How to get fldigi working with Flex 6300 on Windows or macOS

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  • Updated 2 years ago
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In 2015 I had the pleasure of meeting Matt and Gerald Youngblood and staff at the FlexRadio offices in Austin, and I ordered a 6300 on the spot.  I've had fun working many states and countries with the JT65, JT9, and FT8 modes implemented in WSJT-X.  Now I want to try other digital modes using fldigi.  No matter what I try, I can't get fldigi to work with the 6300.  I hope someone can help.

Context:  My computer is a MacBook Pro running macOS 10.12 Sierra.  Using VMware Fusion Pro 8.5.10, I run Windows 8.1 as a guest OS.  I have SmartSDR 1.11.12, SmartCAT, SmartDAX, and WSJT-X 1.9.0-rc3 installed and working together in the Windows VM.  I prefer macOS (and Linux) to Windows.  A few days ago I bought dogparkSDR and Loopback and installed the xCAT and xDAX software kindly offered by Mario Illgen, DL3LSM.  I was able to get WSJT-X 1.9.0-rc3 running on macOS and have made many contacts.

But I can't figure out how to make fldigi work with the 6300 either in Windows or in macOS.  I'm baffled by the arcana of COM ports, multiple rig control mechanisms, and hundreds of configuration options.  Is there a simple, straightforward, well-documented way to get fldigi working robustly with SmartSDR on Windows 8.1 or with dogparkSDR on macOS?  I already spent a couple hundred bucks on dogparkSDR and Loopback and I hope I won't have to buy any more software just now.

Thank you.


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Posted 2 years ago

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Photo of Ted  VE3TRQ


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Official Response
Good choice of system for digital, Scott.

MacOS works very well with the software you have mentioned - of course it's a matter of configuration, and there are a few moving pieces. Having just completed this effort, I'll describe what I went through and provide the configuration screens.

First of all, you need to install Loopback, the licensed version (so there is no injected noise). Create two virtual audio devices in Loopback, as follows (choose names that make sense to you):

Each of the devices will be used for input and output routing, where xDax will be one side, and Fldigi will be the other. Tx in xDax takes the output of one device, and Rx in xDax takes the input of the other device.

Note that I found it important to REBOOT the Mac after setting up Loopback - I had some strange artefacts in the audio until I did that.

xDax is set up as follows:

Set up cat with COM port emulation or Ethernet connection. I chose to use the HamLib "rigctl", which talks to an Ethernet port provided by xCat. Set up xCat as follows (kinda the default, I think):

Use the RigCtl port number in Fldigi as follows:

And finally set up the Audio Devices in Fldigi as follows:

I don't usually even bother with dogparkSDR on the MacBook, because it is relatively under-powered, so I separately control the radio , in my case because I have a 6600M, from the front panel. I have used dpsdr at the same time, and it works fine to control the radio and set up the panadapters and slices (I used the 1.12 beta).

Here's the setup on my MacBook Air with xDax, xCat, and Fldigi doing FSQ:

That should be it - works FB for me, and is more sensitive that a corresponding analog setup with my K3 and SignaLink USB.