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Unable to connect to the radio, Please try again

Over the last week or so, I have been receiving the following error message "unable to connect to the radio, please try again" when starting SmartSDR.  

I've tried a couple of things to fix the problem. First, I turned off the firewall which had no effect. I then performed a complete uninstall of all instances of SmartSDR on my computer. To do this, I followed the 13 step procedure found on the FlexRadio Website. I then reinstalled a freshly-downloaded SmartSDR 3.1.12.

The reinstallation hasn't resolved the problem - when I started the cleanly installed SmartSDR, the usual three windows, one for SmartSDR, CAT and DAX, appeared. I logged into the server and then tried connecting to the radio. Again, I received the unable to connect message. 

While I was writing this message, I noticed a small window pop up indicating that a DAX connection is available. So I decided to try connecting to the radio, I clicked on the connect icon in the SmartSDR window, the radio connected and the usual SmartSDR window opened...  

In addition to seeing one SmartSDR open, there are two SmartSDR CAT and SmartSDR DAX icons showing in the system tray at the bottom of my desktop. The two icons are tied respectively to DAX and CAT windows showing the radio is available and the other two are tied to the usual DAX and CAT control panels.  In the past I haven't seen two variants of CAT and DAX windows.

I also noticed that when the mouse pointer was held over the radio image in the SmartSDR window when I was not able to connect, the ip address shown for the radio was the same as the WAN ip address provided by my ISP. Now, when I mouse over the available radio icon, the ip address showing for the radio ties up with the ip address system assigned by my router ( Also, the network tab in the radio setup window of SmartSDR shows the ip address tied to my LAN.

This is making me think that when SmartSDR starts, there's initially an IP address problem. This problem apparently resolves if I wait long enough. I'm far from an expert on network management, so this is a wild guess on my part... Furthermore, if I'm on the right track I'm clearly not sure how to fix it.

In case it's helpful to know, my radio is connected to the LAN by ethernet cable to a switch which is connected to my Ubiquiti router. The computer running SmartSDR is connected to the LAN via a wireless connection to an access point mounted on the wall in the same room where the computer is located. My ISP is Verizon.  

If anyone has suggestions on what might be the problem and how to fix it, I'd appreciate it.  

Thanks in advance for the assistance,

73, Leon NT8B


  • KD0RC
    KD0RC Broomfield, COMember, Super Elmer Moderator

    Hi Leon, it is probably best to start with the simplest connection possible to pinpoint the problem. I would try the computer and Flex plugged into each other using ethernet cables. If that works, then the issue is likely with the networking setup or WiFi. Start adding equipment back into the mix until you recreate the problem. The last thing added is the most likely culprit.

    If the direct connection from computer to Flex does not work, you have trimmed the problem to three possible candidates; the cable, the radio or the computer. If you have a known good spare cable, see fi you can eliminate that as an issue. Same for the computer. If nothing helps in this scenario, it is probably time to put in a help ticket with Flex.

    Give that a try if you can and let us know how it goes.

  • NT8B
    NT8B Member ✭✭

    Len, thanks for getting back to me. Working with Ken from the FlexRadio Helpdesk, we were able to resolve this problem by changing the wireless network protocol being used on my computer from 802.11n to 802.11ac.

  • KD0RC
    KD0RC Broomfield, COMember, Super Elmer Moderator

    Ok great, glad you got it working!

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