Setting up Fldigi with SmartSDR

Content provided by: Alexander H. Hahn, DH2ID


Fldigi is easy to setup, very stable and shows everything on one screen, making it one of the best programs for digital modes. There are a lot of other very interesting programs on David, W1HKJ's page, like flrig and fllog.

I run all programs on Windows 7 Home Premium both 32 and 64 bit.

Setup for Windows 10 should be the same as for Windows 7, although there have been reports about problems with virtual ports. Be careful to totally remove SmartSDR from your PC before you install Windows 10, then reinstall, having saved your profiles beforehand.

Setup of digital mode programs often opens server ports. You have to allow them on your system, so have a look at both your firewall and antivirus programs if there is no connection. The OS can also create a problem concerning user permissions.

Please tell me about improvements to the tutorials and issues not reported here.


1. Download Fldigi and the RigCat xml files for your Rig. In our case that would be SmartSDR SliceA and SmartSDR SliceB written by Tim, W4TME and recently updated to include the new RTTY mode.

2. In SmartSDR CAT notice the port which was created at installing it and to which 3rd party programs will connect, in my case COM6:

3. Create a virtual PTT port in the Serial ports tab clicking "Add a port", then "PTT" and you should get a COM port pair (COM7-17) in this case:

Notice that I have also created a dedicated CAT port pair (COM8-18) which you
need only if you want to connect other programs which can't use a HRD server.

The COM port numbers can vary on your pc! Be careful that the newly created COM ports are not used by other, already existing, devices!

You can create a little batch file, which I call "View Devices". Just copy the lines into your editor and save the batch file as "view devices.bat"

set devmgr_show_nonpresent_devices=1
set devmgr_show_details=1

Now you can see all your COM ports, even the hidden ones, if so clicked.
This is my list, yours will show different ports:

Sometimes two ports with the same number can crash Windows. In that case
you have to restart in protected mode and change the numbers or uninstall
the offending driver.

4. To connect Fldigi to SmartSDR you need only RigCAT.

Notice that I have used COM8 here, which I have created in
SmartSDR CAT, leaving the main CAT port 6 open for my HRD Logbook and it's corresponding HRD server MiniDeluxe. If you log directly with fllog you don't need to create this extra port in SmartSDR CAT.

Don't forget to click "Initialize" in Fldigi, which is necessary each time you
change settings on different tabs.

How to use Fldigi with two slices has already been explained on this forum

5. If you want to connect to another TRX, a TS-2000 in this case, you can use Hamlib, un-tick it and change TRX by selecting the corresponding CAT file, a very nice touch.

Notice that COM10 is used here because I use a microHAM DigiKeyer II to connect my TS-2000X.

The COM port numbers can vary on your PC! Be careful that the newly created COM ports are not used by other, already existing, devices!

6. Setting up PTT:

7. Setting up Audio:

8. Main screen (PSK63), SmartSDR set to DIGU, 5.0K slice bandwidth

9. Main screen (RTTY), SmartSDR set to RTTY, 400Hz bandwidth

RTTY is spot on if you set the RTTY sweet spot to 2210 in the Configure->Misc->Sweet Spot Tab of Fldigi.

Clicking on the mark tone in the SmartSDR panadapter will center the RTTY signal for decode (Thanks to Bob N7ZO).

Verify that you have got the new and updated XML files from the Fldigi download page. Right click the corresponding XML file and "save as" in a folder under your documents. I made one and named it "Fldigi files" for all my TRX.

If you want to look at XML files, you can open them with this free program: or in your browser.



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