hardwired connections to my network. Both of my pc's and my 6600M had no connection problems with the older switch. Is the 8 port switch a new addition or has it been working with your radio and laptop all along till today? A Windows Update can change settings in Windows that will cause problems especially with a laptop. ( have had that happen with a laptop and a desktop pc before) I have had Windows Update change settings and cause problems like you describe.



  • KG5PTE
    KG5PTE Member ✭✭

    Yes the Laptop and Flex are on the same switch and no there were no Windows updates at the time of this. I am running a Dell G-3 15 Windows 11 laptop. Smart SDR has been on and running fine for over five hours now since the last time it disconnected.

    Thank you.

  • John KB4DU
    John KB4DU Member ✭✭✭✭

    I have had more consistent connection times using a 100Mb switch than a 1gig switch.

  • WA5YOM
    WA5YOM Member ✭✭

    I have the same problem, randomly disconnects......new problem...

  • KG5PTE
    KG5PTE Member ✭✭

    Well well just a few minutes ago 4:20 PM CST my Smart SDR version 3.6.8 just shut off and quit without any warning. After the radio and smart SDR has been on since 9:50 AM CST. I am using the same Dell Laptop with Windows 11. My Ethernet and home network is in good working condition.

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