Quick Guide to WSJT-X on the Icom IC-7100

We had a great presentation today by Wendell, N4VLK,  on the digital mode FT-8 today at the CARS club meeting. I was asked if I have run FT-8 / WSJT-X on my IC-7100. Yep, I have, and it works quite well too. I know where are a number of guys in the club that have the IC-7100 so I thought I would share my setup information.  Here is a very quick guide on setting up WSJT-X on the Icom IC-7100.  I am assuming that you have already installed the Icom supplied USB CAT and USB Audio drivers.  If not, do install them before continuing with the WSJT-X installation.

First, download and install Dimension 4, an app to keep your clock synced to the NBS time source. This is very important to make sure your receive and transmit timing is correct, otherwise WSJT-X will not decode signals and other stations will not be able to decode your signal.  (you can click on the images below to see a larger view)

Website for Dimention 4

Installation is pretty straight forward, select a sever to sync with and click the Sync “Now button.”

Dim 4 Install screen

Once you have Dimension 4 installed, go to the website for WSJT-X and install the Windows version.

Download site for WSJT-X

You can use the defaults for the install.

Run the WSJT-X program and you should see two windows, the waterfall display window and the main window.  In the main window click “File” on the top menu and select Settings from the pull down.

On the General Settings tab, enter your Call and your Grid Square information

WSJT-X General Settings

Then on the Radio tab enter the info for you CAT port for the IC-7100.  Select the radio type, then the serial port, in my case it is Com 6, and select CAT for the PTT. Once these settings are complete you can click on the “Test CAT” button at the bottom right of the window.  If button turns Green your CAT is setup correctly.   You can also test the PTT function with the “Test PPT” button.

WSJT-X Radio Settings Tab

Then go to the Audio Tab and select the USB Microphone and Speakers for the audio interface.

WSJT-X Radio Tab Settings

A couple more settings and we are done!  Now go to the Reporting Tab and set the program to send data to PSKReporter website.

WSJT-X Reporting Setup

Close the Setup window and one final setting is to the “Mode” on the main menu bar of the WSJT-X main screen and set the mode to FT-8.  Can also run other modes with this program if you desire.

WSJT-X Mode Setting

Ok, you should be ready to operate at this point!  I suggest watching for a while to get a feel for what is going on with the program.  Also, reading the user guide will be a great help.

Have fun on FT-8!  If you have any questions that I can help you with email me at bob@n4rfc.com.

Update – 5/13/2020 – I have had several requests to add information on setting up the menus in the 7100 for digital modes.  Below are screen shots of the “Connectors” screens on the 7100.  To get to these settings, press the “SET” button on the front panel, then scroll to the “Connectors” and touch it then you can scroll through the entries.  Everything you need to get the digital mode transmitting is in that setup screen. (The photos below are thumbnails, click on each one to see the full size photo)

73 and GL

25 Comments so far

  1. Richard on May 29th, 2018

    hallo dear OM
    i search for a bit time to run my IC7100 in data modes ( FT8) and found your home page.
    What cables are requested to connect the Transceiver to the computer, i only use a USB cable do i need cat cable ?

    I dont have any CD delivered with my Transceiver, what must i install for programms ?
    Thanks for your help vy73 de Rich

  2. admin on May 29th, 2018

    You only need the one USB cable, both the sound card interface and the CAT interface are on that one USB port. You will need to download the CAT / Soundcard drivers from the Icom website to make all this work. They can be downloaded from this site:

    Have fun!
    Bob – N4RFC

  3. Anders on August 15th, 2018

    Hi Richard,

    How do I stop WSJT-X 1.9.1 to “auto” change my QRG. If running split on 70Mhz the application change my RX QRG to same as TX after first period!

    Regards Anders SM4KYN

  4. Ben on September 15th, 2018


    First, thank you for the above information. I have ft8 running on my Yaesu FTdx 3000 and love it. I wanted to know if you could list the radio settings for the IC7100. Basically anything that needs to be altered in the radio to make everything work fluidly. Thanks for you time.

    Ben (N9LUC)

  5. Steve on September 26th, 2018

    Bob, I am unable to find the Dimension 4 app on the app store. How do I get it?

  6. Steve on September 26th, 2018

    Never mind I found it!

  7. Kevin N9JKP on October 7th, 2018

    I was wondering if you could share or point me in the right direction with respect to the radio’s setting. I have everything setup and it is decoding well, and I can change bands from the computer. My concern is the radio settings such as AGC, NR, NB, etc.


  8. Dave Wickert AE7TD on November 26th, 2018

    Any requirements on the 7100 configuration or does WSJT-X automatically configure the 7100 using CAT commands? I can receive and decode OK, but on transmit, while the radio keys, I do not see any actual RF output. Suggestions? Also, did you have to configure the power output on the 7100?



    _-_-_ Dave, AE7TD

  9. Dennis on May 23rd, 2019

    For some reason I cannot get Dimension 4 to connect to any servers. Windows 10 home laptop. error binding socket to address port or no such server found. Have you had any problems with that? I did get the 7100 working thanks to your settings. Thanks

  10. admin on May 25th, 2019

    Yes, I have had an issue with Dimension 4. I just kept trying servers till I got one to connect. I am not at my radio desk now, but I will look and see what I have set for a sever and reply. Great to hear you have your 7100 working and thanks for reading the blog
    DE N4RFC – Bob

  11. Lars on June 17th, 2019

    Hi Bob.
    I too had problem with D4. Downloaded
    and this works great.

    Is it possible that you can send me your instructions as a file? Having problem seeing the the included “snapshots”.

    73 de Lars SM0CCM SM3CCM J73CCM ( age 82 )

  12. admin on June 18th, 2019

    Haven’t tried that one, but I will give it a look. Thanks!

  13. Mike on July 17th, 2019

    I have followed the above instructions and my PTT test fails. Can someone please give me some direction on the possible issue(s)?


  14. Andy on October 26th, 2019

    Is this article available as a down load ?

  15. Greg on January 20th, 2020

    Did you have to make any changes inside the radio silence

  16. admin on May 13th, 2020

    No changes in the radio, it is plug and play. There are some menu settings and I have updated the posting to include screen shots of the radio setup.

  17. Richard Gallaher on July 29th, 2020

    Your guide was very helpful. I had been struggling with getting the internal sound card to key up, and after following your instructions, it worked. However, I realized that in phone mode, I wasn’t getting any audio out because of the setting for Data Off Mod = USB. I changed it to MIC,ACC and voice worked again. Will I have to change that setting back to USB any time I want to use WSJT or can I leave it as MIC,ACC?

  18. admin on August 6th, 2020

    I have my “DATA OFF MOD” in the connectors menu set to MIC, ACC. When I Click on the mode from the main screen and select the “DATA” mode from the menu it goes selects the USB audio. When I select USB or LSB mode it selects the microphone, no need to change any menu settings. But, you need to select “DATA” from the mode on the main screen. (touch the mode display on the touch screen)

  19. W1SRR on April 7th, 2021

    Thank you for your article and screenshots. I uninstalled D4 and now use JTSync for time sync. It works great and has the added feature of syncing with other stations for example when off-line and no internet. I also use JTalert but will be trying out Gridtracker. I really like JTalert but heard that the other is much better. So far no experience with it. Thanks again.

  20. admin on April 15th, 2021

    I have not used JTSync, but it sounds like it could be very helpful especially where you don’t have an internet connection to get time sync info. I will give it a try. Thanks!

  21. The Flat on March 21st, 2022

    I like the helpful info you provide in your articles. I’ll bookmark your weblog and check again here regularly. I am quite certain I’ll learn lots of new stuff right here! Good luck for the next!

  22. admin on August 23rd, 2022

    No, you don’t need the Signalink with the IC-7100. You connect the radio directly to the computer via the supplied USB Cable. If you haven’t already connected, download and install the Icom USB driver from their website. Do this before you plug the USB from the radio into the computer. Once the driver is loaded, you plug in the USB cable from the radio. Go to the Device Manager in Winders, go down to “Ports (COM & LPT)” and you should see two ports defined. If you already have USB Serial ports, the Icom ones will be new ones. Those two ports are you CAT Control (lower port number of the two) and the audio sound card will be the second (higher numbered of the two ports). You can then use the lower numbered COM Port for you CAT control and the USB Audio Codex for the sound card settings in you FT8 software.

    I hope this explains it for you.
    Regards and GL
    DE N4RFC

  23. Ray W3BFC on November 10th, 2023

    It would be extremely useful to be able to print this info..

  24. Don Morgan on November 27th, 2023

    Thanks Robert for the info. It helped!

    I just got this IC-7100. Having fun!

    AB3BO Don

  25. admin on November 30th, 2023

    Screen shot it and put it into a document then save and print.